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barrel length vs velocity

Discussion in 'The 10 Ring' started by bigred94, Aug 16, 2013.

  1. bigred94


    Sep 23, 2009
    eclectic al
    does anyone have any real numbers on the 10mm with the factory 3.78" barrel (G29) vs the 4.60" barrel G20). I have a 29 and was thinking about selling to the get a 20 to get the full power of the 10mm if there is a big difference between the barrel lengths.
  2. vaquero aleman

    vaquero aleman "ah-lay-mahn"

    Jan 9, 2009
    The Wild Wild West
    The guy that calls himself "Ammo Test" on youtube has a video for the G29 and the G20 so that should give a relatively close evaluation on the different velocity numbers.

    If I am reading his results correctly he is showing an avg with Underwood 200 grain:

    G29 avg 1230fps

    G20 avg 1265fps

    However, this LWD barrel cost me about $135 delivered.


    At 4.6" this barrel gives me the choice of having a G29 or a G20, as far as velocity is concerned.
    Last edited: Aug 16, 2013

  3. eb07

    eb07 Sharkin'

    Feb 19, 2010
    Third Rock From the Sun
    The G29 is THE most versatile semi-handgun. Do not get rid of it. A little under an inch does not affect it that much.

    Here are MY chrono averages out of a stock barrel:

    Buffalo Bore 180gr JHP 1270fps 645ft lbs
    Underwood 135gr JHP 1500fps 675 ft lbs
    Buffalo Bore 220gr hcl 1050 fps 533 ft lbs
    DoubleTap 200gr FMJ 1150fps 587 ft lbs
    PMC 180gr JHP 950fps 360 ft. lbs
    Underwood 165gr JHP 1310 ps 629 ft lbs
    DoubleTap 135gr JHP 1390fps 570ft lbs
    DoubleTap 165gr JHP 1300fps 619 ft lbs
    DoubleTap 155gr JHP 1300fps 582 ft lbs
    Underwood 180gr JHP 1230fps 605 ft lbs

    Other than the low powered PMC load every hot load I have shot and tested has been a winner.

    I do not have G20 data to compare to
    Last edited: Aug 16, 2013
  4. bigred94


    Sep 23, 2009
    eclectic al
    thanks for the great info! there is not enough difference indeed to sell the the 29 and get a 20. what is yalls favorite grain bullet for the 10mm?
  5. vaquero aleman

    vaquero aleman "ah-lay-mahn"

    Jan 9, 2009
    The Wild Wild West
    I keep it simple. The original 10MM was the 200 grain so that is my preferred.
  6. for me the difference between the two maybe a little velocity difference but a big difference in handling recoil of hot rounds. the G20 is easy shooting with the hottest 10mm ammo, the G29 not so pleasant.
  7. I know in loading the .44mag that the barrel length has less effect on heavier bullets. the lighter bullets show a bigger difference in velocity between short and long barrels.
  8. gator378

    gator378 Gator378

    Jan 22, 2001
    St. Peters, Mo, USA
    8 inch 629 240 g XTP 24.0 gr H110 1390 fps

    Model 1894 20 inch 1800 fps.

    The slower burning powders show greater velocity with longer barrels.
  9. I was refering to a couple inches + or -.

  10. TDC20


    Apr 11, 2011
    I agree with this.

    Here are some data points for you. This is my hot 180gr. XTP and 800-X handload:

    G29 stock bbl 1218.4 fps

    G20 stock bbl 1295.6 fps

    G20 LWD 6" bbl 1400.8 fps

    And, a very warm A#9 with a 180 XTP handload:

    G29 stock bbl 1182.3 fps

    G20 stock bbl 1244 fps

    Hope that helps.
  11. agtman

    agtman 10mm Spartiate

    Feb 28, 2001
    Several of the ammo-makers catering to 10mm-fans have posted their own chronograph numbers for their ammo as fired in real-world guns having different barrel lengths. These include the 5" Delta, 4.6" G20 and 3.8" G29.

    DT started doing this a while back, and on one of the 10Ring stickies I thought Mike had posted the fps/fpe stats for DT's 10mm loads (those avaible at that time), chronographed from the G20 & G29. BB does this also for their 10mm ammo, and the fps/fpe stats out of the guns that BB uses can be found on Midway's site.

    From the DT site:

    "Caliber : 10mm
    Bullet : 230gr Wide Flat Nose Gas Check Hardcast
    Ballistics : 1120fps/ 641 ft./lbs. - Glock 20
    1008fps / 519 ft lbs 100yds Glock 20
    Glock 29 - 1075fps
    Box of 50rds

    For what it's worth from my experience, the heavier 10mm bullets, when fired at real 10mm velocites (i.e., the full-throttle stuff) seem to lose relatively less velocity from the shorter barrels than do the lighter-weight bullets. Ballistic experts can probably tell you why that is, but over time I've seen this phenonmena re-appear in the chrono data.

    My preference in bullet-weight for the 10mm AUTO is old school, which is to say "heavy." I've been with this round since the late 1980s and so I prefer the 180gn+ bullets, and when you can find them the 200gn slugs. The original concept of 200gns @ 1200fps defined "heavy & fast," as between the 9mm (light & fast) and the .45acp (heavy & slow), which were the only other practical choices you had in an autoloader back in the day.

    Two years ago I bought 1500 of Hornady's 200gn FMJ-FP bullets, so I got well-stocked there. I also really liked Speer's 190gn truncated FP bullet for reloading and training purposes (loaded to 1200+fps), but it was discontinued in favor of a 180gn FMJ. I picked up some of those, and I also liked the box of 500 Berry's 180gn bullets I got at Cabela's. But that all got loaded up and shot a while back.

    I've also stocked up on - because the were available a few years back at a reasonable price - 1000 Remington 165gn FMJ bullets. Those I still have. But I'd buy another 1500 of Hornady's 200-grainers in a mil-a-sec if I could find them.

    Last edited: Aug 19, 2013
  12. G29SFWTF


    Aug 3, 2012

    As a G29 owner I'm always wondering how much less velocity I'm getting. My typical guess is -80fps. The notion of losing less with a heavy bullet is interesting though.

    Someday I'd like to get a chrono and test the Underwood line for averages from my KKM and the stock bbl.
  13. captaintrips


    Aug 16, 2012
    Based on reading a bunch of numbers that others have put on the internet I figure that a bullet from a 29 will travel around 95% of the speed as one from a 20.

    It is not exact by any means, but gives me an idea when I see numbers for the 20.

    From doubletap:

    Bullet : 150gr. Nosler Jacketed Hollow Point.
    Ballistics : 1475fps / 725 ft.lbs. - Glock 20
    1400fps Glock 29

    1400/1475= 94.9%

    Bullet : 200gr Nosler JHP
    Ballistics : 1250fps / 694ft lbs. muzzle - 5"bbl
    1083fps / 521 ft lbs 100yds 5"bbl
    Glock 29 - 1195fps Muzzle

    1195/1250= 95.6%

    Bullet : 230gr Wide Flat Nose Gas Check Hardcast
    Ballistics : 1120fps/ 641 ft./lbs. - Glock 20
    1008fps / 519 ft lbs 100yds Glock 20
    Glock 29 - 1075fps

    1075/1120= 95.9%

    Based on these numbers and others, I will agree that the drop off is less with the heavier bullets.
  14. many here that have clocked DT ammo say their posted velocities are bogus.
    as far as performance between the 20 and 29 I believe is minimal but the 20 handles much better. the only reason I would get a 29 over a 20 is maybe for regular ccw.
  15. I saw a video on YouTube a while back where a guy compared the muzzle velocity of a stock Glock 29 barrel with a Storm Lake barrel of stock length.

    If memory serves, he was getting 50-70fps more with the Storm Lake barrel.

    I bought one for my Glock 29 and it was been flawless.
    All I did was polish the outside of it.