Any Gunsmiths?

[PhM]

Long Shot (pardon the pun)
Any Gunsmiths frequent this Forum, I need some help advice with a sudden strange fault on a Tikka M590.

 

[uzer]

What's the fault and what caliber?

 

[PhM]

Hi, uzer

308win
It will cycle a magazine of unfired ammunition smoothly as always, however when a round is fired the bolt handle will lift up as normal but the bolt will not open, it is firmly stuck shut. The only way it can be opened is by several very firm blows. Once it moves around a ¼ inch it then opens easily. On examining the fired case no obvious signs of any kind can be found.
All fixings are tight and the chamber has been thoroughly cleaned also the bolt shows no signs of damage or excessive wear, but the problem still exists.

 

[uzer]

Hi, uzer

308win
It will cycle a magazine of unfired ammunition smoothly as always, however when a round is fired the bolt handle will lift up as normal but the bolt will not open, it is firmly stuck shut. The only way it can be opened is by several very firm blows. Once it moves around a ¼ inch it then opens easily. On examining the fired case no obvious signs of any kind can be found.
All fixings are tight and the chamber has been thoroughly cleaned also the bolt shows no signs of damage or excessive wear, but the problem still exists.

Ok, this could be any number of things from how you have described it. How old is the rifle? How many rounds have been put through it? Is this a brand new problem with no prior strange cycles leading up to it? Ie did you have a misfire or anything else abnormal happen then this fault occurred?

First thing I would check is the magazine headspace, sometimes on multiple brands of bolt actions after first fired shot it will deform the casing enough that there is not proper clearance between the bottom of the used casing and the top of the unused casing. Try firing a single shot without either a. Anymore rounds in the mag and b. No mag. This will help determining if it's a feed problem (bottom of chamber) or ejection problem (top of chamber, extractor, firing pin etc etc).


And for the sake of transparency I am not a gunsmith. I have had armourer training (army), own quite a few variants of bolt rifles and use them regularly for both fun and work. I'm more then happy talking it over with you what I think it could be....but the end game will almost definitely be you having to take it to a gunsmith who can physically inspect the rifle or sending it to the manufacturer.

This sounds extremely similar to the old Remington 710 issue that has no known fix except sending to manufacturer and getting a new rifle back from them.

 

[PhM]

Sorry for the late reply, the better weather and the clock change have allowed me to work later.
Thank you for your helpful advice, I have worked in Deer and Game management for over 40 years and during that time I have acquired and used many rifles in many calibres and I have never experienced this problem before. I acquired this rifle new in the early 80s I believe – (how time flies!) I gave it to my son for his 14th birthday and he has used it regularly (10 years) helping me with my Deer Management work. I am guessing it has only had approximately 500 rounds through it.
I have a Sako M995 in 270Win. in almost daily use and it has had well over 1500 rounds through it with no problems.
The rifle has been well maintained and has always performed flawlessly. However recently it has developed this fault the first time a good clean of the chamber appeared to solve the problem. A few rounds later and the problem is back.
All fixings are tight and the chamber has been thoroughly cleaned also the bolt shows no signs of damage or excessive wear (Note-the bolt has never been dismantled), the magazine is in good condition and shows no signs of looseness/misalignment etc, I have tried the rifle with the magazine removed and I have also left the rifle to cool down (case expansion) but the problem still exists.
As you can imagine my son is devastated, he shoots well with it and was expecting to use it for a lot longer.
Unfortunately all of the Gunsmiths in my area have died out (Literally) only have Gun shops now!
I have emailed Sako and await a reply!!
Thanks again for your input, I will keep you informed.
Best regards,
Peter

 

[hyperfish]

Any chance it could be manufacturing variations in the ammo? Maybe try a different batch before blaming the gun.

 

[uzer]

Well that is good to know the rifle has many years of use prior to developing a fault. As hyper has suggested that leaves ammunition as the problem or something more minute in the actual chamber from wear and tear. As this is a new development with years of prior use I'd rule out warping but as with anything metal there IS the possibility that a smaller piece has warped. Do you know anyone with the same model rifle? Would changing bolts be a possibility? I am fairly comfortable self diagnosing my own gun problems and am confident enough diagnosing other weapons if I had some hands on time with it on my gun bench with my tools but geographic issues obviously leaves me restricted to helping where I can via forums or PM.

What specific kind of ammunition is being used? Not insulting your intelligence on the issue but it is .308 ammo and not 7.62 correct? They are almost identical and safe to use but still slightly different cartridges.

 

[PhM]

Hi, hyperfish
Thank you for your suggestion and uzer for your further observations.
Regards ammunition
Definitely 308, for many years used re-loaded, always first time cases and never any problems (Note – I use the same reload in a Howa 1500 and my Daughter uses them in a Tikka T3 never any problems).
Since the problem we have tried several Factory loads, Norma, Sako and Federal all with the same result.
Incidentally all of these including the re-loads have been through the Howa and T3 with no problems.
Unfortunately I do not know of anyone with the same rifle, trying a different bolt had crossed my mind.
Uzer I understand the distance issue and thank you for all your help.
Since the problem my son has been using my Howa, I think I may be losing a rifle!!
In the meantime I will keep trying and also wait hopefully for a reply from Sako.
Thanks again.
PhM

 

[uzer]

Yea the only other thing I can think of that can be checked is to disassemble and have a peak into the first 2 inches or so of the barrel see if there are any burrs that may cause an expanded cartridge to stick. It's probably not the issue but it's a free look that is an easy fix if a burr is spotted.

Keep us updated.

 

[PhM]

Hi, uzer
Now that my son is comfortable using the Howa it is time to fully dismantle the Tikka and more thoroughly check and clean everything, including a close inspection of the chamber and barrel throat.
I forgot to mention I had a Varberger several years ago which would jam the bolt if the forward mounting screw was over tightened; I solved that problem by carefully shortening the screw. Unfortunately this is not the case with the Tikka.
Thanks again for your input I will keep you informed.