Home Forums Hunting & Shooting Ask The Gunwriters Are bolts interchangeable?

I have two Tikka 7mm-08s, both stainless. One is a standard T3, the other is a Superlite. I just sent the bolt from the Superlite off to get fluted but I'd like to continue load development. Is it unsafe to use the bolt from the standard T3 in the Superlite?






P

Maybe, maybe not.

There are some differences between rimmed and rimless bottlenecked cases and headspacing methods over time.

Historically the answer is often not only no but expletive no. Headspace was often if not always specific to a particular bolt, receiver and barrel combination. Then starting new, bolts and receivers would wear. Lost or mismatched bolts have been a serious concern.

Hence in a military maintenance context headspace could be adjusted in armories by changing bolts. SMLE bolt heads come in at least 4 sizes. Fitting for proper timing and proper firing pin protrusion was part of the process.

In those circumstances parts might interchange and work and might not.

These days of CNC machining folks may swap barrels and or bolts and check to find the swap works. Barrels may index and lugs mostly haven't setback.

Gauge the installation and if it works it works; if not hoping won't make it so. I wouldn't bother because depending on things like lug contact - and I doubt the two bolts share even exact full lug contact - the action may flex with different harmonics with different bolts and so invalidate much of the effort and expense.

You'll have to check the head spacing.

You talk purty.

Is that a yes or a no?






P

Using a different bolt for load workup would be like using a different gun. Might work fine, might not.

It would be best to check the bolt with headspace gauges to be absolutely safe.

Gunsmith may have some the right size for your gun which would be a quick and easy check.
Or you could buy a set if you really can't wait.
They don't cost that much and are just an insert shaped like the cartridge you're using that you close the bolt on to see if it will close/lock.

Good luck,
-Ted

Just shoot it and tell us how it works out.

By the time your order a go/ no go guage from midways/ brownells you will probably have your bolt back... patience grasshopper!

I hain't much good wit' patience, but I figger I aughta.






P

I wouldn't do it without checking the headspace, and even then woudn't feel confident that the load results would apply with the original bolt installed.

Wait.

They swapped millions of Mauser bolts

They did? Well then, I'd get them to do the load work up.

Seriously though, like others have said, even if it does work I'd want the right bolt to do load work-up or you may be wasting your time and components. I'd think a different bolt from a different model of rifle, manufactured at a different point in time would have a good chance of affecting the POI and accuracy of the rifle.

I'd wear your best safety glasses and muffs....

Most likely, YES.

As others have said, headspace will have to be checked to know with certainty.

Right idea - wrong question.

If one exchanges bolts from 2 identical rifles, are they safe to swap?

the answer = if the headspace don't become out of tolerance.

If they are off enough, on chamber will become short / tight, and could cause higher pressure. The other will become long and loose, which can lead to head separation.

So check the head space .

I would not do it. Put this project on hold and get ready for rat shooting, I hope you make it up this year.

Do you like your face enough to chance swapping bolts? Hot gas and brass fragments from a case head separation is not my idea of fun. Hope you wear safety glasses.

I have changed bolts in a 700. It is easy to come by bolts that while perfectly fine will not head space properly. In the rifle I did it with, the head space was good with one bolt I bought to replace a damages bolt and not good on the second. I did a complete work up for a load that was almost 1/2 inch prior to the bolt damage and could come no closer than 1 inch.

Were it me, I wouldn't bother simply based on my experience with the accuracy difference even if it head spaced in spec.

Yes, those two bolts will be close enough to allow swapping for safety's sake.

However, for load workup (especially if that means accuracy), you would want the bolt that you're going to use permanently.

You can check the head space with fired/unsized cases from the other bolt. If it wont close, I'd suggest not using it. If it will close, add shims to see how much it takes for a snug fit. If the amount is very little, you'd be fine.