Do standard large ring actions require a magazine alteration when changing overall cartridge length to a shorter cartridge ? In my case I bought a donor rifle , an older Whitworth mauser in 30'06. Great wood lousy barrel. I'm thinking about changing it to 6mm Rem or 7mms mauser.

No, not for those cartridges.

GENERALLY those shorter rounds will feed better with a block in the magazine box to take up some of the extra room....FN did that, worked well

Generally, no. But I love when folks say it is a slam dunk. Ain't no such thing.

Personally, I've never needed a block for 57mm based cartridges but things based off the .308 can certainly benefit at times. And, in fact, my Mk X in .308 came from the factory with a block installed. It feeds slick as snot. My FN .243, too came with a factory block, it never fed worth a damn. I swapped the bottom metal for an unblocked version and things improved, installed an intermediate length follower and suddenly it stared behaving. Never much cared for the .243 so I moved it down the road.

Can there be said to be an advantage using a 7x57 in a 06 length mag since it would enable the bullet to be seated out farther or am I all wet?

Yes.
I put all manner of short cartridges in standard long actions.
7mm, 350 Rem Mag, 6.5 Creedmoor, to name most recent ones.
They all work perfectly.
I'm sure there is a limit to how short they can be.

Some folks like to do that, but sometime COAL is limited more by your chamber (throat) than by the magazine.

Older Mauser Sporters in particular had long throats and those "in the know" preferred a rifle built on a standard length action so they could seat the bullets long. And, to presumably stuff some additional powder in the case as well. Many of the Factory Mauser 7x57's were built on intermediate length actions so 7x57's on standard actions like my Type S were sought after.

I had a 6.5x55 built on a standard length action but it had a short throat and you could not seat a 140 anywhere near the length of the mag box.

Which is why I have throating reamers and for the 7x57, reamers specifically for 140s and 175s.

quote:

Originally posted by dpcd:
Yes.
I put all manner of short cartridges in standard long actions.
7mm, 350 Rem Mag, 6.5 Creedmoor, to name most recent ones.
They all work perfectly.
I'm sure there is a limit to how short they can be.

So do the 7mm ,350 or say a 6.5 rem mag require feed trail modifications or just opening the bolt face? Or will it vary?

quote:

Originally posted by dpcd:
Which is why I have throating reamers and for the 7x57, reamers specifically for 140s and 175s.

My point was to illustrate that mag box length isn't the sole determining factor of COAL.

I bought a Interarms Mark X action with a Douglas bbl. from a place in PA called flaigs in .358 Win. The only ammo that would feed was Factory Win. silvertips. I had a smith remove the block and haven't had a problem with it in over 40 yrs.

Hip

Mr Go; All those cartridges I mentioned feed perfectly from 30-06 and 8mm magazines. Others require feed rail or mag lip manipulation.
It is an art, not a science.