What is involved in changing calibers?

[StringJumper]

This is purely a curiousity question...I am completely happy with the calibers I have now.

Bob257 just had a Sako 30.06 changed to a .280. Obviously the actions must be the same length (long to long or short to short) and the barrel has to be swapped out. But what else?

I am guessing that the chamber needs to have the headspace adjusted for the new caliber. How about the bolt face? New extracter? Anything else change?

Just trying to learn in case someone asks me the question some day.

[southtexas]

Assuming the we are speaking of bolt action rifles:

If the case is the same, such as the 30/06, 280, 270, 25/06, 35 Whelen, then all a gunsmith has to do is remove the existing barrel and relpace it with a new one.

If going from a 30/06 to 300 Win Mag (different diameter brass) then the bolt face and the magazine rails would have to be modified.

In some cases you are limited, for example you can;t rebarrel a short action 243 or 308 to 30/06 because the action is too short.

[snake river rufus]

Southtexas the gunsmith would also need to cut the chamber. And really it's the dia. of the case head that requires the bolt face to be opened. With the exception of the .284 win. cases the case head and the case body were generally the same untill the advent of the short mags- 0.550 body and 0.532 case head.

[southtexas]

srr: Well, of course someone would have to cut the chamber...but a gunsmith could use a takeoff barrel or order one cut from the manufacturer.

With respect to the case head versus body diameter, there are also the rimmed cartridges, semi-rimmed and belted, all of which have different body diameter from the rim diameter. And most of them have different tapers. There are MANY variations.

But I think, if I undrestood his question correctly, the answer to SJ's question is: if you are changing to a cartridge that is based on the same or very similar case, it can be a very simple switch for a 'smith. The more differenct the new cartridge dimensions are, the more difficult (and expensive) it will be. and in some cases it can't be done prectically.

[snake river rufus]

You could pet on a short chamber barrel and finish reaning it and take off barrels generally headspace on a similar action but not always.
You are right I had intended to clarify that this was for modern rimlees cartridges. I type slower than I think and skipped a bit.

[Hi Ball]

Spending lots of money!