Tikka firing pin issue?

[wakedye]

I just purchased two new tikka t3x superlite's. One is a 223 and the other is a 270. I had a t3x 223 and I still have a t3 270 that are both blued and decided I wanted to get stainless superlite models. I went and shot them for the first time yesterday and the 223 I don't know what is going on.

I shot some 77 grain tmk's loaded by stand 1 armory and looked at the primer and it did not look normal. So I shot some factory remington 55 grain loads and those primers came out looking the same. the 2 on the left are from stand 1 armory. the one on the right is a factory Remington load.

Today I took the bolt apart to see if I could see anything and it looks like the firing pin from the 223 is shaped differently near the tip. The taper appears to be further down than on my 270 firing pin. Also, the firing pin from the 270 clearly shows signs of firing live rounds but the 223 doesn't. I shot 7 total rounds in the 270 and 10 in the 223. Does any one know why the 223 firing pin wouldn't show the heat marks? Does the taper location have anything to do with it?

I haven't sold my blued t3 270 yet so I looked at its bolt and firing pin and it looks the same as the t3x 270 with the heat marks and the location of the taper.

I am guessing that maybe the firing pin on the 223 protrudes further into the chamber because of the shape differences and that could maybe be causing the dented primers? I forgot to disassemble the bolts and degrease them so I did that today while they were apart. Should I reshoot it and see if the degreasing fixes it or should I try it with the firing pin from one of my other rifles? If you don't think I should try either of those then I will just contact Tikka and see what they have to say.
Thanks in advance for your thoughts!

 

[Lawnboi]

Those are pressure signs on the primer, dosnt appear the firing pin is causing it. When pressure builds in the case one place the case gives is the weakened primer where the pin strikes. This is an early sign of too much pressure. The primer material begins to flow back into the firing pin hole. Many factory rifles will show these with about any ammo, tikka has pretty good tolerance on their pins from my experience but I will occasionally get a slight crater when approaching pressure during reloading.

That said, I had 2 cases of Hornady match 73eldm all look like that after firing. Those same cases have been loaded another 2 times now and all is still well. They don’t look cratered too bad and if there are no other signs of pressure, such as stiff bolt lift, I’d personally continue shooting. On top of that usually it takes a handful of rounds to really smooth out a barrel, Iv had multiple tikkas show light pressure signs for the first 50 or so rounds.

 

[Hackleback]

The primers do look flat (notice the edge of the primer in the GFL brass compared to the rounded edge in the PMC brass. Could also be oversize firing pin hole in the bolt or soft primers (standard primers instead of the harder mil spec) in the GFL brass.

 

[wakedye]

Here are a couple more pics that are hopefully a little more in focus. The GFL brass is from stand 1 armory and the PMC is the factory remington. The firing pin marks on the PMC brass doesn't look normal to me either. It doesn't show the flattening of the primer like the GFL brass but it doesn't look like the primer marks from all the other rifles I have shot.

 

[wakedye]

So I looked at the bolt faces today and the 223 has a bevel around the firing pin hole. My other two tikkas are pretty much perfectly flat. You can see the bevel on the right side of the 223 bolt face. Could this be one of the sources for the primer cratering? Does anyone else have this bevel on their tikka bolt face?

 

[Wapiti1]

Yes, the bevel is contributing to the primers looking the way they do. The raised ring around the pin strike is the primer flowing into the bevel, and likely the firing pin tip isn't a tight fit in the hole.

Most of the time that ring is caused by a loose fit between the firing pin and hole. It's common with factory rifles and nothing to be concerned about.

It isn't a pressure sign in this case, IMO. If you give the soft primer metal a place to flow, it will. It's just a characteristic of that particular rifle. I say this because your photos show a raised ring, but no real primer flattening and no ejector mark on the rim. Even when in spec for pressure, that primer is seeing 60k psi and it is softer than the case. The point is, it will flow under safe conditions so that isn't an indicator of pressure in your rifle.

As for the shape difference in the pins, that is just manufacturing variation. Manufacturers make small changes based on application, or for whatever reason (improvement, cost, lot variation, etc). The protrusion of the pin itself is dictated by the cocking piece contact with the back of the bolt, not the pin end.

Jeremy

 

[wind gypsy]

Yes, the bevel is contributing to the primers looking the way they do. The raised ring around the pin strike is the primer flowing into the bevel, and likely the firing pin tip isn't a tight fit in the hole.

Most of the time that ring is caused by a loose fit between the firing pin and hole. It's common with factory rifles and nothing to be concerned about.

It isn't a pressure sign in this case, IMO. If you give the soft primer metal a place to flow, it will. It's just a characteristic of that particular rifle. I say this because your photos show a raised ring, but no real primer flattening and no ejector mark on the rim. Even when in spec for pressure, that primer is seeing 60k psi and it is softer than the case. The point is, it will flow under safe conditions so that isn't an indicator of pressure in your rifle.

As for the shape difference in the pins, that is just manufacturing variation. Manufacturers make small changes based on application, or for whatever reason (improvement, cost, lot variation, etc). The protrusion of the pin itself is dictated by the cocking piece contact with the back of the bolt, not the pin end.

Jeremy

^ This

That bevel is causing it and it's possible a sloppy firing pin fit could further contribute. I wouldn't consider that normal in my limited tikka sample size.

I have a r700 that does this with mild loads and softer primers too just based off the loose pin to hole fit. Some folks have their firing pin hole bushed to create a tighter fit. Soft primer cups and high pressure loads can result in primers getting pierced earlier than they would have with a tight fit.

 

[TxxAgg]

So how do they shoot?

 

[wakedye]

They both shoot great!

I am going to start reloading soon and I am just learning and reading about things. The 223 just had me worried as I have never seen the cratering from any other rifles I have shot. from reading it sounds like looking at primers isn’t the most reliable way to see pressure signs but these had me questioning the rifle.

I purchased the new rifles so that when I start reloading I would know the history of the guns but now I’m kinda wishing I had kept my other 223. I had been wanting the stainless superlites for a couple years for no good reason and I finally decided to do it.


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[Wapiti1]

They both shoot great!

I am going to start reloading soon and I am just learning and reading about things. The 223 just had me worried as I have never seen the cratering from any other rifles I have shot. from reading it sounds like looking at primers isn’t the most reliable way to see pressure signs but these had me questioning the rifle.

I purchased the new rifles so that when I start reloading I would know the history of the guns but now I’m kinda wishing I had kept my other 223. I had been wanting the stainless superlites for a couple years for no good reason and I finally decided to do it.


Sent from my iPhone using Tapatalk

You are correct, the primer is a possible indicator of pressure, but you need a lot more info in order to use that as a pressure sign. There are many scenarios for flattened and cratered, even pierced primers in an otherwise safe rifle/load combo.

Your best source of info is a chronograph. Just factor that in at the beginning and you'll never have to wonder what is going on. Even a lower cost ProChono, or Shooting Chrony will do what you need. They are a bit harder to use, but will keep you out of trouble. Reloading is about finding accurate loads, not necessarily the fastest, so keep that in the back of your head. Accurate is low extreme spread, and low standard deviation at the velocity your rifle likes.

You have no reason to be unhappy with that 223, IMO. If it shoots, its going to be a good rifle for you for a long time. If the primer look bothers you, it can be bushed as WG states, and that is about a $150 or so cost. About the same cost hit as trading it off. But not necessary. Shoot it and enjoy.

Jeremy