Reloading Tikka T3x 308 - Fires when chambered after bolt lock

[Rommel Garcia]

New reloader here. Reloading for my Tikka T3x 308. I made sure that before I touched my first brass to reload, I read my Lyman 50th Edition Reloading manual, watched all the YouTube videos on step-by-step reloading, and read a lot on reloading forums. I was able to determine my COAL using the Hornaday OAL Gage and the length of my chamber using the Sinclair Chamber Length Gage. My COAL maxed out at 2.9605". My max chamber length is at 2.0460". This is my first time using a chamber length gage and I tried forcing the brass with the insert to move forward and it was really hard and the bolt was not closing. End up using a vise without damaging the bullet and seated the insert where the bolt closed with some resistance. My brass is Hornady and the bullet is Barnes TTSX BT 168gr. With an FL sized brass, having a case length of 2.0110" I seated a bullet and the COAL was at 2.9095". When I chambered it, it was tight so I backed it down to 2.8805" and I could close it without fighting it but still giving some resistance.

The brass is only fired once and doesn't need trimming since it's way under the chamber length. The case length after resizing was at 2.0080". I tried loading a couple of my available ammo - Hornady ELDX 180 gr (tight fit in the chamber now where before it wasn't), Core-Lokt 180gr (tight fit in the chamber now where before it wasn't and I see the nose getting scratched by the lands, never happened before) and HSM 180gr which run so smooth, no friction whatsoever. The latter has no evidence of scratching. I tried measuring the case length of it which is at 2.0050". It matches exactly what the recipe calls for. The reason I'm trying to go over it is because of what I measured in the chamber. Now I tried to load again the HSM ammo just to make sure it was still smooth and consistent. On my 3rd load, upon locking the bolt, it fired! It drilled a hole in my basement ceiling, went to the kitchen, and stopped at a wall just in front of my dryer. Thank goodness, no one was hurt. But my ears are still ringing after 5 hours.

Now my question is, did I damage my bolt when I tried to force the brass with chamber length gauge to go in further? I've upgraded my trigger using MCarbo Tikka Spring Kit and the trigger pull is at 2lbs. Put blue loctite on the trigger screw. Dropped tested it multiple times and it was not engaging the trigger. I'm thinking of taking it to my gunsmith to have them check it but is there anything I can do before then? The other thing that I did was to replace the magazine with a TIkka 30-06 magazine for longer COAL and the LA bolt stop.

This experience will not stop me from reloading . I just have to be careful next time.

 

[Edsel]

“The gauge is made of 12L14 soft steel so it will not damage your chamber.”

Unlikely, according to Sinclair’s claims…

Be very careful…

…it only takes one innocent mistake to cause a fatality.

Remember this incident as a “blessing” to forever discourage further such events.

 

[Rommel Garcia]

“The gauge is made of 12L14 soft steel so it will not damage your chamber.”

Unlikely, according to Sinclair’s claims…

Be very careful…

…it only takes one innocent mistake to cause a fatality.

Remember this incident as a “blessing” to forever discourage further such events.

Thank you, Edsel. Yeah, I read that too as well. Maybe the sear got misaligned or damaged? It pushed me to chamber round outside the house with the muzzle pointed to the ground next time. That was really scary.

 

[Edsel]

Odds are, it’s your trigger spring.

Trigger tension gauges aren’t particularly reliable.

Although I’m guilty of doing the same modifications myself, my rifles are only range toys which remain unloaded unless I’m at the range…

 

[Edsel]

I have all my triggers down to 500 grams using NRA weights, and they have been reliable.

But, to repeat - my Tikkas are purely recreational rifles.

They are my “unsafe rifles” and are never “put to the test.”

 

[redneckbmxer24]

I’ve had a Tikka fire dropping the bolt and witnessed it one other time. Both times had aftermarket springs.

This is part of the reason why I hate the tikka design how the safety has to be off to run the bolt. It’s dumb. People say it’s no big deal but it’s absolutely a safety issue as you’ve found out fire hand.

 

[Rommel Garcia]

I’ve had a Tikka fire dropping the bolt and witnessed it one other time. Both times had aftermarket springs.

This is part of the reason why I hate the tikka design how the safety has to be off to run the bolt. It’s dumb. People say it’s no big deal but it’s absolutely a safety issue as you’ve found out fire hand.

I’ve had a Tikka fire dropping the bolt and witnessed it one other time. Both times had aftermarket springs.

This is part of the reason why I hate the tikka design how the safety has to be off to run the bolt. It’s dumb. People say it’s no big deal but it’s absolutely a safety issue as you’ve found out fire hand.

This is making me think to reinstall the OEM springs.

 

[Rommel Garcia]

View attachment 8507299

I have all my triggers down to 500 grams using NRA weights, and they have been reliable.

But, to repeat - my Tikkas are purely recreational rifles.

They are my “unsafe rifles” and are never “put to the test.”

I might have to reinstall the OEM Springs. Would it be better to replace the entire trigger assembly with a reputable brand?

 

[XLR308]

I personally use an inert case for initial set up and when satisfied just pull the bullet and put that case back in the batch of brass it came with.
It sounds like you definitely have a sear engagement issue as in you have over adjusted the trigger and your brass has not had the shoulder set back far enough.
You said you had rounds that chambered easily before but now your having issues with resistance closing the bolt.
Its not your chamber and it doesn't work that way, your chamber isn't going to magically get shorter.
Look elsewhere for what is causing resistence, stuck ejection plunger, carbon build up, long headspace on sized brass, or trigger sear issue.

 

[Edsel]

I might have to reinstall the OEM Springs. Would it be better to replace the entire trigger assembly with a reputable brand?

Put the original spring back.

While I personally don’t understand the exact mechanics of the Tikka trigger - it’s like that of the Steyr AUG - mess with the tension and so many things go out of whack.

 

[bax]

I do not understand why you are chambering live rounds in your basement. You used up a lot of luck there.

If you did something make make that weapon fire without pulling the trigger, that is a problem you need to fix first - what everyone else said.

If you are new to reloading, you should first get the basics down. So ... download the SAAMI chart for 308, then look at the cartridge drawing, not the chamber drawing. Your rifle chamber may not match what you see there (this is why we use fired brass) but you need to know the standard.

The official SAAMI spec for 308 Win cartridge shoulder length is 1.634 minus 0.007. In this case SAAMI is less important that your fired brass. Measure the shoulder of a piece of brass fired in your weapon. When you full-length size, the after-size shoulder measurement should be 0.002 to 0.003 less than the fired case measurement. In my case, the fired shoulder length is 1.626-1.627. My sized shoulder length is 1.624 plus or minus 0.001. If your sized brass is as long as fired brass, or longer than fired brass, then you need to make it shorter. Turn the die further into the press.

The official case length for 308 is 2.015 minus 0.020. In my experience, anything less than 2.015 will be fine. If your brass is less than 2.010, you are good, move on.

I guess that you are tracking so far - I haven't told you anything new.

The SAAMI standard COL for 308 is 2.490 to 2.810. Your measurement is 2.909. You used a vice to close the bolt, probably pushing on the firing pin.

My guess is that your loaded rounds are too long, you are seating bullets well into the lands, in order to close the bolt you are pushing the bullet into the brass, and that is why is difficult to close the bolt. I suggest that you use a COL of 2.800 - yes, reduce your COL by 0.110. That ammo should fit in the chamber without binding on anything, the bolt should close easily, and it will probably shoot decently. You said that you are new to reloading, start simple and reliable. When you have reliable ammo then start messing around.

Please don't shoot yourself. It reflects badly on the rest of us and your wife will never let you hear the end of it.

 

[RandyM72]

I would be suspicious of the trigger sear and/or trigger springs. I too have had misfire when loading a round and closing the bolt on a reloaded once fired cartridge thats oversized (shoulder not pushed back enough) or the bullet seating is too long and jamming in the lands. This happens with a light trigger.. 2 pounds for example. You have to ram the bolt with some force to close it and thats enough to jiggle the sear and cause it to fire. Scares the bejeepers out of you. Shoulder bump is a bit of guesswork and bullet seating especially. I found the Hornady bullet seating comparator reloading tool immensely useful for accurate bullet seating. Their case shoulder comparator is similarly useful, but not really necessary as you can fiddle with your die height until it chamber nicely with a couple thousands clearance. In so far as trigger pull goes. I have to be somewhat gentle with them at 2 1/2 pounds or less - just in case. PS - your typical ideal bullet jump to the lands should be about 12-15/1000ths of an inch for optimal accuracy. Chamber an empy round first to undestand if your shoulder needs to be pushed back more. Adjust your die by increments of 1/16 of a turn to find where shoulder clearance occurs - just by a lttle. Lock you lock ring for future. Next bullet seating. The Hornady comparator makes this so easy. Without it try seating a bullt long and try to close the bolt on it (gently). Keep reducing the bullet seating depth incrementally until your bolt closes with ease, then add another 10-15/1000ths inch more deep seating. Simple but time consuming way to get ti right the first time. From there experiment with small variations plus and minus and test at the target range with a decent set-up to compare results.