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Chrony Range Report: Double Tap, Hornady, Prvi Partisan...

Discussion in 'The 10 Ring' started by blk69stang, Dec 17, 2011.

  1. blk69stang


    Jan 10, 2011
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    Yesterday afternoon I chrony'd nine different 10mm loads including offerings from Double Tap, Hornady, Prvi Partisan, and some of my own handloads. If found the results pretty interesting.

    Elevation 4600', afternoon high-desert, temperature approx 53*F, wind light and variable. Shooting was performed kneeling using a bar stool as a rest (placing floorplate of magazine on top of the barstool to stabilize). No sandbag available, so accuracy was only as good as my own skills.

    Chronograph used: "Beta" Master Chrony, set up approximately 5 yards away (the 18' remote cable to the chrony was extened most of the way out). Target was an 8" bullseye at the 15 yard line.

    All loads had the same impact center on the target (which happened to be about 2" left and 4" higher than point of aim... I guess I need to adjust my sights).

    Firearm used: Glock 20sf, factory 4.6" barrel. All stock except for ISMI 22lb recoil spring and stainless guiderod.

    First load tested - PRVI Partisan Factory loads (10mm Lite)
    Group size: 3"
    Average Velocity: 891.9 fps
    Avg Energy: 318 ft/lbs
    Std Deviation: 18.89
    Extreme Spread: 66.56
    Case expansion (first number=unfired diameter at widest, second number=same dimension after firing) 0.423" 0.430"

    As expected, these were *****cats. Mild recoil, no signs of overpressure. Sooty external casewalls (perhaps from not expanding enough to fully seal chamber). Decent target load for the price, delivering good accuracy for range work.

    Second load tested - Handloads (180gr Hornady XTP, PPU brass, CCI Mag primers, 6.0 gr. Unique)
    Group Size: 2"
    Average Velocity: 984.1 fps
    Average Energy: 387 ft/lbs
    Std Deviation: 38.85
    Extreme Spread: 143.3
    Case Expansion: 0.423 0.430
    Advertised Velocity: 1000
    Dev. from Advertised Velocity: -15.9

    Mild starting load for Unique powder. Little muzzle flash/blast, and low recoil. Very tame, tied for most accurate.

    Third load tested - Handload (180gr FMJ-FP pulldowns, Double Tap once fired brass, Win LP primers, 8.5gr Blue Dot)
    Group Size: 2"
    Average Velocity: 1062 fps
    Average Energy: 451 ft/lbs
    Std Deviation: 25.49
    Extreme Spread: 74.62 fps
    Case Expansion: 0.423 0.434"
    Advertised Velocity: 1000-1050 fps
    Dev. from Advertised Velocity: +12 to +62 fps

    Moderate to large muzzle blast with medium muzzle flash and moderate loudness. Tied for most accurate.

    Fourth load tested - Handloads (180gr FMJ-FP, PPU 1x fired case, Win LP primer, 7.4gr Power Pistol)
    Group Size: 3.5"
    Average Velocity: 1090 fps
    Average Energy: 475 ft/lbs
    Std Deviation: 11.53
    Extreme Spread: 39.37 fps
    Case Expansion: 0.423 0.433"
    Advertised Velocity: 1125-1130 fps
    Dev. from Advertised Velocity: -35 fps

    Slightly slower than book prediction based on 5" barrel, so deviation is understandable. OK accuracy. Mild pressure signs in case, primers not flattened. Big, bright muzzle flash, loud muzzle blast. Easily comparable to a .357 Magnum.

    Fifth load tested - Hornady Factory loads (180gr XTP)
    Group Size: 3.25"
    Average Velocity: 1185 fps
    Average Energy: 561 ft/lbs
    Std Deviation: 13.92
    Extreme Spread: 43.44 fps
    Case Expansion: 0.422 0.433"
    Advertised Velocity: 1180 fps
    Dev. from Advertised Velocity: +5 fps

    Excellent, consistent (although pricey) ammo. Only factory load tested that came in at or above advertised velocity. Only mild pressure signs, no flattened primers.

    Sixth load tested - Double Tap 180gr Controlled Expansion (Montana Gold bullet)
    Group Size: 5"
    Average Velocity: 1217 fps
    Average Energy: 592 ft/lbs
    Std Deviation: 19.92
    Extreme Spread: 50.15 fps
    Case Expansion: 0.423 0.436"
    Advertised Velocity: 1350 fps
    Dev. from Advertised Velocity: -133 fps

    While certainly hot, it fell well short of advertised velocities. Accuracy was bad, which I'm chalking up to the bullet. Recoil and muzzle flash/blast were hot but manageable. IMHO, this is full-power plinking ammo. 7 out of 10 have overpressure signs (flattened primers, glock smileys). Would not buy this load again.

    Seventh load tested - Double Tap 200gr Nosler JHP
    Group Size: 2.75"
    Average Velocity: 1096 fps
    Average Energy: 533 ft/lbs
    Std Deviation: 10.0
    Extreme Spread: 31.95 fps
    Case Expansion: 0.420 0.437"
    Advertised Velocity: 1250 fps (5" barrel)
    Dev. from Advertised Velocity: -154 fps

    This was the most accurate DT load of the bunch. It came in WAY under advertised velocity, but is still powerful enough for a defensive cartridge. It is within 100fps of the original Norma loading, and was actually the mildest shooting of all the DT loadings so it's my choice for carry. Nice medium recoil/flash/blast, although 60% of fired cases have "glock smileys" and other overpressure signs.

    Eighth Load - Double Tap 200gr FMJ-FP
    Group Size: 3"
    Average Velocity: 1098 fps
    Average Energy: 535 ft/lbs
    Std Deviation: 7.34
    Extreme Spread: 22.2 fps
    Case Expansion: 0.420 0.433
    Advertised Velocity: 1275 fps
    Dev. from Advertised Velocity: -177 fps

    This load performed almost identically to the 200gr Nosler JHP except for two areas: This load had NO glock smileys, and only exhibited moderate pressure signs, and it's advertised velocity was VERY wishful thinking. This load was the most overrated (in terms of velocity) of all the DT loads. 177 fps slower than advertised is simply not acceptable, and cannot be attributed to environmental or firearm factors. It is pure and simple deceptive advertising. Don't get me wrong, I like this load, it is certainly hotter than the "10mm lite" factory loadings available from other companies, and it is a good value IMHO, but the velocity advertisements need to be re-vamped. DT has had enough notice on this topic that continuing to put out their "pie in the sky" velocity claims is nothing less than fraudulent.

    Ninth load - Double Tap 135gr Nosler JHP
    Group Size: 5"+
    Average Velocity: 1541 fps
    Average Energy: 712 ft/lbs
    Std Deviation: 25.25
    Extreme Spread: 67.38 fps
    Case Expansion: 0.420 0.435"
    Advertised Velocity: 1608 fps
    Dev. from Advertised Velocity: -67 fps

    This was one of the better DT loads IMHO. It came closest to its advertised velocity, and delivers hard-hitting energy levels. In my "milk jug" ballistics tests, it obliterates one milk jug before going frag-nasty and lodging its fragments in the second jug. An excellent SD round if overpenetration is a concern. This round also is extremely flat-shooting. I was hitting "minute of man" at 100 yards, with only about 6" of bullet drop. I don't know of any other semi-auto handgun round that will allow you to aim center-mass at 100yds and still hit the badguy.

    OTOH, the penalty you pay for this performance is extreme recoil, muzzle flip, muzzle flash, and muzzle blast. I tested all my loads while wearing Peltor shooting earmuffs (good ones), and had no problems. When I let one of these bad boys off the chain, it made my ears ring EVEN THOUGH I was wearing the earmuffs. I stopped, and doubled up my hearing protection using both foam earplugs (inners) and the peltor earmuffs (outers). Even then, it seemed as loud as the other loads with outers alone. This load also had a nice fireball coming out the end of the muzzle that was about the size of a cantaloupe. Awesome for night shooting, and since I finished shooting this load as the sun was going down, it made for a nice light show.

    Muzzle flip was intense, and I actually experienced a bit of "trigger guard slap" on my trigger finger when the muzzle would flip back fast enough for the trigger guard to come up and slap my index finger. After about 10 rounds, it made my trigger finger pretty sore (and I'm no slouch!). It was definitely fun shooting since I'm a recoil junky, but it would be VERY difficult to control in rapid-fire. My right forearm is pretty sore today (the next morning) from this little load which is a first for me.

    Lastly, this round exhibited a bunch of overpressure signs with 6 of 13 having glock smileys, and all having flattened primers.

    So there's my data an analysis. My overall conclusions in cliffs notes version are below:

    Handloads are the most accurate. PPU is loaded to 40 s&w specs or less. Hornady is a nice moderate load, and is probably the best factory load tested. Double Tap ammo is nice and hot, and is a decent price, but their velocity claims are WAY WAY WAY overinflated. DT is certainly hot, but not nuclear hot, and Buffalo Bore or Underwood Ammo would probably be better choices for full-house loads if you were going to stake your life on them.
  2. Taterhead

    Taterhead Counting Beans

    Dec 13, 2008
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    Boise, Idaho
    Great report. Thanks for the subjective comments in addition to the objective measurements. I appreciate it.

  3. Glock Vision

    Glock Vision

    May 30, 2009
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  4. 4949shooter


    Aug 14, 2006
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    New Jersey Republik
  5. Any Cal.

    Any Cal.

    Oct 27, 2008
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    Thanks for the report. Especially appreciate the DT chrono #s and the fact that you did so through the stock barrel. Thanks!
  6. _The_Shadow

    _The_Shadow Ret. Fireman

    Jul 23, 2007
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    Southeast, LoUiSiAna
    Great report! That is why I'm glad I roll my own!
  7. Beanie-Bean


    Apr 23, 2011
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    Central Texas
    Thanks for the report, stang. I'm hoping to be able to get out to the range this week to test out some loads, new ammo, and new firearms, too.

    Really enlightening to see that some ammo doesn't really live up to the hype or advertised performance.
  8. bac1023


    Sep 26, 2004
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    Thanks for the info. :cool:
  9. oceanbob


    Jun 26, 2010
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    Good stuff....thank you sir.!:supergrin:
  10. 21Carrier

    21Carrier Until I Gota 29

    Feb 4, 2011
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    Hoover, AL
    I'm surprised to see the 135gr Double Tap load came so close to advertised velocity (that's sad when I'm IMPRESSED to see them FAIL by only 67fps). Usually, it seems they are more like your other DT loads, and at least 100-150fps below rated. I'm also really bothered by the pressure signs with most of the DT loads. In my stock G29 (NOT G20), I've gotten 180gr bullets to 1300fps, and 200gr bullets past 1200fps with ZERO pressure signs. To me, it sounds like DT is starting to use lower charges of fast burning powders. That saves them lots of money, but ramps up the pressures, and kills the velocity. There's just no reason to have SMILES with 180gr bullets at 1200fps or 200gr bullets at 1100fps. 10mm is capable of so much more.

    Thanks for all the info. BTW, I also like that 6.0gr Unique/180gr load. It's VERY accurate. I've gone as low as 5.5gr, and as high as 7.0gr. All of them are very accurate, and the 5.5gr load is great girl ammo. I made it for my girlfriend to shoot, and it just barely cycles the slide. It's SUPER light, but still accurate. Those lower loads are pretty smoky and dirty, though. Also, bump up that BD load some. A GREAT near full-power 180gr load is 10.4gr Blue Dot, CCI 300s, COAL 1.260". I've shot thousands of that load, and it's proven plenty safe in all of my 10s. It's very accurate, and a perfect full-power range load. It should get you about 1250fps or so in the G20.
  11. blastfact


    Aug 15, 2011
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    As I was reading the report concerning DT. I to was thinking faster powder. :)
  12. TDC20


    Apr 11, 2011
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    Great range report, blk69stang. Thanks for the hard work.

    Carrier, it's been a while since I read through all of the stickies and McNett's loads, but I know he was big on using magnum primers (CCI#350) on just about everything. This will definitely get you more velocity with equal charges of most powders (or similar velocity with lower charges), but at the cost of spiking pressures in some loads. I also recall that some GT members dissected some DT loads and the "secret" was shorter OAL and heavy crimp, with less powder than what would typically be needed to get the same velocities . So my guess is, magnum primer + shorter OAL + heavy crimp = higher pressures. And yes, the only reason to do this is to save cost on powder, which for you and I is relatively insignificant, but when you're turning out thousands of rounds a day, it does make a difference. So does using magnum primers, which cost the same as standard primers.

    This is based on data and discussions that were posted quite a while ago, so there could be other factors involved. I haven't shot any DT ammo from my G20, so I really can't comment first hand.

    I use standard primers on all of my 10mm loads now except for AA#9, which uses WLP, and like you I get excellent velocities without excessive pressures, plus low SDs, too. 0.4gr or 0.5gr of powder (or whatever it works out to be) means nothing to me in cost when I'm handloading the best ammo in the world. I haven't tried it yet, but magnum primers would probably work OK with AA#9.
  13. glock20c10mm


    Dec 4, 2004
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    Out West
    Very nice writeup! TYVM

    Pure dishonesty with the velocity claims from DT. Not even a surprise anymore. So much for my last false hope...and then to see somewhat major pressure signs at those menial velocity levels all for the possible sake of saving money...what a slap in the face to the 10mm community.

    It goes that someone, upon asking McNett for the fourth time why he doesn't seem to care about dishonesty with box flap claims, stated;

    Kudos to Underwood and Buffalo Bore for keeping it real!:thumbsup:
  14. 2240


    Jan 5, 2004
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    Thanks for sharing.
  15. Noobiwan


    Aug 15, 2010
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    Thanks for all your hard work.
  16. Kegs

    Kegs Ol 8 fingers ;)

    Oct 26, 2009
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    Cold side of conus

    :rofl: Sure as the sun will rise tomorrow, double tap's ammo velocities will consistently be exaggerated. Count on it.

    Like the others have said: Thanks for sharing your findings!
    Last edited: Dec 21, 2011
  17. Black Smoke Trail

    Black Smoke Trail

    May 17, 2011
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    Perhaps I missed it in another post or thread. Have you tested the Buffalo Bore 180 grain JHP's?

    Great post and nice job!