My Latest 7.62x39mm SubSonic Loads, Forget Puff Lon!

Be careful -- low-volume ratio loads can detonate. Mangement not responsible for load data. Use at your own risk.

Moderators: mpallett, bakerjw

Post Reply
User avatar
tgbrowning
Silent But Deadly
Posts: 173
Joined: Sat Apr 12, 2008 4:45 am
Location: Texas Hill Country

My Latest 7.62x39mm SubSonic Loads, Forget Puff Lon!

Post by tgbrowning »

I made it out to the range again today, Tuesday 17 June 2008, to try my latest loadings in my search for reliable, accurate, and safe subsonic loads for my AR-15 in 7.62x39mm.

I started with the 180 grain Remington round nose bullets I had remaining.

I recorded he following data, using 10.0 grains of Hodgdon H110 powder, CCI 250 primers, Winchester cases trimmed to 1.520â€
"Genius may have its limitations, but stupidity is not thus handicapped."

Elbert Hubbard
User avatar
Artful
Silent But Deadly
Posts: 4392
Joined: Wed Aug 17, 2005 10:47 pm
Location: Phx,AZ
Contact:

Post by Artful »

Good to know, sorry it didn't work better for ya.
"Trying to tax yourself into prosperity is like standing in a bucket and trying to pick yourself up by the handle." - Winston Churchill
David Hineline
Silent But Deadly
Posts: 4289
Joined: Sat May 28, 2005 11:37 pm
Location: South Sioux City, NE
Contact:

308 subsonics

Post by David Hineline »

In my 308 rifle I am very happy with IMR Trail Boss, the powder is shaped like fluffy doughnuts so a loading of 10grains gives about 70% case fill in a 308 case. I suspect in the X39 case it would pretty much fill er up.

In my 26" rifle 8grains keeps 150gr pills subsonic
8.5grains works with 20" barrels and 150gr bullets

9.0grains works for 180 grain bullets.
NFA shooters blow their load with only one pull of the trigger.
User avatar
pmercer
Silent But Deadly
Posts: 614
Joined: Tue Mar 13, 2007 4:43 am
Location: London

Post by pmercer »

tgbrowning, I'm not familiar with puff lon, but I get the idea you're trying. I use couc cous (from the supermarket) to fill the void in my Ruger Old Army(only on my local range because of the noise).

Maybe you could try using that. I also would calculate how far into the case the bullet is going and only fill to that point. Just make sure there is no air gap or as the rounds get bumped around in your bag the cous cous and powerd can swap ends.
"Boi, you're in one hell of a situation. You're on US soil with illegal firearms." - Quote from US customs officer when he opened my suitcase and saw numerous NFA items
User avatar
Artful
Silent But Deadly
Posts: 4392
Joined: Wed Aug 17, 2005 10:47 pm
Location: Phx,AZ
Contact:

Post by Artful »

Cous cous wouldn't be consumed in firing and would clog a suppressor as well as act like a high speed abrasive in your suppressor. At least that is how I envision it acting. :shock:
"Trying to tax yourself into prosperity is like standing in a bucket and trying to pick yourself up by the handle." - Winston Churchill
User avatar
pmercer
Silent But Deadly
Posts: 614
Joined: Tue Mar 13, 2007 4:43 am
Location: London

Post by pmercer »

I agree. I didn't realise I was on a silencer forum, sorry. :wink:

seriously though, we never see the cous cous on the rage after firing it, although we we think it burns away as it comes out of the barrel. Maybe some more investigation is needed.
"Boi, you're in one hell of a situation. You're on US soil with illegal firearms." - Quote from US customs officer when he opened my suitcase and saw numerous NFA items
User avatar
tgbrowning
Silent But Deadly
Posts: 173
Joined: Sat Apr 12, 2008 4:45 am
Location: Texas Hill Country

Cous Cous or Puff Lon

Post by tgbrowning »

With the loads I've developed so far, I don't think I need a ballistic filler of any sort.

I intend to try some different powders for my next loads. For one, I am considering trying some Trailboss powder. It seems to be the powder of choice with 7.62x51 (.308 Win.) So, I am curious how it might work in the smaller 7.62x39 case, but I'm not sure the case has sufficient capacity for this powder.

I am pleased with the loads using H110 because 11 grains fills the case of the 7.62x39 about half way and the 220 grain bullet fills the remaining space pretty well. And the chronograph numbers are good. My main interest in trying a different powder is based on reports of temperature sensitivity with H110.

If anyone has ideas for a good powder/bullet combination for 7.62x39mm subsonic loads, I am always glad to hear them.

Thanks,

tgbrowning
"Genius may have its limitations, but stupidity is not thus handicapped."

Elbert Hubbard
d-mon
Member
Posts: 19
Joined: Wed Oct 19, 2005 5:47 pm
Location: NZ&France

Post by d-mon »

Hello tgbrowning,

Have you tried to weigh your cases and separate them in different groups?

And see if you obtained diffrent speed reading?

Nico
Homme libre, toujours tu cheriras la mer.
User avatar
tgbrowning
Silent But Deadly
Posts: 173
Joined: Sat Apr 12, 2008 4:45 am
Location: Texas Hill Country

Post by tgbrowning »

d-mon asked:
Have you tried to weigh your cases and separate them in different groups?

And see if you obtained different speed reading?
No, I haven't. But, I do separate the cases by head stamp.

Next, I will be loading some 200 grain Lapua purpose built subsonic bullets I finally received. I am also trying a couple of different powders. I have found a load that will cycle the action of my AR-15 7.62x39 about 50% of the time, but I want load that will cycle everytime. So, weighing the cases may be an option to reduce the number of variables in my load testing.

T.
"Genius may have its limitations, but stupidity is not thus handicapped."

Elbert Hubbard
User avatar
wolf
Silent But Deadly
Posts: 2591
Joined: Wed Nov 22, 2006 10:32 am

Post by wolf »

Try using the powder you can get some of that is a tad slower
you will need a bit more to get the same velocity's but the pressure will "stand" a bit longer ,or you could say the pressure will peak a bit later meaning you get more pressure for the cycling ,and thats what you are missing to make it make a full cycle
User avatar
tgbrowning
Silent But Deadly
Posts: 173
Joined: Sat Apr 12, 2008 4:45 am
Location: Texas Hill Country

Post by tgbrowning »

Thanks for the suggestion. Just exactly what powder did you have in mind?

T.
"Genius may have its limitations, but stupidity is not thus handicapped."

Elbert Hubbard
User avatar
wolf
Silent But Deadly
Posts: 2591
Joined: Wed Nov 22, 2006 10:32 am

Post by wolf »

I am in Europa so i am not so used to Us powders
i mostly use Withavuori its a powder from Finland , but i think you can get it in US to
N110 is slightly slower than H110 so that might do the trick ,,if not then N120
Or some like it
The N110 is very temperature stable meaning it dosnt give big variations depending on the temperature
It also is very forgiven about low pressure = it stills burn clean in a less full case
A q to you ,does you cases get black around the case mouth ? if yes then the case isnt giving a god seal
The bad part would be that the solution for that would be a faster powder :roll:

but if you size you cases so that they are just sized enough to freely chamber it might help
I have used the LEE collet die for that reason
It only sizes the neck+ you dont have to lube the cases and is giving a god seal , but you have to use cases that has been fired in you gun to do the trick
clay_breaker
Member
Posts: 49
Joined: Sat Jan 03, 2009 1:49 pm
Location: N.TX

Post by clay_breaker »

I know this is an old thread. But has anyone got any new x39 loads to share.
Post Reply