Subsonic 50 BMG load

[BOLTED]

I have a friend with a form 1 suppressor (hello Dad, hello Mom, ch..ch..ch cherry bomb!) on his 50, and we are looking for info on a subsonic load. Yes, it works with full power loads, minus a little fluf out the end apparently, but of course you still need muffs at full power. This will be fired out of a bolt gun, a Barrett 99 or an Armalite AR50.

I see loads here and there with @35gr of Red Dot and a 690, but we would rather be closer to a full case load of powder. 35gr can get lost in a 50 case. A suggestion of fill 'er up with Trail Boss came around, but I have no way of checking anything. I am hoping that someone with a reloading program could chime in. Will Trail boss work? Is a 690 that is at 2.22 length better than a 750 at 2.43? Or would a standard 647gr projo be best? Would Quickload know? (neither of us have Quickload)

I have been out of FCSA for a couple of years, and I never did any research or brain picking about subs in the 50, so I thought I would ask here.

Thanks for the help!

Dave

 

[abishai]

I wouldnt use trail boss. It left a nasty mess in my rifles (not my 50).
I would be surprised if a 750 would stabilize in a 50s slow twist at sub sonic speeds.
Just say no

 

[BOLTED]

Thanks for chiming in abishai, I agree with you.

I am not going to Load a case full of Trail Boss and "see what it does". That was just a suggestion from someone, and if I cant verify the a load, I will just start small and work up, as with any new or untried combination.

This is mostly just for fun, and I can't imagine the bullet being much more stable than if I threw it like a football by hand. The case is just soooo big for the little bit of powder it would take to push it to @1150. The primer alone has quite a bit of push by itself. Crimp, no crimp, everything matters.

We would like to throw an actual 50 BMG bullet out the end, otherwise I would try a lighter cast bullet with JUST the primer if possible. It would have to overcome the drag through the barrel, so the less bearing surface the better. Kind of like the Aguila 22lr Colibri ammo. Probably be a bit cleaner shot than a full up case of the Trail Boss!

It never hurts to ask, right?

 

[Zero333]

According to Quickload....

With a 800 gr Branes Solid, a Full case of Trailboss (aprx. 70gr) will yield around 1,500 fps in a 34" barrel.

37 gr of Trailboss is around 50% case fill and QL calculates 1,073 fps.

I don't think there is ANY way to get the 50 bmg shooting subsonic.

All other powders in QL show 20% to 30% case fill to get a 800 gr subsonic.

Only logical way I can think of is to cast a very heavy (Long) bullet in the range of 1,200+ gr and use trailboss in a very fast twist 50bmg barrel.

 

[MN50Shooter]

Bolted, I'm a member of the FCSA and did a search in the forum, trying to help you out. I was unable to locate a load that is subsonic. There may be one buried in the forum, that I wasn't able to locate, but my search came up empty.

 

[rockhound78]

An almost max load of TB with a 850gr cast will run about 1600fps with groups about 1.5"@100yds in an AR50. I suspect 35gr of TB under the 850gr cast will be just over 1000fps. Cast bullet engineering has a mold that goes, IIRC, 975gr. and might be more with what you want

 

[dickn52]

Why? You shoot a VW Beetle a mile and want it to be quiet when it gets there?

 

[dcali]

I would be nervous about playing with such light powder charges. Weird things can happen when you get outside of normal parameters. Maybe a stupid heavy cast bullet would help (like a wadcutter to help keep it stable, if possible), although you might have to get creative about making one.

 

[mgunderson]

How much COW (cream of wheat) is too much?

 

[BOLTED]

Thanks everyone, every little bit of info helps.

Why? Because there is hardly any info on the subject. It's no fun just looking up a load, the fun and challenge is in the development. Right? Not to mention the reward of finding a combination that works.

Wow, I just found that Detroit Ammo Company sells subsonic 50BMG. One is actually a match load with a 650gr bullet. That tells me that someone has done this already, and is so confident in it that they are willing to sell it to the public. I don't want to buy it, I want to make it, so this is at least a light at the end of the tunnel.

 

[rockhound78]

I use Grits instead of Cream of Wheat, when I do use a filler. Doesn't seem to pack like C.O.W

 

[Ballisticboy]

One problem for you, even if you find a suitable load, is that the majority of bullet designs I have seen are supersonic shape designs not subsonic. A bullet can fly acceptably at subsonic speeds if it has been designed properly but you should not expect bullets designed for supersonic speeds to work well at subsonic speeds.

 

[BOLTED]

Yep, that seems to be a common problem with almost any rifle shooting subsonic loads. Hopefully some super smart guys will come up with a good subsonic rifle bullet design, or we will just have to change the speed of sound to about 2800fps.

 

[rmr]

if you are going to use it with a suppressor, whatever you do, do not use a filler such as cream of wheat. there is no way to ensure that the filler will not build up in the baffles. worst case, it could build up over many shots and obscure the bore.

i think your best bet is to pick a different chambering for subsonic, 50 American, 500 whisper...

 

[Dusty Stevens]

The post about the subsonic “match load” is funny. A 650gr bullet going that slow isnt a match load even at 50yds

 

[BOLTED]

Right!? Got a kick out of that myself. I just need it to at least go straight at least through the suppressor.

 

[dickn52]

Throw rocks instead...cheaper to make.

 

[Hoser]

I have played a lot with 50 subs. With standard 15 twist barrels, you could not get there from here with decent accuracy. And shooting full power 50 BMG ammo suppressed isnt fun so I had to do something with my can.

In the end I got a fast twist Kreiger barrel (I havent seen them on their site in years) and chambered it for 510 Whisper, which is a shortened 338 Lapua with a 50 bullet on top. They feed awesome through a 338 Lapua action/mags. Working the bolt makes more noise than the round going off.

 

[BOLTED]

That is cool.

Since we are mostly just playing around, we don't have to be accurate.

If no one got the reference from the OP, the can is a glasspack car muffler called a Cherry Bomb. (if you are old enough to remember those, or the song) We just want to shoot some subs through it to see how well it works for an ultra cheap backyard suppressor.

 

[Ray123]

I have a friend with a form 1 suppressor (hello Dad, hello Mom, ch..ch..ch cherry bomb!) on his 50, and we are looking for info on a subsonic load. Yes, it works with full power loads, minus a little fluf out the end apparently, but of course you still need muffs at full power. This will be fired out of a bolt gun, a Barrett 99 or an Armalite AR50.

I see loads here and there with @35gr of Red Dot and a 690, but we would rather be closer to a full case load of powder. 35gr can get lost in a 50 case. A suggestion of fill 'er up with Trail Boss came around, but I have no way of checking anything. I am hoping that someone with a reloading program could chime in. Will Trail boss work? Is a 690 that is at 2.22 length better than a 750 at 2.43? Or would a standard 647gr projo be best? Would Quickload know? (neither of us have Quickload)

I have been out of FCSA for a couple of years, and I never did any research or brain picking about subs in the 50, so I thought I would ask here.

Thanks for the help!

Dave

I have used Trailboss and Red Dot in the 50 bmg, with 650 gr fmj. Red Dot was accurate and so was Trail Boss I used 52 gr of Trailboss, but it was right at 1200 fps in my barrel, so cut it back 4 tp 5 grains and try it there.