just bought a mosin

[revolver junkie]

hey all been a while

I just bought a very nice 91/30 mosin
checked the whole crate and found the best bore and rifling of the bunch all looked like fresh arsenal rebuilds
and a Spam can of ammo

does anyone have exp with the lee C309-200-1R in a mosin
i know i will probably need to slug the barrel
but any advise as far as powders/primers that have worked better than others

going to shoot it tomorrow well make that today

[singleshot]

Too small. Start with a .311 or .312 boolit. Slugging the barrel will confirm (or deny) this.

[Buckshot]

...............If that Lee mould cast a slug even APPROCHING .311" I'd probably faint dead away hearing about it You're correct in needing to slug the barrel of your new rifle. I have 3 M91/30's, a M44, and a M91 and they're ALL different in their bore, grooves, and throats. Oddly, one dated 1943 when things were pretty hectic for Russia has the tightest barrel.

..............Buckshot

[Shyoldman]

I have 3. Just picked up the 3rd. 1944Isk, 310/300, 1931 hexIsk,310,299 and last one a 1938 tula,311/300. Am happy with these bores.
I am working with a 170 gr FL that throws with ww at 312.alox lube. Not doing real well with lighter loads am slowly working up

[revolver junkie]

well i went and shot it this afternoon
WOW color me impressed
gun was holding 3in groups at 100yds iron sights
with surplus ammo

took a couple shots at a 8x12 steel plate at 200yds
hit it on the third shot

kinda figured i would have to get a .312 mould

[Archey]

I have two Mosins. Both of them love the Lyman 314299 with mild loads of 2400 or reloader 7.

[Pigslayer]

I have a 1942. .313/.302. Shoots well with factory ammo. Waiting on my custon mold from accurate. Accurate was specific about needing those measurements. I double checked my groove dia. with my new Starrett which confirmed my original measurement.

[revolver junkie]

thinking im gonna slug it here in a bit
also considering doing some paper patching
sound like fun and wanted to do it for awhile

[revolver junkie]

mine is sluggin out at .315 grooves and .302 lands

[revolver junkie]

guess if i run a .312 cast i might want to run it unsized or should i just size it to 312 and let obturate

[Buckshot]

guess if i run a .312 cast i might want to run it unsized or should i just size it to 312 and let obturate

.............Might, or might not obturate. Best to have the boolit at least the groove diameter. The boolit MUST seal the barrel, and just the tiniest single passage past the boolit is an avenue for the high pressure gas pushing on the slug to race past. Believe you me it will cut and erode that cringing lead boolit to a fair thee well. It's memorable to see such a slug. My first example was with 58 cal Minie' boolits. When I saw it I failed to understand what had happened. It looked like termites had been at work on the surface.

................Buckshot

[ShinyPartsUp]

I don't understand the importance of the land measurement. It is intuitive the bullet must seal the barrel so the groove diameter is critical. Why measure the land diameter?

I slugged my Mosin today and with my crappy plastic RCBS caliper I got 10 measurements of .311 and two of .310 for the grooves. The land measurements were inconsistent but @ .300

So why bother with the land measurement as it seems the groove measurement is the critical measure? What am I missing?

I got some .312 cast Spitzer boolits from a guy who seems to know what he is doing and shoots them in a British .303 rifle. I'm going to try a few loads when a few more items arrive in the brown truck (including a stainless caliper to recheck the measurements).

[Josh Smith]

Hello,

My favorite Mosin slugs to 0.309" and that's considered TIGHT for a 91/30.

A lot of Finns have 0.308" bores, but Mosins tend to run 0.310" on up.

Regards,

Josh

[Buckshot]

I don't understand the importance of the land measurement. It is intuitive the bullet must seal the barrel so the groove diameter is critical. Why measure the land diameter? What am I missing?

I got some .312 cast Spitzer boolits from a guy who seems to know what he is doing and shoots them in a British .303 rifle. I'm going to try a few loads when a few more items arrive in the brown truck (including a stainless caliper to recheck the measurements).

..............If they're a bore rider design and they mic .300"+ on the nose you're gold. Most all modern rifle boolit designs are bore riders, and most of them DO produce slugs (for 30 cal) at .300" or a thou or 2 over. You're very lucky in your bore diameter in that M-N. I have 4 of'em and they're .301/.301/.302/.302. The grooves are a bit more eclectic The 7.62x54R fit's into a group considered to be "Fat 30's. If there was a total listing for all the custom Group Buy moulds done, a heavy percentage of them would have been for the Fat 30's. I'd hazard to say that in addition to the desire for having them drop slugs at .314" or more on the dive bands, nose OD's would also have been biased a bit on the largish side. On a bore rider, if the nose doesn't 'Ride', you have a large portion of the slug that isn't doing anything beneficial, except adding weight.

That's one reason I do so love Loverin designs, especially in old military rifles. But from the mainstream manufacturers the Loverin has fallen from favor in the past 30 years or so.

................Buckshot

[kenyerian]

I've got a Fin 28 that slugs .308 and .300. it is marked with a S Y on the barrel. Haven't loaded for it yet as I need to get some brass. i've got a Lyman 311332 180 grain Mold that I am going to try.