Which cartridge for lots of flexibility (subsonic)?

[hornetguy]

Here is a link to the Wikipedia article about the 300 Whisper. I've also included a significant quote from that article. Apologies for the copy and paste, but I thought it explained it pretty well...

http://en.wikipedia.org/wiki/.300_Whisper

"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. "

 

[Daekar]

I think that your cut and paste answered your own question about heavy bullets. The Whisper, while it has a fantastic energy retention because of its low-drag bullet and smaller cross-section, can only match a 45acp energy level when suppressed. As one of the posters already said, if you have a fixed velocity, the only way to make the round more powerful for hunting is to use heavier bullets. If I were to choose to silence a .458 SOCOM, for instance, that 600 grain bullet would actually allow me to surpass the muzzle energy of a standard 7.62x39 123gr bullet at 2100fps, while remaining subsonic. The 350gr bullets I'm looking at for the 45 Colt will put me squarely into the mid 700s for muzzle energy at 1000fps, and at the short ranges I'd be hunting, I don't need the aerodynamic shape the Whisper offers.

The heavy bullets are not necessary for plinking, you're right. They are necessary when you want to make sure something is good and dead.

You might find this calculator offers insight:
http://www.airhog.com/convert.htm

Just set the velocity at 1000fps or 1050fps, and play with the bullet weights.

 

[jmorris]

I don't really understand the reason for really heavy bullets in this proposed "quiet gun"... but, I'll play along.

The only thing I use mine for is hogs. It has more than enough power to do the job and is so quite when you bust the first one the rest of them just look around and not bolting away towards cover.


I went semiauto for fast follow up shots and so OAL wasn't as long as a pool cue I made the suppressor telescope back over the barrel and machined a special "flash hider" that would divert gases into the blast chamber and locate the can on bore centerline.

 

[jmorris]

if your just plinking a 45acp is cheap and chunks 230's out subsonic or you can save even more money and run 147 9mm's. I run them too but not for hog hunting.

Her is how I made one of my 9mm cans so the oal was only 16.125" with the end cap removed. The tube is TIG brased to the barrel so it only takes one stamp.

 

[Poodleshooter]

.44 magnum in the Encore.
The stock load for my 310gr Lee RNFPGC tops out around 1100fps, just on the transonic edge.

1. It's subsonic with any load you care to make it subsonic with, and most importantly: the stock barrel is more likely to stabilize most of the subsonic loadings because they're closer to standard performance. That's going to be critical if you plan to suppress it. Using rifle cartridges with subsonic loads and a standard twist is always a bit iffy for stabilization. Suppressor baffles won't tolerate that. This is also a good argument for the .45ACP, .45 Colt,etc.
2. Bullet weights for .429"-.430" vary from 180grs to at least 310grs if not more.
3. Brass is easily available and can last a loooong time if loaded light.
4. Components are easily available. You can cast the bullets easily (though also true for most of the other rounds). The barrel is easily available from TC , and is not a custom chambering.
5. This is the tricky part. To my knowledge there aren't any .44Mag suppressors available. However the T/C barrel is threadable, and possibly a durable steel or titanium .45ACP suppressor could be used for subsonic loads only, if the manufacturer vettes it.

 

[hornetguy]

and at the short ranges I'd be hunting, I don't need the aerodynamic shape the Whisper offers.

Got it... I just was misunderstanding what you were trying to achieve. I should have read your original post more thoroughly.

Basically a shortened 45-70 or 444 marlin... which would put you at the 458 Socom, or at worst, the 454, or 45 win mag. Just where you've all been going. I'm just way behind the curve here..

 

[jmorris]

Also, while .30 cal bullets have a better drag cof. they are also designed to expand at 1000fps+ faster than subsonic. So even if a .458" bullet didn't expand at all you still have a larger hole. Factory 45-70 405 grain loads are only 100-200 fps over subsonic so at subsonic speeds they will still perform as designed, at reasonable distances.

 

[hornetguy]

Also, while .30 cal bullets have a better drag cof. they are also designed to expand at 1000fps+ faster than subsonic.

This is true, for the most part... but I believe there are some .30 cal bullets designed for single shot pistols, that should expand at a lower velocity. But I don't really know what their lower velocity threshold is.

I agree on punching a bigger hole. That's why I prefer the .45 Colt over the .44 mag.. and I LOVE my Marlin 45-70. No expansion needed.

 

[Daekar]

I'm still tossing about ideas and doing research. I've read several posts elsewhere stating that 45 colt brass tends to have relatively short lifespan... this is often attributed to the low SAAMI pressure and the resulting lax chamber quality that manufacturers let go. This led me to the 454... which undoubtedly will have tighter chambers thanks to the high pressure. 454 takes the same .452 bullets as the 45 Colt does... so do you think the increased brass life would offset the cost of the 454 brass?

 

[Elkins45]

You can't go quite as heavy as you like, but the 358 Win has a lot of potential with both low velocity cast and heavy jacketed loads. As others have said, 44 mag might also meet your needs.

 

[Ideal Tool]

.38-55 or .40-50 Sharps B.N. both with cast bullets. Ideal/Lyman made a short range .38 mould for a light weight 175gr. bullet. with a 16" twist you can go 300gr.+. The little .40 B.N. can handle 275gr. up to near 400gr.