Back in 2002 I got a lathe, a 257 Roberts Ackley reamer, (4) Lothar Walther light varmint barrels, and built (4) surplus Mauser rifles for myself and (3) hunting buddies.

The first rifle was mine, and we used a new piece of Win 257 Roberts brass as the headspace gauge.
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After that we learned to headspace a 257 Roberts Ackley 0.004" shorter than a 257 Roberts.


We amateurs in 2002 did not know that the firing pin will push a non Ackley cartridge case forward into the sharp Ackley chamber neck base, cutting a ring 0.004" deep. When the powder goes off and the case expands, the case grabs the chamber walls. As the pressure gets even higher, the case head is pushed back against the bolt, thus stretching the brass.

In 20 years I have not set that barrel back. I learned to put 10 gr. of any pistol powder in the case and cover with COW [instant cream of wheat]. I slather the case with moly grease [What my father called 50,000 psi grease] I shoot straight up. If I am at a range and cannot shoot straight up, I poke the case mouth into Ivory soap to hold the COW in the case. This forms at least half a shoulder. With half a shoulder I can use full 257 Roberts Ackley loads with full accuracy.

The irony is that my rifle is more accurate than the other (3) rifles. [maybe because how my brass is formed]. Mine has shot a 0.45" (5) shot group at 100 meters for me. I handed it to another guy who shot one group and that was 0.50" (5) shots at 100 meters.

There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. -Ernest Hemingway
The man who makes no mistakes does not usually make anything.-- Edward John Phelps