Is a 200gr supersonic 7.62x39 possible?

[ToxicSports]

Hello all, I have a really quick question..

I noticed several 300 Whisper supersonic H110 recipes for the 200gr Sierra Matchking which got me interested.

I contacted Hodgdon about this and the responce was:

H110 should never be used in reduced loads. It is a slow burning, hard to ignite powder that does not like low pressure conditions. It will either be massively overpressure or massively under pressure.

Mike Daly
Customer Service Manager

My experiment was this:

I wanted to see how much powder capacity was left when I loaded a Lapua 200gr D166 so I loaded up a fired case, measured and cut. Note--the case was fired with 6gr of trailboss and a 220gr Hornady RN bullet and then ran through the resizer die to make sure everything was back to "normal".
Needless to say, the TB didn't do much to change the case dimensions.



I then filled the case with H110 and measured.


Now here are my questions:

1) Since my 454 casull calls for H110 charges as high as 30gr with a 300gr bullet would my 200gr bullet be safe to use with 18gr? Yes, I know the pressures are completely different in these two cartridges.

I believe that JD Jones called for 13 gr and stated an average velocity of 1350fps or something in that range for the 200gr Sierra Matchkings. If that's the case then we could be looking around 1600fps or so with the added 5gr?

2) THEORETICALLY....if it would be safe what type of velocities would we be talking about? Mainly out of a 20" bbl Rem. 799 bolt action.

3) What, if any, other powders exist that would be a better alternative? I've read that Lil Gun might be a good powder but I have no idea.


I really don't feel like blowing up myself and my rifle by experimenting with this so if anyone can help, as well as recommend a good reloading program, I'm all ears.

Thanks for any help.

Scott

[Rover31]

Tag I am working similar except I am using a 14 barrel in an Encore frame.
Also waiting for a Chrono to help with the numbers.
T

[BWE Firearms]

Scott,

First never try to compare completely different cartridges. You are asking for trouble. Next get yourself a copy of Quick-Load. You will be able to develop loads faster and safer. You will also be able to compare different powders.

13 Grains of H110 will give you a 56% case fill which is lower then I like. A velocity of 1429 FPS and a chamber pressure of 24091 psi.

[ToxicSports]

BWE,

Thanks for the info. I know that the 300 Whisper and 7.62x39 are completely different but I was trying to see what the 300 can offer over the x39. I was thinking about future projects and the 300 is always popping up.

I'll order Quick Load ASAP, thanks for the tip.

As for the H110 and low powder charge I am concerned as well. It was the one powder charge that gave me fluctuating velocities, while testing my other subsonics, and I'm pretty sure it was the low charge/s allowing the powder to lay flat in the case.

That's why I was wondering how much powder could be loaded under the 200gr D166. The 18gr filling the case to the bottom of the heel looked like a great idea but I wasn't about to test it without asking.

If by chance, do you know of a good alternative powder in which 18gr +/- would be able to get a 200gr bullet to travel supersonic without blowing the rifle or myself up? If not off the top of your head I'll play with Quick Load.

Thanks again,

Scott

[amafrank]

A question you didn't answer is what gun are you shooting this in???
If you have a 98 Mauser action or maybe a remington 700 than you might be fine with the experiment but if you're shooting this in an AR I'd be hesitant to even think about fiddling with this. I know the AR isn't a sissy cheap weak toy but when they go its usually much closer to the shooters face. Over pressure in the gas system can cause problems for the shooter too doing things like blowing out magwells etc.
Also consider that the rifle you have may be set up to fire the 123gr standard projo's so what rifling twist do you have? Will your 200 gr slugs stabilize?
Second thing here is like others said....don't compare cartridges for bullet weight, pressure and load. They don't compare and using that info will just make you mad.
Last thing, try something other than H110. As more and more people shoot this powder in oddball rounds like the whisper we keep seeing strange things happen. Temperature sensitivity and load density issues make it a bad powder to experiment with in this way. Look to some of the more consistant types like N110, 2400, H4227 etc. As Richard noted the Quickload program is a good way to get some idea of starting point.

Good luck

Frank

[thehouseproduct]

I shoot 14.6gr of X-teminator under a 200gr Lee cast boolit and its subsonic. It even cycles the AK.

[ToxicSports]

Frank,

It's a Remington 799 with a 20" bbl and a 1-9.5" twist...or so that's what Remington said the twist is. I'll have to run a patch through it and double check.

I'm not sure how strong the Zastava action it is compared to the others you mentioned but I am having a custom rifle built next spring that will have a FNH/Winchester action.

As for the H110, I don't use it in my subsonics anymore at all. I had nothing but fluctuations in velocty. I strickly use that for my 454 but I simply wanted to see how much would fit under the bullet.

As for bullet stability, I have not had a chance to shoot for accuracy since I tested my subsonics for velocity only. If they don't, I have a few friends who shoot the 7.62x54R that will take them off my hands or trade me.

Now, I did get a responce from Acurate powders about their AA1680:

Scott,
We suggest the following.

Caliber: 7.62x39 Russian.

Barrel length: 20-22”

Powder: Accurate – 1680®. (START LOADS ARE -15%)

Bullet weight: 174 grains.

Start Load: 16.2 grains (1575 – 1625 Fps)

Maximum load: 19.0 grains (1800 – 1900 Fps).

Bullet weight: 200 grains.

Start load: 15.0 grains (1425 – 1550 Fps)

Maximum load: 17.5 grains (1625 – 1725 Fps).

NOTES:

It’ important to note that SAFETY is our prime concern therefore we strongly recommend.
1. Caution re A-5744: Take care that double charging does not occur! Especially at low load levels.
2. TO ALWAYS BEGIN LOADING AT THE RECOMMENDED MINIMUM “START” LOAD and develop loads in 2% increments towards the MAXIMUM load.
3. If possible, measure the velocity and correlate with our data.


Regards
Johan Loubser
Ballistician
Ramshot.Accurate Powders

That sounds like a starting plan to me!! I have NO problem sticking with the STARTING load for either of those suggestions so I'm heading out after this week and getting a pound of AA1680.

thehouseproduct,

thanks for the info. Since I don't cast I couldn't even begin to try your suggestion but I have a MAK-90. Do you have a suppressor or just shoot the subs? My subsonic loads with 6gr of trailboss sound like nothing I have heard in a centerfire cartridge before. It reminds me of a CCI CB...kind of a "POP" instead of a POW. Really fun.

OK gang, thanks all for the input and please, anyone else want to chime in please do so.

Scott

[ToxicSports]

Hello all, I hope you had a great Christmas!

I had a chance to get up to the farm today and test a few supersonic loads out of my Rem. 799.

I only tested for function and pressure signs so accuracy and velocity will be conducted in the future. AKA...when it's not 17* and blowing snow.

I do know that the results that I had today will be completely different when tested in hotter weather. What I don't know is how much of a difference.

On to the lack luster test:

Load 1---
The 200gr Lapua D166 .310 with 17.5gr of 1680 worked fine and no signs of problems. The bolt cycled as normal.

Load 2---
I also loaded 18 gr of 1680 under a 200gr Lapua Subsonic .308. I figured that I would test the additional .5gr under the smaller diameter bullet to help ease pressure. Did the smaller bullet help? It seemed to but I didn't get to test the D166 with the same 18gr of powder. I just got WAY too cold to continue.

Results--The primer backed out just enough that I can feel it and can be seen when held just right. It still has it's round edge and the bolt had just a TAD resistance when it cycled. It was light enough that I really had to pay attention to notice it. I'll test the .310 D166 over the 18gr of powder ASAP to compare the results.


This being a subsonic forum I couldn't go without shooting my "go to" load of 6gr of Trailboss. I shot a few 220gr RN as well as a few 150gr fmj's. It was just as fun as ever but the cold weather wasn't fun at all after awhile.

Scott

[rsilvers]

I don't consider H110 slow burning for a rifle powder. It is slow for a pistol powder though.

[AH-1]

I have a ruger 77 MK II with a 1/10 twist .308 bore in 7.62X39.I cast a 185 gr lrngc bullet.any help with a start load would be a great help.
thanks
pete