My cheapo 300BLK

[smokey3550]

Nice

[CJ]

I just weighted her and it came in at 7lbs 2oz empty, and a loaded (147gr) 20rd pmag is 15oz. I feel like I would like it a little lighter on the nose.

Yeah that's pretty good loaded considering it has optics and a heavier barrel.

[gat0r]

I'm assuming it's dimensionally identical to .300 whisper, .300 fireball?

300blk = 7.62x35
Case length is 1.368"
neck 0.334

300 Whisper = 7.62x (~33-34)
Case length is 1.35"
neck 0.330


The 300 Blackout and 300 Whisper are NOT the same round.
300 Blackout is essentially a .300 Whisper with a 1mm longer throat.

You can shoot 300 Whisper/fireball in a 300 Blackout without any problems.

However, shooting a 300 Blackout (high velocity) in a 300 Whisper chamber could get somebody hurt. Subsonic may be ok... ymmv


as an FYI,
There is a guy on silencertalk that says he will ream/convert your whisper/fireball for $50 + ship



from 300blk forum:
Q: Can 300 AAC BLACKOUT be shot in a 300-221, 300 Fireball, or 300 Whisper® rifle?

A: Due to the variation in those chambers, that should be considered a potentially unsafe combination - much like shooting 5.56mm in a 223 chamber. Experimentation has shown that there is a several thousand psi difference in chamber pressure and pressure could exceed SAAMI limits of shot in alternate chambers.


300blk is def. a good option for those that dont reload...since Remington is making lots now.

[CJ]

300blk = 7.62x35
Case length is 1.368"
neck 0.334

300 Whisper = 7.62x (~33-34)
Case length is 1.35"
neck 0.330


The 300 Blackout and 300 Whisper are NOT the same round.
300 Blackout is essentially a .300 Whisper with a 1mm longer throat.

You can shoot 300 Whisper/fireball in a 300 Blackout without any problems.

However, shooting a 300 Blackout (high velocity) in a 300 Whisper chamber could get somebody hurt. Subsonic may be ok... ymmv


as an FYI,
There is a guy on silencertalk that says he will ream/convert your whisper/fireball for $50 + ship



from 300blk forum:
Q: Can 300 AAC BLACKOUT be shot in a 300-221, 300 Fireball, or 300 Whisper® rifle?

A: Due to the variation in those chambers, that should be considered a potentially unsafe combination - much like shooting 5.56mm in a 223 chamber. Experimentation has shown that there is a several thousand psi difference in chamber pressure and pressure could exceed SAAMI limits of shot in alternate chambers.


300blk is def. a good option for those that dont reload...since Remington is making lots now.

Yeah, the whisper cartridge is going to fail long term, just goes to show what happens when you manufacturer proprietary cartridges and try to hold the market all to yourself. If you can't meet demand, demand will kill you. I'm glad you took the time to explain that, now I understand the differences. Considering .300blk is almost .2-.3" longer case length, that's the ticket.

[Nash B.]

are there any advantages to 300 whisper over 300 blackout?

[momo]

are there any advantages to 300 whisper over 300 blackout?

seems like only disadvantages.

[GAP]

I finally got the chance to shoot this rifle. Unfortunately it doesn't cycle. 220gr factory loads move the bolt about a 1/4 of the way back, and 115gr factory loads nearly eject. So my next move is to further open up my gas port. I forget what I have it at now. Something around .115". I'll take it up to .125" or larger now. I need to measure the Adams Arms gas block and see exactly what diameter the port is on it.

[gat0r]

I finally got the chance to shoot this rifle. Unfortunately it doesn't cycle. 220gr factory loads move the bolt about a 1/4 of the way back, and 115gr factory loads nearly eject. So my next move is to further open up my gas port. I forget what I have it at now. Something around .115". I'll take it up to .125" or larger now. I need to measure the Adams Arms gas block and see exactly what diameter the port is on it.

b4 u start drilling, what are your 220 loads? subsonic?
if so, did you play w/ gas block adjustments?
are using standard carbine buffer & spring?

fyi, most start @ around .080"
suppliers usually deliver @ ~.089" for carbine length gas system
most people get it to reliably cycle btwn .107-.115"
(w/ most peeps stating .110" was optimum)

so your stated .125 may be too large...just research it b4 drilling & messing up yur barrel

[CJ]

Is that gas block in the carbine location or pistol?

[GAP]

b4 u start drilling, what are your 220 loads? subsonic?
if so, did you play w/ gas block adjustments?
are using standard carbine buffer & spring?

fyi, most start @ around .080"
suppliers usually deliver @ ~.089" for carbine length gas system
most people get it to reliably cycle btwn .107-.115"
(w/ most peeps stating .110" was optimum)

so your stated .125 may be too large...just research it b4 drilling & messing up yur barrel

Yes, the 220gr are subsonic. I my first shots were with the gas block on the restricted setting. After a few not cycling, I left it fully open when testing. I'm used the standard spring and 2.9oz buffer.

I won't touch the barrel yet. I removed the weights from my buffer. So now it weights 1oz. instead of 2.9oz. I may lighten the spring slightly as well.

[GAP]

Is that gas block in the carbine location or pistol?

Carbine position.

[CJ]

Carbine position.

You're probably not going to be able to cycle subsonic with a carbine block. With a lighter weight/spring you will be able to cycle super sonic rounds. You MAY be able to cycle subsonics with a can attached.

[GAP]

Well, the gas block port is a lot larger than I expected. I was able to gauge it at .156". Even at the carbine position, with enough gas, it should cycle subs right? Then throttle the gas back with full loads.

[CJ]

Well, the gas block port is a lot larger than I expected. I was able to gauge it at .156". Even at the carbine position, with enough gas, it should cycle subs right? Then throttle the gas back with full loads.

I don't know about that. It might not cycle with subs wide open. It should with a suppressor attached though.

[GAP]

Well I trimmed a spare buffer spring down to just a hair under 10". This is just shorter then the minimum carbine length spec, which is 10 1/16". It's about a 1/2" shorter then the two carbine springs I measured.

I'm still contemplating opening the port. The largest reamer I have on hand is .137", and I might just use it