Home Forums Hunting & Shooting Ask The Gunwriters .308 whisper

Where can I get info on how to make this round?

If you are talking about the .300 Whisper its essentially a .221 fireball necked up to .308 as I recall. SSK Industries is the best source as they(J.D. Jones)are the originator of the Whisper family.

The .300 Whisper (also known as .300 Fireball or .300-221) is a wildcat cartridge in the Whisper family, a group of cartridges developed in the early 1990s by J.D. Jones of SSK Industries. It was developed as a multi-purpose cartridge, capable of utilizing relatively lightweight bullets at supersonic velocities as well as heavier bullets (200-250 grains) at subsonic velocities.

The .300 Whisper was originally based on the .221 Fireball case necked up to 30 caliber however, avid reloaders have found the .223 Remington or 5.56 X 45 mm NATO works well when shortened and resized to 30 caliber. Firing in the .300 Whisper chamber results in a slightly sharper shoulder. Magnum pistol powders such as H110 work well for subsonic loads. Sierra 240 grain (16 g) jacketed bullets work well if the barrel has a 1:8 twist. Barrels with a 1:10 twist will stabilize 220 grain (14 g) bullets at subsonic speeds. 125 grain (8 g) bullets will reach 2400 ft/s (730 m/s).

There are a few points to be considered regarding the utility of the .300 Whisper:

Supersonic loads are capable of matching ballistics of the 7.62x39mm and the .30-30 Winchester, making the .300 Whisper very capable as a short range deer hunting cartridge.
The use of heavy bullets, along with the low powder weight and small case capacity, make the .300 Whisper ideal for use with sound suppressors. These subsonic loads offer energy levels similar to that of the popular .45 ACP pistol cartridge, but range is substantially increased due to the longer, more efficient 30 caliber bullet.
Cases for the .300 Whisper can be formed from common and plentiful .223 Remington brass by sizing and trimming to length. However, J.D. Jones has recommended against this, citing the difference in case thickness at the neck (compared to the .221 Fireball) as a potential issue. This problem can be exacerbated when military 5.56x45mm cases are used. (the whisper name is trademarked thusly the only firearms with a 300 whisper chamber are those from J.D. Jones and Tompson Center which licensed the name all other guns are cut to 300/221 which has different chamber specs than whisper particularly in neck wall thickness as 300 whisper is a wildcat cartridge there were no established sammi specs for the camber reamers and the neck were cut to allow for standard .308 neck thickness which is aproximetly the same thikness as produced from forming .223 brass. typically only guns with whisper chambers will have problems with .223 brass 300/221 chambers work very well with .223 brass and the .223 brass is considerably stronger than .221 brass)
Perhaps most importantly, any firearm with a .223 Remington bolt face can be converted to .300 Whisper by re-barreling the action. As such, the .300 Whisper works well in AR-15-based rifles, especially when some type of gas regulator is installed.
In addition to special applications in suppressed firearms, the .300 Whisper has become popular with metallic silhouette shooters due to its low recoil, good long range performance, and very high accuracy.

Great post 257Bob! Thanks for the insight.

Do you want some loads for the .300 Whisper.
We worked them up for a Thompson single shot, .300-223, with bullets from 200 to 250 grains. Works well, loping trajectory like a blackpowder rifle, but kills deer quietly. Great for hunting near houses.

Reckon a .300 Whisper is a .300-.221 Fireball not a .300-.223...

Technically, yes, it is a .308 bullet in a .221 Fireball case.

But some are built on a .223 case, which is a lot easier.
That's the one I have loads for, and actual trajectories out to 200 yards for a Mil-Dot scope.

It's a big advantage because you can build your .300 Whisper on an AR-15 upper with as suppressor, if you need that.

Do you have a comparison to between the cut down .223 and the .221 cases? Is the .223 version used by pushing the shoulder back or will it also require fireforming? Does anyone offer off the shelf dies for the .223 setup?

If you use the Redding Dies on a .223 case, you just need to trim to 1.390, no fire forming. Remington brass is thin, but GI brass will require neck turning (haven't used it). Longer neck, more support for bullets, especially in AR-15.

If you use .221, the SSK spec by JD Jones for the 300 Whisper is 1.355 inches. After you fireform, it ends up about 1.375, depending on your rifle.

.300 Whisper is owned by SSK. JD Jones developed it.
Apparently Redding is selling a die set that works with .223 brass without permission from JD Jones, but I don't know.

Article in American Rifleman on 300 Whisper
The latest issue, May '08, p.46

Can shoot lead bullets in it, as it is low MV.
RCBS 30-150 FNGC
Lyman #311332 (185-gr)

I am doing the same thing with a CZ 7.62x39 carbine.Load 7.5 grs of Trail Boss with a 180 bullet,1" @100yds and quiet,sounds like a .22 Hornet.I can't have a suppressor in Michigan...

Rifle,
What kind of speed do you get from that? I use a 280gr cast flatpoint in a .35 whelen with bullseye for my "silent loads", I get about 750fps and it is quiet, much less than a .22 short and more like a primer.

VZ, have .35 Rem carbine. Been thinking of 'practice loads' with 158 SWC's at the same velocity range you mention. Quiet bigbores are nice here in NW Ohio farmland.They don't scare the megahouse yuppies who now live in the woods, in which you used to hunt. Paco Kelly and Jim Taylor have developed .32-20 'garden gun' loads which they label as "cat sneeze". About the loudest thing is the fall of the hammer.

The heavy bullet you have is from where, if I may ask? Sounds like an authoritative round for multiple purposes.

My concern in all the mini-powder charges is a possible detonation, I may be dating my era, but is this still considered a concern in loading this type round?

In any event,I'd sure like to use OTC bulk cast bullets as plinkers in the handy little .35. I have a couple thou that I bought for .38Spec, so it'd be a two-fur convenience. Any loading suggestions?

thanks,

John

Even without a suppressor, the bullets at 900 fps sound like a .22 short. When you step away a few feet in the woods, it is not noticeable. It makes an excellent round for shooting near houses, or a second shot at a pack of varmints.

John,
I picked up the original load off of Paco Kelly's site and they did not recommend a filler. I keep hearing trail boss is good for the reduced loads due to its volume but I have never had a problem with the bullseye.

The heavy flat point was bought from a local caster that is no longer in business. Im pretty sure it was an off the shelf mould and was supposed to be 290grs but as cast was about 281. I tried to soften the nose for expansion but it just does not have enough speed. Maybe if a hollow point was made deep enough and thin enough it would peel open. I popped one coyote in the backyard a couple months back with the load and it worked fine, entered at the tail and came out the neck, did not bother to look for expansion.

reloader 7 with 208 A-Maxs was the most accurate combo I could find for my 30-221. I like the remington 223 brass. Just cut it off at the shoulder run it through the form die and trim to length.
A tip for an easy way to cut your brass down is to use a wilson case trimmer bushing for .223 and a chop saw. I was shortening them in my lathe until I figured how quickly I can lop them off with the abasive chop saw and still have minimal trimming. I do not plan on deer hunting with mine but I sleep better since I got mine. Darm Armadillos were making the dogs bark....problem solved.

Thanks for info, V.S.,

Will do some more look-around. Prolly should go review Paco's articles. Looked at a new 1/2 stock Marlin .32-20 at Gander Mountain, yesterday, thinking of those quiet loads that Jim Taylor once described over on leverguns.com. After reading your heavy bullet experience, don't see any reason a .35 couldn't be that quiet.

It'd take care of some suburban-vermin, adequately. ;~`)

That's a whacker of slug you got there. I'd guess most charging 'possums, coons, feral domestics and the like are pretty much one shot stops. With a working 'crater point' in the end, you could prolly make some hide money selling the empty skins, seeing as everything inside of it would be blown out the backdoor by a frontal shot!!! ;~`) Good luck with y'r development on that.