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LPP vs. SPP in .45 ACP

Posted: Thu Dec 05, 2019 1:42 pm
by Morne
***CHRONY DATA***

38 F, 30.06" Hg, 62%RH

.45 ACP 230-gr X-Treme CPRN @1.255" COAL
S&W 625 with 4" barrel

W-231 Powder 5.6 grains:
WLP - AVERAGE = 768 fps - ES = 15.1
CCI500SPP - AVERAGE = 714 fps - ES = 91.2


Red Dot Powder 4.8 grains:
WLP - AVERAGE = 777 fps - ES = 21.6
CCI500SPP - AVERAGE = 743 fps - ES = 85.0

Promo Powder 5.1 grains:
WLP - AVERAGE = 826 fps - ES = 73.9
CCI500SPP - AVERAGE = 796 fps - ES = 31.3

WSF Powder 6.2 grains:
WLP - AVERAGE = 720 fps - ES = 26.5
CCI500SPP - AVERAGE = 697 fps - ES = 48.6

So as you can see the average ES is tighter for the LPP loads than the SPP loads with all other factors held equal.
The average of the ES:
LPP = 34.28
SPP = 64.02

Furthermore, the average velocity is 35.25 fps faster with the LPP rather SPP.

So now we have hard data that says not only is SPP .45ACP brass annoying but it is also demonstrably worse. 8)

Re: LPP vs. SPP in .45 ACP

Posted: Thu Dec 05, 2019 3:11 pm
by JustaShooter
Thanks for that data! I've been culling SPP .45 ACP brass and setting it aside to sell/give away ever since it started showing up, glad to know I'm going the right direction.

Oh, and for the uninitiated:

LPP = Large Pistol Primers (as God and John Moses Browning intended the .45 ACP cartridge to have)
SPP = Small Pistol Primers (an abomination produced by tree-hugging leftists in their "non-toxic" .45 ACP loadings)

Re: LPP vs. SPP in .45 ACP

Posted: Thu Dec 05, 2019 8:09 pm
by Dave Shooter
I've found I need ~0.2 grains more of the powders I've been using lately in .45 ACP (Bullseye and WST) to get same velocities from SPP as LPP.

If anyone is giving away small primer .45 brass please contact me. Not having to switch my 1050 priming system over is an advantage.

Hope everyone has a blessed Christmas season!

Re: LPP vs. SPP in .45 ACP

Posted: Fri Dec 06, 2019 1:17 pm
by cpg
Morne wrote:So now we have hard data that says not only is SPP .45ACP brass annoying but it is also demonstrably worse. 8)
:lol: :lol: you got that right!!

Re: LPP vs. SPP in .45 ACP

Posted: Sun Dec 08, 2019 6:44 am
by weakhand luke
Why, do you suppose?

Re: LPP vs. SPP in .45 ACP

Posted: Mon Dec 09, 2019 10:35 am
by Morne
weakhand luke wrote:Why, do you suppose?
Not entirely sure why. Anybody else?

Re: LPP vs. SPP in .45 ACP

Posted: Mon Dec 09, 2019 11:03 am
by cpg
Here's what I've heard, but have no data to back up.
Smaller primer = smaller explosion. This is what creates the drop in velocity due to slightly slower powder ignition. Some folks talk about using small magnum primers to help adjust the velocity back to normal LPP levels, but I'm not sure how effective or repeatable that would be.
I curse every time I see a small pocket 45. :x

Re: LPP vs. SPP in .45 ACP

Posted: Mon Dec 09, 2019 3:28 pm
by Sevens
While I believe the result you found is the likely result that should be expected, I would like the test better if it were like branded primers. CCI-500 and CCI-300 for example. And then, it would be even more interesting to toss the CCI-400 (small rifle primer) in there also.

However, as I am not the guy doing the tests and reporting the results, I get what is offered! :D

Interesting and appreciated.

Re: LPP vs. SPP in .45 ACP

Posted: Mon Dec 09, 2019 4:10 pm
by Morne
Sevens wrote:While I believe the result you found is the likely result that should be expected, I would like the test better if it were like branded primers. CCI-500 and CCI-300 for example. And then, it would be even more interesting to toss the CCI-400 (small rifle primer) in there also.

However, as I am not the guy doing the tests and reporting the results, I get what is offered! :D

Interesting and appreciated.
Your point is well made.

For two of these loads I also have CCI-300LPP data but I would caution that having been shot on a different date I don't recall the meteorological data and that might sway things. To truly test Gala Apples to Gala Apples I would like to shoot them same day:

W-231 with CCI-300LPP gave 699 fps and 28.8 ES. That is slower than either CCI-500SPP or WLP. The ES is tighter than CCI-500SPP but looser than WLP.
WSF with CCI-300LPP gave 703 fps and 27.1 ES. That is faster than CCI-500SPP but not as fast as WLP. The ES is tighter than CCI-500SPP and virtually identical to WLP.

Re: LPP vs. SPP in .45 ACP

Posted: Mon Dec 09, 2019 8:33 pm
by Dave Shooter
Sevens wrote:While I believe the result you found is the likely result that should be expected, I would like the test better if it were like branded primers. CCI-500 and CCI-300 for example. And then, it would be even more interesting to toss the CCI-400 (small rifle primer) in there also.
d.
My .2 grain observation was with Federal LPP and Federal SPP, for what it's worth.

Re: LPP vs. SPP in .45 ACP

Posted: Tue Dec 10, 2019 3:39 pm
by cpg
Does anyone know if the flash hole is the same diameter & length regardless of the primer pocket size? I'm sure tolerances are wide, but would imagine some kind of industry standard would be in play.

Re: LPP vs. SPP in .45 ACP

Posted: Tue Dec 10, 2019 8:06 pm
by JustaShooter
cpg wrote:Does anyone know if the flash hole is the same diameter & length regardless of the primer pocket size? I'm sure tolerances are wide, but would imagine some kind of industry standard would be in play.
They should be the same, though I've not inspected the two to be sure. But in all other cartridges the flash hole is the same size - I know this because my flash hole deburring and uniforming tool works in all of them...

Re: LPP vs. SPP in .45 ACP

Posted: Wed Dec 11, 2019 9:58 am
by Whirlwind06
What kind of accuracy are you getting with the Extreme plated bullets?

I have loaded up 1K of 9mm 147 grain Extreme plated and I'm not impressed with the accuracy.

Re: LPP vs. SPP in .45 ACP

Posted: Wed Dec 11, 2019 11:13 am
by Brian D.
Whirlwind06 wrote:What kind of accuracy are you getting with the Extreme plated bullets?

I have loaded up 1K of 9mm 147 grain Extreme plated and I'm not impressed with the accuracy.
Being on the heavy side, they do better in barrels with faster rifling, as you likely know.

Re: LPP vs. SPP in .45 ACP

Posted: Wed Dec 11, 2019 3:49 pm
by Whirlwind06
My carry ammo 147 Grain Winchester Ranger (I forget the exact one) has acceptable accuracy from my pistols.
This is not just in 9mm. I have been shooting 45 ACP all summer. Started with ploy coated 185 grain that was giving me great results out of a G41.
Switched to Barry's plated 200 gain FP and wasn't nearly as good. Now using 200 grain blue bullets ploy-coated and I'm getting good results again.

I'm hitting the range like 3 or 4 times a week. When used to go only once a month or so I would blame myself for poor results.
Now I'm also seeing that sometimes it is the ammo and not just me. :)