So, I wasn't sure whether to put this in gunsmithing, or milsurp, or here, so I'll try here first.
I acquired an M96/38 on the weekend and shot it for the first time today. I'll start with the condition of the gun - the stock disk indicates that, even when it was re-armoured, it was somewhat shot out. Bore is indicated at 6.54 (brand new factory should be 6.50) and #3 accuracy rating (it's either 1, 2 or 3 from best to worst). When I cleaned it, I never did get it completely clean (30ish patches of solvent and carbon cleaner, with some scrubbing thrown in).....it's been well used, as indicated by other very general observation, and so could be bored out even worse than when it was re-armoured. But it locks up well and the internals look as crisp as you would want, for a 1909 action. Lots of rifling left, for example.
So, I didn't have any strong accuracy expectations, and didn't think I would see pressure signs as I loaded to minimum average from 2 books I have. Chrony indicates that it's not making the expected speed even extrapolating downwards for the slightly shorter 24.5" carbine barrel. Using RL22, 43.5gr was 2175fps and 44.5 was just over 2200fps with 139gr Scenars. Just more indication, to me, of a 'loose' bore. They stabilized fine and, once I learned the iron sights, shot where I pointed.
My concern is twofold, likely related.
1. backing out primers. I shot 7 rounds, 4 of them showed significant travel of the primer. This is in brand new first time being shot Win brass. 4th one from left is obviously unfired.
2. significant blowby. First couple had no issue, but I was a little surprised to see the rim groove almost totally full of carbon on the 3rd shot (with the lighter load) - it's the one furthest right in the pic. Shot a couple of the heavier load just to get a speed indication, first came out clean but the second was covered with carbon head to toe - kinda hard to see in the fuzzy cam pic, but it's the case in the center.
So what do I have? Loose chamber? Load em hotter so the cartridge doesn't rattle around in there?
Headspace way out of whack? Danger Will Robinson?
As an aside, I had read how pleasant these are to shoot but it far exceeded my expectations! Even with that steel butt plate, just a pussycat to shoot, hardly any recoil at all!
I acquired an M96/38 on the weekend and shot it for the first time today. I'll start with the condition of the gun - the stock disk indicates that, even when it was re-armoured, it was somewhat shot out. Bore is indicated at 6.54 (brand new factory should be 6.50) and #3 accuracy rating (it's either 1, 2 or 3 from best to worst). When I cleaned it, I never did get it completely clean (30ish patches of solvent and carbon cleaner, with some scrubbing thrown in).....it's been well used, as indicated by other very general observation, and so could be bored out even worse than when it was re-armoured. But it locks up well and the internals look as crisp as you would want, for a 1909 action. Lots of rifling left, for example.
So, I didn't have any strong accuracy expectations, and didn't think I would see pressure signs as I loaded to minimum average from 2 books I have. Chrony indicates that it's not making the expected speed even extrapolating downwards for the slightly shorter 24.5" carbine barrel. Using RL22, 43.5gr was 2175fps and 44.5 was just over 2200fps with 139gr Scenars. Just more indication, to me, of a 'loose' bore. They stabilized fine and, once I learned the iron sights, shot where I pointed.
My concern is twofold, likely related.
1. backing out primers. I shot 7 rounds, 4 of them showed significant travel of the primer. This is in brand new first time being shot Win brass. 4th one from left is obviously unfired.

2. significant blowby. First couple had no issue, but I was a little surprised to see the rim groove almost totally full of carbon on the 3rd shot (with the lighter load) - it's the one furthest right in the pic. Shot a couple of the heavier load just to get a speed indication, first came out clean but the second was covered with carbon head to toe - kinda hard to see in the fuzzy cam pic, but it's the case in the center.

So what do I have? Loose chamber? Load em hotter so the cartridge doesn't rattle around in there?
As an aside, I had read how pleasant these are to shoot but it far exceeded my expectations! Even with that steel butt plate, just a pussycat to shoot, hardly any recoil at all!