8mm military reamer is generous

[nekshot]

Ok, after getting tired of huge chambers and large eroded throats in some vz24's I bought some brand new barrels from Copes. I shot the one gun today and it went great. What blew me away was the generous proportions with the neck. I forget the outside of cardridge demension at neck but it takes a .330 boolit to snug it up. None of my molds come close to that so we will pp these babies. What I like now is I have a perfect throat to work with and hopefully all the new barrels are identical internally. I knew the military reamer would be bigger than normal but at least dirt or dented brass is not gonna slow me down right aways!

[UBER7MM]

Wow! Sounds like a reamer for a heavy machinegun. Room for heating up a bit! If you have a chance, make a chamber cast. I'd like to here the true dimensions, and the barrel's as well.

Thanks in advance.

[Outpost75]

Shades of the .333 OKH!

[Nobade]

Check out the SAAMI drawing for the 8X57. It is supposed to have that giant neck. I have tried patching boolits to fit the fired case, and they are way too big to enter the throat. So, 8X57 is one of the few cartridges that must be resized before reloading. Get yourself a Lee collet die, and try that. I set mine so it sizes the case just enough for a slip fit on a .325" patched boolit, and they shoot lights out. Regular dies size the cases way too much and they don't last long.

-Nobade

[nekshot]

I am working on the lee crimp die, got it out of wack and need to reset it. I did make a .329 sizer to try for paper patching but I need some other paper. I am very optimistic with these barrels once I get it sorted out. After 5 shots looked down bore and perfect bright and shiny, thanks to Bens red.

[nekshot]

here is a picture. I believe 06 brass might do the trick. I am happy!
98667

[nekshot]

So I sized some RP 30-06 brass to 8mm and with boolits sized I get a snug (too snug) fit in chamber. They shoot great though I must turn the necks a little bit. Well I am pleased with everything so far and I am sure if all else fails these barrels will give very good jacket accuracy. Not bad for 39.00 brand new barrel!

[tomme boy]

Stay away from Remington 8x57 brass. It is way too thin in the neck. I had my best luck with reformed 3006 brass. Just make sure to anneal it after forming.

The way I formed it was to take out the expander assembly on a Lee FL die and just ran the 3006 brass into the die. It would squirt out the top of the die. Then trim it off and run it back thru the die again with the expander in the die this time. Then anneal them. You will get a lot less splits in the neck and shoulder. These Yugo barrels shoot really well for what they are.