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View Full Version : Receiver Bolt faces and Barrel shank sizes



Toftwo
02-05-2017, 05:02 PM
As I'm trying to research my 300/338 Norma Mag build, it seems that mostly everyone says to use a large shank receiver. Is there a difference in receiver lug faces (not 100% sure what the correct terminology is) in a large shank receiver vs a small shank? If not, then why would shank size affect bolt thrust? Which seems to be the main concern stated in the forums. If the receiver lug faces are larger, I totally get it, because they look a bit thin, but if not, wouldn't shank size really be for case rupture?

Thanks!

RC20
02-05-2017, 06:19 PM
Good questions.

Not my expertise at all, but have not seen a response, here goes

The large shank was originally if I have it right a Short Magnum response to case swelling.

So yes, that's why its large.

Bolts are the same, only the head changes.

338 Norma is not one I am familiar with, I don't even know if its belted.

I think the design has then shifted to large shank for the belted magnums but I think that is some and some and not all are.

On the other hand, at least belted magnums were made in normal shank for a very long time.

Maybe a bit of insurance.

Toftwo
02-06-2017, 10:56 PM
Good questions.

Not my expertise at all, but have not seen a response, here goes

The large shank was originally if I have it right a Short Magnum response to case swelling.

So yes, that's why its large.

Bolts are the same, only the head changes.

338 Norma is not one I am familiar with, I don't even know if its belted.

I think the design has then shifted to large shank for the belted magnums but I think that is some and some and not all are.

On the other hand, at least belted magnums were made in normal shank for a very long time.

Maybe a bit of insurance.

Thanks for the Response RC!