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.