I am trying to work out a quite subsonic load for my AR 15 with a can.  I used the data from the makers of trailboss and loaded some 55 gr. FMJ's with 4 grains.  The gun end was nice and quite but I was still getting the crack of the bullet from down range.  With only 60 ft/sec below the standard speed of sound, using Hodgesons data, I am thinking 4 grains in my gun was not subsonic.





So... I am thinking trying 3.5 and 3.8 grains.  I am wondering if any one else has experimented with Trailboss and 55 gr bullets.  Any input would be appreciated.  Thanks.




 

I tried 4.0 gr. with a 55 gr. Hornaday SP a while back through a 23" T/C Contender.   I only fired three shots through the chrono.  Velocities were 1035, 885, 923.  

Later on I ran some 50 gr. Nosler bullets with 4.0 and 3.7 gr., with 10-shot strings of each.  Loads were much more consistent, averaging 1087 and 1071.  

I'll have to get out and try some again some time.  I've still got a couple of cans of Trailboss.  I played with it a little with a bolt-action .243 that I'd had threaded for a can too.

i found that Clays was more consistant for me when using Hornady 55gr FMJs.

Just drop in a .22 conversion, and you'll be in the same performance range.

I used 3.6 or 3.8 grains (can't remember) of Trailboss with the same bullet out of a 16" barrel and most remained subsonic.  I think they all would have been subsonic if I had used them at the same time of year that they were developed.

Thanks for the input.  I worked up a 3.8 grain load of Trailboss and all remained subsonic.  It is very very quite.  It sounds just like in the movies.  The performance was still enough to plow through three 2 inch pressure treated boards and then into a log on the other end.  The load sounds as loud as a 22 with out the can it is so quite.  



Thanks again.  



PS  I thought of running a 22 LR upper, but my dealer said that with my can, which cannot be user dissasembled, I would end up over time clogging the can with the residue of the 22 LR.  Plus this is a whole lot cheaper than buying an upper or a new 22 LR AR.


 

My load data says I went 3.1 grain of titegroup. They all stayed sub sonic. I only tried it once as a novelty. I have a suppressed .22lr that is so much more practical.

i checked my notes and chrony records.  I was using 3.4gr of Clays.

With this load i was getting consistand sub-sonic preformance out of a 16" barrel using Hornady 55gr FMJs.