1892 Berthier Carbine

[dantoweed64]

I took my Berthier to the range today. Had a number of loads to try. Started with PPU factory rounds. Kicked really hard with those. so I stopped after 3 shots. Then tried full case loads of Trail Boss.(18 grains) Much more tolerable. Also had full case loads of Wc867(48 grains)slightly compressed surplus powder. These also kicked like a mule but showed no signs of overpressure. And did they ever boom! More like artillery, several people at the range commented on the noise! Thought I was shooting an elephant gun! I expected some unburned powder in the barrel, but none. Any way, all my shots were on target, that is to say, on the black of the man target. Open sights and bad eyesight, g765807658176582ood enough for me. The cases expanded considerably. To the point of increasing case capacity by almost 5 gr of powder! (wc867) Several of them split in the middle with a longitudinal separation about an inch long. I am using a 200 gr RNGC bullet sized to .329. Since most of my cases are now fireformed to this chamber I wont resize. The case mouth opened up to .330 upon firing. Anyway, is this kind of normal? having a chamber so oversize like that. and what would cause that to happen? My carbine is Model 1892 MD with a 1920 barrel. Also has the N on barrel and action.
I don't feel the gun is unsafe, I put 80 rounds through it. Just wondering about the chamber. Advice/comments welcome!

[texassako]

My R35 Lebel carbine is the same way. Old milsurp chambers cut to fire cartridges when dirty. Cases are quite a bit larger after firing, but I have not had splits like yours. Shoot almost the same loads too, except I use the 8mm Max boolit at 327" and 255gr. Pretty good thump and bang over a case full of WC860.

[mace2364]

I loaded bullets cast from the 8mm Karbiner mold with 10.0 grs of Unique for a nice little plinking load. It was a nice little plinking load.

[JeffinNZ]

I would suggest quicker burning powder for the top end. That short barrel is going to roar like a lion with slow powders. You want the pressure at muzzle to be declining. How about a mid range charge of H4985?