Suppressors Threaded barrel adapters and increase in sound

[thebeast862]

Ok so in a previous thread i had questions about using threaded barrel adapter on my M&P 15 in 300 black out. I purchased the adapter and threaded it on and it is very nice. Everything is constrict and have had no problems with baffle strikes. My problem is that it is still very loud. I have tried both my pistol and 308 can. I have watches a bunch of videos on youtube about different setups, and i know that no video can be an accurate representation of what the can really sounds like but we are not even in the same ballpark. Here is my setup and ammo.

Cans: AWC thundertrap chambered for 308, AWC Jupiter Eye for 40cal

Amm: Remington umc 220gr ot fb
Remington 220gr gr otm
Hornady 208gn amax

All seem to have a distinctive crack and the umc is definitely going supersonic.

 

[CoryT]

If it's supersonic the crack is pretty loud. You need to keep it below 1025 fps or less. Shoot some over a chrono and see where you are. Just because the ammo is labeled subsonic does not mean it is in your gun.

 

[nso123]

Like said above, chrono your load and make sure it is truly sub. I loaded some test loads to function check mine one evening and went to my deck to check them at about 10:00 at night. Guess what? They were not sub and it was a little loud. True sub loads are pretty quiet. My sub loads are much louder hitting my steel targets than they are leaving the muzzle.

 

[RollingThunder51]

Couple of things.

A thread adapter should have no impact on suppression values.
As mentioned above chrono everything and report back as your rifle with subs is very quiet.
How quiet? I have had a muffed spotter be surprised to see the impact as they did not hear the ignition with full case .308 subs (bolt.)
You mentioned the Jupiter's Eye, did you send the 300 bo through that suppressor? Wet or dry? Small volume in that can as it was designed for a pistol and to be run wet.
Can you turn off your gas block? I don't know that model. If not, can you borrow a bolt gun and try again?

 

[thebeast862]

I'm going to try to run a few rounds through my chrono. I have been having problems with it wanting to read in overcast weather. I tried dry and wet in both suppressors with no significant change in sound. I need to mention that it is a 16" barrel on the blackout, I'm thinking that it's letting them go faster than 1020fps. The Jupiter eye did hold up to a few rounds of sub blackout but that's all I have shot was about 3 rounds. Should I not use it anymore. I know that people use pistol cans for sub blackout

 

[thebeast862]

Ok so my chronograph cooperated with me.
Remington umc: 1164, 1166
Remington 220gr: 1136, 1141
Hornady: 1084, 1052

 

[NYCEGUY01]

Those all look pretty fast....
Order a box of Gem-Tech 187 and give it a try.

The Rem 220's are always supersonic in my gun and at my elevation etc...

I shot some Gem-Tech 187's and Hornady 208's earlier today... Nice and Quiet...