The UK's Finest Independent Forum for Shooters and Gun Owners. Est 2010.

Anybody out there tried slugging various Mosin Nagant Barrels and obtaining comparison results of bore size.
Have you tried both 308 and 311 FMJBT and compared shooting results following slugging results and bore size matching of land and groove. Does anyone have any information regarding bore discrepancies in Early and late war rifles and Manufactures.

My Finnish M24 Mosina shoots 308 bullets quite nicely! I've not slugger it, but based on the history of the rifle the Finn's rebarreled the M1891 Mosina's with either a Swiss or German heavy barrel, with my rifle having the later Bohler Stahl stepped, heavy barrel. The intention was to use standard 7.62x54mmR cases and a 308 projectile.

My handloads hit Fig11 heads at 400m and full Fig11's at 600m. I don't see any keyholing when shooting paper at 100m.

My experience is the opposite of the Welsh ones......mine hate .308" bullets (inadvertently loaded a load of .308" bullets, don't ask me how) but loves .311"- .312" ones.

I haven't slugged the old girls but you'll find that Russian Mosins will be in the .311" region unless well worn and as WelshShooter pointed out a lot of rebarreled Finns are .308"......to be honest I'd slug a Finn to be on the safe side though I have not found any info that would suggest that there is a safety issue firing the larger bullets through a Finn, but accuracy would be a concern.
One of the references that I found suggested that the .308 bored Finn rifles also had the neck of the chamber tapered down to the smaller size. This makes me wonder if the sticky extraction with some types of milsurp ball ammo is somehow related to the tight neck dimensions.The Finnish 7.62x53r designation should be more like 7.62x53.5r, the Russian's rounded up to 54 and the Finns rounded down to 53.I know a few people who stick steel-cased Russian milsurp through their Finnish Mosins and it also seems to be common when reading through US sites and forums.

There were two Arsenals in Russia producing the Mosin, one at Tula and the other in Izhevsk.Some folks (mainly Tula owners) claim that Tula-made rifles are somehow "better" but I don't think there is any real evidence though I will say that pre-war 91/30s do often have a better fit and finish than wartime production rifles.I have a 1926 Izhevsk ex-Dragoon with its original barrel that has one of the best bores I've seen on a Mosin and a 1939 Izhevsk 91/30 that has definitely been in action and has a frosty barrel but both shoot pretty much as well as each other......the '39 dropped a Fig11 at 900m, with irons and Russian steel-cased ammo, on the third shot at Sennybridge!.
I also had a 1944-dated Izhevsk M44 Carbine that was absolutely mint and unissued and the machining and fit etc were spot on for a wartime rifle and was one of the nicest ones I have seen so even late war rifles can be very good.

Regardless of age or manufacturer barrel size will vary depending on use; some of these rifles will have had a very hard life and getting on for over a century of use!

My first Mosin was a 1954 Polish M44 carbine, unissued, unfired (apart from proof)I got it fresh from the manufacturer's crate. Groove diameter was .3176"! So it had to go. f the two I currently own one is 1934 Izhevsk in a 1932 Tula stock and hardly any rifling the speak of but slugs out at .314". I shot a 42.2 with it at 900 yards last month. It has also shot .308 155g SMKs well. The other is marked up as a 1924 vintage which I've yet to slug due to needing to sort the bedding first. But it is shooting the Lee .312-185 just as well as the other Mosin, that bullet casts out at .3155" and I size them to .315"