300 blackout vs. 300 whisper

[DCP]

So I am looking at the 300 blackout

I find out S&W makes a M&P AR in

300 whisper,
that shoots a 300 blackout.

I figure it must be safe but what about accuracy.

Also Remington is coming out with a a bolt 300 Blackout this month

Any help will be appreciated

Thanks


If this is in the wrong place Mods please Move

[bruce drake]

Normally, if its chambered for 300 Whisper it WON'T chamber a 300 BLK as the BLK it is slightly longer.

I have an AR in 300BLK and its able to safely fire the 300 Whisper as well as the 300/221 Fireball.

If your local gunshop told you that about the rifle he's probably misinformed as Smith and Wesson would probably rather chamber the rifle in 300 BLK as its not a proprietary chambering from SSK Industries who own patents on the Whisper series of cartridge. They try to get a royalty kickback supposedly on every rifle chambered for 300 Whisper.

[GRUMPA]

I was reading recently about rifles coming out that had the ability to use both the 300 Blackout as well as the Whisper cartridge. The Whisper as far as I know was never approved by S.A.A.M.I. but the 300 Blackout was and is becoming more popular. The Whisper has a smaller neck diameter than the 300 Blackout and as stated the Whisper is just a bit shorter with the Whisper round not being as high powered as the 300 Blackout. The Whisper case was made from 221 Fireball cases because of the thinner neck, the 300 Blackout can be made from 5.56 cases with some ease but it can be kinda involved. You can use the Whisper in a 300 Blackout chamber but not a 300 Blackout in a Whisper chamber.

I don't use that round I just make the cases for the 300 Blackout and given a choice between the 2 I would grab the 300 Blackout without question. As far as accuracy goes that's up to the user and reloader, what works well for one shooter aint worth a plug nickel to the other.

I'm sure there be more folks chiming in on this but all I've read is favorable reports from the users of the 300 Blackout cartridge.

[scb]

I have owned a 300 Whisper for about 10 years. The 300 whisper is formed by necking up 221 Remington Fireball brass, no other changes. This makes for comparatively thin wall brass in the neck. 300 blackout can be formed by sizing 223 / 5.56 brass in a file trim die and cutting off what sticks out of the top of the die. Doing this the case neck is formed from the side walls of the 223 case making for a heavier walled neck. If one attempts to fire a case formed from 223's in a whisper chamber there may not be (in my rifle IS not) enough clearance in the chamber neck to properly release the bullet causing pressure to spike dangerously.

http://sskindustries.com/brass

[Moonie]

You really can't go wrong with either. My son and I both have 300 Blackouts and they are a blast to shoot. Making cases is a small chore but not much of an issue. The issue with SAAMI is that they will not take copyrighted cartridges for submission. The 300 BO was designed to standardize the few .223/300 wildcats that were out.

Keep in mind that generally 300 whisper data can be used for 300 BO loads. Of course reduce 10% and work up, as always.

[Idaho Sharpshooter]

I had a whisper, I now have a blackout. I used 223 for both, but had to inside neck ream for the whisper.

The BLK is simple with a Giraud trimmer.

[Blammer]

This month's copy of American rifleman has an article about the 300 BO and the Whisper. Interesting read.

[DCP]

Very good article answered a lot of questions. [smilie=w:
I really thougt more would chime in.
Maybe this round is not going to as populer as I thought. :violin:

Thanks to all.



This month's copy of American rifleman has an article about the 300 BO and the Whisper. Interesting read.

[wlc]

Very good article answered a lot of questions. [smilie=w:
I really thougt more would chime in.
Maybe this round is not going to as populer as I thought. :violin:

Thanks to all.

Its probably more popular than you think. My guess as to why no more than have chimed in on here is that "most" 300BO owners are using it in black rifles and probably don't hang out on a site dedicated to cast boolits. Could be wrong, just a guess. There is a whole forum dedicated to the 300 BO and several other sites have a sub-forum for it and/or other suppressed rounds.

[scb]

Its probably more popular than you think. My guess as to why no more than have chimed in on here is that "most" 300BO owners are using it in black rifles and probably don't hang out on a site dedicated to cast boolits. Could be wrong, just a guess. There is a whole forum dedicated to the 300 BO and several other sites have a sub-forum for it and/or other suppressed rounds.

http://castboolits.gunloads.com/search.php?searchid=4537620
http://castboolits.gunloads.com/search.php?searchid=4537631

165 separate threads mentioning 300 blackout. 332 mention 300 whisper. A lot of these questions have been asked and answered before. Not saying one shouldn't ask but try the search function.

[DCP]

Thanks but I always try the search function, and it sucks. I found more with Google

I found only 1 load using 700x using these rounds and it didnt say how many grains.

By the way your links stop working.



http://castboolits.gunloads.com/search.php?searchid=4537620
http://castboolits.gunloads.com/search.php?searchid=4537631

165 separate threads mentioning 300 blackout. 332 mention 300 whisper. A lot of these questions have been asked and answered before. Not saying one shouldn't ask but try the search function.

[L1A1Rocker]

I have owned a 300 Whisper for about 10 years. The 300 whisper is formed by necking up 221 Remington Fireball brass, no other changes. This makes for comparatively thin wall brass in the neck. 300 blackout can be formed by sizing 223 / 5.56 brass in a file trim die and cutting off what sticks out of the top of the die. Doing this the case neck is formed from the side walls of the 223 case making for a heavier walled neck. If one attempts to fire a case formed from 223's in a whisper chamber there may not be (in my rifle IS not) enough clearance in the chamber neck to properly release the bullet causing pressure to spike dangerously.

http://sskindustries.com/brass

I ran into this issue also. I ordered a conversion reamer to bring my 300 Wisper chamber into 300BLK specs. It was a very easy process.

[scb]

I ran into this issue also. I ordered a conversion reamer to bring my 300 Wisper chamber into 300BLK specs. It was a very easy process.

I had thought about that but this upper shoots so well I'd hate to take a chance on messing it up.


By the way your links stop working.

I see that must be they time out or something.

Try this search method, works a lot better for me
http://castboolits.gunloads.com/showthread.php?t=127829

[3006mv]

I have a Model 1 Sales 300 Whisper. I make my own brass from .223/5.56 and load the lead Lee 300Blackout boolits. No issues at all once I figured out my load and loading steps (flare case first = no leading for me). I don't know why S&W went with 300 Whisper, let's just say I don't mind :-) I would consider buying one of their uppers. It is to my understanding that in the S&W you can shoot either but normally it is recc to not shoot 300 Blk in a 300 Whisper, my guess is the throat of the S&W chamber is cut to accept the slightly longer leade of the 300Blk

[Love Life]

The 300 blackout is interesting. Looks like I can get an upper in 300 Blackout and still use the same mags, BCG, etc. With the same ballistics of the 7.62X39 I can dispence with having two different models of modern sporting rifles. Then I can make a fancy case to hold both uppers with mags and all that. Hmmm.

[john hayslip]

I found many loads for the 300 "younameit" on Hornady's web site. From the Rifleman article both should use the same loads. Using a converted heavier 5.56 case should require reduced loads to start off with due to the heavier than the 223 case. I notice they are loading to pressures way below the 5.56 and still getting functioning.
I have a bolt action pistol in 300 Whisper and a upper in 300 Blackout but have not yet shot cast bullets in the upper.

[MakeMineA10mm]

Sorry to dredge up an old one, but I have a couple questions now that I've read the American Rifleman article.

First, and foremost, the were extremely few differences in dimensions on the chamber reamers. The only major differences I saw were:

Length from base to shoulder- Whisper is .0026" longer
Length of shoulder- Whisper is .0002" shorter
Length of neck- Whisper is .0024" shorter
Length of freebore- Whisper is .010" longer
Diameter of chamber at case head- Whisper is .001" tighter

There was ZERO difference in neck diameter, so the often-reported "fact" that the Blackout was designed for use with cut-down .223 brass without needing to be neck-reamed or neck-turned appears false to me. Can someone who knows for sure the American Rifleman's illustration about this may be wrong, provide a link to SAAMI, or another industry-level reliable source to proove otherwise?

If the dimensions in the article are all correct, with the exception of the thousandth tighter base diameter, the Whisper chamber is bigger (actually longer) than the Blackout, and therefore the Whisper can accept both Whisper and Blackout ammunition easier than the Blackout. (Though, this difference would probably only come up with handloads where the previously-fired rounds through the Whisper did not have their shoulders bumped back quite enough for a blackout chamber, such as when one tries to minimally size to not overwork the brass.)

This also says to me that reloading data is mostly interchangeable between these cartridges, with the exception of bullets over 220gr, where the advantage goes to the Whisper due to it's longer freebore. (I would NOT use Whisper load data for the 240/250gr bullets in the Blackout.)

[gds]

Having both I can say it Does not matter. 2 barrels are cut with a custom reamer that is close to 300 whisper specs and then one is a 9.5 inch 300 blackout barrel. All my brass is made from LC 5.56mm. I shoot mostly cast bullets from 130gr to 247 gr NOE. I will never get rid of mine have killed 9 deer so far the cartridge.

[MakeMineA10mm]

Gds, good info - thanks. If you can bear another question:

Are your Whisper barrels from SSK?