Please be kind, it's kinda long and I didn't have anyone to help me ... Damb phone kept falling over so this was my 5th or 6th attempt

MP5 SD & Styer SPP Adapters

Edit to add, I'm using my SWR Octane suppressor

Interesting.

Any idea if there is ATF opinion if the thread on blast chamber is considered a "suppressor part"? I could certainly see an argument that it is.

I know you mention it's purpose, but is it effective in lowering 115 grain and/or NATO spec 124 grain to subsonic velocities? Any opinion on sound versus a real SD and/or a normal MP5 with the same can attached via tri-lug?

If all the right boxes were checked, I would be interested in having one made for my Obsidian.

quote:

Originally posted by DaBigBR:
Interesting.

Any idea if there is ATF opinion if the thread on blast chamber is considered a "suppressor part"? I could certainly see an argument that it is.

I know you mention it's purpose, but is it effective in lowering 115 grain and/or NATO spec 124 grain to subsonic velocities? Any opinion on sound versus a real SD and/or a normal MP5 with the same can attached via tri-lug?

If all the right boxes were checked, I would be interested in having one made for my Obsidian.

It's no more a suppressor part than any other adapter, it's shorter than the barrel, in fact the barrel extends into the suppressor ... Without a suppressor installed it won't suppress anything.

Also, I haven't tested it without a suppressor installed because the adapter, being shorter than the barrel, is still inside the handguard, so it wouldn't be safe to shoot without a suppressor installed.

I haven't done any formal testing comparing an MP5 with a 3-lug to the MK5 SD adapter, as far as velocity I can only tell you there is a sonic crack in a suppressed MP5 with NATO ammo but no sonic crack with NATO ammo in the SD. Lowering the velocity of the bullet, is a function of the barrel, not the adapter.

Are you saying that this should be ran by the ATF tech branch?

This message has been edited. Last edited by: kimberkid, June 13, 2017 03:52 PM

I'm not necessarily saying it should be run through ATF, but my point is that when the adapter is ported to allow gas to escape into it and lower round velocity, I could absolutely see an argument that it is a suppressor part. Look at the ATF ruling on wipes from earlier this year. Or the device Sig tried to market that was basically a giant muzzle device that actually made the gun louder until a sleeve was installed to "make" it a suppressor.

I would be very interested in having a similar device, but have some concern about ATF opinion.

I don't mean it as an insult, but I'm not sure how familure you are with the SD design, so here's a picture of the barrel;



As you can see, the ports are on the barrel, that's where the reduction in velocity takes place; not in the adapter, the adapter is just a means of attaching the suppressor to the barrel. The only difference between this adapter and Any other adapter is the length.

I'd be more concerned with the fake suppressors that are on the market for the MP5 SD and what they do with the the gasses that come through the ports in the barrel, and how those gasses are handled. Here's a picture of the adapter installed on the suppressor, this is before the flutes were cut;