Test results; SPP vs LPP in 45 acp
Meant to get this done sooner, but here it is.
Load is 6.7 grains of Unique under a 225 weight TC bullet.
Brass was used mixed makes, made up of 50, small pistol primer pockets, and 50 large pistol primer pockets.
Selection process was to load all 100, then select 7 from each primer size, and then pick 3 from the remaining group. So basically, I loaded 50 each of spp and lpp, and selected 3 from each group at random.
Results for SPP loads
1) 943 fps
2)931 fps
3)941 fps
Average velocity is 938 fps
Results for LPP loads
1) 925 fps
2)972 fps
3)935 fps
Average velocity is 944
Average difference between the 2 is 6 fps.
I do not think there is enough difference in the primer size to even worry about it.
Also tested my favorite load of 6.2 grains of Unique ;
1) 874 fps
2)870 fps
3)820 fps
Average velocity is 854 fps. Damn near a perfect velocity for the 45 acp in the 1911 platform with factory springs per Colt Specs.
All loads chronographed, gun was Colt 1911 with 5 inch National Match barrel.
So, there ya go, for those who had questions or concerns.
Disclaimer; start at manufacturer suggested load data for beginning loads and work up.
Exiting comment; An average velocity of 944 fps with a lead 225 weight bullet is nothing to sneeze at. One of my favorite factory loads was a 40 S&W 180 weight XTP for outdoor and general use. It is advertised at 1100 fps, and that was with blended powders. I tested it and it is very close to advertised velocities.
For special purposes, I can easily load the 45 acp to blow any 40 out of the water. the 6.7 grains of Unique load and bullet combo is not showing any signs of high pressure, and I could easily bump this load up considerably if needed, although, I dont want to abuse my gun.
But the next time anyone asks what the 45 can do that the 40 or 9mm cant, I have something for 'em.:wink:
Load is 6.7 grains of Unique under a 225 weight TC bullet.
Brass was used mixed makes, made up of 50, small pistol primer pockets, and 50 large pistol primer pockets.
Selection process was to load all 100, then select 7 from each primer size, and then pick 3 from the remaining group. So basically, I loaded 50 each of spp and lpp, and selected 3 from each group at random.
Results for SPP loads
1) 943 fps
2)931 fps
3)941 fps
Average velocity is 938 fps
Results for LPP loads
1) 925 fps
2)972 fps
3)935 fps
Average velocity is 944
Average difference between the 2 is 6 fps.
I do not think there is enough difference in the primer size to even worry about it.
Also tested my favorite load of 6.2 grains of Unique ;
1) 874 fps
2)870 fps
3)820 fps
Average velocity is 854 fps. Damn near a perfect velocity for the 45 acp in the 1911 platform with factory springs per Colt Specs.
All loads chronographed, gun was Colt 1911 with 5 inch National Match barrel.
So, there ya go, for those who had questions or concerns.
Disclaimer; start at manufacturer suggested load data for beginning loads and work up.
Exiting comment; An average velocity of 944 fps with a lead 225 weight bullet is nothing to sneeze at. One of my favorite factory loads was a 40 S&W 180 weight XTP for outdoor and general use. It is advertised at 1100 fps, and that was with blended powders. I tested it and it is very close to advertised velocities.
For special purposes, I can easily load the 45 acp to blow any 40 out of the water. the 6.7 grains of Unique load and bullet combo is not showing any signs of high pressure, and I could easily bump this load up considerably if needed, although, I dont want to abuse my gun.
But the next time anyone asks what the 45 can do that the 40 or 9mm cant, I have something for 'em.:wink:
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Very good test and read, gman! Seeing as much as 445 ft./lbs. of energy exhibited there with that load gen'ing up 944 fps, for the folks who care about such things. That's a lot of thump anyway it is sliced.
I'm guessing you're running a standard recoil spring, 16 lbs?
6.7 grains of "old" Unique and a 230 grain jacketed or cast lead round nose bullet used to be my mainstay load and, for experimental purposes, was taken higher to some published maximum a dab over 7.0 grains. No percentage in battering things so backed down. With traditional Unique I got 898 fps at the max loading. The jury's still out on this new "cleaner burning" Unique so I've further backed down to 6.3 grains for my shooting. Haven't chronographed it but seems to function about the same as factory loads.
Unique seems to be "warmer" than it was. I did a side-by-side test of an old can of Unique and a new can of Unique with another cartridge yesterday over the chronograph to find both higher velocites and apparent pressures with a newer lot of Unique.
I'm guessing you're running a standard recoil spring, 16 lbs?
6.7 grains of "old" Unique and a 230 grain jacketed or cast lead round nose bullet used to be my mainstay load and, for experimental purposes, was taken higher to some published maximum a dab over 7.0 grains. No percentage in battering things so backed down. With traditional Unique I got 898 fps at the max loading. The jury's still out on this new "cleaner burning" Unique so I've further backed down to 6.3 grains for my shooting. Haven't chronographed it but seems to function about the same as factory loads.
Unique seems to be "warmer" than it was. I did a side-by-side test of an old can of Unique and a new can of Unique with another cartridge yesterday over the chronograph to find both higher velocites and apparent pressures with a newer lot of Unique.
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I think the new is hotter Bryan. I am going to stay within the realm of 850 or less for my general shooting enjoyment.Maybe back down to 6.0 which puts me around 750-800ish.
I have seen listings for up to 7.6 grains of Unique, although I can't imagine shooting that. I saw a post in another forum by a member who seemed to know what he was talking about warn against using that published data and was dismayed that Lymam had published it. He got 1100 fps with it, and warned that the design was not intended for that pressure.
But a 230 weight 45 caliber pill at 1100 fps would be quite the load if one wanted such, and really wouldn't need to look elsewhere.
I use the factory #16 in my gun.
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Great info gman! Thanks! I finally found some primers on my vacation trip up North and am currently on the lookout for unique powder.
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That looks like a pretty good load.
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I see that! That's cooking with gas!
I only ever played with 185 grain lead SWCs and 230 grain jacketed round nose bullets for experimental "+P" .45 ACP loading. 7.2 grains of Unique gave 995 fps with the 185 grain lead SWCs from a 5-inch Colt 1911. Data's from my notes of August of 1979 and Unique has been reformulated and the company making it has changed since that time.
I have always thought that Unique struck the best balance for building heavy .45 ACP handloads. At least I always seemed to get the best velocities without any perceived excessive pressure signs. This has also held true in .45 ACP revolvers for me. The .45 ACP doesn't do well with powders as slow as Blue Dot and fast-burning powders like Bulls-Eye and 231 aren't the place to dally if one has a view of building "nuclear-powered .45 ACP handloads.
It's possible that the slightly slower-burning Herco would yield a bit more velocity than Unique in some straight-walled, non-magnum handgun cartridges while keeping pressures acceptable. It is said that the double-base propellants Unique and Herco contain about the same energy per unit of weight. Unique is faster burning though so has a higher ballistic efficiency (or the percent of stored powder energy translated to bullet kinetic energy on firing), but Unique accomplishes this at the expense of raising peak chamber pressures 20% or even more, because it peaks faster. When comparing Unique and Herco, grain for grain, Unique will give higher velocities, however if the Herco charge is raised until it's peak pressure matches that of the original Unique charge it makes up for any differences in ballistic efficiency and gives the higher velocity. Of course all this is achieved at the expense of burning a bit more Herco.
That's not an original thought. I read it in a book, or online someplace. I've used Herco in the .45 ACP but never "heated things up" with heavy loadings to see what would happen. I've played with Herco a bit in .38 Special, .45 ACP, and just this week, in the ancient .38 S&W. I'm favorably impressed with the stuff. Especially since several of my tests are finding significant differences in "old" Unique and "new" Unique. HS6 and Accurate No. 7 might also bear some study for velocity efforts with the .45 ACP but I've never used them.
It also must be said that the .45 ACP is not shabby at all if run at standard velocities. It is a handgun cartridge that answers to the great majority of chores that could reasonably be asked of handguns.
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