A question for suppressor users

[oremike]

I've been tasked with making a sub-sonic load for a rifle with a can on it. Does the can add velocity like barrel length does? My gut level instinct says no because the gasses are venting into the can. What say you all with greater experience in such matters. I plan on getting the CV Arms single shot and having the barrel cut to 16" and threaded but thought I could do the load development while I wait for the suppressor to get out of jail.

Read More

 

[mhayd93]

I've been tasked with making a sub-sonic load for a rifle with a can on it. Does the can add velocity like barrel length does? My gut level instinct says no because the gasses are venting into the can. What say you all with greater experience in such matters. I plan on getting the CV Arms single shot and having the barrel cut to 16" and threaded but thought I could do the load development while I wait for the suppressor to get out of jail.

There can be a slight gain in muzzle velocity, but it is typically very marginal (like 20fps or less if you are lucky).

 

[VinnieBoomBah]

The concept is called Free Bore Boost, the idea that the velocity will increase because there is still pressure behind it but there is no friction / drag from the rifling, and the short answer is *maybe*

The longer answer is that the amount of boost isn't likely to be enough to make a subsonic round go super/tran/sonic and if you are that close you should back off a bit anyway

 

[oremike]

Thank you, what you guys are telling me works with what I'm thinking. If I cut 8" off of a barrel I'll lose velocity but not gain it back with an 8" suppressor.

 

[VinnieBoomBah]

Thank you, what you guys are telling me works with what I'm thinking. If I cut 8" off of a barrel I'll lose velocity but not gain it back with an 8" suppressor.

Corect, what round are you loading for?

 

[lucusloc]

I've been tasked with making a sub-sonic load for a rifle with a can on it. Does the can add velocity like barrel length does? My gut level instinct says no because the gasses are venting into the can. What say you all with greater experience in such matters. I plan on getting the CV Arms single shot and having the barrel cut to 16" and threaded but thought I could do the load development while I wait for the suppressor to get out of jail.

Echoing the other answers, it will change velocity enough to impact POI at longer ranges, it should not be enough to bump a subsonic round to super if you are maintaining healthy margins. All my research indicates that at most under optimal conditions you should see a ~30fps boost, but I think in real world conditions it will be much less than that.

I have several cans on the way and I look forwards to validating these metrics for myself.

 

[oremike]

Corect, what round are you loading for?

44 Mag

 

[VinnieBoomBah]

Oh, simple. Get some 44 spl cases and use the starting load data, you should be fine

 

[oremike]

If my customer was happy with over the counter ammo he wouldn't have commissioned me to make what he's asking for.

 

[VinnieBoomBah]

If my customer was happy with over the counter ammo he wouldn't have commissioned me to make what he's asking for.

Fair, guess I should have typed the long version:

Get some 44 spl cases and use the starting load data and work up a load that is accurate and efficient for that rifle.

 

[oremike]

Fair, guess I should have typed the long version:

Get some 44 spl cases and use the starting load data and work up a load that is accurate and efficient for that rifle.

Or just start off with the right cases for the rifle and develop rifle ammo for the rifle.

 

[VinnieBoomBah]

Or just start off with the right cases for the rifle and develop rifle ammo for the rifle.

44 spl is just as much the right case for that rifle as a 38 spl is in a 357 mag. If the goal is subsonic the only thing you gain from using the 44 mag case is more internal case volume.

 

[aasbra]

Or just start off with the right cases for the rifle and develop rifle ammo for the rifle.

I load 44 mag subsonic for a couple suppressed rifles. You have loaded more ammo than I have Mike, but if you want any feedback on what I have tried, and settled on for loads after testing for accuracy and measuring velocity and consistency with a chronograph, drop me a message.

 

[VinnieBoomBah]

You have loaded more ammo than I have Mike

@oremike I admit I had forgotten that

 

[oremike]

@oremike I admit I had forgotten that

No problem Vinnie, I make alot of off the shelf ammo and once in a while a interesting project comes along so I jump on it to do something out of the norm.