Post war Marlin 32 Special and tight bores?

[Canuck Bob]

Over on cast boolits were guys slug barrels for sizing purposes it turns out that for a number of years Marlin produced 32 Win Special rifles with tight bores. .318 has been measured and reported often enough for me to accept it as fact. These rifles must have spit out truck loads of .321 bullets in there life.

http://castboolits.gunloads.com/showthread.php?t=15025

For years Ruger produced the little ranch rifle in 7.62X39 with a 30 cal barrel of .308. This seems to be common knowledge. For sure these things spit out tons of Commie Bloc stuff with steel jackets, cores and whatever else anyone can guess in .310 to .312.

I personally know guys who rebarreled 303 Brits with 30 cal barrels and load 30 cal and shoot factory at .311.

I've seen it reported Paco has suggested the 8MM for 32 Special but have not verified that report. Can anyone here verify the validity and source?

Not a single reported blowup. I know you have guessed where this is going. I am wondering about 8MM bullets for 32 Specials with a touch of freebore jump and careful work-up of loads.

Please note: If you are a new reloader you would have to be insane to do this. Every time this is discussed many experienced people warn of dire consequences.

[earlmck]

If your 32 special is chambered generous enough in the neck so those 8mm bullets chamber with no resistance I'd think you are good to go. (Assuming you're talking jacketed bullets). But if you feel them chambering hard you may want to back off before you get pressure problems from the neck not releasing the bullet easily, rather than any effect from an oversized bullet going down the barrel.

I've read that the 303 Savage used 311 bullets in a .308 barrel because Mr. Savage thought he got better accuracy that way. Maybe that was the same thought for Marlin using a .318 barrel?

[6pt-sika]

I had three 32 Special rifles that Marlin made !

One was from about 1912 and old enough that the barrel was stamped 32 HPS , had one of the model 1936 rifles that was made sometime in the late 30's and finally a 336SC that was made in 1951 . I shot bullets that were sized at .323" in all three . Granted I used only bullets I cast myself from aircooled wheelweights . Just as a point of reference Ranch Dog made his mold for the 32 Special at .323" also .

[6pt-sika]

FWIW , when I was shooting lots and lots of cast 30-30 rounds I ALWAYS sized my bullets in a .312" die !

[Canuck Bob]

One guy was guessing the Marlin thing might have been based in a good deal on German barrels as this size matches the 8MM early size. I suspect the twist of an 8MM would be much closer to an 03 so that would add some credence if known.

The Savage 303 info seems to be reported widely as well. The reason is given as a) to get a velocity jump due to the swaging effect or b) as a perceived need to seal against the new smokless powder pressures. Maybe some of the 99 collectors might know.

The throat and chamber neck seem very generous in both Marlin and Winchester rifles. As 6PT reports .323, the same as commercial 8MM, cast bullet sizing is common so neck interference seems unlikely. There will be no tight neck interference allowed. Ken Waters method of measuring brass expansion for pressure will be used and of course I now can justify a chrono for safety reasons. It won't happen for months with new cancer therapy looming anyway.

This is for bullet selection. Paco talks about clipping the noses off of spitzer bullets for the 30-30 a lot. I don't hunt much anymore but a Nosler partition in a 32 has some appeal for bear country. Say clipped to 180 grains and a scoop of Leverevolution powder it might make a dandy griz protector up close. The Hornady 170 RN would make a stout jacket bullet for controlled expansion options.