300 Blackout Upper vs. Barrel

[vipermd]

Interesting. Good to know. As it is, I have not even shot this Sport yet. I may not use it until I get the upper. I assume that if I hold off I won't have to be concerned about the bolt.

Shoot it!!! That is why you got it. Also as mentioned earlier 9mm can will be threaded1/2 X 28 and the blackout upper will be 5/8 X 24. What kind of can were you going to get?? I would be curious which company is certifying 9mm and 300 whisper through the same can??? Be Safe,

 

[GMC man]

Im going to get the S & W 300 upper, I just got a new S & W lower for it and it seems like there are a lot of good reviews for the S &W 300 but it is a bit pricy but I like the melonite barrel .

 

[Stebo]

Good review of the M&P15 Whisper here Just Enough Gun: Smith & Wesson M&P15 .300 Whisper - Guns & Ammo and an interesting article on 300 Whisper vs Blackout here NRA Mobile.

 

[Dikinalaska]

I would think it'd be fine to use the bcg in the new upper since it's new still, but I don't believe you should use it on both. You're going to have to get a new one either way in my opinion. If you use it occasionally for both, it won't wear to a specific upper and could eventually wear to the point it won't work in either. I'm not an expert though, just my thoughts on it.

 

[Cdog]

I had a .300 for a couple of months. Other than being subsonic friendly, it does nothing as well as what I already had. I've tried different calibers, and only stayed with two in the 15 size platform. The 6.8 SPC and the 5.56/.223.

The short overall length of the .300 concerns me too. Although I haven't personally confirmed it, it appears to me that a pointed .300 could chamber in a 5.56 chamber. With the bolt and magazine being identical, if you do choose a .300 mark your magazines.

I still have a few loaded rounds, dies and such. I simply don't want to have to beat a stuck .30 caliber from one of my 5.56's to find out.

There are pics of a mangled upper at the link below. Be careful!

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=3067632

 

[frdfandc]

I had a .300 for a couple of months. Other than being subsonic friendly, it does nothing as well as what I already had. I've tried different calibers, and only stayed with two in the 15 size platform. The 6.8 SPC and the 5.56/.223.

The short overall length of the .300 concerns me too. Although I haven't personally confirmed it, it appears to me that a pointed .300 could chamber in a 5.56 chamber. With the bolt and magazine being identical, if you do choose a .300 mark your magazines.

I still have a few loaded rounds, dies and such. I simply don't want to have to beat a stuck .30 caliber from one of my 5.56's to find out.

There are pics of a mangled upper at the link below. Be careful!

300 ACC blackout /5.56 question - Sniper's Hide Forums

This is where you must be careful. You must ALWAYS be careful. After all you are dealing with a firearm.

What about those that put .380's into a 9mm. Same type of scenario could happen. But with diligence it can be prevented.

And I think to get a .300 to fully chamber in a 5.56, you probably would have to physically jam the bolt forward, due to the larger diameter of the bullet itself.

 

[Cdog]

Are you aware of just how short the .300 is? It may set some bullets back into the case a bit, but I don't think you'd have to force it to close on many pointed profile bullets.