MaremApril 1982 s: Number 60 US. &Canada, $2.50 2 Foreign, $3.00
The Magazine for Shooters (ISSN 01 62-35831 Volume 14, Number 2 March-April 1982 IN THIS ISSUE Testing Scope Adjustments,... Mike Venturino The Reliable Krag,... Favorite Guns... 6x50mm S&H... Remington Model 725.... Vented Pistol Barrels... Ludwig Olson Layne Simpson.Jon Leu Don Zutz Bill Corson Remington Two-Ounce Trigger... Stuart Otteson Wet-Pack Testing Muzzle-Loaders.... Hugh Awalt Another Approach to a Light Rifle.... Gil Sengel Making a Steel Trigger... Ron Swartley 16 20 24 28 30 32 35 38 40 42 DEPARTMENTS Spotting Scope.....5 Dear Editor...8 American Gunmakers.....10 Rifle Patents.,...12 Classic Rifles..... 14 Aiming for Answers......15 Trophy Pointers......66 ON THE COVER When Remington announced its.280, Fred Huntington of RCBS improved it with more shoulder, producinga fine cartridge. On an FN action with a Marquart barrel, Talley scope bases and other hardware, a 4x Leupold scode. and a stock by Sterlinq Davenport, this.280 RCBSstands out anywhere. Photograph )by Ken Howell Rifle Magazine. copyright 1982. IS published bimonthly by Wolfe Publishing Co.. Inc., (Dave Wolfe. President) P.O. Box 3030, Prescott. Arizona 86302. Telephone (6021 445-7810. Second Class Postage paid at Prescott. Arizona and additional mailing offices. Single copy priced current issues - $2.50. Subscription price: six issues - $13.00, 12 issues. $25.00; 18 issues. $37.00 (Outside U.S. possessions and Canada - $16.00, $31.00 and W6.OC.l Recommended foreign single copy price - $3.00. Advertising rates furnished on request. All rights reserved. Publisher of Rille is not responsible for mishaps of any nature which might =cur from use of published 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 01 address: please give six weeks' notice. Send both old and new address, plus mailing label if possible, to Circulation Dept.. Rifle Magazine. P.O. Box 3030, Prescott. Arizona 86302 The Staff Dave Wolfe, Publisher Ken Howell, Editor Jana KOSCO, Advertising Manager Wyatt Keith, Assistant Editor Dave LeGate, Art Director Mark Harris, Staff Artist Barbara Pickering, Production Supervisor Joyce Bueter, Circulation Director Susan Barney, Circulation Manager Terry Bueter, Accounting Shelley Goff, Executive Secretary R.T. Wolfe, Ph.D., Consultant Technical Editors John Bivins Bob Brackney Bob Hagel A1 Miller Ludwig Olson Stuart Otteson Homer Powley Layne Simpson Ken Waters - 4 RIFLE 80
Answers I Twist for 7x57mm I have just read Ken Waters most interesting reply to Tom Jordan s inquiry in Rifle 76 regarding twist for the 7mm-08. It was especially interesting as I am having a 7x57mm barrel fitted to my Mauser 98 action and have ordered a barrel with a nine-inch twist. It is my hope that this twist will ensure stability with 170-grain bullets at the longer ranges; that is, 250 yards plus. In the light of your findings and Mike Venturino s very good article on twists, I find it hard to believe that the,308 Winchester can handle 200-grain bullets at ranges out to five hundred yards and with a twelve-inch twist. Both the.30-06 and the venerable.303 (similar calibres) have ten-inch twists. Remington had problems with their.244 made with a twelve-inch twist. It was OK with ninety-grain bullets but could not handle the longer hundred-grain (1.02 inch long), and this supposedly contributed to its early demise. I am looking forward to your Pet Loads series for 7x57mm and hope that you will give bullet lengths as well as weights and velocities, to enable me to learn more about this obscure subject of twist. Best wishes for the continued success of your excellent magazine. Please don t change the format and get tangled with shotguns and pistols. Keep Rifle pure rifle. E W D Corke Durban, South Africa You are far from being alone in expressing confusion on the subject of the rates of rifling twists and their effect on the stability of bullets. Probably the best answer that I can give you in this short space is to show you how to apply the old Greenhill formula (worked out by Sir Alfred Greenhill at Woolwich). For the usual jacketed bullet with lead core, proceed as follows: Divide the length of the bullet by its diameter in hundredths of an inch. Divide the constant number 150 by the result from step one. MARCH-APRIL 1982 Multiply the result of step two by thc diameter of the bullet. The result of the calculation in this las step will be the required rate of twist. Example: a 170-grain Sierra 7mn round-nose bullet 1.23 inches long. Step one: 1.23 divided by 0.28 equal: 4.393. Step two: 150 divided by 4.393 equal 34.145. Step three: 34.145 multiplied by 0.21 equals 9.56, indicating a rifling twist o one turn in nine and a half inches. Thus your nine-inch twist would b adequate to stabilize a 170-grain round nose bullet in the 7x57mm barrel tha you are having fitted to your 98 Mauser. As for your question about a.308 wit1 two-hundred-grain bullet, I ran threc bullets through the Greenhill formulr with the following results: A two-hundred-grain Speer round nose 1.18 inches long calls for a twist o eleven and a half inches. A two-hundred-grain Speer flat-bast spitzer 1.27 inches long calls for a twis of 10.6 inches. A two-hundred-grain Sierra spitze boat-tail 1.385 inches long calls for I twist of nine and three quarters inches. From this, it would appear that onl: the shorter two-hundred-grain round nose would be adequately stabilized b a twelve-inch twist. The longer spitze bullets call for a ten-inch twist. To somi degree, however, the effect of a slowe twist can be offset by an increase ii velocity - thereby increasing th bullet s number of revolutions pe second, the key to stability - so that ii actual practice, spitzers weighing twi hundred grains can be used if they hav flat bases - that is, without the longe boat-tail. Kenwaters Answers Policy We will be pleased to ask the members d the staff to answer your questions. However, due to their heavy volume of correspondence we must ask that you enclose four dollars and a stamped, selfaddressed envelope to partially defray the cost of researching and writing each answer. Please limit each letter to one specific question, for many general questions require a lengthy article to answer adequately, and cannot possibly be answered in a letter. Questions should be addressed to Aiming for Answers, Rifle. P.0. Box 3030, Prescott, Arizona 86302. 5
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Making. a Steel Trigger for the Ruger Number One Ron 300 L t HE RUGER Number One single- T shot has become a classic platform for custom guns the world over. The gun must have a lot of inherent quality, or such well known customizers as Bill Dowtin, Joe Balickie, and Friedrich Wilhelm Heym (of West Germany) wouldn t waste their time on it. But the gun isn t perfect - nothing ever is. Take as simple a thing as its trigger, for example. It s made of black anodized aluminum. That means that the custoinizing potential for the trigger is almost nonexistent. There is little you can do to its shape if you want the racy lines of a shotgunstyle trigger, a wide target style, or a smooth hunting style. And you can just about forget about gold plating, nickel plating, color case-hardening, nitre bluing, or heat strawing. When the anodizing wears off, about the only thing that you can do is paint it, since most shops refuse to accept such a single part for anodizing. So the Ruger Number One owner is up the proverbial creek as far as trigger customizing is concerned. Or is he? There is one other option, and that involves the custom building of the trigger assembly itself. Tony Fleming of the JJ Jenkins Enterprises restoration shop in Goleta, California, has come up with a Ruger Number One trigger made from carbon steel. It is attractive and functional, and it allows the customizer to do all those things with it that you can t with the original anodized-aluminum trigger. There is only one minor drawback - you can t make those little postinstallation adjustments on it that you can with the factory trigger. The new trigger has to be adjusted to fit the shooter when it is installed, and then left that way. For the advanced amateur gunsmith or professional metal worker desiring to make such a custom trigger, the basic steps follow. The Jenkins outfit mentioned above will make and install a bright and shiny one for a hefty 175 dollars, if you think the metal work is beyond yours or your local metalsmith s capability. First, scribe the outline of the old trigger onto a 1.6-inch-square by 0.300-inch-thick piece of mild carbon steel (1010, 1015, 1018, or 1020 cold or hot-rolled steel will do). Obtain the steel from any fair-sized welding shop. Machine the top section, using the holes and flats of the upper part as reference points. Leave the bottom area square for easy clamping in a vise. Shape the lower section (where your trigger finger goes) using a hacksaw and files. Sculpt the metal to the desired shape. These two Ruger Number - one finibhed, one still both made from a block o the one that they are lying _---. \ \ Fit the trigger to.the gun, using finish-filing techniques. You ll see from the drawing that the trigger retains the standard Ruger searengagement adjustment screw. The weight and overtravel are adjusted in this final fitting. Finish the trigger according to your particular taste (blued, gold plating, etc)..- Depending on the quality of his workmanship, the Ruger Number One customizer should end up with an improvement in appearance and a better-fitting trigger. 0 One minor drawback: on a custom trigger mad like this one, all adjustments have to be mad when it is installed, then left that way. None ca be made after assembly of the gun. 7 42 RIFLE 80