The D-Rock Bullet Modifi cation System
Part 2 Steve Boelter
this second and final part to the D- Rock Bullet modifi cation tool. Because of space constraints, I had to split this article into two parts in order to fi t the general layout. Let’s pick up where we left off, starting with the Federal 712 ammunition.
I FEDERAL 712 The Federal 712 Sporting ammuni-
tion is a 38-grain copper-plated hollow- point round that’s popular with many varmint hunters. It’s in the high-velocity range with a listed muzzle velocity of 1,260 fps, and tends to be one of the more inexpensive choices for shooters to choose from. The hollow-point opening is small, being just a pinhole at the end of the rounded bullet. This conservative design has given it a good reputation for feeding well in a wide range of semiau- tomatic rifl es and pistols. I started the modifi cation process
with the hollow-point punch to give the 712 a bit more bite when it hits the target. Working the bullet into the die required little more than a gentle push to seat the rim into the base of the die. With the hollow-point punch, I worked in small increments of expansion until I was able to expand the hollow-point opening from 0.054 to 0.097 inch, and a depth change from 0.062 to 0.128 inch. The lubrication on the outside of the bullet is pretty dry from the factory, so I didn’t feel any need to re-lubricate the bullet. The second modifi cation was with
the fl at-nose punch. I had to again work in small increments with the punch or the bullet would develop tiny cracks and have the copper plating fl ake off. I reached a point where the tip was nice and fl at, but the hollow-point opening became fi lled in with displaced lead. To correct this, I switched to the hollow- point punch to press the 712 out from the die. This reformed the original hollow-point opening. Overall, the 712 was easy to work with in the forming
Federal fl at-nosed bullet in medium.
die, and other than the care needed to keep from fl aking off the copper plating, it makes a good round to modify. FEDERAL 712 ACCURACY
AND TERMINAL PERFORMANCE After fouling the short barrel with
15 rounds, I fi red the fi rst 10-shot group and then followed it up right away with a second 10-shot group. Both groups were about as accurate as I had ex- pected, hovering a little over a half-inch in size. There were a few rounds that drifted out of the group, but for the most part these would easily connect with a squirrel at this distance. Moving over to a fresh target, I fi red a pair of 10-shot groups with the modifi ed hollow-point bullets. I was pleased to see that the POI remained consistent between the factory and modifi ed bullets, but the accuracy didn’t seem to improve at all. In fact, it got a little worse. I was a little troubled by this, so I
moved on to the fl at-nosed bullets and fi red a pair of 10-shot groups. Again, the groups didn’t improve, but they weren’t far off from the factory round’s group size. Like the hollow-point bullets, the POI remained the same. On the second day of testing, the
longer factory Anschutz barrel pro- duced results which were more in line with what I was hoping to see. With the longer barrel, the fi rst two groups of the factory ammunition produced roughly the same group size, but when I switched to the modifi ed hollow-point bullets, the groups tightened up nicely with a noticeable drop in vertical disper- sion. Like before, the 712 seems destined to contain its fair share of fl iers, but it appears that with the right barrel and chamber combination, modifying the bullet’s shape has the potential to im- prove accuracy. As with the hollow-point bullets,
want to thank all of our readers for sticking around and reading
Federal Results. Left to right: Factory Federal, Flat-Nose modifi cation, Hollow-Point Modifi cation.
www.varminthunter.org Page 17
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