Tikka T3X Failure to Fire

[Eleven]

If I’m following correctly; you’re getting primer strikes but not ignition on both reloads and factory ammo every 15 rounds or so. And if you are to believe the person who sold it to you this is a new problem. If all of that is correct my first thought's would be something in the bolt (firing pin spring, bolt lift, etc). I’d probably also check headspace only because it’s easy. But id’ bet that isn’t it.

 

[SloppyJ]

I quit messing with barrel nuts because theyre a pain if you want to swap IMO. I red locktite them and spin it on like a shouldered barrel when I get it right. That's about the best you can do.

A go gauge with two layers of scotch tape on the bottom works great as a no-go gauge FYI.

Do you have a comparator to measure a fired round compared to an unfired round?

 

[Ac338]

Had this same issue on a savage recently after I swapped barrels. Had to screw the barrel in a bit until bolt closed with just a slight resistance on go gauge if I remember correctly. Was also a .223AI shooting non FF brass. No ftf for over 100 round since. At first 6 in every 10 were ftf. PS: double check after tightening barrel nut it can change some while torquing. Took me a few tries to get it where I wanted

 

[Rugger7622]

Yes, I’m getting FTF on 1/15 or so rounds, both factory and my loads. 500 rounds on the gun, shoots like a dream with 75 ELDM’s and 77 TMK’s. Brass is growing 2.5 thou from reloads to fired - seems normal to me. I’m through 100 pieces of pre-prepped LC brass. I’ll resize them all, load up another 50 and try it again.

Would pictures of the bolt broken down help? I’ll work on getting a set of gauges as well

 

[UpSideDown]

Remove your firing pin and check headspace. The lower-left primer on the shell in your first pic worries me. Looks like you may have a ton of headspace, or lots of firing pin flow inside the bolt.