30 carbine primers

[cwheel]

It would be nice to find a shop that has that setup to have these 2 checked/or repaired as necessary. Anyone know a shop that has these fixtures to check out carbines ?? Until then, will load from only a magazine, kids will get the proper training as well. Next loading I'll go to the harder primers. One last note. I have a can of
LC-72 CMP 30 carbine ammo. Other day, I took some of those rounds out and did the same test on them. Loaded in singles, primers were slightly marked, but none out of 50 discharged. All had a mark on the primer about equal to what fired the CCI primed reloads. I know the one from the DCM makes a mark just as deep as the one from a unknown, no difference. Yes, I'm sure it's likely both were worked on at some point, carbine #2 has a BA rebuild mark on the stock and some mixed parts. Carbine #1 has all Winchester parts ( DCM carbine ) and no rebuild marks. Only reason I mention any this to begin with is the OP is asking about primers and if it could make a difference. I would answer yes to that. In the interest of safety, thought it good to mention what happened with mine. I'm sure that there are many other carbines out there that will slam fire this way as well. Be safe,
Chris

[jimb16]

I think you guys are barking up the wrong tree! In a carbine, a slam fire is an out of battery firing that will smash the whole firearm. If the round fires and the case extracts and ejects normally, the problem is in the sear and hammer contact and not the bolt. The bolt is normally broken by slamfires in carbines. Check your sear engagement before you do anything else! I've owned and shot carbines for many years and had 24 at one time. I've been smithing them for years too. What is being described does not sound like slamfire, but failing sears instead.

[cwheel]

With the safety engaged ??? No broken bolts or damage of any kind resulted from this. And I can repeat this almost at will, 1 fires out of about 20.
Chris

[jimb16]

In a carbine, an engaged safety only stops trigger movement, not sear movement. No damage indicates a close bolt. Slamfires unsually occur without the bolt being fully closed, thus damage to the firearm. Repeatability is another indicator of sear problems, not slamfires. Take the action out of the stock and with an empty chamber, allow the action to slam shut. If the hammer drops even once, then you have a sear problem and should replace the sear and hammer, BEFORE THE CARBINE GOES FULL AUTO ON YOU!.

[cwheel]

Thanks, I'll check it out.
Chris

[cwheel]

Finally got time to get back to the carbine slam fire issue. Without the gages to be able to check out firing pin at the 7 1/2 degree thing, that aspect remains unknown. jimb16 suggests above that sears are slipping off as the action closes, and I checked this one out. Actions out of the stock and in a vise, actions cycled 100 times each, sears never slipped. ( could have some bounce taking place as well as the action closes ) Same test, safety off, same result. I'm reluctant to chamber a live round and let the bolt fly home again. Discussions about broken bolts and lugs have me avoiding this. What I will do is to continue to use these only loading from the mags from now on as Larry Gibson suggests. Once I find someone who has the gages, then I'll have them properly checked out. Doesn't seam to be a issue when loaded from the mags.
Chris

[barnetmill]

I think you guys are barking up the wrong tree! In a carbine, a slam fire is an out of battery firing that will smash the whole firearm. If the round fires and the case extracts and ejects normally, the problem is in the sear and hammer contact and not the bolt. The bolt is normally broken by slamfires in carbines. Check your sear engagement before you do anything else! I've owned and shot carbines for many years and had 24 at one time. I've been smithing them for years too. What is being described does not sound like slamfire, but failing sears instead.

When I took a course for the NRA highpower rifle shooting, for the single shot part of the course of fire there is single loading of US Army Ammunition Plant 30-06
Never release a bolt that is fully retracted on a chambered single round. Release the bolt from about the half way point of retraction. This is just enough force for the extractor to ride over the rim and secure the cartridge.
The SKS is literally the worst really for slamming a round when released on a single chambered round relative to the firing pin dent.

EVEN FROM A MAGAZINE
THE ACT OF CHAMBERING ANY ROUND IN SEMI-AUTO GUN CAN RESULT IN A DISCHARGE. RARE BUT IT CAN HAPPEN. 22 RIM FIRES ARE MORE PRONE TO THAT. WHEN EVER CHAMBERING IN ANY GUN POINT AT SOMEThing THAT YOU AFFORD TO DESTROY.

[kerplode]

Wow...Really exhumed this one from the grave didn't we.

So yeah, since we're here, I've had good luck with regular small rifle primers in the 30 Carbine. The Mags (41, 450, etc) will work, but the milder primers ignite the charges just fine and seem to produce better uniformity.

Agreed on the slam-fire prevention stuff, but I submit that the slamfiringest rifle is not the SKS, but rather an M1 Garand chambered in 308.

[barnetmill]

Wow...Really exhumed this one from the grave didn't we.

So yeah, since we're here, I've had good luck with regular small rifle primers in the 30 Carbine. The Mags (41, 450, etc) will work, but the milder primers ignite the charges just fine and seem to produce better uniformity.

Agreed on the slam-fire prevention stuff, but I submit that the slamfiringest rifle is not the SKS, but rather an M1 Garand chambered in 308.

We will have to have a contest LOL to see which one wins a most dubious prize.

[kerplode]

LOL! Yeah, a slamfire throwdown...Two rifles enter, one rifle leaves!

I like it!

[1hole]

Wow...Really exhumed this one from the grave didn't we.

Everything is new to me until I have read it.

Back in the mid-60s I had range time fun when I cast for, loaded and shot a lot of .30 Carbine ammo. I found that any brand of primers labelled "Small Rifle" worked quite well.

I never had nor heard of anyone else having a slam-fire.

[35 Whelen]

Everything is new to me until I have read it.

Back in the mid-60s I had range time fun when I cast for, loaded and shot a lot of .30 Carbine ammo. I found that any brand of primers labelled "Small Rifle" worked quite well.

I never had nor heard of anyone else having a slam-fire.

In the last three years I've loaded and fired an almost embarrassing amount of .30 Carbine with every type of primer that will fit the pocket. No slamfires.

35W

[kerplode]

As long as you're using small rifle primers and you're feeding the rounds from the mag, then there really isn't too much risk of a slamfire.

You can get into trouble by subbing small pistol primers or by dropping a single round into the chamber, hauling the operating rod back and then letting the bolt fly home on the chambered round.

The little carbine is pretty forgiving, all things considered...

[Texas by God]

Dropping a round in the chamber and releasing the bolt can result in a slam fire from an AR15, too. Been there, done that only once.
Like a Mauser, always feed a semi auto from the magazine.


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[popper]

Single rnd dropping the bolt, it doesn't have extra friction from the bolt over-riding another rnd in the mag. Bolt has more inertia and FP hits the primer with more force. Happens in AR10 too.

[jimb16]

Replace the sear and hammer and I bet the problem disappears!

[barnetmill]

Another possible option to make sure that if you have an M2 round bolt, to replace it with a flat M1 bolt. The original bolt was replaced with a heavier M2 to facilitate full auto fire when the selector switch was so positioned. Basically the action closes with more force and likely velocity.

[35 Whelen]

Another possible option to make sure that if you have an M2 round bolt, to replace it with a flat M1 bolt. The original bolt was replaced with a heavier M2 to facilitate full auto fire when the selector switch was so positioned. Basically the action closes with more force and likely velocity.

The Round Bolt

"Contrary to widely circulated rumors, the round bolt was not specifically
designed for use with the select-fire Model M2 Carbine. It was an evolution
of the bolt for all U.S. Carbines, cal. 30. When the Model M2 Carbine was
later introduced the round bolt had already been in use with production of
the Model M1 Carbine and was simply the standard when the M2 Carbine
production began. Either bolt was acceptable for use in either model
during Ordnance inspection and rebuild operations."

[Alferd Packer]

The drag of a free floating is higher when pointing the weapon horizontal or at a 45 degree angle.When pointing the weapon vertically up or down I think the firing pin has least drag when charging in this position.
Having said that, the only discharges experienced were with the weapon in the vertical position.A man in my company accidentally killed his buddy carrying a rifle at sling arms on guard duty when he sneaked up and jerked down the charging handle to chamber a round.
The rifle discharged as the man leaned forward away from the man pulling down on the handle.
The sling caused the rifle barrel to slide forward pointing the barrel under the lip of the old GI helmet.The slug went up the back of his head at a steep angle killing the man instantly.
They had entered the Army under the buddy system and were like brothers.
This happened at Ft.Benning in 1969.
Again, later in Viet Nam, aboard a chopper inbound to an LZ, "lock and load " , resulted in a rifle held vertical on a man's lap, discharged thru the helicopter top.
Again, 'surprise'.
1970,
Only two I know of for sure.
Many Officers advised the men to discard the chambered round from both pistol and rifle into a separate bucket when returning from guard duty or a mission
The rounds always showed a slight dent from the firing pin.
Considered to be a risk if used more than once as the top round in the magazine.
I know many MP outfits that practiced this as well, except when issued revolvers as sidearm.
Some people in the military knew more about ammo sensitivity than was written down.
The MO. Highway Patrol also practiced this with their 10mm pistols.
Never reload a round that has been chambered back into the magazine as the top round.
You take enough chances out there.
It's only for those who .bother to think things out.
Having said all that, I have never experienced a slam fire etc. .
Does that mean it will never happen?
Only God knows.

[fal_762x51]

I have been using CCI 41 and Wolf small rifle primers. Never had a slamfire or out of battery.