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Thread: 7.62x39mm ammo tested in bbl lengths from short to long

  1. #1
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    7.62x39mm ammo tested in bbl lengths from short to long

    Over on AR15.com I offered to compile a bunch of data concerning how 7.62x39 preforms in diffrent bbl lengths. I figured I'd share it with you guy's as well.

    The rifles used for this test differed greatly from one another so please don't take this as "one size fits all" data.

    The rifles used were as follows

    1. A norinco 16.5" paratrooper SKS .310bore

    2. is a 20" Model 1 Sales AR15 upper .310bore

    3. a custom bolt gun with a 1/15 inch twist bbl that's 26" long and has a .308 bore

    All chrony readings were taken at 12 feet with a model F1 without sky screens against a uniformly Grey overcast sky and an air temp of 55 degrees. Perfect chronographing weather.

    Part 1 factory loads

    154 grain WOLF sp


    16' bbl........20" bbl........ 26" bbl
    2042............2106............2273
    2025............2110............2265
    2015............2113............2261
    2041............2125............2256
    2033............2124............2250

    avg velocity
    2031............2115............2261



    123 grn Monarch FMJ

    16' bbl........20" bbl........ 26" bbl
    2354............2432............2599
    2345............2418............2595
    2377............2405............2593
    2315............2453............2548
    2330............2422............2601

    avg velocity
    2344............2426............2587


    125 grn Remington SP

    16' bbl........20" bbl........ 26" bbl
    2265............2261............2428
    2238............2308............2444
    2202............2304............2437
    2191............2366............2485
    2224............2264............2486

    avg velocity
    2224............2300............2456


    Part 2 [B]hand loads[/B

    for these loads the 26" rifle was omitted and the SKS had the gas piston removed due to slamfire and cycling concerns

    170grn Sierra .308 diameter 30-30 flat point, magtech SR primer, 28.0grs H335

    16' bbl........20" bbl

    1921............1968
    1924............1967
    1931............1970
    1936............1970
    1896............1985

    avg velocity
    1921............1972


    125 grn nosler b-tip, magtech SR primer, 25.5grs AA1680

    16' bbl........20" bbl

    2256............2359
    2226............2355
    2243............2361


    avg velocity
    2241............2358



    The only real loser in all this is the anemic Remington ammo, this stuff just reinforces my assertion that anything METRIC factory loaded in this country is going to suck.

    The most interesting find was just how fast and accurate these loads were when fired from as accurate platform as possible through a 26" tube

    5 shot groups for the factory loads in the Stevens 200 were as follows
    154grn Wolf 1.2"
    123grn Monarch 1.37"
    125grn Remington 1.0"
    I can see and understand both sides of the fmj/jhp argument, but the fact of the matter is, no matter what you get shot with, you're still getting shot....

    random internet poster

  2. #2
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    Very interesting and greatly appreciated.

    I'm curious, what is Monarch brand? Also, any reason you didn't test any combloc stuff besides the 154gr Wolf? Tests I've seen elsewhere suggest that 123gr combloc gains only 50-100fps when going from a 16" AK barrel to a 23" RPK barrel. I'd be curious to see your tests of:
    Wolf Military Classic JHP
    Wolf 123gr FMJ
    Golden Tiger FMJ

  3. #3
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    I tested what I had on hand. Excluding a box of mil classic I had, as my AR15 will not set the stuff off at all.

    The monarch stuff is Acadmey's store brand, but the ammo is actually made by Barnual.

    If you guy's want to send me whatever off the wall 7.62x39 ammo you may have I'll be more than happy to run the stuff over my chrony for ya.
    I can see and understand both sides of the fmj/jhp argument, but the fact of the matter is, no matter what you get shot with, you're still getting shot....

    random internet poster

  4. #4
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    Interesting. I wonder what my 8in SBR 7.62x39 would do? I typically use the russian surplus 123 gr which looks excatly like that Monarch I saw in Academy. Any guessestimates?

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    Excellent post. Good info.
    .
    The Socialists told us long ago that since they could not beat us with force, that they would destroy us slowly from within. So far it is working pretty well. - Think 2010

  6. #6
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    as best I can calculate the ballistics are as follows, based on a 200yd ZERO

    154 grain Wolf SP, ballistic coefficient .3302

    range........elevation........velocity........energy

    16.5" bbl

    100yds........+4.64"........1813fps........1124 fpe
    200yds........+0.00"........1614fps........890 fpe
    300yds........-17.78".......1432fps........701 fpe


    20" bbl

    100yds........+4.20"........1891fps........1223 fpe
    200yds........+0.00"........1685fps........971 fpe
    300yds........-16.39".......1497fps........766 fpe


    26" bbl

    100yds........+3.46"........2029fps........1407 fpe
    200yds........+0.00"........1811fps........1121 fpe
    300yds........-14.35".......1612fps........888 fpe



    123 grain Monarch FMJ, ballistic coefficient .257?

    range........elevation........velocity........energy

    16.5" bbl

    100yds........+3.44"........2042fps........1139 fpe
    200yds........+0.00"........1765fps........850 fpe
    300yds........-14.72".......1517fps........628 fpe


    20" bbl

    100yds........+3.12"........2118fps........1225 fpe
    200yds........+0.00"........1833fps........918 fpe
    300yds........-13.74".......1578fps........680 fpe


    26" bbl

    100yds........+2.66"........2268fps........1404 fpe
    200yds........+0.00"........1971fps........1061 fpe
    300yds........-11.71".......1701fps........790 fpe


    125 grain Remington SP, ballistic coefficient .267


    range........elevation........velocity........energy

    16.5" bbl

    100yds........+3,93"........1941fps........1046 fpe
    200yds........+0.00"........1684fps........787 fpe
    300yds........-16.15".......1454fps........587 fpe


    20" bbl

    100yds........+3.57"........2012fps........1124 fpe
    200yds........+0.00"........1747fps........847 fpe
    300yds........-15.02".......1510fps........633 fpe


    26" bbl

    100yds........+2.97"........2157fps........1292 fpe
    200yds........+0.00"........1879fps........980 fpe
    300yds........-13.11".......1629fps........736 fpe
    I can see and understand both sides of the fmj/jhp argument, but the fact of the matter is, no matter what you get shot with, you're still getting shot....

    random internet poster

  7. #7
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    Very nice, thanks for sharing!

    Now I want to know is the velocity difference between two barrels of the same length, one with .310 bore and the other .308. If only this sort of testing weren't so expensive.
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