The. Handloader. I Magazine .:* Number 28 love-dec. I970. J.S. & Canada, $I.oo. %reign, $ I.25

Transcription

1 The Handloader I I Magazine.:* Number 28 love-dec. I970 J.S. & Canada, %reign, $ I.25 $I.oo L

2 The Handloader Magazine Dave Wolfe Publisher Neal Knox Editor Roger T. Wolfe, Ph.D. Associate Editor Maj. George C. Nonte Jr. Associate Editor Norm Lammers Technical Adviser Homer Powley Ballistics Adviser James D. Carmichel Cast Bullets Parker 0. Ackley Wildcats & Gunsmithing Wallace Labisky Sho tshells John Wootters Gun Tests Harvey A. Donaldson Historical Adviser Ken Waters "Pet Loads" Edward M. Yard General Assignment Don Zutz General Assignment Bob Hagel Hunting Adviser John Buhmiller African Cartridges Barbara Killough Production June Skillestad Circulation Manager Leah Close Asst. Circulation Mgr. Tina Taylor Data Processing Rod Guthrie Staff Artist Carolyn Reinhold Editorial Assistant Trudy Kluever Promotion Nov.-Dec., 1970 Vol. 5-No. 6 Box 3030, Prescott, Ariz features: New Explosives Legislation Neal Knox 7 Why Handload? John Wootters 14 Bumping A Round Maj. George Nonte 18 Pet Loads:.30 Remington Ken Waters 22 Loading For International Skeet Don Zutz 24 Bullet Performance Bob Hagel 28 Proving Handgun Accuracy Jim Carmichel 34 ASession With Brenneke Slugs Wallace Labisky 38 Pressure Factors: Caliber Lloyd Brownell, Ph.D. 42 Changing Times Ken Waters 62 Departments: Editorial Ctg. Of Month Lock, Stock, Barrel Propellant Profiles Tip-To-Tip Index: Volume Reader Bylines Harvey Donaldson The HANDLOADER, Copyright 1970, is published bi-monthly by the Dave Wolfe Publishing Company, P.O. Box 3030, Prescott, Arizona (Also publisher of Rifle Magazine.) Telephone (602) Second Class Postage paid at Prescott, Arizona, and additional mailing offices. Single copy price of current issue $1.00. Subscription price: six issues $5.00; 12 issues $9.00: 18 issues $ Outside U.S. possessions and Canada $6.00, $11.00 and $ Recommended foreign single copy price, $1.25. Advertising rates furnished on request. Publisher of The HANDLOADER is not responsible for mishaps of any nature which might occur from use of published loading data, or from recommendations by any member of The Staff. No part of this publication may be reproduced without written permission from the editor. Manuscripts from free-lance writers must be accompanied by stamped self-addressed envelope and the publisher cannot accept responsibility for lost or mutilated manuscripts. Change of address: Please give one month's notice. Send both old and new address, plus mailing label if possible, to Circulation Dept., The HANDLOADER Magazine, P.O. Box 3030, Prescott, Arizona Offkmt Publication of Sanm Barbeta Reldi~ Assaclation Your November-December Cover Antique ammunition display boards, now avidly sought by collectors, apparently inspired modern bullet display boards such as the ones on this issue's cover. To the manufacturers' surprise, the bullet boards, which were conceived principally for gun shop advertising of handloading bullets, have been snapped up by handloaders wanting them for reference and loading room decorations, as well as by collectors. Since these representative boards were photographed, new bullet board designs also have been announced by Sierra bullets and Nosler. 4 HANDLOADER - November-December. 1970

3 PRESSURE i EARLIER ARTICLES of this series were based on analysis of the major factors that influence r pressure. These factors the powder charge (or load) L, seating-depth factor S, freebore-travel 1 - factor F, and powder quickness q. Before consideration of the two 'remaining major factors, caliber and case volume, a technique called Systems Ballistics was introduced to permit a closer bok at the relative quickness q (test) as determined from test firing data. This technique is useful in the analysis of the more subtle factors such as case shape, case diameter and minor variaths in bullet, bore and groove diameters aad is especially useful in the analysis of the influences of quickneas, caliber and case volume. Procedures for use of the method in analysis of values of relatives quickness q(test) for IMR 4227 powder were introduced in Part XI: Systems Ballistics but the analysis itself was omitted for control of length of the article. In this article we return to a basic factor, diameter. The coverage of diameter is limited to this one article on caliber, the major diameter of the bullet. This is not completely satisfactory as diameter has a number of different and significant influences on pressure and performance. The truth is, the multiple influences of diameter are too significant to overlook and too complex to cover in one short article. As a compromise some of these effects ire described only briefly in words and without compdtations so as to avoid complete omission. The major diameter of the bullet or caliber is involved in the sectional density of the bullet, which is a fundamental factor in describing the capability of the bullet to accelerate or decelerate. Sectional density and the refore caliber influence the relationship between bullet mass and pressure. Another major influence of I I I I Part XI1 caliber 1s IC:, &fect UII UIC volunle UL powder gas in the bore at the peak pressure, which affects the magnitude of the pressure. This volume is equal to "/4 times the caliber squared multiplied by the length of the bore traveled by the bullet to reach the peak pressure. The caliber also influences the value of q(test) for IMR 4227 powder, as shown by Subsystem B, mentioned in Part XI: Systems Ballistics. This information on Subsystem E is necessary for determination and elimination of the 1.ifle barrel factor, thereby permitting evaluation of the other influences ofb caliber based on test-flring data. Caliber may be considered as the designation of the gross or macrodianieter as described above. In regard to the relationships for caliber, the sectional density of a 200-grain.30 caliber bullet, for instance, differs greatly from that of a 200-grain.35 caliber bullet. But whether the.30 caliber bullet has a precise diameter of , or inches is not significant in its influence on sectional density, bore volume at the pressure peak or relative quickness of IMR 4227 powder. However, the microdiameter values of , or inches can have a major influence on pressure and on accuracy. This influence, when present, can be observed in differences of diameter of only a few ten thousandths of an inch. It is true that a diameter of as compared to inches may or may not produce a significant difference in pressure for a specific load combination. Whether it does or does not depends in part upon the value of the bore and groove diameters of the barrel, bullet hardness, and upon the pressure range used. This influence explains many TRAVEL IN CALIBERS Ficjure 61. lntluene of Loading Density L/Vo on Travel Distance b/2 to pressure peak at 'heretofore puzzling anomalies and w3: L I I I I I I I I a m constant powder quickness (q = 1.OO) for heavy anti-aircraft gun, according to Corner. the diffc ces in p,ure nrnduced by

4 CaLer ten different.30 caliber 150 grain bullets fired in the same rifle barrel using the same seating depth, cases, primer and charge of 51 grains of IMR 3031 powder. Although the variation in microdiameter and bullet performance can be of a random nature possibly because of large tolerances in manufacture, this need not be the case. Where high accuracy is desired the microdiameter may be deliberately increased as with some Centrix bullets. Not only is the value of the major diameter significant to the inch but the engagement length at this diameter also is important. Herein is one of the major differences between the physical characteristics of Speer and Hornady bullets. The diameters of both the bore and groove of the barrel are of about equal importance as the bullet diameter because the bullet and bore are mating parts. The relative fit before bullet upset depends upon the allowance between bullet and barrel groove diameter and the tolerances ysed in manufacture of both bullet and barrel. After bullet upset these dimensions are not significant so this influence depends in part upon when upset occurs. Experience shows that some bullets perform better than others with certain barrels. The explanation is believed to be related at least in part to this influence of the microdiameters of the bullet and barrel. This subject and the influence of case diameter are not scheduled for inclusion in the present series but these influences must at least be noted. density is used in external ballistics as a measure of the bullet s ability to overcome air resistance and to maintain its velocity. For this reason the handloader knows that a high sectional density is generally advantageous in external ballistics. However, from consideration of obtaining maximum velocity, a high sectional density is a disadvantage as it means that the bullet has greater inertia. A high sectional density necessitates some c o mpr omise between bullet weight, muzzle velocity and velocity at the target. Sectional density is usually defined as the weight of the bullet in pounds divided by the square of the bullet diameter in inches. This gives sectional density the units of psi, the same as for chamber pressure. The ratio of pressure divided by sectional density becomes dimensionless if the gritvitational constant is included to convert pounds force to pounds mass. This ratio is a useful quantity as it is a measure of the force available for acceleration divided by the force required for acceleration. Sectional density was used in this way in Report 2 of the Dupont Ballistic Grant Studies at Michigan to correlate data for bullet weights from 60 to 476 grains. If the sectional density is multiplied by a ballistic coefficient, which is a function of the shape of the bullet, the resistance or drag in passage through air can be determined, which is part of the procedure in external ballistics for computing the loss of bullet velocity. In the internal ballistics of the rifle barrel the bullet is accelerated rather then decelerated, but the usefulness of sectional density still applies. The acceleration of the bullet at any pressure may be computed from the sectional density and the pressure on the base of the bullet, Relating acceleration to time gives the velocity. In the barrel the resistance at the surface of the bullet is between the bullet and the barrel rather than the bullet and the air and here the jacket factor may be considered to be a coefficient of sectional density for bullet travel through the barrel. To use the concept of sectional density in the product equations developed earlier in this series the sectional density must be included. This is possible in Equation 24 by replacing the quantity m/k by the quantity m/kd2 as shown in Equation fa)- Equation 24: m(ql)4 R(jSF1 P= K Replacing m/k with m/kd2 and RGSF by J(R SF) gives Equation (a): In Equations (24) and (a) the terms R(j) and JR are equivalent except that R(j) is based on reference pressure (See Part 6 Seating Depth) and JR is basqd on test pressure for IMR 4227 powder. The terms k and K are constants and m/d2 is sectional density. This procedure was used in Report 2 in the Michigan studies. The procedure is I Returning to the characteristics of the macrodiameter or caliber and sectional density of the bullet, most handloaders are aware that sectional

5 correct if limited to only one caliber such as.30 caliber, the only caliber used in these studies. But if the relationships are extended to other calibers, another influence of caliber must be introduced. This is the influence of the caliber on the bore volume available to the powder gas at the peak pressure. As a result, the relationship given in Michigan Report 2 is limited to.30 caliber and in fact to the cartridge because the influence of volume is not limited to chamber volume, as will be shown in Part XIII: Case Volume. These modifications were in preparation for unfinished Michigan Report 3 and are presented here to extend the original relationships to all calibers and all cartridges. The relationships presented here and in Part XIII: Case Volume are completely general in their applications and supersede the earlier relationships which were limited to the cartridge. The bore volume available to the powder gas at peak pressure is equal to the cross sectional area of the bore d2/4 times the distance b/2 that the bullet travels to reach the peak pressure. The value of distance b/2 can be determined by the relationship for b in Le DUC S equation for bullet velocity. Le Duc s velocity equation states that the velocity v of the bullet for any travel distance x in the barrel equals ax/(b+x) where a and b are constants for a given powder, bullet, rifle barrel, case volume and loading density. A simple analysis shows that the value of b is equal to twice the distance of bullet travel to reach the pressure peak. As a result, the value of b/2 times the bore cross-sectional area gives the volume of bore Vb added to the case volume Vo at peak pressure. Most of the pressure factors discussed in earlier articles influence the value of b/2. Those with a major influence are loading density L/vo, powder relative quickness q, and mass ratio m/l. Figure 61 shows the influence of loading density L/Vo (in units of gm/cc) on the value of b/2 as described by J. Corner in Theory of the Interior Ballistics of Guns, p Three pressure versus bore-travel curves are shown for three loading densities L/V0=0.73, 0.62, 0.44 gm/cc, with bullet mass, case volume and powder quickness constant. Bullet travel in calibers is shown along the horizontal scale and the values at the peak 44 pressures are indicated by the dashed line. These data are for heavy anti-aircraft gun rather than a rifle, but serve to illustrate the relationships. On page 159 Corner shows a similar set of three pressure versus bore-travel curves for the same gun barrel, bullet, case volume and with the loading density held constant at L/V0=0.62 but with powders of three different relative quicknesses; qz1.36, 1.00 and The six values of b/2 from these six curves are listed in Table 23. Column (e) on the right of Table 23 lists the product (b/2)*(q)*(l/vo). Note that the products are nearly constant with a value of about 2.66 gm/cc. Equation (b) expresses this relationship: For m constant and based on Corner s values: Or for any gun with a constant bullet mass m, and L/Vo equal to k L/VO, gm/cc. Equation (b): -=R b k -V 2 q-l The value of b/2 also is influenced by the ratio L/m of charge weight L to bullet weight m, but to a lesser extent. This influence of mass ratio is considered later. Note again that the bore volume Vb behind the bullet at peak pressure is n d2/4 times the bullet-travel distance b/2 and that the constant k of Equation (b) can be combined with the constants /4 of the area term and with the case volume Vo (a constant for a given cartridge) to give a new constant and Equation (c), expressing the reciprocal of Vb of: Combining constants and taking the reciprocal gives Equation (c) Equation (c) is written for the reciprocal of vb so as to place vb in the denominator where it should appear in the product equation. This is true because the peak pressure varies inversely with the volume available to the nearly isothermal powder gas. This is predicted by Boyle s law if the temperature is considered constant as discussed briefly in Part V: Seating Depth. There the pressure was shown to decrease in direct proportion to the increase in volume available to the powder gases as a result of use of a smaller seating depth. The same relationship is involved now except that the bullet has now moved out a distance b/2. The relationship of Equation (c) must now be combined with the product Equation (a). However, Equation (a) already contains the terms for quickness, q and charge weight L. Only the new terms involved in changing the cartridge caliber are transferred from Equation (c) to Equation (a). The powder quickness q and charge weight L appear in both equations but each term is raised to the fourth power in Equation (a) and to the first power in Equation (c). The quantities q4 and L4 can be written as q3.q and L3.L. The last term of q and L raised to the first power can be considered as the contribution of the influence of bore volume. With these substitutions Equation (a) can be modified to include the influence of bore volume as well as sectional density as given by Equation (e), thus Equation (4: Combining terms gives Equation (e): Where: W=J.R *S-F W=Combined effective factor for bullet, barrel, seating depth, and freebore factors. An additional factor, the ratio L/m of charge weight L to bullet weight m is needed to complete the factors that influence bore volume Vb at the maximum pressure. From Equation (b) note that the bore volume Vb is directly proportional to the case volume VO and inversely proportional to quickness q. Also note in first group on the right side of Equation (dj that the pressure p is directly proportional to bullet weight m and to q3, the cube of the quickness. In the next article, p is shown to vary inversely with Vo3 the cube of the case volume. By analogy the influence of bullet weight m on bore volume Vb must be proportional to the cube root of the influence of case volume and HANDLOADER - November-December. 1970

6 I quickness. As Vb is directly proportional :to Vo it is also' directly proportional to (n~)'/~. As the influence of bullet weight m is treated as the dimensionless ratio (L/m) the value of (l/vb) must be proportional to (L/m)'I3. To include the influence of weight ratio, Equation (d) is modified to give Equation 51 : may be eliminated from the influence of caliber. This requires a Systems Ballistic treatment of the data for these cartridges, which was made using Dupont data for q(test) for IMR 4227 powder. This disclosed Subsystem B, which involves the influence of caliber on the relative quickness of IMR 4227 powder. Determination of Subsystem B permitted evaluation of R as used in Part IV: Jackets. The value of R also is defined as the product (R' -S*FJ. shape but differ only in caliber. Those selected are the.264 Winchester, 7mm Remington and.338 Winchester magnums. The case volumes reported by Ken Waters for these three cartridges are 0.318, and cubic inches respectively. These values are within cubic inches of the same volume and all shoulder angles are 25'. For the purpose of computing k rather than the pressure p, Equation 52 is rewritten as Equation 53 I In Equation 51 the caliber d raised to the 4th power may be considered as extracted from constant k, a specific constant for each specific cartridge. In Equation 51 caliber as a new variable d4 expresses the combined influence of d in regard to both sectional density and bore volume. Another change in Equation 51 as compared to Equation 24 is the introduction of the dimensionless ratio (L/m) raised to the one-third power. This can be considered as a minor refinement associated with caliber which was not detectable in the earlier analyses based on a single caliber. Furthermore, the values of the exponents on q and L as used in the product equations vary with the pressure range from a low of 1.0 in the low-pressure region of 20,000 psi and less, and increases to 4 at absolute pressures of 50,000 and 60,000 psi. This is an important change and the variation of this exponent or pressure index should be the subject of a future article so as to modify the equations for use with handgun loads. Equation 51 with exponents of 4 on q and L applies to high-pressure (50,000-60,000 psi) modern rifle cartridges. Modified equations are required for low pressures of less than 20,000 psi such as are used in handgun ammunition operating in the pressure range of black powder loads. For the present, attention must be turned to the verification of Equation 51 with test-firing data. The type of data most suitable for this proof should involve a variation in caliber while holding case shape and especially case volume constant. The simultaneous analysis of both caliber and case volume requires greater length than permitted and as mentioned, Case Volume will be covered in Part XIII, the final article in the series. The influence of other factors such as the jacket factor, seating depth, freebore travel and rifle barrel factor must be established first so that they HANDLOADER - November-December, 1970 But so many other subsystems were interwoven with the values of q(test) 4227 that they first had to be eliminated by the process of normalization to permit evaluation of Subsystem B. This was accomplished by the determination of q(norm). The analysis as described in Part XI: Systems Ballistics involved estimates for values of both e for the bullet and x for the barrel to give the freebore travel f based on knowledge of reported seating depth s and case neck length n. Since the data on the values of e and x are not available, the values of freebore travel length f were estimated directly, taking into consideration the values of s, n and pressure. This procedure was used to arrive at the values of f and F used in the calculations for Subsystems C, D, E, G, N and q(norm) for all belted magnum cartridges. These values of q(norm) plotted versus caliber give a diagonal line of values for q(norm) versus caliber from the 6.5 Remington Magnum, the smallest, to the.458 Winchester, the largest caliber. Equation 52 describes the slightly curved line obtained by this plotting and defines Subsystem B, the influence of caliber on q(test) 4227 and therefore, the influence of caliber on q(norm) for IMR 4227 powder and for a rifle barrel factor R' of This equation for Subsystem B may be written as follows: Where: B=value of q for IMR 4227 powder for barrels with R' equal to The value of B defines correction to q(test) 4227 for caliber dzcaliber, bullet major diameter, inches. The validity of Equation 52 can be determined by use of data for cartridges that have the same case volume and case Where: W=J.R' SS-F Wzcombined influence of bullet, barrel and seating depth. The values of W &ere determined from the Systems Ballistics analysis of q(test) for IMR 4227 powder described in Part XI. The value of k is determined by Equation 53 for the 7mm Remington Magnum cartridge for the 150 and 175 grain bullets, IMR 3031 and IMR 4320 powders and Dupont data. All pressures are in the range of 52,000 to 53,000 psi crusher value which corresponds to 66,000 psi absolute or true pressure (see Fig. 14, Part 2, Bullet Weight). This corresponds to 66/53 or 1.24 psi absolute per psi crusher. This conversion factor of 1.24 is used in the following computations rather than converting to psi absolute. Note that for other pressure ranges a different conversion factor must be used. For: 7mm Rem. Mag., 15O-gr., 52.4 gr. 3031, 52,000 psic, Wz1.65, qz1.0, using Equation 53: x fsy'3 x 1.65 k=m io4 Substituting additional loads for the 7mm Rem. Mag. in Equation 53 gives the following results: For 150-gr., 58.0 gr. 4320, 52,000 45

7 psic, W=1.65,.\ q=0.91, k=338x104 For 175-gr., 51.0 gr. 3031, 52,000 psic, W=1.67, qz1.0, For 175-gr., 56.0 gr. 4320, 51,500 psic, W=1.67, q=0.91, For 175-gr., 63.0 gr. 4350, 52,000 psic, W=1.67, qz0.81, The applicability of the value of 330~10~ for k for the 7mm Remington Magnum cartridge to other cartridges that have essentially the same case volume of cubic inches, such as the.264 Winchester and.338 Winchester Magnum cartridges, is demonstrated by calculation of the peak pressure by E.quation (52). For:.264 Win. Mag., 100 gr., 58.5 gr. 4320, 53,000 psic, W=1.57, q= ). (O.;lg.5) p= (3,3 OO,OOO( 1.24) =52,900 psic (compared to 53,000) Similarly, for:.264 Win. Mag., 140-gr gr. 4320, 54,500 psic, W=1.81 q=0.91, ~~53,800 psic (compared to 54,500) For:.338 Win. Mag., 250-gr., 62.0 gr. 4320, 53,900 psic, Wz1.83, q=0.91, p=54,500 psic (compared to 53,900) The computations demonstrate the BRILLIANT FLUORESCENT RED TARG-DOTS IMPROVE YOUR AIM Self stncking for a SUPERIOR aimmng poqnt! In 5 sizes. New lh" dia. FREE detail~/lamples. PETERSON LABELS validity of 330x104for k for belted magnum cartridges with a case volume of about cubic inches, as well as the d4 relationship for caliber for the.264 Win. Mag. and the.338 Win. Magnum cartridges. k=317x104 The examples selected for demonstration were based primarily on computations for IMR This powder has a quickness of 0.91 in the belted magnum cartridges. This value is k=329x104 more constant and is less influenced by caliber than the other Dupont powders. Computations can be made for these cartridges using the other powders but in general, consistently good checks of k=332x104 predicted pressure are obtained only if the approriate quickness values as listed k meanz338, 332, 329, 317, 312~10~; in Tables 19 (Part 10) and 21 (Part 11) use 330~10~. 46 are used. The exception is IMR 4227, the powder for which we have a relationship for quickness as a function of caliber. Here good checks of predicted pressure can be obtained using Equation 54 for Subsystem B. The computations cannot be extended to all the other belted magnum cartridges listed in the Dupont tables until the factor for case volume is introduced. However the.308 Norma and the.358 Norma Magnum cartridges have nearly the same case volume as the 7mm Remington Magnum, permitting the use of 330~10~ for k. To demonstrate the usefulness of the new relationships, Equation 52 is rearranged as in Equation 55 to permit computation of the powder charge weight L of IMR 4320 for the.358 Norma and 250-gr. bullet. The value of W used is the same as determined for the.350 Remington Magnum and is The peak pressure will be assumed to be 52,000 psi crusher value. For:.358 Norma Mag., 250 gr., L=?, 52,000, Wz1.65, q=0.91, k=330x104, using Equation 55: (x) For: 7mm Rem. Mag., 150-gr., L 4 gr. 4227, 52,000 psic, Wz1.65, - k=330x1 O4 (&I q( 4227)= 1.54 l3 52,000( 1.24)(3,300,000) 250 (1.65) q( )=1.54 (-) /3 = )X ( p= (3,3 00,OO O( 1.24 ) *L estimated as approximately 65 grains. 1.50(36.0) o.283)4 (-y =5.15 x 10' (1.57) x1.65 =49,800 psic (compared to 52,000) To demonstrate further the influence of caliber on both quickness and pressure made for the.338 Winchester Magnum for the 250-grain bullet with a L= 0.91 charge weight of 36.5 gr q(4227)=1.54 (-)1'3=i.59 For:.338 Win. Mag., 250 gr., 36.5 gr. 4227, 53,400 psic, W=1.83, k=330x (36.51 P=(3,300,~~~(1.243 (0.338 ) x1*83 = = 8.10 x 10' Taking 4th rpot gives: -= 0'91 (8.10 x = (0*3582 = 66.5 grains The computed value of L for the 250-grain bullet in the.358 Norma Magnum cartridge for IMR 4320 powder is 66.5 grains, compared to a maximum of 68 grains listed by Speer and 68.3 grains listed by Hornady. The versatility of the relationships has been increased greatly by the inclusion of caliber. In the final article of the series the versatility will be extended to cover all cartridges with the inclusion of the factor for case volume. (compared to 53,400) 0 HANDLOADER - November-December. 1870

8 Norma 1010 BY John wootters ORMA ioio- A fast burning, N d ouble-base, easily ignited powder for use in most pistol and revolver cartridge s gram canister... $2.25. The above paragraph, quoted from the 5th Anniversary Edition, Handloader s Digest, represents the sumtotal (to the best of my knowledge) of what has been published on Norma s quick handgun propellant in the American shooting press. There seem to be several reasons, the first of which is that this is the newest handloading powder on the market, being marked NEW! in the 1970 Norma Ammunition and Components Catalog and Technical Information book. Another reason is that Norma is seldom generous kith technical dope, especially on powders, so writers and editors have very little to publish about the line. Thirdly, with the exception of the slow-burning N205 for rifles, the line seems not to have the widespread distribution of the competition, and so Eeaders do not demand information. The fact is that Norma 1010 is, in a way, one of the most significant new I- powders to appear in years, being the first modern challenger of that mo s t-e ntrenched of all handloading propellants, Hercules Bullseye. A curious point is the marking on the Norma 1010 canister, Made in Great Britain ; no such announcement appears on cans of Norma rifle powders. Physically, 1010 is made up of light gray discs, unperforated, which average.0085-inch in thickness and -056-inch in diameter. Under magnification, the surface appears rather porous, without coating or graphiting, and containing minute silvery flecks. No bulk density data is available. Individual flakes of 1010 are more than twice the size of Buheye particles,. which may account for the fact that the Norma powder works better through three different rotary-drum,powder measures in my tests than does Bullseye. ballistic change in extremely damp weather or prolonged dry periods. Norma 1010 appears on no relative-quickness scales, not even in Norma s literature, and in very few independently-published loading tables where deductions can be drawn from comparative data with competitive powders. I have tested the powder for almost a year in several cartridges and it is my opinion (and that, only) that Norma 1010 is very slightly slower than either Bullseve or Olin s 230-P ballpowder. This would make it the second or third-fastest burning powder available to handloaders, but the difference between it and the two quicker numbers on the list is so small as to be negligible. In most applications (keeping in mind that 1010 is suitable for any Like Bullseye (40% nitroglycerine), Norma 1010 is a double-base propellent, qlthough the nitroglycerine content is not known to me. This means that 1010 may attack the plastic reservoirs of handloaders powder measures and should never be left in the hopper, even over night. The nitroglycerine component also provides higher energy content in a given volume than is possible with single-based powders, and contributes to the nan-hygroscopic qualities of this propellant. It is subject to a remarkably limited degree of 1

9 nwn s eye. substitution of the same for a proven Bullseye load is probably safe, but, of course, any new load should,be worked up with care. As in the case of any such quick-burning propellant, very small increases in charge at near-maximum levels can produce abrupt pressure increases; with Norma 1010 in most cartridges, the reloader must pay attention to tenths of grains. Very good reloading data is available from Norma for 1010 in seven pistol cartridges, from the.25 ACP through the.38 S&W and.38 Special. Super Vel has published a modicum of 1010 data for use with their bullets in the 9mm Luger, and there are a few IOIO loads listed in the new Speer Manual No. 8. I know of no other sources of reliable loading information for this powder at this writing. One minor mystery is the total absence of 1010 loads for the.45 ACP cartridge, even from Norma, when Bullseye has been a standby in that round for a generation. Obviously, standard pistol primers are suitable with this powder. In data E primers were used wi loads, Speer lists primers used, and CcI caps will serve with the Super Vel data. Norma 1010 has proven to be a very satisfactory powder in my experiments, clean-burning at all charge levels, and quite accurate. Velocity variations through my chronograph have been nominal, and no undue pressure problems have arisen. I find 1010 to have a marked advantage over Bullseye in the convenience of use in a conventional rotary -drum powder measure. I've burned quite a bit of Norma 1010 in so-called squib loadings with light cast bullets in rifle cartridges, although the powder is nowhere recommended for such application (nor is Bullseye, which is also good for such noiseless, ultra-low velocity loads), A maximum of two (2) grains is a pretty good load with the lightest alloy slugs available in almost any cartridge not larger than the in capacity, although even better loads are frequently found with even smaller charges (see Pet Loads table). These host literally silent, with the feet-per-second range slower, and quite accurate at the ran+( for which they are intended, which never exceed 25 yards and rarely 25 feet.! Norma 1010 is available only in the aforementioned nine-ounce canisters, Leave it to Handloader to be with the most; we have just exp the body of American literature on this overlooked new Norma powder by 1,800 percent! (c *"I * Jet.Aer burp., Paterson, N.J While Supplies Last, Back Issues Of "Collectable I' Gun Magazines. uy NOW for Your BEST Investment Handloader Magazine When supplies are gone, prices will skyrocket! Nos. 4 and $8.00 each Nds. 2 and 7 -- $5.00 each NOS. 1, 3, 8, 15, 22 and 24 - $3.00 each Nos. 5, 6 and $2.00 each - All others at $1.50 each Bound Volumes I and II (first 10 issues) -- $35.00 Bound Volumes Ill and IV (issues 11 thru 22) -- A 7 Rifle Magazine Cartridge Conversions Maj. George Nonte's book is one of the best buys a reloader can make. Issue No. 3 in short Limited Supply of Other A "must" in every gun library. Onlv supply, at $3.00 each. All Gun Magazines Available $8.95 postpaid. others $1.50 each. Fill in your set while prices are low. Gun Report American R if leman Most issues available, Most issues in 1930's including some very rare early available at $5.00 each. editions at $10.00 per copy. Editions in 1940's are $3.00 each, and 1950s are price Prices list. based Send on your publisher's want list $1.50 each. A few issues in and we'll quote a price. Values Send Stamped Envelope for Price Sheet PADCO Enterprises 1920's. $7.00 each. are sure to climb. Box 3203 Peoria, Illinois c