Tikka - bolt closing issue

[buckchaser]

I experienced something for the first time tonight. I was putting some range rounds through a new Tikka T3x Battue 308. When I went to chamber a round, the bolt wouldn’t close properly. I was using factory Federal Power Shok Copper 150 grain. I tried a few other rounds from the same box and they worked fine - but there were a few that the bolt wouldn’t close after clambering. I had no issues running Federal “blue Box” 150 grain earlier this month.

Any ideas?

 

[NascarManiac]

I've had the same issue with my 22-250 Tikka a few years ago...I believe its a OAL issue. Only a few shells from the box would not load properly. I put them both in my press and sat them a little deeper and no issues afterwards.

 

[IvoB]

make sure the neck isnt bent on the round

 

[Cameron SS]

When you say the bolt won't close, be more specific. Does it feel like a gradual increase in resistance like something is starting to get squished, or is a hard stop like coming up against something solid. How far did you get in the bolt travel before it stopped?

If there is a round to round difference, measure the rounds and look for a pattern.

Its highly unlikely that the brass is so out of spec, or the chamber is so tight, that its a cartridge length or bullet seating issue, but anything could happen.

When the bolt fails to close, does the round extract OK? is there any obvious sign of stress or damage to the case or bullet?

 

[buckchaser]

When you say the bolt won't close, be more specific. Does it feel like a gradual increase in resistance like something is starting to get squished, or is a hard stop like coming up against something solid. How far did you get in the bolt travel before it stopped?

I could run the bolt in, but when I went to close it there was immediate resistance. I didn't want to force the issue so can't really say whether it was "hard" or "soft" - I stopped right away.

If there is a round to round difference, measure the rounds and look for a pattern.

Its highly unlikely that the brass is so out of spec, or the chamber is so tight, that its a cartridge length or bullet seating issue, but anything could happen.

When the bolt fails to close, does the round extract OK? is there any obvious sign of stress or damage to the case or bullet?

The rounds ejected without any problem. I couldn't see any obvious signs, but I'm far from an expert in that.

 

[cyclops666]

Are you feeding them in one at a time or from the magazine

 

[buckchaser]

Are you feeding them in one at a time or from the magazine

From the detachable magazine.

 

[guntech]

Possibly a minimum head spaced chamber and slightly over size factory ammo... it would not be the first time that has happened...

 

[Cameron SS]

The rounds ejected without any problem. I couldn't see any obvious signs, but I'm far from an expert in that.

Do you have a set of calipers and access to the SAAMI specs for the cartridge?
I would suspect the ammo before i would suspect the gun.

If you don't have calipers or know what you are looking for, find a friend who reloads and ask for help measuring the rounds against the specs for that cartridge. Any novice reloader should be able to help you measure the chamber as well, if you rule out the ammo being the problem.

Once the rounds have ejected, get a magnifying glass. You are inspecting the bullet for rifling grooves, tiny little scratches, 5 or 6 of them, right around the ogive. https://encrypted-tbn0.gstatic.com/...N2n7tWIIb7AIbpaYRv5GkcIYHoLUjPJCAdER94Azjhg4A

They might be very small, or very pronounced. If you bullet is seated long, chambering it will jam the bullet into the rifling and marks should be observable. I doubt this is the case given you said rounds ejected without problem.

The second thing you are looking for is crimping at the case neck. This is the edge of the case where it holds the bullet. Note the differences in shape of the edge of the case. https://encrypted-tbn0.gstatic.com/...EtMcsEkLTlqz3JWFH1o9puqTG5HuiS9Q5M_6ZUoMeT7Fw

The actual crimp is irrelevant for our purposes, what you are looking for is differences, or deformities, between rounds that have failed to chamber properly, and rounds from the same box that have yet to be chambered, if you have any.

Its possible that if your chamber is below minimum specs, or the cases are too long, the case neck is getting crimped by the act of chambering and deforming (slightly, because you aren't pushing TOO hard, which is a good thing).

Thats kind of the low hanging fruit.

The simple solution, is to avoid brands of ammo where this is a known problem. If you aren't seeing any other signs of over pressure, then just avoid those rounds and move on.

If its keeping you up at night, then you might need a reloading friend to explore it with more detailed measurements, or a gun smith.

 

[Turillo]

This happened to me before and it was a result of carbon buildup in and near the chamber...took a very good cleaning to make it right again.

Let us know how it works out.

 

[stickhunter]

I experienced something for the first time tonight. I was putting some range rounds through a new Tikka T3x Battue 308. When I went to chamber a round, the bolt wouldn’t close properly. I was using factory Federal Power Shok Copper 150 grain. I tried a few other rounds from the same box and they worked fine - but there were a few that the bolt wouldn’t close after clambering. I had no issues running Federal “blue Box” 150 grain earlier this month.

Any ideas?

Like other mono-metal bullets, I suspect you'll find the Federal Power Shok Copper projectiles to be significantly longer and have a different profile than the corresponding Federal Power Shok lead projectiles, so you may be testing the limits of the headspace of your rifle. I wouldn't fret it, and would probably just switch to different ammunition.

 

[guntech]

Like other mono-metal bullets, I suspect you'll find the Federal Power Shok Copper projectiles to be significantly longer and have a different profile than the corresponding Federal Power Shok lead projectiles, so you may be testing the limits of the headspace of your rifle. I wouldn't fret it, and would probably just switch to different ammunition.

you may be testing the limits of the headspace of your rifle

Bullets have absolutely no relationship with head space ...

 

[stickhunter]

you may be testing the limits of the headspace of your rifle

Bullets have absolutely no relationship with head space ...

Yes, you're correct, and I should rather have said testing the limits of your chamber. The dimensions of the copper bullet are different (typically longer and with a different ogive) than the lead bullet, so it's not that surprising to me that the cartridges with lead bullets feed fine while the copper would not. In any event, if other factory loads are fine, I don't think there's anything to worry about and/or do.