Accuracy 7.62x39 vs 5.56

[letaz77]

It is well know by everyone that AR15s are inheretly more accurate than AK's in part because of the loose tolerances of the AK. But the question is about the ammo. Is the 7.62x39 bulk ammo less accurate than the 5.56 bulk ammo? What are your thoughts?

Would an AR15 in 7.62x39 solve the accuracy problems and be just as accurate as a 5.56 AR15?

[letaz77]

I also forgot, if anyone of you folks has any experience with x39AR's, which brand of magazines did you find to be more reliable?

Thanks y'all

[GLSHOOTER]

Bore size matching the bullets is one thing that is a concern. A 308 bullet in a 312 bore like many load can be an issue as it just isn't goingto get a god fit. The 312 in a 308 can be a bit tight and I would be loath to do that.

The bulk OTC ammo is a 123 grain pill that is 312 and I don't think the QC is quite as good as it could be. Mil Spec 556 is watched pretty closely and I believe would tend to out shot the run of the mil 7.62.

Handloading a 7.62 might help but IMHO the chances of it consistently out shooting a similar 556 is very slim. I could be all wet on that but I'll stay with the 556 or an LBC case since it is the same head size as the 7.62 and we know they will shoot very well. Not cheap but good results down range.

G

[dr69er]

In my recent outing with the new upper AR-15 in X39mm, I did notice a considerable difference in power levels (velocity) and from the chrono, a old lot of Sivler Bear (122gr.) vs. a new batch of Winchester 123gr. FMJBT Target rounds...there was over a 100 fps. difference between the the two brands.

Since I did not yet have any mods done to the AR-15 firing pin or bolt, the Russian ammo experienced light primer strikes and failed to Ignite more than 50% of the time...accuracy was quite good w/ the Silver Bear and was excellent w/ the Winchester brass cased target ammo as was the feeding and ejection (100%) using ASC x39 magazines. The group below
was first shot at 3 O'clock the working counter clockwise
using Win. target ammo,The barrel has a .310" bore...
distance was 100 yards.



HD video clip...

www.youtube.com/watch?v=U_9GqbLF1kw&feature=youtu.be

illirianengineeringc.ipage.com/

[letaz77]

Thanks for the video, pretty cool. It seems like you were using an internally railed upper, is that right?

Where did you get the 18" mid-lenght barrel ? I want one!!!!

[dr69er]

Apr 19, 2012 20:40:17 GMT -8 letaz77 said:

Thanks for the video, pretty cool. It seems like you were using an internally railed upper, is that right?

Where did you get the 18" mid-lenght barrel ? I want one!!!!

I Purchased it as a complete upper kit and then added some
more custom parts and accessories like the Leapers quadrail
FF handguards etc. The kit was made by Del-Ton Inc. it was
a custom order as they don't have them as normal stock Items.

The S.S. 18" Mid-Length Gas Bbl. is made by Wilson Rifle
Barrels in CT. It was very accurate and well made...It has
a .310" bore which is perfect for the modern x39mm round.
I plan to reload for it using .308" pills, so .310" bore is perfect.

When I compared this AR-15 in x39mm caliber vs. a
Milled SKS in x39mm for accuracy, It was a no contest,
the AR blew away the SKS in accuracy.

I have now done the firing pin/bolt mods to it,
and now it should be GTG with both steel cased
commercial and surplus ammo. I also lightly
ground/melted and polished the M4 feedramps/bbl.
extension ramps to a nice polish for superior feeding.

I was really considering getting a Wilson Tactical barrel
in 7.62x40mm, or even a .300 WTF as they compare well in
ballistics to the x39mm...but, I took the chance and went
with the x39mm Instead and I'm glad I did.

The project was done for my son who want something
"real cool" like a "zombie tactical rifle", Lord knows
he spends enough time on that PS3 console...