changing a bolt face size

[260]

I have a tikka 595 in 223 and have been considering have it rebarrelled to 260/6mmbr/similar.

I m asking if would be feasible to machine the existing bolt face to the required diameter.

a friend has a 595 rebarrelled from 22 250 to 6mmbr and when the bolts from the 223 and 6mmbr are side by side the extracter and ejecter appear to be located in the same position, despite the 

difference in bolt face size so look asif they would operate correctly

can the bolt face simply be machined to the required diameter

 

[Ronin]

If the "223" and "308" bolt faces share common located extractor and plunger then probably.

The gun would need reproof if this were done, but would be subject to proof regardless with rebarrel.

[baldie]

If the extractor is sat in the bolt face to pick up a .223 round, how is it going to work when you open the bolt face up ?

Think about it....the case head is going to hit the top of the extractor, rather than push it to the side of the case, and over the rim, upon closing the bolt.

You might be lucky, and get away with it. If not, the extractor slot would need welding up and re cutting, 

[260]

So would it be more economic to source a 308type bolt /shot out action rather than risk machining my existing bolt ?

[Big Al]

6 hours ago, 260 said:

I have a tikka 595 in 223 and have been considering have it rebarrelled to 260/6mmbr/similar.

I m asking if would be feasible to machine the existing bolt face to the required diameter.

a friend has a 595 rebarrelled from 22 250 to 6mmbr and when the bolts from the 223 and 6mmbr are side by side the extracter and ejecter appear to be located in the same position, despite the 

difference in bolt face size so look asif they would operate correctly

can the bolt face simply be machined to the required diameter

 

Yes its possible, I have done it and it works perfectly, no need to source a .308 bolt at all.

Its not difficult to make a few measurements/comparisons as you have done to see how Tikka originally did it, there is no need for welding or anything other than relatively simple machining and the fitting of a new .308 extractor claw. 

Open the bolt face to the required diameter and then replace the .223 extractor claw with a .308 version, the claws are a different depth to give the correct offset to engage the rim. The extractor claw slot in the bolt is the same width and depth on both bolts and it is the extractor claw thickness that differs to give the required offset.

You can buy .308 extractor claws from GMK although you will need someone with an account to get it for you. GMK sell it as a kit with both a .223 and .308 claw as well as a new plunger and spring, RRP is about £50 if I remember correctly. The bolt can then be re-proofed along with the new barrel. 

Its a simple machining job and if your rebarreling the rifle at the same time you can also take a small cut from the bolt face if required to clean it up before chambering and setting the head space. 

[baldie]

11 hours ago, 260 said:

So would it be more economic to source a 308type bolt /shot out action rather than risk machining my existing bolt ?

I have around a dozen in stock, both T3 and 595's. Pop in and have a look, i'm sure a deal can be struck.