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-   -   7.62x39 Experiments (http://www.quarterbore.net/forums/showthread.php?t=9381)

ToxicSports 12-18-2011 02:36 AM

7.62x39 Experiments
 
Hi all, been awhile since I've posted but I wanted to show everyone some fun rounds I've been playing with. I shoot them out of my 20"bbl Rem 799 with a Remington stated 1-9.5" twist rate.


This thread
http://www.quarterbore.net/forums/showthread.php?t=5470

started these fun loads.
L-86gr SJRN and R-90gr XTP
http://i39.photobucket.com/albums/e1...Bullets2-2.jpg
http://i39.photobucket.com/albums/e1...lbullets-1.jpg

I have gone down as little as 3gr of Trailboss with a piece of toilet paper filler. I can put up a tutorial of what I did and it really seems to have helped. I used 2ply T-paper, separated the sheets, folded into fourths and cut about 1/8" off the folded edges.

Out of the 10 each, I loaded, all exited the barrel and ended up somewhere out in the Hay field.

Now, I never did get them over a chrony nor did I really test for accuracy. I just wanted to test for reliability...IE- Hope they didn't get stuck. Now that my new house and gun room are starting to come together I will be testing for velocities and expansion.

It will be interesting to compare the cold weather results with next years summer heat results with these rounds.

Now on the other end of the spectrum I've loaded and tested these.

R-225gr Hornady Match L-210gr Berger VLD hunting
http://i39.photobucket.com/albums/e1...200grsmall.jpg

I tested Accurate 1680 for pressure signs at higher velocities. However, before moving I was testing 18gr for the Berger and 17.5gr with the Hornady. The test bullets were shot into a Hayfield as the others. I'll not only get these over a chrony but I'll also get them on paper to see if they keyhole. I say it's gonna be iffy with the twist rate but still a REALLY fun experiment.



Scott

Spook 12-18-2011 10:44 AM

Nice! Keep us posted ....chrony figures and targets next time?:smile:

Fritzcat 12-18-2011 11:49 AM

I was using my AR 762x39 for sub-sonic hog hunting before I built my 300 and then got into 458 Socom sub-sonic. The 762x39 barrel is 16" with a 1-10 twist and Horn .308-220gr RN with 9 1/2gr Win 296 and went around 1050fps and 2"groups @ 100yds through a YHM 762 SS QD. Also Speer 200gr SP with 9 1/2 Win 296 and went around 1050 and group well. It has been a while back, but I post reports with picks of pig to show damage. The boat tail match bullets will likely not stabalize with your twist, so shoot paper before you put your can on.

Titleiiredneck 12-18-2011 01:58 PM

Quote:

Originally Posted by Fritzcat (Post 34944)
I was using my AR 762x39 for sub-sonic hog hunting before I built my 300 and then got into 458 Socom sub-sonic. The 762x39 barrel is 16" with a 1-10 twist and Horn .308-220gr RN with 9 1/2gr Win 296 and went around 1050fps and 2"groups @ 100yds through a YHM 762 SS QD. Also Speer 200gr SP with 9 1/2 Win 296 and went around 1050 and group well. It has been a while back, but I post reports with picks of pig to show damage. The boat tail match bullets will likely not stabalize with your twist, so shoot paper before you put your can on.


was going to post basically the same thing, try the speer hotcor line "180~200gr" also. aa#9 should work well as I used this in my old 9" x39 barrel I had, h110 should be good out of your bolt gun too.

ToxicSports 12-18-2011 02:08 PM

Spook, I'll try to get some this week.

Fritzcat, I don't have a suppressor for my 799....just a plain ol' "boring" pipe.

Scott

ToxicSports 12-18-2011 02:25 PM

Titleiiredneck, must have responded while I was typing the other response.

The other 200gr+ bullets I use are the Hornady 220gr RN as mentioned and Lapua's "subsonic" and D166. All three shoot pretty good out of the 799.

I've used H110 in the past due to the high number of suggestions. However, I was getting a fluctuation in velocities with it in my initial tests so I decided to keep that for my 454 loads. I might try it again in the near future to see if I can figure out the problem.

The slowest "heavy" subsonic I have loaded with good results was 6gr of trailboss under the Hornady 220gr RN. It sounded like a Large CCI CB rimfire...a nice POP instead of a POW. It's been awhile since I shot those and I don't want to misquote myself, since I can't find my notes, but I recall they were well under 1000fps and I could see the bullet fly down range and hit the target.

On another note about powders...have any of you tinkered with the Vihtavuori Tin Star powder? I haven't seen any locally yet.

Scott

ToxicSports 12-18-2011 05:04 PM

Well, decided to try to test the handful of remaining test loads on paper and over the chrony.

OK, here's the setup. Range 25yrds, off sandbags, around 44* and all the POA were the center X. Rifle was NOT zeroed for the cartridges.

First up is the 86gr w/ 3gr of Trailboss and filler
http://i39.photobucket.com/albums/e1...86gr25yrds.jpg

The three velocity readings were:
800.3
773.7
683.8


Next up is the XTP w/ 4gr of Trailboss and filler
http://i39.photobucket.com/albums/e1...0xtp25yrds.jpg

What's interesting about this is that I had 2 sets of speeds.

The upper two (in one hole I might add) were running at
1041
1057 fps

The lower two were clocked at
878.3
877.4 fps.

I know I'm not a pro at reloading but what do you think could have caused this? I use a powder trickler and a digital scale that reads down to .02gr.

The next was the 210 berger w/ 18gr 1680
http://i39.photobucket.com/albums/e1...rger25yrds.jpg

This shows real promise and no seen stability issues at this close distance. Further distance might tell more.

The speeds were
1579
1601 fps....again only had 2 left to play with.

The final were the 225gr match Hornady w/ 17.5gr 1680
http://i39.photobucket.com/albums/e1...25gr25yrds.jpg

these two ran at
1555
1518fps.

As you can see they didn't go in straight but maybe would have worked in a short range SHTF scenario.

OK gotta go

Scott

2bad4u2 01-01-2012 10:33 PM

^^^ Try the lighter bullet loads using Trail Boss without the toilet paper filler. Could be your issue. I've used TP in Trail Boss lighter .308 Win. loads and accuracy was absolutely horrid. I was seeing up to 24" vertical dispersion at 100 yds. Once I got rid of the filler, the problem resolved itself.

I wouldn't expect miracles using those bullets but they should be decent enough for accuracy between 50-75 yards - 100 may be pushing it. Part of the fun is experimenting to find out, right? :wink:

ToxicSports 01-02-2012 12:43 AM

2bad,

thanks for the heads up. I have 5 w/out filler ready for testing. One quick question....did you tip the muzzle up before each test load or not?

Quote:

I wouldn't expect miracles using those bullets but they should be decent enough for accuracy between 50-75 yards - 100 may be pushing it. Part of the fun is experimenting to find out, right?
I couldn't have said it any better! It seems that I've went from loading hunting ammo to experimenting more and more and it just gets more fun with each new test load.

As for miracles, it would be a miracle if I could actually get some of my normal hunting loads loaded for coyotes but I'm having way too much fun and too many different loads to test.:grin:

Scott

2bad4u2 01-02-2012 11:28 AM

Quote:

Originally Posted by ToxicSports (Post 35394)
2bad,

thanks for the heads up. I have 5 w/out filler ready for testing. One quick question....did you tip the muzzle up before each test load or not?



I couldn't have said it any better! It seems that I've went from loading hunting ammo to experimenting more and more and it just gets more fun with each new test load.

As for miracles, it would be a miracle if I could actually get some of my normal hunting loads loaded for coyotes but I'm having way too much fun and too many different loads to test.:grin:

Scott

Hi Scott,

No, I never bothered worth tipping the muzzle up with .300 Blackout. I've tried it with .308 Winchester loads before using Trail Boss, however, if there was any benefit to having done so, it wasn't enough to notice it on paper.

I think the bullet may be just too short for running in a .300 Blackout standard throat. The more I try, I'm lead to believe there may be just too much jump to the rifling. I can easily get 10-shot 2.5 MOA groups @ 100 yds. using Hornady 110 .30 Carbine FMJ bullets in .308 Winchester with 12.5 gr. Trail Boss. The Blackout has been a challenge using these bullets. I had high hopes they'd work as I have several thousand of them and I'd like to use them up. Where the 7.62x39mm is throated for 123gr. FMJ bullets, you may not experience this problem.

The Speer Plinker has a good reputation for plinking accuracy in .308 Win., .30-06, and .30.30 Win. I've yet to read where anyone has tried them in .300 Blackout. I suspect they won't be much better than the .30 Carbine bullets but one will never know until they try. :wink: For 7.62x39mm use they may be useful.

Keep us posted on the progress. If you CAN get it to work, a lot of us would like to know.


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