Issue with a carcano, too long of a firing pin?

wd113

wd113

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Recently I bought a carcano (not exactly sure of the model yet) I found out it was an 'Eatons' Carcano. Rechambered for 6.5 x 54 mannlicher schoenauer. Fun trying to get ammo for it. Lucky for me CanadaAmmo had some. Well I went to the range today with it for the first time. First 2 shots I look at the casings. Seems ok other than the primer looks like it was hit real hard.... hmmm... 3rd shot I feel a bit of a blast in the face! Looking at this casing I notice the primer was not seated as deep as the other two. But when I hold it to the light I can see light right through the thing.....needless to say, that was enough with that one today!
Would anything other than too long of a firing pin cause this?
 
Excessive headspace can cause the firing pin to punch the center out of the primer.

When you pull the trigger the firing pin hits the primer and pushes the case forward until the shoulder of the case contacts the shoulder of the chamber. The cartridge goes bang and gas pressure forces the primer back out of the primer pocket. This forces the primer back over the firing pin until the primer contacts the bolt face. This action acts like a cookie cutter and punches the center out of the primer.

Below is a normal animated firing sequence, first the chamber pressure pushes the primer out of the primer pocket until it contacts the bolt face. As the chamber pressure increases the brass case will stretch to meet the bolt face.



If the head clearance or cartridge headspace is excessive the firing fin will push the center out of the firing pin hit on the primer. In simple English the primer is taking a double hit and the second hit acts like a cookie cutter and punches a hole in the primer.


Military ammunition normally has crimped primers to prevent them from moving to the rear in longer headspaced military firearms.

Below in more detail is a commercial British .303 cartridge being fired in a longer military chamber, watch the primer being pushed back over the firing pin after it has already been hit igniting the powder.



Below, a reloaded .223 case fired in a AR15 with a uncrimped primer, the case was over resized creating excess head clearance or cartridge headspace.



Below the same thing but the primer anvil acted like a cork and plugged the hole in the primer.

 
Thank you. Great explanation. For starters, I'm going to look at the shape of the pin. From there I guess I need to get the headspace checked. Reading bigedp51's explanation, A headspace issue could be caused by bad ammo?, or a bad bolt? Would I be able to see any signs of the case stretching?
 
wd113

When you reload and start at the suggested starting load the primers will always protrude from the rear of the case, this is called headspacing on the primer. As you increase the powder charge the primer begins to protrude less and less as the powder charge is increased. You reach a point when the chamber pressure is great enough to cause the brass case to stretch and meet the bolt face, meaning the primer will be flush with the base of the case.

The amount your primer is protruding from your case indicates the possibility your rifle has excessive headspace along with your punctured primers telling you the same story.

You have two choices.
1. Have the rifle checked by a qualified trained gunsmith for headspace, and to fix this it might cost more than you want to spend.
2. If you reload you can fireform your cases to fit your chamber and not puncture your primers.

If this was a conversion you need to have it checked out for proper chambering.
Question, are the same lines on the rear of the cartridge on the boltface as well?
 
Yes. The lines match the bolt. and this means........?? Also, while looking at the bolt, the firing pin looks nice and round. I compared it to a enfield bolt/pin that was on my bench. Once again. thanks, I'm learning lots today...
 
You can also get punched-out primers from having a primer cup which is too hard to start with; at one time there was a LOT of that going around.

Primer on the far right looks to be flattened excessively, possibly oversize: pressure or headspace or both, depending on the actual diameter of the primer.

People demand performance, so the factories load their ammo absolutely "to the nuts" in order to get the final ounce of performance from every round. There are some makes of ammunition out there which carry this much too far; I started having primer punch-outs and blow-outs and hard extractions with a certain brand of European ammo in 6.5x55. There was absolutely nothing wrong with the rifle, but the cases were exhibiting the same problems as yours. In the end, I put a couple of the rounds aside in the 'general collection' tub and pulled the rest of the box down and reloaded it with a load which I KNEW was safe. No more problems.

The Italians generally were pretty careful with headspacing their rifles. It is much more common to find rifles with bolts on the TIGHT side than it is to find them with bolts on the loose side. Cooey also was careful in rebuilding these rifles (they started with Fucile 91s).

If it were my ammo and my rifle, I think I would be inclined to pull down the remaining ammo and reload it with a charge you KNOW is not excessive, replacing the primers at the same time.

Question: when you chamber a round and lock the bolt down, is there any resistance from the bolt? If it is tight at that point, the problem is NOT the rifle.

To test if the ammo is okay, you should be able to load in a round from the magazine, lock the bolt, unlock the bolt and CHECK to be sure that the Extractor is HOLDING the cartridge to the face of the Bolt. Then you turn the rifle away from you and fire that one round from the hip. Open up the rifle and check the casing. Same problems? If so, it's the ammo for certain.

BTW, any Carcano should be loaded through the Magazine, same as any other Mauser variant. Tossing a round into the chamber and slamming the bolt shut runs an awful risk of damage to the extractor. There were 3 types of extractors..... and 2 of them are turkey-teeth. I DO hope you are using a Clip to load your rifle.

Good luck, friend.

Hope this helps.
 
Hi Smellie, First off. I just learned something else new. Yes, I was single loading the shells. I don't have a clip for it. I just studied the bolt a little and I think I see what you mean about the extractor. It needs the proper sequence to engage the shell properly. Otherwise I am just slamming it over the end of the case.

Secondly, The bolt works just fine with no unusual resistance when closing. It was tight opening it back up after that third shot.

And lastly.... I've read a lot of your posts and I feel like a kindergarten student talking to a professor. Thank you for all of them.
 
When I got my carcano I didn't have a clip for it. What I did was I removed the bolt, clipped the cartridge to the boltface by hand so the extractor was holding it and then I inserted the bolt with the live round into the gun, chambered and shot it. Takes awhile but it works if you want to check function.

And yes I also feel that Smellie is a rocket scientist and I'm a half wit construction worker sometimes.:)

The man knows what he's talking about!!
 
I would agree - smellie brings good value to this forum as I'm sure others do as well.
Without digging out a carcano - I'm trying to wrap my head around the single load vs the magazine load and potential for fdamage to the extracter - I have been doing some reloading for this rifle and as part of the process of working up, have been single shooting cartridges. How does a magazine loaded cartridge fare better - does it slide up into the extractor from below?
 
The M block clip hold tention on the round its full length, forcing the base of the round to slid up under the Extrator, while being pushed upwards by the follower. by the time the base of the round is past the end of the Clip, the round is fully supported by the chamber and the Extrator. Before I recieved my Clips, I singely loaded by pushing the round down slightly against the follower arm, and slid the bolt forward slightly, allowing the rear of the cartrage to slide up the bolt face till it was seated under the Extractor. Goes fast once you get the feel of it.

Ken
 
Speaking of reloading ( and hopefully somewhere in the vicinity of the original post) - I had gotten some Norma 6.5 x 54 brass from Buffalo arms way back before the world went crazy - who would be good in canada for 50 more - I see Tradeex has some PRVI - any other suggestions?
 
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