View Full Version : Fluted chambers on G3 / HK91 and clone rifles
Are the cases totally un-useable for reloading after 1 firing because of the fluted chamber?
And since the outside of the cartridge "floats" on powder gases, does head space even matter in these guns? I assume the powder gases on the outside of the case must be at equal pressure to those on the inside of the case otherwise it would rupture around the flutes on the chamber. If this is true, why would head space matter (other than maybe getting so excessive that firing pin contact was affected)?
My cases are totally trashed and not reloadable. I switched to steel cased ammo. The cases looked like a spline shaft. No amount of sizing would restore the case mouth.
HighPowerShooter
01-29-2010, 04:33
I used a HK-91 for my very first year of HighPower shooting.. made expert with it to boot... I reloaded my cases with no problems what so ever. BUT!! I DO have a case port buffer on my HK.... I averaged 12 reloads per case before experiencing cracked necks... for 200and 300 yds I use 40.5gr Varget and a 150gr SMK...
S.A. Boggs
01-30-2010, 10:17
Take a pair of pliers and gently iron the neck out so that the expander ball can go in. In is IMPERATIVE that when reloading ANY RIFLE CARTRIDGE that a headspace gauge be used to set the headspace, if not execessive headspace will result. My preference is Wilson gauges. The G3 series is easy to reload for, the flutes won't hurt and unless the neck is damaged in the same place this also won't hurt. Military cases last longer then commercial due to greater thickness.
slamfire
01-30-2010, 11:05
Yes the upper 2/3 case floats, but I would not want to find out that the gas lubrication is uneven or erratic.
Cartridge headspace should be controlled in this rifle as in all rifles. You do not want the case to overstretch and rupture.
I purchased this Port Buffer from RTG, I think it is the best price around, and my cases are very reloadable. Even the ones with dents on their sides.
I have reloaded lots of 308 cases with side dents. As long as the dent has not punctured the wall, I do not believe that a dent is a problem. To me, as long as the case will provide a gas seal, dents are cosmetic.
So I size the stuff, and if it enters the chamber, it will get fired.
I will use cases until they develop case head separation, brass splits, and until the primer pocket gets too large.
I recommend using "fast" powders in the PTR-91. Powders that are in the 4895 burn rate or a little faster. I have tried IMR 3031, IMR 4895, H4895, and AA2520, all shot well and functioned well. I am of the opinion, but I have not tested it yet, this action may not do well with powders that have a high residual breech pressure. Which would be slower burning powders like IMR 4350. I would not try Varget or IMR 4064, great powders they are, as these are slower than the 4895 series of powders.
I did shoot 174 grain bullets in my PTR 91, and I found the recoil objectionable. The bolt really hit the buffer with a hard slap. That tells me heavy bullets may be iffy in this rifle. To date, the rifle shoots 150 grain bullets fine. I am not going to load any lighter bullets, like 125's, but lighter should be easier on the action than heavier.
http://www.robertrtg.com/pofport_carry.html
http://img.photobucket.com/albums/v479/SlamFire/Rifles%20various/PTR91PortBuffer.jpg
S.A. Boggs
01-30-2010, 12:18
I was looking to pick up one of the CETME and use G.I. brass, IMR 4350 with my 160GC lead.
My experience loading cases fired in fluted chambers is that they load just fine: .-93 in 223, -91 in .308 and Tokarev in 7.62x54R. They just look awful.
I used to come across some brass fired the Michigan State Police in full auto H&K .223 rifles that had been converted to semi-auto only, and they destroyed the brass.
CDD
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