Subsonic 223 in a bolt gun. Shooting supressed

[arco_shooter]

I am trying to build an ultralight 223 bolt gun. I plan to shoot 77gr subsonics with a suppressor. But I want it to be as short a barrel as possible (sbr length).
At what point in cutting down the barrel would subsonics lose the required speed for rodents and other small game?
Thanks all!

 

[Greenmoustache]

I've played around with subsonic 223 just for fun back when TrailBoss wasn't impossible to find.

Is there a specific reason you want to go with 223 vs. 22lr? I assume it's the 77gr projectile, but in my experience a 45-55gr projectile is more than enough for rodents/squirrels etc and most standard velocity 22lr will be subsonic out of a SBR.

I found it was extremely finicky trying to get heavier projectiles subsonic with 223 due to the low case-fill and the line between supersonic and squib became extremely thin. 55gr projectiles on the other hand were much easier to consistently load in the ~950-1000 fps range but now you are back at 22lr performance just more expensive.

edit: If you aren't totally set on 223, I had a lot of luck loading subsonic 300 blackout with 110gr vmax projectiles and TrailBoss. They are also comically quiet and pack a decent punch at 1000fps if you are set on something heavier than standard 22 loads

 

[arco_shooter]

I've played around with subsonic 223 just for fun back when TrailBoss wasn't impossible to find.

Is there a specific reason you want to go with 223 vs. 22lr? I assume it's the 77gr projectile, but in my experience a 45-55gr projectile is more than enough for rodents/squirrels etc and most standard velocity 22lr will be subsonic out of a SBR.

I found it was extremely finicky trying to get heavier projectiles subsonic with 223 due to the low case-fill and the line between supersonic and squib became extremely thin. 55gr projectiles on the other hand were much easier to consistently load in the ~950-1000 fps range but now you are back at 22lr performance just more expensive.

edit: If you aren't totally set on 223, I had a lot of luck loading subsonic 300 blackout with 110gr vmax projectiles and TrailBoss. They are also comically quiet and pack a decent punch at 1000fps if you are set on something heavier than standard 22 loads

Thanks. I wanted something heavier than 22lr but not as big as 300 blackout. So I was looking at heavier 223 because they pack enough punch while still subsonic

 

[redbullitt]

A bolt action 38special or 357mag would be my pick. Great bullets meant for those speeds and fast fluffy powders are very quiet if you have more than an 8 inch barrel and decent can

 

[99mpower]

A bolt action 38special or 357mag would be my pick. Great bullets meant for those speeds and fast fluffy powders are very quiet if you have more than an 8 inch barrel and decent can

bolt action 38spl? that sounds fun

 

[arco_shooter]

bolt action 38spl? that sounds fun

A bolt action 38spl does sound fun!

 

[redbullitt]

Yes indeed! The ruger 77 ones, especially as an sbr do very well. If you don't mind the barrel length a 16 inch 38 or 357 lever gun is a perfect suppressor host I think. Longer barrel is quieter noticeably if thats your focus. Cast bullet and a few grains of a fast fluffy pistol powder is super quiet, not too far off a 22lr, but hits harder and penetrates much better. Can even get expansion if bullet is chosen well.

For me the ruger 77 357 and 357 Marlin with Suppressors and 900fps loadings are discreet murder on varmints lol.

A cast and coated wide flat nose, dead soft lead, at 900 fps is a great choice here and can be driven much slower safely than jacketed if you need max sound reduction.

Best part is you're using a cartridge that thrives using fast pistol powders, low velocities and bullets that work well at that speed. Other cartridges will do it ok, but the 357 and 38 like doing it lol.

 

[MarshallDodge]

You'll need a pretty fast twist to stabilize the 77s at low velocity. They need to be stable when exiting the muzzle due to the possibility of baffle strikes in the suppressor.

Also, they don't expand. Even a subsonic 53 Vmax will not expand in water testing.

 

[roostercogburn98]

bolt action 38spl? that sounds fun

Bolt action 30 carbine maybe?

 

[264win]

Another option if you want to go down the rabbit trail, is 22 hornet. Most factory rifles have slow twist barrels that aren’t very sub friendly. But if you can find a 10 twist you will have some options with 55 ish grain bullets. But a 7-8 twist is better for 70+ grain bullets