Sniper Country Duty Roster collective wisdom


Calibres/cartridges - 300 Whisper:


I've been very interested in the .300 Whisper concept of a .30 caliber sub-sonic round capable of MOA accuracy out to around the 300yds. range using a bolt gun as a weapon of choice.

I won't be surpressing the rifle as silencers are illegal for civilian ownership here in Canada.My goal is to have an accurate,light recoiling,low signiture,sub-sonic weapon in .30 calibre..

My rifle is a Mauser 98 chambered for .308 Win.I'm really not interested in the .300 Whisper as per say because chambering the rifle to this caliber would be not only expensive but not very practical;at least for me anyway.The flexibility of the .308 Win chambering is more important to me.

There are only a few commercial sub-sonic .308 Winchester loads available in the marketplace to date.

I would like to hear from any of you out there who've experimented with .308 Win sub-sonic ammunition.Does anyone have any pet loads they would care to share.

The .300 Whisper uses big 220 gr. Sierra Matchkings loaded in modified .221 Remington Fireball cases with small amounts (usually under 10 grs.) of fast burning propellents (pistol/shotgun powders I believe).

I can imagine that there are probably some pressure related concerns with trying to down load .308 Win to sub-sonic velocities.For instance can the ignition be irratic and possibly even detonate using reduced powder charges in a case the size of .308 Win. ?

Any help would be greatly appreciate as loading data for this application is basically non-existent.

Thanks,
 
Jeff Babineau <2jeff@blaikies.ns.ca>
Truro, N.S. Canada - Thursday, November 05, 1998 at 18:02:43 (EST) 


Jeff B,

on the detonation due to the reduced charges, I've seen lots of conflicting claims and counterclaims both ways, both on the internet and in the printed media. At this stage I am not yet convinced either way. BUT, if there's a danger that I'm gonna blow my face, I tend to be VERY VERY careful.

Marius
Marius Ferreira <mferreira@lantic.co.za>
Watched my oldest son's créche concert tonight, RSA - Friday, November 06, 1998 at 16:06:25 (EST) 


Jeff B. In Truro N.S. The 300 Whisper is an interesting caliber and I happened to do a great deal of testing with it. The rifle which I have is onn a Sako action, Douglas air gauged barrel in a McMillan A-3 stock topped with a Leopold M3 L/R 3.5 X 10. Sierra Pistol manual has a good amount of data on the Whisper and I have found in my rifle that 2400 powder seem the most accurate. To make the cases, use 223 ammo and get a case trim die and chop off the neck, trim the neck, and resize in a full length resizing die. It is a better way to go than to try to neck up a 221 Fireball. You will ruin too many cases because going from a .224 dia. to a .308 dia is a pretty far stretch. Or just go out and plunk down $22.00 American Dollars (that probably about $374.632.54 Canadian) for a box of COR-BON ammo who do make the 300 Whisper ammo.

al
Al Ostapowicz <aaostapowicz@worldnet.att.net>
Prepping myself to locate Sarge's lair in the High Country in the Foggy Republic of , Ohio USA - Sunday, November 08, 1998 at 10:27:22 (EST) 


Jeff B.,
Another consideration to think about while trying to duplicate .300 Whisper loads with a .308: a .308 will stabilize a 220 gr. Sierra at .308 velocities but will not at anything below 12-1300 fps. It will take a 1-8" twist to stabilize under 1000fps. These barrels are not easy to find or cheap. I shoot a .300 Whisper Contender with a 1-10" twist and I have had 220 Sierras come out end over end when I have tried them sub sonic. They shoot 3\4 moa at max loads. As far as detonation from small powder charges being myth or not, I figure Hodgen doesn't publish reduced loads for H110 for some reason!

endwrench

endwrench <toddfant@bigsky.net>
MT USA - Monday, November 09, 1998 at 00:28:03 (EST) 


Jeff B.,
Another consideration to think about while trying to duplicate .300 Whisper loads with a .308: a .308 will stabilize a 220 gr. Sierra at .308 velocities but will not at anything below 12-1300 fps. It will take a 1-8" twist to stabilize under 1000fps. These barrels are not easy to find or cheap. I shoot a .300 Whisper Contender with a 1-10" twist and I have had 220 Sierras come out end over end when I have tried them sub sonic. They shoot 3\4 moa at max loads. As far as detonation from small powder charges being myth or not, I figure Hodgen doesn't publish reduced loads for H110 for some reason!

endwrench

endnd och <toddfant@bigsky.net>
MT USA - Monday, November 09, 1998 at 00:28:03 (EST) 


Back to Hot Tips & Cold Shots