Cetme cast bullet reloading

[splotch]

Hey is it safe to wax reduced loads to get the Cetme to cycle with cast bullets - I use to use 22 grains of 4759 and a 170 grain bullet to get an HK 91 to function. I don't remember where I came up with the idea to wax (car wax) the loaded shells before shooting. But being young at the time I didnt think of possible problems. But now years latter I am wondering if that was really smart to do - any ideas? Thanks

[Kskybroom]

IMOP Car Wax contains Cutting Compounds may ad wear to to chambed an other parts,,,,

[Lloyd Smale]

I used cast in mine. I used enough 2400 to just make it function with a 180 cast. The nice thing is it didnt tear up brass like it does at full pressures.

[MtGun44]

The purpose of the fluted chamber in HKs is to reduce the grip of the brass on the
chamber to ease extraction. The system is called a delayed blowback by HK, and they
had a detailed mathematical workup that showed that the rollers acted as tiny levers
to provide leverage to let the lower mass of the carrier working against a mechanical
'disadvantage' to act like a heavier breech block. When you are using a lower powered
load, it would seem that reducing the case friction would let it apply bolt forces a bit closer to
a full power load (while actually at far lower pressures) which would seem to be a good
way to get the action to unlock and function.

I don't think you want to lubricate full power loads, but for low power loads with a system
like the HK (and CETME) design it does seem like the right thing to do.

Non abrasive wax (not a 'Polish and Wax') would seem to be good to avoid extra wear
on the system. Maybe Johnson's Paste Wax would work if buffed and let dry. I don't think
it has any abrasives.

Bill

[georgewxxx]

In Castpics Articles by members, I wrote a piece on the M-1 Garand. Here's part of it that pertains to your question..

I traded my 308 M-1 way back in 1974, so for these tests, I borrowed a friends M1-308, plus his CETME, L1A1, and AR-10B just to see how good or how bad cast will work in other semi-autos. If you have function failures in your semi-auto, a light oiling of the ammunition might help. It’s stated in Small Arms of The World that it’s recommended for the CETME and other delayed-blowback weapons. George Nonte said in his Modern Handloading that a mist of oil or wax sprayed on the cases with these reduced loads in semi autos works well. That’s why the smooth finish of some of the slick looking milsurp lacquered steel cased ammo feeds so smooth. The length of the driving bands on the bullets, not the weight, is the reason for so few mould moulds being used. It’s best if you do not seat bases below the neck. Case necks on the .300 Savage, 7.65 Argentine, and the 308 are all very short, and not easy to load cast or jacketed bullets straight and above the base of the neck. This second chart will show 308 M-1 test results only, but anyone with an M1-A, or other 7.62 NATO, or bolt 308 rifle, might find these loads helpful.

[splotch]

Went to the backyard range all 100 cycled and function correctly. Group size at 50 yards was about 1.5 to 2". No damage to the brass and resizing effort was minimal. Thanks for the feed back