300 whisper/300 aac blackout

[crracer_712]

I have the Lee 300 aac blackout dies and a couple of M&P 15 300whisper chambered rifles.

I've read all about both ammos, and how you can cut down 223 brass to make 300 aac blackout brass. Also read the the whisper was originally based on the 221, or there abouts.

My question is, how will the Lee dies work on the Hornady brass from the 300 whisper ammo? I bought 400 roundes of this stuff, half in the 208 amx and half in the 110 vmax. I'd previously purchased some 208 amax bullets for use as reloads.

Haven't done any reloading for this yet, not acquired much brass and haven't really shot them much to date. But I'm gearing up to scope one of them and start seeing what they'll do.

 

[GRUMPA]

I sell that stuff on another site and I do over 10K of them a month. Yes I cut down 223 brass and I use one of those mini chop saws to do it and I cut them down to 1.355 and they will grow when you neck size them. Your dies will work on any brass, but you'll need to play with the die for sizing, you don't want to over work your brass, you want it so your bolt just closes on the brass and them give it a very small turn (the die) which will make it .002 or there abouts clearance.

When I make mine I use the 223 brass but all are not created equal, the brass thickness does change from manufacturer, so I ream all of the brass I make. Yeah it's tedious as all get out but my customers just love the stuff. I can use any 223 brass on the market and have it work flawlessly.

If you plan on making your own brass from 223 make sure you lube it real well. I don't frequent this forum much so if you want to get in touch with me do it through PM.

 

[Nikdfish]

Not really sure if this applies to your question, but it is something I ran across when using a Lee die set to form 300 BLK from cut down .223. When checked with a L.E. Wilson case length headspace gauge, I found the cartridge base sitting a bit proud of the high step. I couldn't get a result that consistently fell within the high step/low step range until I honed down the shell holder a bit (literally - I used a diamond grit sharpening stone). This allowed the brass to go in far enough to set the cartridge shoulder a bit farther back (and was easier than modifying the die itself). There just wasn't enough adjustment available until I did so.

I really recommend a case length headspace gauge for double checking your product if you don't already have one. Your die set may not need the mod, but mine did.

Nick

 

[GRUMPA]

OK here's the deal between the 2 you mentioned. 300 Blackout and 300 Whisper are not the same animal. 300 Whisper was a wildcat cartridge that is a lower powered round than the 300 Blackout. The SAAMI spec on the case neck for a 300 Blackout with a .309 diameter bullet is .334, the 300 Whisper I believe is .330.

The length of the brass for the 300 Blackout is 1.368-.020 and for the 300 Whisper it's a bit shorter.

So you can use a 300 Whisper in a 300 Blackout chamber and all will be OK, NEVER try to do it the other way around, a 300 Blackout in a 300 Whisper is a big NO-NO.

 

[crracer_712]

So you can use a 300 Whisper in a 300 Blackout chamber and all will be OK, NEVER try to do it the other way around, a 300 Blackout in a 300 Whisper is a big NO-NO.

Well, that's odd. Smith and Wesson say the M&P15 300 whisper is a 300 whisper chamber, but safely shoots 300 AAC blackout.

I do understand that the Whisper was a .221 cartridge versus a .223. Perhaps Smith just made the chamber a little looser, but then if that were so, how would they label it a 300 whisper chamber?

Either way, Until I bought this Hornady 300 whisper ammo, I hadn't had any to shoot, only shot some 300 AAC blackout in it.

I WAS planning to possibly cut some 223 down for cases, but that was before I bought all this whisper ammo, which I will now use those cases for reloads.

 

[RhinoDefense]

Forget the Whisper crap. Stick with the SAAMI standard which is the Blackout.

 

[crracer_712]

Forget the Whisper crap. Stick with the SAAMI standard which is the Blackout.

OK. But I'm not loading whisper, at least that I know of. I only have data on the 300 AAC. Was just asking about using the lee 300 aac dies to full length resize the whisper cases once I shoot them and want to reload them.

 

[GRUMPA]

Then what you have will be fine for that.

 

[crracer_712]

ok, thank you!

 

[highlander 5]

I have a 300 Blackout and made my cases from both comercial and military brass. I bought a form die from Redding and an extended shell holder. Ran the case thru the form die,cut off the excess with a sawzall and trim to length then deburr. Did 200 cases a night took about a week to make 1500 cases.

 

[cfullgraf]

I guess you do not have to ream the necks of 300 Blackout cases formed from 223 Remington et al cases?

 

[RhinoDefense]

No, reaming is not necessary.

 

[GRUMPA]

Actually reaming the ID of the necks makes them uniform. I used gauge pins during my initial forming and found out that alot do indeed have as much as .003 taper in the ID. I just take that part out because alot of my customers use a cast bullet and that means it's larger than your standard .308 diameter bullet.

You should see the pile of shavings I get when I get done doing 1k of them. And any foreign case that gets made into a 300 Blackout is not a good idea to use unless it's reamed.

W.C.C. cases so far are the best with minimal removal of material in the ID with LC coming in at a close second, I can run 1K and just barely graze the ID with my reamer with almost all of them but there are about 1% that I end up taking .002 and just a bit more on during the run.