200 grain 9mm subsonic

[Barry54]

For those of you who are interested in subsonic loads, I thought I would share.

I’m using the Lee C358-200-RF mold. Boolets are sized to 0.356” without a gas check. 1.2 grains of Vihtavuori N310 cycles my blowback carbine and is quiet.

Beware! Seating depth causes pressure to spike rapidly!

I’m weighing each charge.

[steve urquell]

Very interesting. How deep can you seat them? I can't get the 158RF to chamber in anything except my Alpha Wolf barrel which has a very deep chamber throat.

[Barry54]

I started at 1.160” overall length. These chamber fine in the only barrel I tried. Probably a BCA barrel iirc.

[steve urquell]

I started at 1.160” overall length. These chamber fine in the only barrel I tried. Probably a BCA barrel iirc.

Very cool. Probably easier due to the rounded nose profile. Does it bulge your cases at the base at all?

[Barry54]

They fit and feed in an ETS magazine.

Yes there is just a smidge of bulge in the Winchester brass shown in the photo.

I’ll report back after trying a few other brands of brass.

[Kestrel4k]

Which carbine; S&W FPC ?

[Barry54]

This is what 1.2 grains of N310 looks like to those of you who aren’t familiar with it.

[Barry54]

Which carbine; S&W FPC ?

Frankenstein AR with discounted parts from MidwayUSA on birthday pricing.

[Barry54]

Well unfortunately attempt two stuck a bullet in the barrel!

I went down to 1.0 grains of N310 and seated deeper to 1.145” in an attempt to increase the chamber pressure. The first shot was 379 FPS. The second shot sounded funny and didn’t ring the steel. I found it resting close to the muzzle, so hopefully it won’t be too difficult to pound it out.

Since the carbine was dead in the water, I finished them off in my pistol. 373 FPS average velocity, for a whopping 62 foot pounds energy. They are not hearing safe in a pistol btw. It doesn’t even attempt to eject either. About half of them didn’t let the slide close fully. Not sure if it’s the leade in the barrel or bulge in the brass. I didn’t intend to use these in a handgun anyway, so I won’t be testing further in it. It was just the most convenient way to dispose of the remaining rounds at 1.0 grains charge weight. Imagine getting 7000 rounds to a pound of powder though...

Pistol velocity reading were
358
427
344
312
379
399
396

I didn’t weight sort the boolets. Also, I’m not comfortable with the accuracy of the digital scale weighing charges this small. It’s less than the Lee 0.17 cc dipper holds.

Next attempt will be going back to the original 1.2 grains and the reduced seating depth of 1.145”
Then maybe start testing different brass to see which brand allows for deepest seating without a bulge.

More to follow after I get a brass dowel to remove the barrel obstruction.

Anyone have a source they would recommend for them?

[steve urquell]

Well unfortunately attempt two stuck a bullet in the barrel!

I went down to 1.0 grains of N310 and seated deeper to 1.145” in an attempt to increase the chamber pressure. The first shot was 379 FPS. The second shot sounded funny and didn’t ring the steel. I found it resting close to the muzzle, so hopefully it won’t be too difficult to pound it out.

Since the carbine was dead in the water, I finished them off in my pistol. 373 FPS average velocity, for a whopping 62 foot pounds energy. They are not hearing safe in a pistol btw. It doesn’t even attempt to eject either. About half of them didn’t let the slide close fully. Not sure if it’s the leade in the barrel or bulge in the brass. I didn’t intend to use these in a handgun anyway, so I won’t be testing further in it. It was just the most convenient way to dispose of the remaining rounds at 1.0 grains charge weight. Imagine getting 7000 rounds to a pound of powder though...

Pistol velocity reading were
358
427
344
312
379
399
396

I didn’t weight sort the boolets. Also, I’m not comfortable with the accuracy of the digital scale weighing charges this small. It’s less than the Lee 0.17 cc dipper holds.

Next attempt will be going back to the original 1.2 grains and the reduced seating depth of 1.145”
Then maybe start testing different brass to see which brand allows for deepest seating without a bulge.

More to follow after I get a brass dowel to remove the barrel obstruction.

Anyone have a source they would recommend for them?

Sorry to hear you stuck a bullet. My cheapest load has been the Lee 147TC over 2.1gr of TiteWad for 800fps. Reliable cycling in pistol and my AR9.

[Barry54]

Well the lodged boolet pushed out easily with a cleaning rod!

Test three was the 0.17cc Lee dipper used normally as a dipper. Digital scale read 1.5 grains for four charges and 1.4 grains on one charge. Still using Winchester brass and Ginex primers. 1.145” oal again.

Velocity readings:
583
588
595
589
580

Average velocity is 587 FPS. 153 foot pounds of energy. Getting into 22 mag energy territory and more quiet than a 22 long rifle at this combination. 40 yard group on the steel target looks useful too. These were obviously louder than the 1.2 grain charge weight. Velocity was much more consistent than the 1.0 charge, and I didn’t stick any in the barrel! I’ll happily accept 15 FPS extreme spread.

[country gent]

The 147 grn 9mm load was designed to be subsonic in the military teams silenced carbines. Depending on elevation above sea level thats around 1100 fps.

If you can get that 200 grainer up to around 650-700 it might make a handy critter round.

While the data shows 22 mag energy the kenetic energy of that heavier slug will hit harder and penetrate better.

[Barry54]

Further testing revealed a boolet sized to 0.358” will chamber. I went back to the original 1.2 grain charge but reduced the oal down to 1.110” AND switched to RMI brass I purchased new for this project. https://www.rmrbullets.com/ Advertised it as not getting the bulge with deep seated 147 grain bullets. I did get a very visible bulge but this batch chambered, and cycled flawlessly.

I’m pretty happy here. The load is hearing safe in the 16” barrel I tested in. The bulk of the noise is the bolt reciprocating and the ring of the steel target.

The only improvements I see from here are a custom boattail boolet mold. It would need to be a design for coating to maintain a good amount of bearing surface. I would copy this Lee mold basically but add a significant boattail to increase boolet weight and not bulge the case. Hopefully wind up around 230-250 grains.

Another improvement would be to defeat the semi automatic function and the associated noise. I’m plotting a solid brass buffer next. Maybe even drill it to accept regular tungsten weights if it isn’t heavy enough on its own. I’m running an A2 stock with an aluminum spacer at the rear of the buffer tube to allow for a heavy 9mm carbine style buffer. If I removed that spacer and put that length onto the brass buffer, it would significantly add to the buffer weight.

Lastly, a ridiculous scope with one of the Christmas tree reticles would be beneficial with the rainbow trajectory.

Same 40 yard target with the 1.2 grain group beneath the 1.5 grain group.

[P Flados]

Thanks for posting your results.

I have run a bunch of stuff through Quickload looking at what it takes to get low muzzle pressures. It looks like you are right in the "sweet spot" range for a 200 gr in the 9mm combination.

Note that Quickload is useful, but tends to overpredict velocity for the combination of small case and longer barrel combinations. When using factory handgun ammo, real testing (ballisticsbytheinch.com) has shown that velocity peaks mid travel (frequently after around 10") where Quickload shows velocity increasing over the full length even out to 24". With the low charges used as described in this thread, I would expect max velocity to be reached after only 4" to 6" of travel.

As for going heavier, I am not sure it would be worth it. If you keep your predicted chamber pressure within limits, any heavier and I think you will end up lower than I would want for velocity.

If you wanted to go fast enough for longer range targets or chasing critters (say 900 fps) you would likely need to drop down to a 180, use a powder such as AA#5 or Bullseye and live with a predicted muzzle pressure of about twice what you get with the 200 gr boolit over 1.5 gr of N310.

[6.5X284ever]

Barry, what's your goal with the subsonic 9mm ? I have quite a bit of experience with subsonic/suppressed 9mm. Mostly with Berry's plated 147s. Mostly Red Dot, WSF, Titegroup, N320. Unfortunately I haven't kept very organized records, but I have some. Now that I am about to start casting and PC, will probably try some heavyweights. In my case, the longest barrel I have to account for (as far as velocity) is a full size MP5 SMG (8"). If I can keep it down to 1050fps in that one, the shorter ones will be ok too, just a little slower. I'm interested in something in the 160gr range.

[Barry54]

Barry, what's your goal with the subsonic 9mm ? I have quite a bit of experience with subsonic/suppressed 9mm. Mostly with Berry's plated 147s. Mostly Red Dot, WSF, Titegroup, N320. Unfortunately I haven't kept very organized records, but I have some. Now that I am about to start casting and PC, will probably try some heavyweights. In my case, the longest barrel I have to account for (as far as velocity) is a full size MP5 SMG (8"). If I can keep it down to 1050fps in that one, the shorter ones will be ok too, just a little slower. I'm interested in something in the 160gr range.

My goal for this 200 grain load was “silent without a silencer” and I got pretty close with a 16” barrel. I would like a 24” barrel for further drop in muzzle pressure. Then hopefully I could increase the charge slightly and bring velocity up some to flatten the trajectory a little more.

But Spit or get off the pot, right? Use what you’ve got. I’m pretty pleased with the results. And I never anticipated that a load this weak would cycle the action. Especially this reliably! It’s like a 22 for grownups. Good practice for judging wind and compensating for drift and drop with this combination.

[Barry54]

Attachment 326291

Look at that! A photo finally posted right side up for a change.

For those of you interested in cat sneeze loads, I found this interesting.

http://guns.connect.fi/gow/arcane1.html

[muskeg13]

For those of you who are interested in subsonic loads, I thought I would share.

I’m using the Lee C358-200-RF mold. Boolets are sized to 0.356” without a gas check. 1.2 grains of Vihtavuori N310 cycles my blowback carbine and is quiet.

Beware! Seating depth causes pressure to spike rapidly!

I’m weighing each charge.

I use the same boolit in my .38 Special revolvers with good results using mild charges of Unique that are published 195/200gr data found in older Lyman load manuals.

[steve urquell]

Barry, what's your goal with the subsonic 9mm ? I have quite a bit of experience with subsonic/suppressed 9mm. Mostly with Berry's plated 147s. Mostly Red Dot, WSF, Titegroup, N320. Unfortunately I haven't kept very organized records, but I have some. Now that I am about to start casting and PC, will probably try some heavyweights. In my case, the longest barrel I have to account for (as far as velocity) is a full size MP5 SMG (8"). If I can keep it down to 1050fps in that one, the shorter ones will be ok too, just a little slower. I'm interested in something in the 160gr range.

Be well aware that your PC boolits will lead your suppressor. I really wanted PC to work for me but the PC or Hitek coating blasts off the boolit base and the vaporized lead condenses in your can. Mine was heavily leaded and I caught Hitek and Smokes PC boolits in water to see what was happening. Both have pitted bare lead bases.

[Barry54]

I use the same boolit in my .38 Special revolvers with good results using mild charges of Unique that are published 195/200gr data found in older Lyman load manuals.

I tried it in 38 special and 357 when I first got the mold. It would crimp in the crimp groove and fit the cylinder in 38 special.

Have you done any performance testing with your loads? One gallon water jugs are next on my list of things to test. I wish I had kept some deer skin...