Handloading the 300 Whisper

[45ACPete]

I posed this question on another forum without a reply yet so thought I'd try here as well. Is anybody shooting and reloading for the 300 Whisper? This is a cartridge developed (as I understand it) as a subsonic sniper round based on the 221 Fireball case necked up to take a .30 cal. bullet. I am thinking of rebarreling a Remington 722 to a version of the Whisper but would like a bit more powder capacity--maybe using the .222 or .223. as the parent case. I want a mild recoiling 200yd shooter for cast bullets. I think the powder capacity of such a case will be enough for my needs. I remember once reading a gun magazine about such a cartridge used (with jacketed bullets) for silhouette shooting and how even the rams were knocked down with an authority all out of proportion to what might be expected from such a puny appearing cartridge. This was years ago and I don't even remember where I saw the article. Anyway, if anybody can give me some information as to barrel twist and bullet weights used in the Whisper I would appreciate it. Thanks, Pete

[rjrivero]

Consider using instead the realtively new 300 AAC Blackout. The 300 Whisper, 300-221, 300 Fireball, and the 300 AAC BLACKOUT are all of the same vein. They all use a .223 or .221 cartridge and neck it to a 30 caliber bullet. The only difference is that the AAC BLACKOUT has been submitted to SAAMI for standardization.

Which means, you will be able to get FACTORY LOADED AMMO (Right now produced by Remington) and factory brass for reloading as well.

The main differences that I have seen in the discussions and the comparison is the throat length.

The nice thing about this cartridge is the fact you can load it with 220gr bullets and shoot them subsonic making it a nice PDW type firearm and suppressor friendly.

You can also load this with lower grain bullets and have a pretty effective deer rifle out to about 200 yards or so, depending on your confidence.

There has been a lot of discussion on this round, including chamber reamers that can convert the other 300-221 based rifles to this new standardized caliber on www.silencertalk.com

There are dies available from Forester. You can use a .308 Crimp die cut down to work with the shorter round. (I'm uncertain how much needs to be cut off just yet, but I'll figure it out based on the case length differences.)

I'd hate for you to spend money on a round that has been newly standardized. (Or will be newly standardized in the very near future.)

[45ACPete]

What is the head dimension of this cartridge? I shoot reduced-course high power matches and therefore I believe I am limited to rounds that can be loaded in stripper clips. That, to me, means the 308 size head, the 7.62 X 39, or the .223. I kind of lean toward the .223 size head, as the action I plan to use, a Remington 722, already has the proper head-sized bolt. Actually, I think the 7.62 X 39 has just about the right powder capacity and I've been advised by a really knowledgeable cast bullet shooter of long standing that if this round is tailored to a gun with a "Lapua chamber" it can be very accurate. Still trying to decide--appreciate all input. Pete

[rjrivero]

The dimentions are very similar to the 300 Whisper. The only difference is in throat length and maybe the angles of the shoulder. These function in the AR platform with the same BOLT, and the same magazines as the .223. The case is a .223, cut down and re-sized for the .308 bullets. Essentially the same idea as the 300 Whisper, but standardized and submitted to SAAMI.

[45ACPete]

Thanks, R. J.--with dies and match chamber reamers available I think I have the answer and am ready to go ahead with this project. Will provide posts on progress as it develops. Pete

[rjrivero]

Looking forward to it, Pete. I've got a 300 BLK project on the front burner right now. I look forward to comparing notes with you.

[Whisper 300]

I reload and shoot a lot of 300Whisper aka 300-221 Fireball
Almost all of it subsonic out of a custom rifle based on a Rem. 700XR with Jewell trigger set at 4oz.
The barrel is a Lilja 1/8 twist heavy contour.

Prior to going to a custom bullet from Lehigh Bullets I shot mostly Sierra HPBT in 240 and 220 gr.

Very very accurate round @ 100 yards and IF you range your target very accurately you can go out farther but remember that it drops on a rainbow trajectory even though it retains its velocity quite will-a trait of a high BC bullet at subsonic speeds.

With the proper bullet and shot placement I have taken a number of deer.
My experience is that you will get extraordinary penetration without expansion with most bullets. See Lehigh website for their subsonic bullet- it does shed its 4 petals quite nicely at subsonic speeds and is very effective on whitetails with a heart lung shot. Otherwise most rounds tend to "pencil" through and you will be left with a 5 mile jaunt trailing a shot deer that is not leaving you a blood trail-read lost deer that will die 3 days later-bad thing to do in my world.

Anyway, nice round, like it a lot.
Have used both 221 Fireball cases and cut down 223 Rem. but watch the neck thickness with milsurp 223's.
Powders I like are Lil'Gun, H-110 and AA5
You will need to measure powder carefully as very small increases will toss you into supersonic range with the attendant "crack".
Remember, you can suppress the report not the crack of passing through the sound barrier.

Hope it helps, always available if you get into it and have questions.

Gary