Should I be comfortable with this?

[Kermit1945]

On the line at the club the other day and got into a Contender conversation. Turned to IMHSA and then to .32-20. I told him I have a .32-20 (.308) barrel and a bunch of loaded .32-20 ammo, cast bullets, that I loaded for a Marlin I no longer have. I said I guessed I should pull the bullets and reload with .308's. His suggestion was to just go ahead and shoot the .312's out the .308 barrel, "since it's only 4 thousandths." I consider him experienced and knowledgable, but...

Would you shoot 'em as he suggests?

[imashooter2]

If they chamber easily, I'd pull a few, work up to ensure the load is safe and then shoot the rest. I size .312 for a .308 barrel Marlin all the time. But I worked up the load using .312 boolits.

[Nobade]

It works fine. The throat is tapered and set up to do exactly what you are describing. The 32 H&R mag is the same way.

[Kermit1945]

Thanks for helping a castboolit newbie. I'm learning. Not sure I have enough years to even think about catching up with you guys though.

Here's what I've got:

90 gr SWC, 13 gr IMR4227, WW sm rifle primers
118 gr FP, 4.6 gr Unique, same primers

[Shooter]

I shoot .312 boolits in my Contender all he time. No worries.

[zuke]

Doesn't the Ruger Ranch rifle have a .308 bore but fire's 7.62x39 ammo?

[uscra112]

Quickload workup on the O.P.'s loads yields 14K psi for the 90 grain load with 4227, and under 13K for the Unique load. I'd say there's plenty of safety margin in a Contender.

Shoot 'em.

[imashooter2]

Quickload workup on the O.P.'s loads yields 14K psi for the 90 grain load with 4227, and under 13K for the Unique load. I'd say there's plenty of safety margin in a Contender.

Shoot 'em.

...as long as they chamber easily.

[ShooterAZ]

I shoot .311 boolits in all of my 30 cal rifles...30-06, 308 etc. They work better for me than .309. The key really is working up the load. Never start out at max!

[BruceB]

Yep.....here's another one who loads .311" cast bullets in all the .30 calibers. I've found that they work perfectly, chamber easily even in the autoloaders, and save the trouble of slugging barrels.

By the same token, my .303 British rifles are now dining happily on NOE 316299s, which are fully .315" and lubed-only in my .319" sizer die.

Incidentally, my Ruger M77 7.62x39 has a groove diameter of .3105", for whatever that's worth. Definitely NOT a standard .30-caliber bore.

[pietro]

Doesn't the Ruger Ranch rifle have a .308 bore but fire's 7.62x39 ammo?

FWIW, 7.62mm = .308".


.

[HangFireW8]

FWIW, 7.62mm = .308".


.

No, 7.62mm = .300 inch

HF

[45-70 Chevroner]

FWIW, 7.62mm = .308".


. Not always. Most military 7.62X39 rifles are .311 and so is 7.62X39 military ammo. Ruger short 30's are .308. Lee dies have both .308 and and .311 expander plugs to accomadate either one. I have not personnaly tryed it but I know guys that have shot 7.62X39 military ammo in thier Ruger short 30's. What I should have said is 30 cal is a nominal number when it comes to military rifles, they can range in size from .307 all the way up to .314. I think the 303 British is considered a 31 cal and the barrels made for it are all over the place for size. I don't think I have ever saw one that was .303. There just numbers anyway. (That one will get me in trouble.) I think HangFire is right 7.62 = .300", I haven't check it though.

[Kermit1945]

Had a little time to waste today before physical therapy, and shot up the 15 rounds of the Unique loads. Three 5-shot groups all inside the 10-ring of 100yd smallbore targets set at 25 yards--over a rest, stock iron sights. I'm going to be playing with this barrel some more!

Thanks, folks!

[leadman]

Just to add another complication in trying to figure out 30 cal. bore sizes. I recently bought an unfired Norinco SKS and the bore slugs at .313" X .303". The commercial ammo is loaded mostly with .310" to .311" bullets.

[cbrick]

Sure as long as they aren't top end loads.

My 32-20 Contender couldn't care less about boolit diameter as long as it's at least .310". I also use 32-20 brass in my 30 Carbine all the time just for the rimmed bass. Fire formed it comes out just a tick shorter than 30 Carbine brass and eliminates the case trimming.

Dunno if it's true across the board but in all the bores I've slugged there is more and larger variation in 30 cal. bores than anything else I've run across. My 30-30 Winnie has a great bore, clean sharp rifling, no loose or tight spots and it's .310" from one end to the other.

Rick

[zuke]

Not always. Most military 7.62X39 rifles are .311 and so is 7.62X39 military ammo. Ruger short 30's are .308. Lee dies have both .308 and and .311 expander plugs to accomadate either one. I have not personnaly tryed it but I know guys that have shot 7.62X39 military ammo in thier Ruger short 30's. What I should have said is 30 cal is a nominal number when it comes to military rifles, they can range in size from .307 all the way up to .314. I think the 303 British is considered a 31 cal and the barrels made for it are all over the place for size. I don't think I have ever saw one that was .303. There just numbers anyway. (That one will get me in trouble.) I think HangFire is right 7.62 = .300", I haven't check it though.


:bigsmyl2:

[swheeler]

7.62 mm is refering to BORE diameter, not GROOVE diameter. 7.62x.03937=.2999 inches

[bobthenailer]

When loading for the contender with a .308 bore make sure the expander button in the die set is for 308 dia bullets not .311/.312 dia bullets .
also neck size only , as you will probly be less accurate with FL sized brass.