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Unexpectedly low velocities. Altitude maybe?

Discussion in 'Handloading and Reloading' started by AZAndy, Sep 13, 2008.

  1. AZAndy

    AZAndy Well-Known Member

    Finally got a chronometer and checked some handloads and reloads. Here's what I'm seeing:

    .45 ACP plated 230 grain with 4.4 grains Titegroup, OAL 1.275", CCI 300 primers:
    Low 634/ High 724/ Average 681 (fps) from 5" barrel
    Book numbers show more like 800 fps for this powder weight (using lead bullet data).

    .38 Special 158 grain LSWC with 4.25 grains Universal, OAL 1.475", CCI 500:
    Low 650/ High 714/ Avg 672 from 1 7/8" barrel
    Book shows more like 950 for this charge, but I'm sure they're using a longer barrel than I am.

    9mm Makarov 93 grain lead RN with 3.65 grains Universal, OAL .972", CCI 500:
    Low 733/ High 944/ Avg 829 from 3.75" barrel
    Extrapolating from book numbers gives ~950 for this one.

    I'm shooting at about 5500 feet altitude and it was in the mid-50s Fahrenheit. Since the air is less dense, I would expect velocities to be a bit higher, not lower, although I don't know what effect higher altitudes would have on the way powders burn.

    These will work fine as plinking and practice rounds, and I'm okay with that, but I'd like to get a little closer to factory-load standards in all these calibers-- say around 850fps for .45 and .38 and 1000fps for the 9x18. I'll increase the powder weights a tad and try again-- but I'm confused as to why the velocities are so far off from what I expected, given the load data from Hodgdon.

    I'd be grateful for any assessments or wild guesses anyone might have!


  2. DaveBeal

    DaveBeal Well-Known Member

    I agree with your expectation. My understanding is that powder burns by providing its own oxygen, so I don't see how high altitude would result in lower velocity.
  3. joneb

    joneb Well-Known Member

    I doubt its the altitude, I would use AA#5 to get closer to the velocities you want, getting 850fps in a 1.875" .38spl may not be achievable with a 158 SWC at standard pressure.
  4. ReloaderFred

    ReloaderFred Well-Known Member

    Now you've really messed up what was an enjoyable hobby. Your purchase of a chronograph is going to mess with your mind.

    I've owned two of them, and still have my PACT Professional model, but to tell you the truth, I very rarely take it out and actually put rounds across it. As long as my loads are accurate, I don't care how fast they're going, except when I'm working up a new load in a caliber I haven't worked with before. I recently did that with the 9x25 Dillon and found that the advertised velocities were on the high side of what I actually got with the loads, and I live at sea level.

    My suggestion would be to buy some factory ammunition in the calibers you load and shoot it across your chronograph through your guns. That will give you a base for your loading and something to work towards. You'll probably find that most of the factory ammunition isn't giving the advertised velocities through your guns. This is quite common, as the test barrels used in the ballistics labs are normally used in universal receivers, which don't cycle and aren't vented in most cases, like a real handgun would be.

    Hope this helps.

  5. joneb

    joneb Well-Known Member

    Andy, you might try Universal for .45acp and Titegroup for the 9x18 mak I think with combination you should be able to work up closer to your desired velocities.
  6. ants

    ants Well-Known Member

    Your powder choice is excellent. The 4.4 grain charge is right on the money for 45acp, probably the same for the others.

    Pull some bullets to make sure your powder measure is actually throwing 4.4. I have made every mistake in the book, including setting a Titegroup charge at 3.4 instead of 4.4. I've also accidently put HP-38/W231 in the hopper, because they look identical to Titegroup.

    Your OAL of 1.275" is also slowing the 45 down a bit. It provides a larger combustion volume and holds the bullet more loosely in the neck. So the bullet starts to move sooner and expands the available combustion volume more rapidly. The fast Titegroup powder can't do what it is made to do - create peak pressure quickly and pop the bullet rapidly down the tube like a blow dart.
  7. rcmodel

    rcmodel Member in memoriam

    It's been my experiance that Universal isn't a particularly good powder for any handgun load.

    It only works well at maximum pressure. Back off a little and all kinds of weird things start happening because it doesn't all burn.

  8. Galil5.56

    Galil5.56 Well-Known Member

    I have seen where Hodgdon uses a 7.7" barrel in their pistol data section, but no mention of this in the cowboy data area where it seems you got your data. Speer 13 lists 4.6 grains of Universal/158 LSWC as a non +P max of 902 fps. What you are getting seems basically in line, and I would definitely bump the charge to the Speer max if you can safely and want to continue with Universal. BTW, the Speer rec starting charge is 4.2 grains for 827 fps.

    Although you can not always extrapolate exactly/safely, Unique has a very similar burning rate and I routinely use 5 grains of it to achieve an avg velocity of 882 fps from my 3" S&W model 60 in .38 Special. Again, I am not saying you should extrapolate data from burning rates, but IMO and experience what you are seeing seem in line with the charges you are using in a sub 2" barrel. Also, you think that data is bad, you should have seen some of the Winchester Western data for 30/06/150 gr bullets from the early 80's... Book says 2900, I was getting 2640 fps from 2" less barrel. Would be nice if we could always get what we think we should, but then again, that's why I reload.
  9. Crimp

    Crimp Well-Known Member

    My load for my 5" XD45 is:
    230gr Winchester FMJ
    4.9gr Titegroup
    CCI 300
    1.260" COL

    Here's my chrony data (7 shots):
    HI:834 LO:820 AV:827 ES:14 SD:4

    I'm very happy with the results.

    Sierra's 'most accurate' listing is ~850 fps, 5.2gr Titegroup, FMJ @ 1.270".
    I went up that high, but wasn't impressed with the performance in my XD.

    Good Luck!
  10. 35 Whelen

    35 Whelen Well-Known Member

    Andy, it sounds to me like the same bizarre readings I used to get when I used a Chrony. And it was usually worse when I chronoed pistol load that had quite a bit of muzzle flash/blast. Is a Chrony the brand chronograph you're using? Mine was a POS. I now have a CED Millenium and love it. So simple and has 1" display numbers and an easy to decipher keypad.

  11. AZAndy

    AZAndy Well-Known Member

    Wow! This here High Road joint is a great place. Thanks for all the observations and suggestions!

    jibjab: I may branch out into other powders one day, but for now I'll stick with these two (and maybe some Unique) until I understand them.

    ReloaderFred: Yes, I've probably made a mistake. It's my inner scientist, I guess. At some point, though, I'll be doing some competitive shooting, and knowing what my "power factor" is will be essential. I'll definitely try some factory loads to see what they're doing!

    ants: Thanks for the pointer on the OAL. I'll shorten it up a bit on my next test loads!

    rcmodel: I'll take the charges up to the speed limit and see if that helps. Would you say that Unique would be a better choice? I'd like to have one fine-ground and one not-so-fine, and Universal seemed pretty good for the latter. On a smaller charge, I like a larger-volume powder because it's going to be more accurate when I measure by volume.

    Galil5.56: 7.7"?! Well, no wonder! Thanks for the Speer info; I've made a few cartridges with 4.5 grains and will test them today. 4.6 I'll hold in reserve.

    crimp: I've loaded a few test rounds with 4.7 to see how that goes. I'm using plated bullets, so I don't think I could go to 4.9 like you do, but that is a delicious sounding load.

    35 Whelen: It's a ProChrono, and I'm standing back 10 feet so as to minimize any muzzle flash/blast effect. If I ever test 7.62x25, I'll stand back 50 feet. ;)
  12. Walkalong

    Walkalong Moderator

    4.8 Grs of Titegroup with a Ranier 230 Gr RN @ 82 degres gave me an AVG 747 FPS with an ES of 106 from a 5" 625 and AVG 793 FPS with an ES of 34 from a 5" 1911 with a fast barrel, so your Titegroup numbers in .45 don't look far off to me. I was unimpressed overall and don't load anything with it right now, although I am still going to try it in a couple of more applications.

    rcmodel is right about Universal. It does great at high pressure, but is sub par at low pressure like .38 Spl.
  13. Galil5.56

    Galil5.56 Well-Known Member


    I think you will find Unique to be an excellent choice in service type 38 Special 158 grain lead loads, as I mentioned in my initial post. I have used 3.2 grains of Unique with 148 grain loads too, resulting in a nice easy going consistent 670 fps avg velocity from my 3" S&W 60. I think you will find Unique to generally work well in 45 auto, and a whole bunch of other pistol and light cast rifle loads too.

    If you load 9mm, Unique is great for this caliber cast and jacketed, and it loads up some very nice "International style" 12 gauge 1 1/8 oz loads too. It's so versatile, generally forgiving, easy to get, reletivly inexpensive, made in the USA... Great stuff, and still going strong after 100 years of production and proven use.
  14. Owen

    Owen Moderator Emeritus

    the other thing to do is make sure your screens are exactly the right distance apart.
  15. AZAndy

    AZAndy Well-Known Member

    Well, here's this morning's update:

    .45ACP 225gr plated FN with 4.7gr Titegroup:
    High 775/ Low 724/ Avg 749
    which is in keeping with Walkalong's numbers above, I see.

    .38Spec 158gr LSWC with 4.5gr Universal:
    High 776/ Low 628/ Avg 701
    and was very smoky!

    Universal seems to vary pretty widely, doesn't it? 150 fps spread is kinda weird. I'm thinking some friendly thoughts about Unique, after all I've read about it-- I think I'll pick some up today and see what's what.

    Thanks for the further observations, Galil and Walkalong!

    owen: Alas, I can't change the spacing of the diffusers or the sensors on my unit. The attachments are not adjustable. Given Walkalong's numbers above, I'm satisfied that the chronograph is fairly accurate, though.
    Last edited: Sep 14, 2008
  16. Owen

    Owen Moderator Emeritus


    I asked because my chrono doesn't have a rail. I mounted the screens to a 2x4, that I use as the bar on a sawhorse.

    they are supposed to be 24" apart, but mine are 23 1/2", because I can't measure.

    If your setup has a fixed distance, you're all set.
  17. Shoney

    Shoney Well-Known Member

    The only cartridge that has not been adequately addressed here is the 9X18 Mak.
    Your 3.65 grains Universal load seems quite low and the extreme spread is way out of line. You did not mention what press you are using, nor the method you are using to meter or weight powder. I would think that erratic velocities are more due to powder weight fluctuation.

    I will confine comments to 95 gr only.

    Speer lists max:
    Universal Cl. 4.5 965

    Hodgdon lists max:
    Universal Cl. 4 1030

    Sierra lists max:
    Universal Cl. 4.7 ??

    When loading lead, I seat in one operation and crimp very lightly in a second. My ES was more like 50 - 80 fps. Although I've tried around 10 powders, I settled on Universal loaded at or over max, and red dot for light practice.
  18. AZAndy

    AZAndy Well-Known Member

    Shoney: I was hoping someone would chime in on the Mak round.

    I based the charge on being middle-of-the-road between Hodgdon (and Lee) data for a 90gr lead bullet, since 93gr is pretty close. They're saying 3.5-3.9 and I was trying for 3.7. I'm measuring with a Lee powder disk at .40cc and then weighing, oh, every tenth round or so on a Lyman 555. The powder disk is pretty consistent, as far as I can see.

    The cartridges are produced on a Lee Turret with Lee carbide dies. I'm not using a "factory crimp" die with this particular cartridge (since Lee doesn't offer a set that has one).

    It's really depressing to realize how wildly some of these "do not exceed" numbers can vary. When my next bullet shipment gets here, I'll try some with 3.9 or maybe even 4.2 Universal and see what happens.

    Thanks for posting those numbers. Nice to know there are other Mak reloaders in the world.
  19. Steve C

    Steve C Well-Known Member

    Andy, you are listing your loads to .05 grs, as no powder scale measures that close, are you using a pre-set dispenser like the Lee powder measure with various disks? Its been my experience that Lee's charts display the absolute maximum that you could possibly get from either their powder dippers or other set dispensers and the usually throw much lighter than what the charts say. This could explain your lower velocities. You need to check measure your powder dispenser with a scale to see if its really throwing what you think and if you are using an adjustable measure you should check at least every 10th throw to see if its throwing a consistent charge.

    Universal is very similar to Unique and should produce similar results though a load of 4.2grs of Unique would be fairly light behind a 158gr LSWC in the .38 spl. Your velocities are not really that off the mark for a short barrel firing a light or standard level charge. If your standard deviation for the velocities measured are much over 20 I'd look to your charge to charge consistency as the culprit.
  20. AZAndy

    AZAndy Well-Known Member

    Steve C: I'm not actually measuring in hundredths, but half-tenths aren't that hard to determine. If a setting for 4.2 reads a little above the zero line on the scale and 4.3 is an equal amount below the line, then it's pretty close to 4.25, and that's where I get my wacky numbers. (On my previous scale, the el cheapo Lee, if you could see both tenths lines, it was likewise halfway between the tenths.)

    Thanks for the pointers on the powders. I guess I shouldn't be trusting the load data that the powder people provide (alliteration alert!), but don't want to fly entirely blind either, or I may find myself blind indeed!

    I've built some test rounds of the .38 Special with 4.8 grains Unique and will chronograph them later today. The next largest powder disk hole gives 5.1 grains, and I'm not sure I want to go that high at this point. The pistol is +P rated but the cases aren't...

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