Gunsmithing 300 win mag to 300prc

[408w]

A friend has a custom 300 win mag (rem 700 action) and wants to rechamber the barrel to 300 prc. Any potential issues to look out for. I don’t know the specs of the 300 win mag reamer but could get them. Is this a pretty straight forward job. His gunsmith has not done a 300 prc yet when talking over the phone. So he is going to need a reamer.

 

[TheChief]

I'd be willing to bet that the twist of that .300WM barrel won't work out too well for the 300PRC. Most of the 300PRC barells I'm seeing are 1 in 9. Thats not too common of a twist for any .300WM's I've seen. He might just be better off buying a 300PRC barrel and calling it a day. The bolt face is the right size for that swap anyways.

 

[RemCustom6]

TheChief is correct, most 300 PRC’s are at a minimum 1-9 twist, and a lot of folks are running 1-8’s nowadays. If running the PRC as a BDl setup, you will need to modify the feed rails as well as open up the feed ramp. Our shop also installs a Wyatt’s extended PRC Mag box and follower as it is made to correctly get the more straight walled case to tuck up under the feed rails correctly. With this modification you have to open up the mag box area to accept the new extended length mag box. You will also need to modify the bolt stop to allow the bolt to come back far enough to pick up the next round. This cartridge is best run off of an Ultra mag action, as it is basically just a extended mag box setup change, no need to modify the rails and feed ramp. One must account for the long winded 200+ grain bullets the PRC is intended to run. A DBM setup is a bit easier. CIP Lapua mags (badger DBM) are the ticket with this one in our opinion.

Hope this helps a little.