Gunsmithing Subsonic round idea. Comments?

[kombayotch]

An idea I've been tossing around in my head...

I've been looking at options for a new subsonic round for my M700. Its a switch barrel, so its easy to just get a new barrel if I want to try something different without building a whole new rifle (custom reamers are cheap in comparison). I want something that can fire heavy subsonic bullets, but can also be used for hunting in Indiana.

Criteria:
-Caliber must be larger than .357 (Indiana law for hunting with rifles)
-Case length no longer than 1.625"(Indiana law for hunting with rifles)
-Works in M700 SA
-Compatible with 308 Win. bolt face
-Feeds from AICS magazine
-Dies and brass available
-Bullets that are reasonably priced and easy to find
-Availability of factory loads would be good (don't have to be subsonic)

So, I looked at various options. And the option I came up with was 45 Winchester Magnum. However, my thought is to go with a .458 cal barrel and throat it long so that I can use Hornady's 500 gr. Interlock RN bullets. These should hit pretty hard, and if I drill the tips, I can probably get some decent expansion and still retain a lot of their weight. It doesn't have to use that bullet or be subsonic for hunting though...

Dies are available. The seater may need to be honed out a bit...

Brass is available. I can get higher pressures if I cut down 308 Win brass.

260 gr. HP factory ammo is available (if in a pinch, will be reloading) and would probably still work. Although, it may not be that accurate and may require single feeding. I think rounds with the 500 gr. RN bullets will feed fine since they are long.

Thoughts? Pitfalls I didn't think of?

 

[cwshooter]

Re: Subsonic round idea. Comments?

I'm considering something along the same lines, and have had limited success with replys on this topic. It looks like a 50 Beowulf or a 458 Socom might be interesting. I checked into the Socom, and exchanged several emails with Marty at Teppo Jutsu. 338 is smaller than I'd like to shoot. The reamer is proprietary. I wouldn't doubt that there's a clone reamer available somewhere. Short action, and mag length, kinda limit the options in the higher BC pointy bullets. The 45 WM is an interesting option.
If you find a magic caliber, let me know. I'm currently working on a similar project, and chambering my very first barrel in 308. I'd like to have a switch barrel for a suppressed hog killer.
http://www.snipershide.com/forum/ubbthre...233#Post1363233
CW

 

[ArcticLight]

Re: Subsonic round idea. Comments?

My dad wastalking about something like that - Sounds VERY plausible.

That's weird on the case length restrictions.

get a 45-70? or is that too long?

Just a straight old 45 colt type rifle?

Or a 44 mag rifle...

 

[cwshooter]

Re: Subsonic round idea. Comments?

... rimmed cases

 

[AKA-Spook]

Re: Subsonic round idea. Comments?

On again / off again projects for the last few years 458 SOCOM (lots of reamers out there) shooting 525 gr subsonic and 458 necked up to 50 caliber.

I'm about to start up the 458 again with a 9.3 twist and some lathe turned bullets. Also shooting 30/221, 338br and 510 Lapua short mag , cuz its only a whisper if JD makes it.

It shouldnt be too awfully difficult to come up with a set of 375 BR Dies and reamer .

 

[kombayotch]

Re: Subsonic round idea. Comments?

458 SOCOM - case length is ok, but case head is not compatible with the 308 bolt. Nothing 50 caliber is going to feed from the AICS without modifying it. The idea is not to...

QL estimates the 45 Win. Mag can launch that 500 grainer at 1355 fps. with 296 in a pistol case and 1467 fps. if cut down rifle brass is used. Haven't found anything else that meets all of my criteria.

 

[fireball168]

Re: Subsonic round idea. Comments?

The SOCOM case head is .473, the same as your 308 bolt.

I've sold several barrels in .458" and .510" for hunting here in Indiana.

Last I knew, you can get AICS magazines for the 300 WSM - which shares a "close enough" cartridge base diameter as the SOCOM case to feed, might need a little bit of a delrin ramp in the front of the magazine though to kick them up.

Here's a Savage I screwed together awhile back, feeding the SOCOM case.

http://www.youtube.com/watch?v=WsYyfQrzo2I

 

[bohem]

Re: Subsonic round idea. Comments?

44 auto mag long.

I have a wildcat that's 44 caliber and the case length can be made however long you want, it's straight walled.

Think of how the 450 Bushmaster is made but my dad and I did this 7 years ago with 30-06 cases instead.

You can keep the 473 bolt face, it feeds from the mags, you can shoot light bullets (180 xtp's) @ 3000 from a long barrel, or you can load it up with a light charge of Red Dot and a 460gr lead bullet and keep it subsonic.

In the past 5 years I don't think my dad has used anything else on a deer, he's gotten every one of them with a suppressed shot through the head.



The case OAL is the same as a 223, quite literally, we developed the same thing as the 450 Bushmaster but Bushy has the ability to market it, we didn't.

If you want the case length to be shorter to stay under 1.625 he could do it since you can hold the reamer short and it headspaces on the mouth of the case.

 

[AKA-Spook]

Re: Subsonic round idea. Comments?

Isnt the 450 Bushy derived from the back end of a .284 Win case?

 

[kombayotch]

Re: Subsonic round idea. Comments?

I looked at the 450 Bushmaster, but the case is 1.7" long...

 

[bohem]

Re: Subsonic round idea. Comments?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: AKA-Spook</div><div class="ubbcode-body">Isnt the 450 Bushy derived from the back end of a .284 Win case? </div></div>

Yes, exactly. This is how we cut down a 30-06 case.

The 1.7" case is too long, but if you want to cut them back some more to 1.600" or use the 44 caliber version from a 30-06 parent case it will work.

The reamer for the 44 wildcat can be run to custom depth for however long you want the case length.

Either way you're looking at hand loading them, even if you go to a 44 automag you are going to pay $3 per loaded round and not be able to find it in the stores.

 

[CountryBoy19]

Re: Subsonic round idea. Comments?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: fireball168</div><div class="ubbcode-body">The SOCOM case head is .473, the same as your 308 bolt.

I've sold several barrels in .458" and .510" for hunting here in Indiana.

Last I knew, you can get AICS magazines for the 300 WSM - which shares a "close enough" cartridge base diameter as the SOCOM case to feed, might need a little bit of a delrin ramp in the front of the magazine though to kick them up.

Here's a Savage I screwed together awhile back, feeding the SOCOM case.

http://www.youtube.com/watch?v=WsYyfQrzo2I

</div></div>

+1

I think 458 Socom is the only cartridge that fits all of your requirements almost perfectly.


Criteria:
Check -Caliber must be larger than .357 (Indiana law for hunting with rifles
)
Check -Case length no longer than 1.625"(Indiana law for hunting with rifles)

Check: may need slight magazine/feed -ramp work-Works in M700 SA

Check -Compatible with 308 Win. bolt face

Not positive on this one, but fireball would be the guy to ask -Feeds from AICS magazine

Check -Dies and brass available

Check, .458 cal has one of the widest selections of bullets there is. They can be purchased anywhere from 87gr on up to 5-600 gr and more and in many different designs styles and compositions -Bullets that are reasonably priced and easy to find

While there aren't a lot of factory offerings out there, and they aren't cheap, there are a couple manufacturers making it and it is likely to gain in popularity -Availability of factory loads would be good (don't have to be subsonic)