I'm curious about the effect load density has on velocity with the powders Unique and Bullseye loaded to standard pressures in a 1911 chambered in 45 ACP with a 230 grain bullet.
Has anyone measured the velocity difference with powder-back and powder-forward (pointing the muzzle up before firing and pointing the muzzle down before firing) with standard pressure loads with these two popular powders?
If you have the data, I'd appreciate it. Otherwise I'll post the data myself, once I've measured it. Thanks.
Yes, I've chronographed for just that effect, deliberately, many times.
The extreme spreads that result are, as you'd expect, based upon just how full the case is of powder, as well as the bullet used. Standard pressure is more position sensitive than Plus P loadings, and less position sensitive than lower velocity loadings. Again, just as you'd expect. High velocity 185's with their shallower seating are more position sensitive than high velocity 230's with their deeper seating, even given that the powder charges with the 185's are larger. A function of the variability of the shot start pressure of the lighter bullet, and the extra powder doesn't make up for the shallower seating.
If standard pressure is taken to mean 230's at ~830 fps, and 200's at 900+ fps, extreme spreads (not averages, but rather highs and lows) will generally be 50 fps or less using cases of the same make. If the bullet seats shallowly, like some of the once popular 155's, and loads are more moderate, extreme spreads may approach 100 fps. This is not unusual with the best of powders, and Titegroup, while being fairly position insensitive, is really not more so than the more bulky Bullseye and Unique.
If you want bulkiness at low charge weight with relative position insensitivity, you'd tend more to Red Dot.
I say "relative" because there's no powder I've tested that is completely insensitive to position, even in the stubby ACP case.
A powder that has proven curiously position sensitive when exposed to this testing is Universal. I would appreciate if you could confirm this in your own testing.
If you want figures, I'd be happy to post them. I've done this with a number of other powders as well.
That's great info. Thanks. I would love to see the averages from the data you have, especially for Unique and Bullseye. Although, from what you've already written, the potential velocity difference (50 fps) doesn't seem meaningful in terms of recoil, point of impact or terminal ballistics.
My evolving intent is to create a load that mimics the Speer Gold Dot (advertised at 890 fps). Carry the Gold Dots and practice with my cast bullet handloads. Since I have Bullseye and Unique on hand, I'd start with those two powders--and stick with them too if they recreate the Speer factory ballistics.
I'd be happy to test the Universal for you. It might be a month or two, as I'm still looking for the right buy on a 1911.
As long as we're talking about it, I'd be curious to know what load you practice with, assuming you've got one that mimics factory ammo. Thanks.
Last edited by lever101; 11-14-2011 at 09:50 PM.
I carry 230grn Speer Gold Dot Short Barrels in my 4" Kimber, my practice load is 6.5grn Unique under a 230grn FMJ... it's pretty darn close to each other in terms of velocity, recoil and POI. The .45ACP is so darn silly easy to load for...
I do have a batch of test cartridges loaded up... same charge weight with different COAL's. I have yet to get to the range with the time to spend with them running them over the chrono and checking their POI. Maybe Christmas when I'm in Nevada...
I practice with the 0.71 cavity in my PAD measure, dispensing 4.7 grains of Promo or Red Dot (amount dispensed by weight is identical with these lots I have). The Promo in the most recent lot averages about 820 fps or so in mixed cases; the Red Dot averages about 855. Both using the Lee 230-2R.
That's when I'm duplicating ball. With a HG 200 the same charges get around 870 to 890 fps, with close enough recoil to ball to at least give reasonable similarity.
Velocity difference? I don't know for sure what you're getting at, I guess. While Red Dot in this charge weight using a cast lead bullet is a little faster than a standard velocity 230 FMJ is supposed to average, the difference isn't enough to notice, and the Promo load pretty much duplicates it exactly. The spec is around 825 fps +-25 fps, if I recall correctly. Sources vary slightly but that's right in the ballpark. I call the 4.7 Red Dot load my "heavy ball" loading because it duplicates the velocity of the faster lots of military 45 ACP I've chronographed, most of it marked "Olin Mathison Chemical Corporation" in the plain brown boxes.
The ones I've shot dated from the mid to early sixties. Dad got mad when he found out that I shot up a lot of the military ball he had squirreled away, but he forgave me when I started to reload. I was smart enough not to toss the cases.
That's a great story about the military ammo. Good thing you hand a mind to save the brass.
I was unclear in my post. By velocity difference I was referring to the ignition phenomenon caused by less than 100% load density (powder-back and powder-forward). I was trying to verify my assumption that from your tests with Red Dot (and maybe Unique and Bullseye) you found the difference in velocity (powder-back and powder-forward) acceptable.
I was also inferring that you found a 50 fps spread with Unique. The 100 fps spread with Universal you reported seems unacceptable to me. (I'll go ahead and test the Universal for you to see if our results are consistent with each other).
I am starting to reload 1911 with Bullseye and 230's myself so this is interesting. I will be using lead though. What loads are you using?
Marlin League #54
Team 45/70 #22
Marlin 1895 CB 45/70
Marlin 1895 STBL 45/70
Marlin 1894 CB 45 LC
Marlin 336 30-30
Pedersoli Sharps 45/70
Bond Defender 45 LC
Springfield 1911 Stainless loaded 45 ACP
3 Great Western II 45 LC SAA
2 Uberti 45 LC SAA
"Coyote Cap Special Edition" Model 1887wse-18
Winchester Classic 30-30
Winchester Lone Star 30-30
GGeilman: If I may reply. I too have been experimenting with Bullseye/230 grain plated bullets and my results don't match a lot of published data. For one, many sources give 5 grains as a max load, with velocities approaching 900 FPS. I loaded up some of these loads and they chronoed at 739 FPS out of a 4.5" M&P and mixed cases. 5.3 grains of Bullseye brought velocities up to 756 FPS. Using 5 grains of Bullseye and a 230 grain FMJ produced 717 FPS in my Chrony. My next test load will be 5.6 grains of Bullseye. I've got them loaded and hope to get to the range tomorrow. I've also noticed that with 230 grain bullets, plated bullets are about 50 FPS faster than FMJ bullets over the same powder charge.