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.358 Win / .308 headspacing match mismatch ?


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I have a few uppers and some extra barrels. So I want to do some swapping around. But there's an issue with bolts not being from the same manufacturer as the barrel.

So - I DO UNDERSTAND that it's best to buy a bolt to match a barrel and run those together as a pair.   I have also been reading up and watching videos re. headspacing.     But here's what's happening - specifically :

I have a .358 Win barrel from KAK and I'd like to fit it to a side charging upper from Bear Creek. I thought I'd be able to order a bolt from KAK to fit into the side charging BCG that fits my new Bear Creek upper...   Only KAK .308 pattern bolts have been on backorder for months, and there's no word on when they'll be available.

What should I do ?   If I try to match a bolt to that barrel, it's obvious that damage will occur if the specs of a bolt are incompatible with the barrel extension.      But if i can mic a bolt and it has the specs that match would that be okay ? 

I do have a KAK BCG and I can use that as a reference for checking specs against.  And I could also use that BCG with the upper , except it's already run with it's own upper.

I'm just trying to find the simplest solution to this problem, and hopefully I've stated this question in a way that's not confusing.

To break it down to one simple question :  Can .308 headspacing gauges be used to measure headspacing on a .358 W,  for the purpose of matching a bolt to a barrel ?   

I appreciate the level of expertise of the members here and problem solving help 

Thank You in Advance - Happy New Year !


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2 hours ago, BeeKay said:

Can .308 headspacing gauges be used to measure headspacing on a .358 W, 

Same gauges, so yes. I'm not sure what your "matching" but if it heaspaces good then shoot it, as a rule I try to keep a barrel and bolt together once they are broke in but if the tolerances are correct no reason you can't do it.

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Thank You

I read cautionary posts on using a bolt that's from a different manufactured source than the barrel.

Also I sometimes see pics of damage to bolt lugs, for reasons that are uncertain - Either design incompatibility, or metallurgy.

So : Here i am unable to get a bolt from the maker of the barrel - and if it ends up that design incompatibility of the bolt lugs is off the table as being a likely source of problems, then that leaves headspacing as being the main issue with cross matching a bolt to a foreign barrel....  I reckon

So I was hoping to find someone who has a .308 W No-Go Gauge in stock and they're unavailable.

I think that Brownells had the pair in stock for around $70  - But I'd really like to spend the money on ammo than buy a Go Gauge that I will probably never use.

Any help ?


Happy New Year !!

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