Undar a magnifying; glass it is relatively easy to male* measurements within .01 incb
Then a small brass rod was chucked in the lathe and two slots sawed in it sufficiently far apart to make the two pieces. A diamond pointed tool was then adjusted in the lathe tool holder at an angle so that the sides of the point cleared both the lengthwise and crosswise faces. Cuts were taken with great care, using the saw cuts as reference points, and the same scale and magnifying glass were used lor the measurements.
On this job the critical dimension happened to be the distance from the upper edge of the saw cut to the shoulder on the stud. The second photograph shows one of the studs placed against the edge of the scale. This illustrates bow coarse and easily read the hundredths of an inch divisions appear under a magnifying glass. It is clear, even from the photograph, that.the dimension in question is a trifle over six and one half divisions and is, therefore, approximately .066 in., the required size. A check-up after the studs were finished showed one of them calibrated .066S in., the other .0672 in.
The matter of getting proper light is extremely important. Have the light evenly diffused from both aides, and check each measurement from two positions if possible.
Special Purpose Shotgun Ammo
Birdshot, buckshot and the rifled slug are three standard rounds available for the 12 gauge shotgun. While these loads are adequate for most applications, certain situations call for special ammo. Each of the five following loads is designed to overcome a shortcoming fojnd in tne standard 12 gauge rounds. 16 or 20 gauge shells may also be used. The procedures are oriented to non re-loaders who will be buying and rrod-' ifying preloaded ammo. The processes should be easy to modify for those of you wtio have reloading setups. a
The factory loaded rifled slug is adequate to stop most iredlum size garre and penetrate most thin metal barriers. Large bones and steel over 1/8" thick will cause the soft lead slug to rapidly mushroom arid stop before it has penetrated the target. A round headed steel wood screw in the tip of the slug will Increase the degree of penetration by delaying this mushrooming action. Drill a hole in the exact center of the slug and turn the wood screw in flush with-the slug's tip. It Is important to keep the screw from projecting past the end of the shotshell case* If a shell with an exposed point were loaded in a tubular magazine, the gun's recoil could cause the point to detonate the primer of the shell in front of it. This is the reason all lever action rifle ammo is of the round nose type. B
This load is used to penetrate a steel armor plate, Kevlar body armor and bullet proof glass. It would also be useful against tempered aluminum alloy armor found on current riot control vehicles. A standard shotsnell is cut in half lengthwise with a razor blade. The cut should extend from the front end to the edge of the brass base. Carefully peel the two case halves back and remove the shot or slug and the large cardboard wad.
The lower wad and powder charge a"e left intact. Carefully drill a hole
In the center of the large wad anc insert a carbide or hardened steel burr or grinder bit into the hole In the wad'. This projectile should no: weigh rrore than the original slug or charge of pellets. Additional weight can cause excessive chamber pressure and may damage you or the 9un. If you ere a relpader, it's a simple chore to weigh the new projectile on a bullet scale and then charge the case with the appropriate arrojnt of powder. After the wad and tool blt are inserted, the case r's sealed with a soldering gun. Just touch the cut to reseal it. Seal the sides only as the end should be free to unfold when the shell is fired. It is sonnet ¡ires possible to seal the case with scotch tape but this causes feeding proolems In some shotguns. C
Standard rifled shotgun slugs have a usable range of only 100 yds. If a lighter rifle bjllet is substituted for the slug, the range is increased several times. This is accomplished by encasing the bullet In a 3 piece collar called a sabot (sa-'bo) defined as a thrust-t ransmi tt ing carrier that positions a projectile in a tube). Tie sabot travels down the barrel with the bullet and falls aside a few feet after leaving the muzzle. This principle was first usm with artillery rojnds and is the ba sis of the new Accelerator rifle round. The Accelerator carrics a 22 cal. bullet with a surrounding plastic sabot. The bullet/sabot combo is fired from a standard 30.06 case. The .22 bullet reaches a velocity of about '«.OCO feet per second. This is CLrrertly the highest velocity round available in small arms animo. Several years ago a 12 gauge shotshel l/sabot load was available commercially> The sabot carried a 50 cal. machine gun bullet. This rojnd is now out of pro-
Was this article helpful?