.30 Carbine NM Blackhawk primers

[montana09]

Hello,

I recently purchased a NM Blackhawk in 30 Carbine and am planning to work up some pistol loads for it. Currently due to all the shortages for powder I only have 2400, Unique, and H4350. I found some good load data using 2400 but I don't have any small rifle primers and can't find any in town or online. Can you use small pistol magnum primers like I use in my loads for my .327 or is a small rifle primer a must and I'm S.O.L. until I get some?

[Sevens]

It has been passed down to us from ATK techs back when ATK still owned CCI that the CCI-400 small rifle (non-magnum) and the CCI small pistol magnum are in fact the same primer, so I would feel confident if your primers are CCI. If your are some other brand then I don't know.

The .30 Carbine is a 40,000 PSI Max pressure cartridge, the use of the small rifle primer here is likely more to contain the pressure rather than a hotter burn from the primer.

You won't be making any .30 Carbine ammo with H-4350 and the Unique won't make a full-spec load but the 2400 is a fine powder for .30 Carbine.

Free advice as I'm an owner and handloader for a Ruger Blackhawk .30 Carbine...

More than any other gun that I own for certain, trim length is critical for this particular revolver. If you trim your brass too short, the firing pin will not hit them and you will be effectively making dummy rounds. And if you don't trim the brass when you "should have", the rounds will happily thumb in to the cylinder and pretend to fit UNTIL they advance up near the top where the recoil shield properly provides the headspace and then they will DEAD LOCK the revolver and of course, you will not be able to rotate the cylinder backwards <insert expletive laced tirade here> and to get out the offending rounds, you will have to pull the pin and remove the cylinder and it becomes a royally frustrating experience that will do it's level best to ruin your day.

[Unclenick]

CAUTION: The following post includes loading data not covered by currently published sources of tested data for this cartridge. USE AT YOUR OWN RISK. Neither the writer, The Firing Line, nor the staff of TFL assumes any liability for any damage or injury resulting from the use of this information.

I got that same info, but a recent call to a CCI tech resulted in a strong denial that they are any longer the same. Allan Jones, in his primer article mentioned that primers change more frequently than handloaders realize, so it may have changed. I looked around for supplies of small quantities to make test measurements, but I couldn't find any current production available anyplace.

That said, a magnum pistol primer should handle 30 Carbine pressure, as its old CUP MAP is lower than .357 Magnum's (and despite its newer psi MAP being 14% higher than that same cartridge). They aren't really very far apart, so as long as you aren't mushrooming or piercing primers, you should be fine. Also, if you load with H110/296, the operating pressure with 110-grain bullets is about 9% below maximum anyway.

[LeverGunFan]

A consideration for the actual M1 Carbine rifle is slam fires, where the firing pin indents the primer on bolt closing enough to discharge the cartridge. For that reason rifle primers are usually specified for the 30 Carbine cartridge, with some reloaders using mil spec or primers with a reputation for being harder. The Sierra 5th edition has a special section on reloading for gas guns that discusses primer selection.

In a Blackhawk there is no danger of slam fires, so the magnum pistol primer should work fine.

[montana09]

Thanks guys, I'll keep all that in mind. I'm only planning on using the 2400, and this Blackhawk is my only 30 carbine gun so no slam fire worries! I use the same primers to load 327 federal which operates up to 45,000 psi and have had no issues with those loads and primers at all. And yep all are CCI primers.

I'll keep the trim length in mind, first batch of work up loads will use all new unfired Starline brass so shouldn't have to worry about trimming for a bit.

[Sevens]

Just for clarity... while I am always in favor of using that which has proven to work, Federal has always used CCI-400 small rifle primers in their factory .327 Federal ammo.

[zxcvbob]

You can use any small primer in .30 Carbine with 2400 powder. It's a high-pressure cartridge, but not all /that/ high. And 2400 does not need a magnum primer. And your Blackhawk will set off rifle primers just fine.

If you load them with pistol primers, you might want to keep them away from a real M1 Carbine rifle.

Sevens is right about trimming the brass. Resize first, then trim, every load. Sometime the trimmer won't take anything off and sometimes it will.

[Unclenick]

Sevens,

Are you saying Federal doesn't use their own primers in 30 Carbine? They do make a standard level, military hard primer of their own, the GM205MAR.

[Sevens]

I haven’t got half a clue what Federal uses in .30 Carbine hahaha, but the techs at ATK assured me that all the .327 Federal factory ammo was built with small rifle primers.

[Unclenick]

Right, but why CCI small rifle primers (normal lead styphnate sensitizer) instead of Federal small rifle primers (basic lead styphnate sensitizer)?

[montana09]

All interesting points, I reload for my .327 with Alliant 2400 and CCI small pistol magnum primers. I've had no issues yet.

[T. O'Heir]

Slam fires are caused by improperly loaded ammo. Usually high primers. Slam fires have nothing to do with the firearm anyway. Certainly not with a Carbine.
There is no need for so-called "milspec" primers either. Those are just magnum primers and nothing else. Nothing different about the cups used in magnum primers either.
There is .30 Carbine pistol data in the Lyman Pistol and Revolver manual. I don't recall seeing either 4350. Both 2400 and Unique are in it using cast bullets, as I recall. I'm not at home to look.
The data is pretty much the same as regular Carbine data too. When the .30 Carbine hand guns first came out, long ago, there was no data or ammo made for 'em. Regular milsurp, etc was used.

[Unclenick]

T. O'Heir,

Please stop posting inaccurate information you've been corrected on in the past.

Slamfires can be caused by a damaged safety bridge in the gun. The military reduced the mass of the M16 firing pin to reduce its inertia because that caused slamfires, and those with the old style firing pins still have to watch out for that.

Out-of-battery firing in the Garand can happen from primers being too sensitive (see board member Slamfire's well-documented pair of OOB-fires). The military type primers are not just magnum primers. They have their sensitivity reduced to match the military h-test sensitivity spec. They are not all magnum. For example, the Federal GM205MAR is not magnum but has an extra thick cup to cut the sensitivity down. The CCI #41 and #34 are magnum, but they have reduced sensitivity accomplished by making a change in the anvil geometry to a shorter, wider-legged version.