I really like the new NEMO 300 Win Mag AR, but not a big fan of the price tag.
Is anyone manufacturing a complete upper receiver in 300 WSM to fit a 308 lower receiver ??
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I really like the new NEMO 300 Win Mag AR, but not a big fan of the price tag.
Is anyone manufacturing a complete upper receiver in 300 WSM to fit a 308 lower receiver ??
Armalite used to make one in 300 WSM. Apparently they no longer support them, and they took lots of proprietary parts.
I believe that you could probably find someone to make you one, but it would likely be a custom deal particularly if you are talking about a DPMS pattern.
Some of the big disadvantages would be the limited OAL you can feed from a standard 308 AR mag, and bolt thrust. This is limiting in regards to running long, high-BC bullets without eating up too much powder space into the cartridge. I have 7 WSM bolt gun and optimal cartridge length with a 162 A-max is MUCH longer than the factory stated max OAL. Also, the bolt head is considerably larger on a WSM = reduced bolt strength, so you would likely have to watch the pressure of your loads.
I still think it would be pretty neat, but I just don't think you would get quite all of the advantages you would imagine from the WSM cartridge.
There was also something done with the 300 SAUM which was essentially the same as a WSM but a little better suited for autoloading rifles. I'm very curious as to what direction could be taken now that .308 AR's keep getting more and more popular as time goes on instead of them being a novel afterthought in the market.
The ArmaLite was chambered for the SAUM, not the WSM. I seem to remember SSK offering WSM conversions, but I don't think that they list them anymore.
Be careful with these things. No one makes an extractor that works with the magnum rim dia. Well, someone grinds them down to make them work and then they break. When the 308 extractor travels out far enough to snap over the rim the back of the extractor contacts the lugs of the barrel extension and stops forward movement of the carrier.
How much trouble would it be to fabricate one that is satisfactory? Is it simple enough to do that a gunsmith or a machine shop could make a few? Does Armalite still make spare parts so an extractor could be gotten as a sample? Also, so nobody currently makes one--how long will it take for a company to get tired of there not being someone doing it to take it upon themselves to do it?
Extractors are a pain in the ass to machine. I'm sitting here looking at a room full of CNC's and I wont touch extractors. They are small and have too many ops from different sides. They are too cheap to make money producing them. I purchased the last 4 RSAUM extractors from DPMS in 2008...every one they had. Armalite didn't have any back then.Quote:
Originally Posted by yellowfin
There are more problems than just extractors, the mags don't feed well even if you can find a RSAUM follower. IMO it's another one of those "not worth it" things until someone machines a lower that will handle a mag to get a true double stack and someone makes a barrel extension with a relief cut so the extractor can clear the 2 lugs.
The last thing being the best option for using a magnum in a 308 rifle.
At least that way the extractor is full strength.
I was going to try it again in 2011 with the RCMs, They are smaller in dia and work better than the RSAUMs and WSMs. Then I couldn't get enough AR10 style barrel extensions. I would still like to build a 338 RCM but until the mag options get better I'm staying out of it.
H,
On a bit of a side-note to this thread, did your AR-12 project lose steam or are you still making components for that?
Randy is machining the upper receivers now. I machined the barrel extensions early this month. I had one of the final design receivers in my hands last week.Quote:
Originally Posted by hunt_ak
When I know those receivers are done and right I'll start machining the bolts and carriers and send a PO out for some 308 barrels. At this rate it will still be next summer. After the SHOT show it will take 4-6 months to get barrels. Probably start with fluted 16 or 18" to keep the weight around 7lbs for a bare rifle.
The 2 GPC cartridges 6.5 and 6.8x45 reamers should be here Fri so I can start testing those...not that they would be of any interest to the public but they are perfect size for the Nexgen (12)
Sweet. Who are you going to source the barrels from and can we supply a barrel for an upper build?