300 WSM AR10

[bamban]

I have an itch to scratch. I have all the components to build a lightweight AR10 (yes Armalite) in 300WSM. I have a 10T barrel, reamer, GG, barrel extension, superlative adjustable gas block, KAK magnum BCG, and Armalite build kit. Even have 100 pieces of 300 WSM virgin brass.

Those of you who runs an AR308 type 300WSM, could you possibly share the good, the bad, and the ugly in running one? I am aware of mag limitations for heavier bullets, that's not a concern of mine at this point. I can address that separately. I am interested in knowing other stuff besides mag limitations.

TIA

Nez

 

[Earnhardt]

Go with either rifle +2 or +3 gas length, with an adjustable gas block
-Minimum 9.3oz up to the XXH 15oz -Slash heavy buffer.
Tubbs flat wire
-Use loctite 620 on the barrel extension
-TO ME the heavier the over all weight on the gun, the better it runs
-go with a mid weight bullet at average speeds
-use medium the faster burning powders
-a good brake really calms down the over all action/movement of the gun

 

[Gunpowder]

These are fun rifles. I have the factory built DPMS 300 Saum. They did these with a 20" barrel and rifle length gas. Any longer and I'd definitely extend the gas system like Earnhardt said. I run a standard buffer but haven't tried any others.

I think the KAK bolt is a hp type with smaller diameter fp. Mine is not, and will pierce primers with bullets over 168's, even with non-max loads and cci 34 primers. So I stick with 168's and H4350 and it works well.

I made a single stack mag that holds 6 iirc and it works well. Pmags work for 3 or 4 and the same with some steel mags but mag bulge becomes an issue after 3 or 4 rounds.

 

[Earnhardt]

Yup, P-Mags will only hold 3 reliably, and 4 is pushing your luck
Gunpowder, how'd you make the mag that holds 6 rounds?

 

[Gunpowder]

Forgive the crudeness of the prototype, I intended to build another but I didn't really need more than one. Basically, it's a 556 mag laminated inside a 308 mag. Mod the 308 follower to fit, and use the 556 spring. Cut the 308 feed lips off. The small screw in the back is threaded into the tail of the plastic follower to activate the bolt stop as the follower doesn't ride quite high enough. That's about the gist of it. This mag has never failed to feed, 0 malfunctions.

 

[jbs2014]

I have an itch to scratch. I have all the components to build a lightweight AR10 (yes Armalite) in 300WSM. I have a 10T barrel, reamer, GG, barrel extension, superlative adjustable gas block, KAK magnum BCG, and Armalite build kit. Even have 100 pieces of 300 WSM virgin brass.

Those of you who runs an AR308 type 300WSM, could you possibly share the good, the bad, and the ugly in running one? I am aware of mag limitations for heavier bullets, that's not a concern of mine at this point. I can address that separately. I am interested in knowing other stuff besides mag limitations.

TIA

Nez

Make sure you get a well made extractor.

What barrel length are you going to go with?

 

[bamban]

Thank you for the inputs, will let you guys know how the project progresses.

 

[bamban]

Make sure you get a well made extractor.

What barrel length are you going to go with?

Have not decided yet, I have a 26 inch medium Palma I will chamber and cut to any length I want. I've chambered a few AR308s in 6.5CM, 6XC, and 308s, but never a 300WSM in a gas gun. Funny two of the 6.5CMs are 18 inches, and there are two at 26. That's what my buddies wanted.

The KAK extractor will have to do for now.

 

[jbs2014]

Have not decided yet, I have a 26 inch medium Palma I will chamber and cut to any length I want. I've chambered a few AR308s in 6.5CM, 6XC, and 308s, but never a 300WSM in a gas gun. Funny two of the 6.5CMs are 18 inches, and there are two at 26. That's what my buddies wanted.

The KAK extractor will have to do for now.

Could the 26" barrel allow you to fully capitalize on the cartridge's full capability maybe? With ARs a bit of the gas consumed by the gas system lowering velocity. With a 26" you may be able to compensate for that with the velocity gained by the longer barrel

 

[bamban]

Could the 26" barrel allow you to fully capitalize on the cartridge's full capability maybe? With ARs a bit of the gas consumed by the gas system lowering velocity. With a 26" you may be able to compensate for that with the velocity gained by the longer barrel

That would most likely be the case. I may get a #4 and use it instead of the medium Palma if I were to run a 26. I had a 26 inch hunter AR10 in 308 one time, have forgotten how well it worked, you reminded me about it. Thanks.

 

[jbs2014]

That would most likely be the case. I may get a #4 and use it instead of the medium Palma if I were to run a 26. I had a 26 inch hunter AR10 in 308 one time, have forgotten how well it worked, you reminded me about it. Thanks.

No problem, just don't want to see you go through the same pain I am with that 22" barrel 6.5 Creedmoor that I have. I lose a great deal of velocity from the shorter barrel and the gas system. It's like I'm paying for Creedmoor prices and getting Grendel performance.

 

[jbs2014]

There is an outfit out of Colorado that makes ARs in 300WSM. Maybe they have a magazine solution for you?

Custom AR10 Rifles Accuracy Systems Gunsmith Gunsmithing AR 10

AR10 Rifles customized by Accuracy Systems Inc. ASI does custom gunsmithing, builds Custom Rifles and rifle Rebarreling on AR10 rifles.

ar-10-rifles.com

 

[bamban]

There is an outfit out of Colorado that makes ARs in 300WSM. Maybe they have a magazine solution for you?

Custom AR10 Rifles Accuracy Systems Gunsmith Gunsmithing AR 10

AR10 Rifles customized by Accuracy Systems Inc. ASI does custom gunsmithing, builds Custom Rifles and rifle Rebarreling on AR10 rifles.

ar-10-rifles.com

Thank you for the information.

 

[Zen Archery]

You'll need to open up the ejection port slightly for cases to eject properly.