300 whisper upper

[Ray F]

Does anyone know if a 300 whisper upper from Smith & Wesson be mounted on a m&p ar15 lower?

 

[Bushmonkey9]

yes, why wouldn't they?

 

[LbulletM]

Yes, there are a large number of uppers that will fit on a standard AR lower. Just google AR calibers and you'll find a lot of lists of them with everything from .22lr to .50 Beowulf. 300 whisper is one of them. I would personally go with a 300 blk. It's kinda like 5.56 vs .223. You can shoot whisper in a blackout, but you can not shoot blackout in a whisper.

 

[Argonnakid]

I use my S&W 300BLK upper (SKU# 812012) on my M&P 15T lower (SKU# 811041) all the time. It's great being able to use the same mags.

 

[WilsonFlyer]

Yes, there are a large number of uppers that will fit on a standard AR lower. Just google AR calibers and you'll find a lot of lists of them with everything from .22lr to .50 Beowulf. 300 whisper is one of them. I would personally go with a 300 blk. It's kinda like 5.56 vs .223. You can shoot whisper in a blackout, but you can not shoot blackout in a whisper.

If I'm not mistaken, the S&W Whisper is also certified to shoot Blackouts. The only reason I think I know is because I've been looking a the S&W to get a .300 option on my AR.

I know it's unusual to hear that combination but I guess it's because S&W paid the royalties and chooses to tout the Whisper side for promotional purposes.

Someone will certainly correct me if I'm wrong.

 

[Mack]

I use my S&W 300BLK upper (SKU# 812012) on my M&P 15T lower (SKU# 811041) all the time. It's great being able to use the same mags.

Using the same mag is a - not a + considering some of the spectacular kabooms.

 

[sithlord]

Using the same mag is a - not a + considering some of the spectacular kabooms.

Using the same mag means nothing; a .50 beowulf uses the same .223 pmags, it just holds 10 instead of 30 (see liberals; it's only a 10 round magazine)...

The problem is that the 300 BLK round will CHAMBER in a 223/556 barrel. The bullet gets pushed back into the casing slightly. The .50 will not chamber....

So yes, there is an added risk. There are LOTS of recommendations on how to mitigate that risk, including using silicon wrist bands:

Of course, visual inspection and proper range safety (only one caliber active per lane) will mitigate the risk further.

Please do us ALL a favor and stop spreading the FUD (fear, uncertainty, doubt).

 

[moe smith]

I'm not sure I understand the attraction. First, getting an "upper" anything simply gives you one and a half guns for almost the same price. Why not just buy a second rifle? Second, if I'm considering a heavier caliber, magazine compatibility, though attractive, would not be the selling point for me. Ammo availability would. The ballistics of the hard to find 300 are similar to the 308 (7.62), which are available everywhere, so why not just pick yourself up a complete S&W AR10 ?

 

[Smitty357]

Like my .300 BLK a lot. But i'm in the process of building a 6.8 to step up the game.

.300 BLK is a good round and its a great round when its suppressed. But from my experience, its not easy to get proper shot placement. At 100 yards it works perfectly fine. Getting past 100 u better start aiming high and i mean much higher than u would normally.

So if u intentions are to build a very quiet weapon with better knock down than the 5.56. This is ur better option. But if u want something that will reach out and touch something without a problem but dont intend to run in suppressed. The 6.8 is the better route to look at. Just my opinion.

 

[sithlord]

I'm not sure I understand the attraction. First, getting an "upper" anything simply gives you one and a half guns for almost the same price. Why not just buy a second rifle? Second, if I'm considering a heavier caliber, magazine compatibility, though attractive, would not be the selling point for me. Ammo availability would. The ballistics of the hard to find 300 are similar to the 308 (7.62), which are available everywhere, so why not just pick yourself up a complete S&W AR10 ?

As I am in the process of getting a 300BLK SBR upper and I own a S&W M&P VTAC II, I can tell you at least *my* reasons.

1) SBR with subsonic or supersonic ammo. Supersonic good to 300+ yards, although ppl have 500, 750, and 1000 yard consistent shots with a SBR.

2) Sub MOA from a 8" barrel (potential CQC/HD applications)

3) My lower is already configured nicely. Sure, a new lower could be configured in a similar manner.

4) .380/7.62 casing has a larger taper, and has been known to cause feeding issues with standard PMAGs. Requires frankenmags and a different BCG. Technically all you need a is a new barrel for the 300 BLK.

5) 300BLK ammo is getting easier to find; also, it's very popular for reloaders because it uses arguable the most common parent cartridge (.223) with the most common reloaded bullet (.308). It's only 3 years old, give it time! Maybe it will become a bit more popular and stocked in more places.

In short, it's a round designed to run in an SBR, suppressed with subs or supers with excellent terminal ballistics and penetration capabilities.

Sure, you could get a complete rifle for the cost of just the upper. Nothing wrong with that. Or you could go with an AR-10.

To each their own, though..

 

[Smitty357]

In short, it's a round designed to run in an SBR, suppressed with subs or supers with excellent terminal ballistics and penetration capabilities.

If this is what ur intentions are with a .300 BLK. Then this is exactly what u want. These things are great when it comes to building them like this. The way they were intended to be built and ran.

As far as a standard 16" rifle running supersonics. If i had to do it all over again. I'd go with 6.8 or .308 in AR10 format. And that is exactly what i'm doing.

You can buy a complete rifle for the price u can a .300 BLK upper. And then u have something thats much better than .300 BLK when it comes to being a 16" rifle running supersonics.

Dont get me wrong i still enjoy my .300 BLK by all means. But i've learned my lesson as far as which way the .300 BLK is a better weapon. Suppressed SBR hands down u cant beat the .300 BLK.

 

[sithlord]

If this is what ur intentions are with a .300 BLK. Then this is exactly what u want. These things are great when it comes to building them like this. The way they were intended to be built and ran.

Which is why I'm not looking at the S&W whisper/blk, since it has a 16" barrel.

The 300 BLK round, to me, fills the 'darn good at a lot of things' rather than being the best at one or two things.

I like that flexibility for SHTF, plinking, or virtually any other use case.

Again, to each their own.

 

[Smitty357]

Which is why I'm not looking at the S&W whisper/blk, since it has a 16" barrel.

The 300 BLK round, to me, fills the 'darn good at a lot of things' rather than being the best at one or two things.

I like that flexibility for SHTF, plinking, or virtually any other use case.

Again, to each their own.

Suppressed in SBR is surely darn good at alot of things, lol. Actually better at most things than it is in a 16" barrel. This thing is apples and oranges when its compared in SBR to 16". As 16" honestly doesnt stand much of a chance against it. The SBR even covers the distance as good as the 16" and carries the punch to go with it.

 

[Argonnakid]

I like that mag well art work.

Yes, there is limits to what the .300Blk can do. But that can be said for any caliber. The range of it is not the best for sure, but in my case using my rifle for a hunting platform in tight trees and even tighter bush, I find the .308 bullet does very well. In all my years of hunting here in Virginia and North Carolina, I have never had a shot(ethically) over 250yds. The cost of ammo is up there, but last time I checked so was about every other thing that goes bang. As another poster said, the cost of this round is going down. Case in point, this past weekend at a local gunshow, I haggled a guy down to $8.75 per 20 on UMC 115gr. but I bought 18 boxes to do that.
With the concern of mixing mags of ammo between a 5.56 and a .300BLK. Yes, that is a very real threat to your safety. Just like dropping a .380acp into a 9mm mag. These are not toys to be lightly regarded. Attention needs to be heeded.

Now, the things that I see as a plus. It's nice having basically a spare upper with all the parts(sans barrel). Same bolt group, same mags and mag parts, same upper receiver parts. The cost of reloading is on par with most other rounds. As said by another poster, .308 bullets can be found rather easily. The brass can be gotten from different sources. And the range of bullet weights is pretty good in my book.
That's just my 2 cents.

 

[LbulletM]

I'm not sure I understand the attraction. First, getting an "upper" anything simply gives you one and a half guns for almost the same price. Why not just buy a second rifle?

Lest you forget the ease of getting an upper delivered to your doorstep instead of having to deal with a transfer!

 

[Kilibreaux]

If I'm not mistaken, the S&W Whisper is also certified to shoot Blackouts. The only reason I think I know is because I've been looking a the S&W to get a .300 option on my AR.
Someone will certainly correct me if I'm wrong.

Yes the Blackout can chamber and safely fire the Whisper. The BO has a longer neck, otherwise they are dimensionally identical and utilize virtually the same load data.

This is why one should purchase a Blackout upper over the Whisper upper.

 

[thecatch8]

I use my S&W 300BLK upper (SKU# 812012) on my M&P 15T lower (SKU# 811041) all the time. It's great being able to use the same mags.

This is awesome...I'm so glad SW decided to enter the black market! Now, finding reasonably priced 300 BO ammo....

 

[Ibmikey]

You really need to load your own to get full enjoyment from this caliber. I load only supersonic and use pulled 147 gr bullets for general plinking. The round is so much fun to shoot I built a complete rifle around a Rainier barrel ....that way it can be conspicuously marked as to caliber. Having a bunch of speciality uppers laying around is not my style, a lower is not that expensive.

 

[wfa17332]

300 AAC Upper

I've had my S&W upper on Colt, PSA, S&W, and "don't have a clue" lowers. It worked fine on all of them. The "main attraction", for me, was that the S&W has a "free float" forearm and S&W customer support. My upper fires subsonic without a "can", no problem. Even without the suppressor, the report of the 300 AAC is MUCH less than the 5.56/223 - both super and sub. Accuracy seems to be limited to the skill of the pilot and I've not noticed any POI shift as the barrel warms (which takes a LONG TIME given the small powder charges). I use only 10 and 20 rd PMags for the 300, and each has a large RED nail polish dot on it's side. If it's a 30 rd or metal, it's for the 5.56 uppers.

 

[jdh]

I'm not sure I understand the attraction. First, getting an "upper" anything simply gives you one and a half guns for almost the same price. Why not just buy a second rifle?

An upper is not a firearm and can be shipped direct.

In some jurisdictions it is no longer possible to buy another "Assault Weapon" or the approval process is difficult.

For starters.

 

[Argonnakid]

I heard that "one is none and two is one". So, I would think the more, the merrier.

 

[chessail 77]

very good info...thanks guys

 

[thecatch8]

Like my .300 BLK a lot. But i'm in the process of building a 6.8 to step up the game.

.300 BLK is a good round and its a great round when its suppressed. But from my experience, its not easy to get proper shot placement. At 100 yards it works perfectly fine. Getting past 100 u better start aiming high and i mean much higher than u would normally.

So if u intentions are to build a very quiet weapon with better knock down than the 5.56. This is ur better option. But if u want something that will reach out and touch something without a problem but dont intend to run in suppressed. The 6.8 is the better route to look at. Just my opinion.

agree completely, and unless you are doing your own reloads which can be very costly and time consuming, 7.62 ammo is actually cheaper than .300 blackout.

 

[Ibmikey]

The last post has me a little confused, .308 requires three times the powder and uses a large rifle primer with the same bullet how can it cost less to load than the Blackout? I load both..buy a lot more powder when loading for my LR-308, all other components cost the same. Reformed brass for the Blackout is no more expensive than purchasing .308 cases and both will last many loadings.
As stated before my Blackout is for plinking, hog hunting and fun. I shoot as much as I want and then reload the empty brass which in itself is more fun for me and when using pulled 147's in either cartridge it is very economical.

 

[sithlord]

agree completely, and unless you are doing your own reloads which can be very costly and time consuming, 7.62 ammo is actually cheaper than .300 blackout.

The last post has me a little confused, .308 requires three times the powder and uses a large rifle primer with the same bullet how can it cost less to load than the Blackout? I load both..buy a lot more powder when loading for my LR-308, all other components cost the same. Reformed brass for the Blackout is no more expensive than purchasing .308 cases and both will last many loadings.
As stated before my Blackout is for plinking, hog hunting and fun. I shoot as much as I want and then reload the empty brass which in itself is more fun for me and when using pulled 147's in either cartridge it is very economical.

Agree 100% Ibmikey;
Unfortunately, right now, 7.62x39mm and 7.62x51mm cartridges are more expensive than 7.62x35 [300 BO]. I suspect this is due more to the newness of the cartridge than anything else. If/when more ammo manufacturers produce the 300 BO, prices will come down, possibly lower than 7.62x51mm.

If cost of ammunition was the overriding factor in ANY decision to shoot a particular round, then we would only be shooting 22lr (although that's becoming not the case!). Cost savings are only PART of a reason why people reload.

There are plenty of other NEW cartridges that are 'hot' or 'popular' right now, from the 6.5 to 6.8 to the .50 beowulf. Of these new 'hot' cartridges, the 300 BO is one of the most economical not only to build but to shoot.

 

[Ibmikey]

I understand new pricing, it was strictly reloading I was referring to. I have shot many hundreds of rounds in mine yet have never purchased a $35 box of factory ammo.