[bbbean]

After a frustrating back and forth between too weak and too strong, I finally dialed in my "just right" load for Single Stack (just in time for the SSN!). I'm pretty amazed at the wide range of results I got in both feel and velocity within a pretty narrow range of charges and OAL. In the end, I quit looking at my scale and started dialing in by 1/8 turns on the powder measure and hit what feels like a pretty ideal load with (for me) pretty consistent results:

Date 4/27/2009
Powder Clays OAL 1.22
Charge 4.25 Cal 45 ACP
Bullet HAP Gun EB Kobra
Weight 230 Primer Winchester LP
Temp 80
FPS PF PF less hi/lo
733 167.86 167.86
741 169.69 169.69
751 171.98 171.98
738 169.00 169.00
741 169.69 169.69
732 167.63 167.63
757 173.35 173.35
746 170.83 170.83
740 169.46 169.46
744 170.38 170.38
735 168.32 168.32
749 171.52 171.52
734 168.09 168.09
749 171.52 171.52
735 168.32 168.32
732 167.63 167.63
760 174.04
754 172.67 172.67
721 165.11
743 170.15 170.15
Mean = 741.75 169.86 169.89
stdev 9.73 2.23 1.79

If you're checking the math, I used a bullet weight of 229 to allow for light samples.

[Dan Sierpina]

If you're planning on using that load at a major match, I'd bump it up. You'll never feel the difference between a 169 PF and 179 PF after the buzzer goes. You could come across an uncooperative chrono though, and be 164.9....and minor.

[bbbean]

Dan Sierpina, on Apr 27 2009, 12:17 PM, said:

If you're planning on using that load at a major match, I'd bump it up. You'll never feel the difference between a 169 PF and 179 PF after the buzzer goes. You could come across an uncooperative chrono though, and be 164.9....and minor.

I could feel the difference between this load and the 175 PF. I'm also fairly sure my chrono is slow. It gave me a PF of 158 when I tested Atlanta Arms 230 FMJ, which should have been at least 164 or 165 in a slow barrel.

This post has been edited by bbbean: 27 April 2009 - 10:38 AM

[bkeeler]

bbbean, on Apr 27 2009, 11:35 AM, said:

Dan Sierpina, on Apr 27 2009, 12:17 PM, said:

If you're planning on using that load at a major match, I'd bump it up. You'll never feel the difference between a 169 PF and 179 PF after the buzzer goes. You could come across an uncooperative chrono though, and be 164.9....and minor.

I could feel the difference between this load and the 175 PF. I'm also fairly sure my chrono is slow. It gave me a PF of 158 when I tested Atlanta Arms 230 FMJ, which should have been at least 164 or 165 in a slow barrel.


Date 4/27/2009
Powder Clays OAL 1.22
Charge 4.25 Cal 45 ACP
Bullet HAP Gun EB Kobra
Weight 230 Primer Winchester LP
Temp 80
FPS PF PF less hi/lo
733 167.86 167.86
741 169.69 169.69
751 171.98 171.98
738 169.00 169.00
741 169.69 169.69
732 167.63 167.63
757 173.35 173.35
746 170.83 170.83
740 169.46 169.46
744 170.38 170.38
735 168.32 168.32
749 171.52 171.52
734 168.09 168.09
749 171.52 171.52
735 168.32 168.32
732 167.63 167.63
760 174.04
754 172.67 172.67
721 165.11
743 170.15 170.15
Mean = 741.75 169.86 169.89
stdev 9.73 2.23 1.79

So your saying you can feel the difference between these two.

You may want to bump up a little in my opinion up to you though.

BK

[Chills1994]

Are they actually going to run a chrono stage at this year's Single Stack Nat's?

They didn't last year.

They also didn't weigh guns either.

[Alan Meek]

Chills1994, on Apr 27 2009, 02:55 PM, said:

Are they actually going to run a chrono stage at this year's Single Stack Nat's?

They didn't last year.

They also didn't weigh guns either.

Last year they did run the Chrono, just no scale or a box. I would bet this year they will have the USPSA box and a scale along with the Chrono.

[Chills1994]

Oops, my bad... on the chrono... I do definitely remember NOT getting my pistola weighed, but that was probably because somebody commented to me since I was an RO about all the brass mag base pads they saw..."Uggh, aren't they weighing guns this year?"

I think that was the comment I heard from one competitor.

My ammo/gun, I guess didn't get chrono'ed because I was an RO.

Getting back more on track here with this thread. I figure a 172 PF is a good buffer to go for. It gives you some wiggle room above the 165 cutoff.

I guess the OP is using some sort of Hornady jacketed bullet.

[bbbean]

Chills1994, on Apr 27 2009, 02:14 PM, said:

I guess the OP is using some sort of Hornady jacketed bullet.

"Hornady Action Pistol" - Its a jacketed hollow point for competition - no cuts or posts to enhance expansion, just a hollow point.

http://www.hornady.c...ets_Handgun.pdf

This post has been edited by bbbean: 27 April 2009 - 01:06 PM

[Chills1994]

Aha! Okay... they sound expensive. How much per 1K?

[bbbean]

Chills1994, on Apr 27 2009, 10:32 PM, said:

Aha! Okay... they sound expensive. How much per 1K?

They weren't too bad - maybe $10 or $20 higher than the FMJs.

[bbbean]

FWIW, I ended up bumping my load back up a notch before the Single Stack Nats, but didn't need to. Turned out my chrono and my scale correlated very well with the chrono and scale at PASA. My equipment showed me using a 42.2 g gun with a PF of 175. Their equipment showed me using a 42.2 g gun with a pf of 174.8.

Score one for the $95 ProChrono PAL!