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Does an aftermarket barrel provide better ballistics?

Discussion in 'The 10 Ring' started by BigCheese03012, Aug 15, 2013.

  1. BigCheese03012


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    Dec 6, 2012
    I was at the range the other day shooting winchester silvertips thru my G20 with stock barrel. Upon examining the brass I noticed that their was resitude along one side of the brass...not alot but some...and it was consistant. I've also noticed that my stock barrel does fit the bullets somewhat loose. My question is if aftermarket barrels have been shown to provide better ballistics in a 10 due to better chamber support.
  2. OregonG20


    Likes Received:
    Sep 5, 2011
    I've actually read, and it's been stated, that polygonal rifled barrels provide a few fps better performance because of a better gas seal which leaves more energy pushing the bullet. I couldn't tell you if it's true or not, I don't science that way.

    I guess someone with a stock barrel and an after-market barrel will have to post some stats so we can put this one to rest. I can't wait to find out!

  3. SDGlock23

    SDGlock23 Homunculus

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    Jan 7, 2005
    Under the dome on the flat earth
    I've wondered about this too, and I have seen better fps out of conventionally rifled aftermarket barrels than out of Glock barrels. I'm not sure whether it's the difference of rifling, the better case support or a mixture of both. Just some random thoughts here, but I think the conventional rifling bites into the bullet more which can raise pressures slightly causing higher velocity, or that could be completely wrong.

    Lets not forget twist rate too, I think my KKM barrels have quite a bit different twist rates than what Glock uses.

    Also, in the loose(r) Glock chamber it allows the brass to expand somewhat, and while this way of thinking may be totally wrong, it also increases internal case capacity slightly (due to case expansion) which lowers pressure causing slightly lower velocity. An aftermarket bbl with good support doesn't allow this case expansion (or maybe I should say as much) to occur which helps out velocity a little. Just a few theories to be tossed around.

    I began to wonder about this when comparing velocities out of my 3.1" Kahr CM40 vs the 3.5" Glock 27. The Kahr has very good case support, conventional rifling with a different twist rate and without fail the shorter barrel Karh posted higher velocity than the longer barreled G27 with all loads, some in excess of 50 fps faster.
    Last edited: Aug 16, 2013
  4. happie2shoot


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    Jan 5, 2008
    There are many factors that can cause velocity change,lead or free bore and loose chambers are two big ones.