300 Whisper or 30 Br or ?

sillymike

sillymike

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Ok, since we're stuck with the long gun registry for another little while... I figured I'd celebrate the situation with another non-restricted target gun :yingyang:

I initially wanted something with a little more punch than the 308 (Like a 300 Win. Mag)... then I realize that I seldom get to shoot past 300M-500M... so why not got with something a little smaller... and why not go subsonic while at it.

I'm thinking a 300 Whisper or 30 Br would be nice to play with... Anybody got to play with either (in subsonic mode)?

Finding a AR magwell conversion kit would ease up the "selection" process...

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I have and use them both, but in bolt action guns with match barrels, and of course only use cast bullets in them. The .30 Br. is much easier to get accuracy from and way more accurate overall, the Lapua cases are nicer to work with and initial case forming is much easier. I guess if looking strictly at subsonic the .300 Whisper may be the way to go, although mine shoots much better at near max. loads. I use .222 Rem.cases, sized, and necked up with a tapered expander from Redding(I use redding dies), then there is alot of trimming. I tried using Fireball brass which was easier but I wanted thicker walls on the case neck as my chamber would accept that.
 
I've played with both subsonic. 30 BR subsonic is also referred to as 302 Whisper. There is also 338 Whisper, which is just 30 BR necked up to 338.

BR based whispers works in the AI mags... and there is no/minimal conversion to the brass. Plus, you can re-barrel to a 308 based cartridge if you get tired of it. Or, have the recoil lug pinned during the conversion and make it a switch barrel.

Honestly though, I would build a regular 308 Win. with an 18" barrel. Its very easy to get consistency with subsonics in a 308 Win. when you get the barrel below 20". And it makes a handy bush rifle.
 
I just finished a 30 br douglas barrel threaded for a savage, have not tested it yet. It is a fast twist bbl I had on hand. My hope was it would make a good heavy bullet subsonic shooter.
 
kombayotch said:
Honestly though, I would build a regular 308 Win. with an 18" barrel. Its very easy to get consistency with subsonics in a 308 Win. when you get the barrel below 20". And it makes a handy bush rifle.
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Isn't 18.5" the shortest for a non-restricted rifle? I would LOVE to build a setup like you are saying if it is non-restricted....
 
18.5" for semi-auto, 18" for a manual repeater. Go 18.5" if it comforts you, the half inch won't make a difference.
 
You will have to give some serious thought to barrel twist in the BR as benchrest shooters are using 125gr. bullets and 1-17" twist, cast bullet benchrest shooters are using 1-12 or 1-10 twist and 165-220gr. cast bullets. If one was using 220-240 j-word bullets you might need a 1-8" twist or some such. My experience shows that cast bullets don't like a very fast twist, but it wouldn't hurt to experiment.
 
I've used the RCBS 220, and it will stablize in a 1:10 barrel. In fact, I'm experimenting with Frontier .308" 260 grain plated bullets. First couple shots seem to indicate they also stabilize in a 1:10.
 
ben hunchak said:
You will have to give some serious thought to barrel twist in the BR as benchrest shooters are using 125gr. bullets and 1-17" twist, cast bullet benchrest shooters are using 1-12 or 1-10 twist and 165-220gr. cast bullets. If one was using 220-240 j-word bullets you might need a 1-8" twist or some such. My experience shows that cast bullets don't like a very fast twist, but it wouldn't hurt to experiment.
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This is a critical point. Sub-sonic bullets require completely different stabilization, and if making a sub-sonic 30BR, you need to consider not only the twist, but the throat. 30BR's have little or no leade for the 115-125 grain bullets. Typically, a SS cartridge uses big'uns (and much longer)

To my thinking, the 300 Whisper is the better of the two choices, simply because there is much more data out there, but the idea of a BR based whisper cartridge is cool for sure (There was a thread on CGN a few years ago about a guy concocting a 338 based on a 7.62X39 case... never heard any more about it.)
 
There's a huge thread devoted to the .300 Whisper/Fireball in the black rifles forum. For .30cal 200gr + bullets running subsonic, you'll need at least a 1-10 twist, most guys are running 1-8 twist to get stabilization. Here's my beast, still trying to finish it.

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To go below 18", doesn't it need to be "manufactured" that ways though? How does that work with a blank that you're fitting?
 
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