Please help with a subsonic 9mm loading!

[fordemti]

My dad and I were trying to come up with a subsonic loading for my MP5 in case the gentleman that had the suppressor is there this time. Last time all I had was supersonic ammo. I bought some XTP 147gr bullets from sportsmans warehouse. My dad is currently using bullseye powder. We've gone all the way down to 3.2gr and in my MP5 it's still going supersonic. Anyone know of a loading or how low we have to go to get this stuff slowed down? This is in a factory German MP5 8.85 inch barrel.

 

[Clicker]

What other powders do you have? I load 9mm subs with Universal and VV N330.
Universal @ 3.7 under a 147 FMJ averages 981 FPS in my MP5.
N330 @ 4.2 under a 147 FMJ averages 1020 FPS in my MP5.
Call me if I can help.

 

[fordemti]

That's all the powder we have right now. But I'll try and pick some up soon. I was just hoping we could use this stuff.

 

[P-1]

I can make some up if need be...anything below 1050 fps is fine.

 

[fordemti]

I'm going to try and pick up a box of that Universal powder. I'm going to try to go as slow as possible and still cycle the gun. We could definitely tell a difference between the 147 with 3.2gr versus the 115 WWB ammo. But was still going supersonic.

 

[Underdude]

These are both subsonic, but only fired out of a pistol.....both using 147gr XTP
Universal 3.0 grs approx. 800 fps
HS-6 4.2 grs approx. 760 fps

Both launched from a Sig 226

 

[Clicker]

147's with 3.0 Universal will not cycle in my 7.5" AR15 upper with a Enidine buffer. Even at 3.5 they were iffy, didn't try them in the MP5.

 

[velodemon]

I load 4.2 grains of WSF with 147 gr Montana Gold bullets. They stay subsonic out of a 16 inch barrel.

 

[gigamortis]

147's with 3.0 Universal will not cycle in my 7.5" AR15 upper with a Enidine buffer. Even at 3.5 they were iffy, didn't try them in the MP5.

The max loading for Universal behind a 147 grain bullet is 3.3 grains for around 800fps. I tinkered around a while back with Universal and some 147s to try to make minor power factor in my CZ for IDPA (850fps needed). I ended up bumping up to 3.7 grains and was seeing pressure signs on the primer at 860-870fps. Definitely out of bounds on pressure at 3.7 grains.

Titegroup seems to be the friendliest powder concerning chamber pressure when using heavy bullets in the small case volume of the 9mm.

Universal powder is right at home with some 124gr 9mm bullets, though, 4.3 grains will get you into the low 1000 fps range and do it at very safe pressures. The 124s at this loading will have more ft/lbs of energy to cycle your action, too.

You can check out Hodgdon's powder load data here: http://data.hodgdon.com/cartridge_load.asp

 

[Clicker]

First the load Universal @ 3.7 that I suggested is published data, check out Modern Reloading by Lee. I'm well aware of the max recommended by Hodgdon.

Second we are talking about a load which functions in a roller locked submachinegun not a pistol. The lighter loads of Universal simply will not reliably function in my guns therefore I sought out other data.

Third the use of Titegroup might be great but I've never used the stuff. However I have compared the pressure data and the 3.7 Universal load shows 26,000 CUP while 3.6 grains of Titegroup hits 27,500 CUP. Looks to me as if the Universal would be a wee bit easier on the gun although not by much.

However if you refer to Hodgdon's site they list 147's with 3.3 Universal at 31,000 CUP so I don't know what to make of that. All I can tell you is this load has run safely in MY guns for years.

 

[P-1]

Of course, all these formulas are always changed by COAL and crimp. On 9mm, pressures change alot even to the littlest adjustment using the same grain weight.

J