300 BLK Compatibility w/300-221 Question

[Flewis]

I know the general answer is there is no definite answer because there has never been an official specification for 300-221 and a ton of different manufacturers have been cutting the chambers.

But, if I have a 300-221 chambered AR and I have a box of Remington 220gr 300 Blackout ammo, how would I go about determining whether it is safe to fire?

I noticed that the Remington 220gr ammo has an OAL of 2.089. That is shorter than my 220gr Matchking load (mine is 2.170) that works well, so I can assume I am safe there. Also their published safe powder type and load are well within the ranges that I've worked successfully with.

I don't actually have box of the ammo yet, so I can't try this yet. But assuming it chambers and extracts ok is there anything else I should check before firing a few rounds?

I see people saying the chamber is .004 larger in diameter than a whisper, so I'm guessing I could have an issue chambering the Blackout ammo.

I guess the question is that if the manufacturer can't answer the compatibility question, how can I determine it myself? We know some manufacturers (Shilen?) have cut chambers that turned out to be compatible with the Blackout before the Blackout was ever mentioned.

Any input/advice?

[rsilvers]

Where is it said to be 0.004 larger in diameter? Do you man the neck area?

[1911man]

Comparing 300 Whisper and 300 BLACKOUT chamber reamer prints I see the following differences:

Throat (lead) is .001" larger on the BLACKOUT
Throat is .0235" longer on the BLACKOUT
Breachface to shoulder is .0117" shorter on the BLACKOUT

[rsilvers]

The headspace is measured from the bolt face to a certain diameter on the shoulder and the headspace of 300 AAC BLACKOUT is the same as 221 Fireball, and the same as the CIP 300 Whisper(TM) standard (within 1/100 of 1 mm or so).

[sha-ul]

Comparing 300 Whisper and 300 BLACKOUT chamber reamer prints I see the following differences:

Throat (lead) is .001" larger on the BLACKOUT
Throat is .0235" longer on the BLACKOUT
Breach-face to shoulder is .0117" shorter on the BLACKOUT

those aren't very big differences.

[martineta]

I stopped in my favorite Gun store the other day. I asked a guy at the gun counter about the 300 blackout. He told me he had not seen anything in Remington's catalog about the caliber in ammunition or in production rifles. This is a gun store,,,,,not some clothing store like Bass Pro or Gander Mountain or Cabela. This store has thousands of firearms of every make, model, and caliber. Green Top is the name. They are located outside Richmond VA.

Like every year, he and a couple of the other guys are going to the Shot Show in Las Vegas next month. He promised to ask about the cartridge. He also said Remington was famous for coming out with 3-4 new wildcat cartridges a year that never really end up in production. He was a tad skeptical to say the least.

If Remington is serious about this cartridge, I would think they would be put the Blackout in a marketing campaign to their dealers and retailers along with whatever other new goodies they have coming out.

Anybody on this board call customer service at Remington and ask?

[BWE Firearms]

The Blackout is going to be one of the hot things at the Shot Show this year. I have talked to a number of the different AR manufacturers I shoot with at our super secret testing facility and all of them are working up a Blackout for the show. I may have some mock up suppressors on some of there guns as I am working on some integral suppressors for some of them. Everyone got caught with their pants down on this one. RSilver can correct me if I'm wrong but I bet Remington and AAC are waiting for SHot Show for the big reveal.

[martineta]

Very good to know.

[Shadow 300]

I called Remington about two weeks ago and asked if and when a Rem 700 in this cartridge would be available. The woman I spoke to said they are considering introducing one the middle of 2011.

[rsilvers]

We are just ramping up production before advertising it. Right now if there were a rush to buy guns and ammo, there would not be enough to meet demand. We will advertise it when we have a big ammo flow. By the end of February there should be over 1,000,000 rounds loaded.

[robrob]

With the increasing popularity of NFA suppressors I do believe the future of the 300 Black is bright. You can't beat its flexibility from subsonic plinking to supersonic hunting and all with a standard .223 bolt and magazine. I'm hoping Remington and Savage sell factory rifles with threaded muzzles. I know the threaded muzzle is pushing it but i can dream.

[Shadow 300]

Remington already sells one rifle with a threaded muzzle, it is a .308.

[rsilvers]

Yes:

http://www.defensereview.com/remington-model-700-sps-tactical-aac-sd-bolt-action-marksmansniper-rifle/

AAC will make a Model-7 in 300 BLK, but it is a few months away.

[robrob]

Remington already sells one rifle with a threaded muzzle, it is a .308.
http://www.defensereview.com/wp-content/uploads/2010/05/Remington_Model_700_SPS_Tactical_AAC_SD_with_Suppr essor_1_small.jpg

Sweet! Thanks for the link. I'll take that exact rifle in 300 Blackout please!

[HUNTER2]

One million by Feb., thanks - you going to have any for everybody else?

[BWE Firearms]

Like the song says "The futures so bright I gotta wear shades" :cool:

I can't be happier that subsonic cartridges are finally going to have some serious money behind them. I also hope this will help push suppressors into the main stream and change peoples minds that they are only for assassins.

[Shadow 300]

That will be a tough one. Our local Sheriff will sign for a machine gun but not a suppressor, even for the local LEOs. No problem though, that's what trusts are for.

[BWE Firearms]

Are county Sheriff is the same way he will sign for everything but suppressors.

[rsilvers]

The Remington brass is awesome. The primers are sealed and it has an extra step in the manufacturing process to harden just the case head so that it lasts in the primer area. Remington tested it with 10 cycles of reloading. It also has the necks annealed, and then left unpolished to allow for visible verification of annealing.

[HUNTER2]

Any idea when brass and expandable ammo will be available? ? AAC or Remington going to come out with a 16.5" model 7 with fast twist (8), threaded? Have talked to some that wants the whole deal...

[rsilvers]

Brass is looking like late January, maybe Feb.

Premium expanding ammo is looking like late Feb.

Model-7 with 16 inch lightweight 1:8 twist threaded barrel is looking like late March.