New Oly AR-15 rifle/upper .300 OSSM

Evil_Lurker

New member
I have a link to one of the first customers to receive their new upper in this caliber.
It's shooting a 150 gr. bullet at 3000 fps, so it's around 100 fps faster than the 30-06.

Drop-on fit to an AR lower. They also offer the entire rifle in camo similar to the Remington R-15.

Overkill for coyotes and bobcats, but it should be good for pigs, cougar, deer, antelope, elk, bear and moose.

Here's the link, if you just interested in the pics, skip to page 5.
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OA2.org link 300 OSSM
 
I cant say that I want one but it looks pretty cool. Always thought they could keep necking that thing up to 45 or 50 caliber and that would be fun.
 
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Well, here's the ballistics for it, you might change your mind.

110 grain Hornady V-Max
Powder 50 gr. H735
Ave. pressure, 60,300 psi
Ave Muzzle Velocity 3480 fps

115 grain (solid brass with plastic tip: Barnes?, not sure, details not provided)
Powder 48 gr. H735
Ave. PSI 55,700
Ave Muzzle velocity 3358 fps

150 gr. (bullet unknown at this point)
Powder IMR8208XBR (new powder)
Powder charge (varied from 45-51 gr.)
Ave. PSI 56,6000
Ave. Muzzle Velocity 3043 fps

I'm trying to get some actual chrony data from an owner, but no luck yet. They seem to be sticking by those "development" numbers, though.
 
Originally Posted By: dk17hmrI cant say that I want one but it looks pretty cool. Always thought they could keep necking that thing up to 45 or 50 caliber and that would be fun.

I've been necking them up for a few years, and have gone up to the .358 so-far. The .358 just became deer-legal in Indiana and has been quite popular.

I think you will probably see Olympic Arms release a WSSM necked up even further than the .358. I would guess it will be a .50, but don't know for sure.
 
The day I say oly advertise the 30 oly, I emailed them immediately about other offerings.. They told me that the other were on their way.. 6.5 and 358 being a couple of the offerings..
 
It says on the page HSM is producing the round and even gives a price somewhere...........so I'd imagine it'll stick around for awhile!
 
I saw a picture of 150,000 rounds stacked up at the factory. It's not cheap. RCBS could build you a die if you sent them a fired case, and I think you could fire-form brass like D-Tech was doing for his 30 AR cases.
 
Now thats some cool stuff. I was just about to pull the trigger on putting money down on a dtech build in 243, but a different project popped up. [beeep] that AR bug just wont go away. That 300 sure is some nice firearm as well.
 
I'm more of a .243 WSSM or .25 WSSM guy, but the .30 WSSM's certainly have gotten strong interest. I just finished a couple of .30 WSSM uppers but had run out of test ammo. This morning I annealed a couple dozen pieces of brass, fire-formed, and loaded them with Varget and 170 grain Speer bullets.

I am going to try and get one of them out this weekend to shoot it over the chronograph. I think my lukewarm load will probably put the 170 grain bullet out at about 2800 FPS. Not bad for an AR-15!

Here's a shot of some of the brass that has been and will be fire-formed.
IMG_0977s.jpg


Here's a few of the loaded rounds, and fired test rounds.

IMG_0981s.jpg
 
Originally Posted By: Evil_LurkerMike,

Are you considering buying a reamer and offering a 30 OSSM upper?

More than considering. As soon as I get the dimensions worked out, lead, neck-diameter etc. I will be ordering a solid-carbide reamer. I was actually doing a little work on that project today!

The price of a reamer, even a carbide one, is very little compared to the interest and sales of the big-bore wildcats.
 
The felt-recoil on any round fired from an AR is just a fraction of what that same round fired from a bolt-action rifle would be. The heavy bolt/carrier moving in the opposite direction of the bullet really tames the recoil.

That being said, shooting any of the big-bore WSSM's are not like shooting a .223/5.56. I am not a big fan of recoil, but even the 220 grain bullets fired from the .358 WSSM is not unmanageable.

The compensator that I have been installing takes the muzzle-jump out, and reduces the recoil by about 25%. I've got a short video of my brother test-fireing the .358 WSSM. It had a fluted barrel with a compensator. The rifle twisted him slightly (pivoting at the hip)but no muzzle-jump, and not bad recoil. If I could figure out how to up-load the video, and post a link, I think the reaction would surprise you.
 
Mike speaks the truth. My 243 WSSM with his comp really put some enjoyment in shooting it. My first one didn't have a comp and I was developing a flinch because of the power of the round. To me, it's about like a .223 on steroids. Not bad at all.
 
Been looking at this and the 25wssm over at J&S. He has them in stock ready to ship......very tempting but I want the 25 real real bad.......

The 30 offering will really open up the AR to large game hunters and even distance shooters if the twist rate is right on the 300 Ossm barrels. I thing they are 1-12 right now but I could be wrong.
 
Hmmm. Now this sounds like a very interesting caliber! My kid's don't get an allowance, but if they did, it would be cut as of now. Gotta save somehow!
 
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