Straight pull bolt action

[Rock8296]

So I have 2 PA10 uppers currently, a 14.7 with a 10" FF and a 20" M110 profile with a 15" FF. I'd like to step up to something bigger and longer range and what I am thinking is using a DPMS slick side hi-rise upper as a single shot or perhaps "switchable" straight pull. I am thinking of putting a reciprocating side charger and milling a slot on the upper reciever for it and then enlarging and lengthening the ejection port and chambering for .300 WSM with a .280 freebore. So it can function with gas on as a mag length repeater with my A191 inspired clone loads, or function with gas off as a single shot with 230 SMK loaded to 3.2 oal. The concept or inspiration for this build is my NRA High Power rifle. Most competitors use mag length ammo, 77gr 2.260 oal, for 200/300 and such and a long loaded 80gr SMK or the like single loaded to 2.550 oal for the 600 yd slow fire. So I guess my question more so is has anyone done something like this yet? and does anyone have any constructive ideas or comments for such a build?  Thanks for your time.

Rock

[edgecrusher]

This is a first for this board. The frames be big enough for the round but I don’t know of anyone doing it. You will be fabricating your own bolt or bcg, as it will have to be shorter, I think.... this one poses more questions than answers at the moment. @98Z5V

[Rock8296]

The frame should be large enough as there are already many builders of WSM, RCM, and SAUM cartridges. Finding an original DPMS SAUM bolt is hard to come by these days but KAK makes a specific bolt for it as well as an extractor so a regular ar bolt face could be opened up and ran. I think running it as a switchable gas gun, with the bolt locked back would leave enough room to drop a long loaded round into an enlarged ejection port and then release the bolt catch or push bolt forward manually.

[98Z5V]

3 hours ago, Rock8296 said:

 I think running it as a switchable gas gun, with the bolt locked back would leave enough room to drop a long loaded round into an enlarged ejection port and then release the bolt catch or push bolt forward manually.

Measure your bolt, locked to the rear - to the chamber face (the furthest rearward edge of the barrel extension).  See if that's gonna be enough room for the length of the single-load longer cartridges you have planned.  You can usually put the BCG back another 3/16" beyond that, beyond the bolt catch, as well. You can always guide the projectile into the chamber, and cheat that dmension a little.

Your limiting factor on cartridge length will be how large that chamber is when the BCG is back, because once that buffer bottoms out in the receiver extension, it's not going back any further than that.