Sport Pistol Accuracy Issues

[JimmyZip]

On 9/4/2020 at 6:09 PM, Batmo said:

About halfway through 8 lbs of Sports Pistol with no accuracy or any other problems.  Two different coated bullet manufactures and three different bullet designs...145 and 147 grain.  Just destroyed a 1 inch orange dot with 10 shots at 15 yards this past week....now if I could just do that without a rest.

I finally learned to shoot decent off hand groups by shooting static steel painted white. Center your first and just keep aiming at the last shot. For some reason I can do it on paper now to. I can usually get a 2 1/2 group at the end of each shooting session to make me feel better especially if I have a bad practice lol. This is with my G17 mind you. With other pistols I have with single action triggers I can work out just under 2. This is at 15-18 yards. From a rest I can get it at 25. Not too much longer though, my eyes are getting poor now. 
Im watching this thread cause Power Pistol is all I have left now when my press gets back from Dillon 

[Batmo]

On 11/24/2020 at 3:39 PM, JPHoka said:

I'm working up loads for DG 147 FP with Sport Pistol. Curious as to your load data. Looking for a starting point. 

3.0 grains of Sports Pistol is my standard load for all 147 grain coated bullets.  OAL may vary depending on bullet shape.  This load produces a powder factor of about 129.  For competition loads where a coronagraph will be involved I load at 3.1 grains just to be sure I don't go sub-minor

Edited November 27, 2020 by Batmo

[chgofirefighter]

On 8/26/2020 at 12:23 PM, lll Otto lll said:

I don't see how you could determine the accuracy of a load shooting at 7yds.

Funny I was thinking the exact same thing... 

[JPHoka]

On 11/27/2020 at 10:13 AM, Batmo said:

3.0 grains of Sports Pistol is my standard load for all 147 grain coated bullets.  OAL may vary depending on bullet shape.  This load produces a powder factor of about 129.  For competition loads where a coronagraph will be involved I load at 3.1 grains just to be sure I don't go sub-minor

Thanks for sharing, I am confused on the PF data. I did end up finding Aliant's data sheet for 147g and was starting just as you recommended with 3.1. I started with the following minus 10% which is your 3.1. 

9mm Luger

147 FP

Federal

1.08

4

Fed 100

Sport Pistol

3.5

890

 

I have not chrono graphed these yet just doing the math at this point to estimate PF which gives me an approximate of 118. FPS @800 X147 = 117747. I am shooting out of a 4" barrel for my IDPA weapon. I'm new to a lot of the PF requirements so wondering if I'm computing my "guestimates" incorrectly.  

[Boomstick303]

2 hours ago, JPHoka said:

Thanks for sharing, I am confused on the PF data. I did end up finding Aliant's data sheet for 147g and was starting just as you recommended with 3.1. I started with the following minus 10% which is your 3.1. 

9mm Luger

147 FP

Federal

1.08

4

Fed 100

Sport Pistol

3.5

890

 

I have not chrono graphed these yet just doing the math at this point to estimate PF which gives me an approximate of 118. FPS @800 X147 = 117747. I am shooting out of a 4" barrel for my IDPA weapon. I'm new to a lot of the PF requirements so wondering if I'm computing my "guestimates" incorrectly.  

 

Others and I on this board have found 147 gr bullets to be more accurate at faster velocity depending on their gun. My grouping using Sport Pistol @ 3.2 gr with 147 gr bullets at 10 yds was the size of a grapefruit.  Once I bumped the PF up to around 135 using 3.5 gr of Sport Pistol is when the grouping became acceptable. About the size of a golf ball. I am shooting an X5 Legion. 

[Batmo]

2 hours ago, JPHoka said:

On 11/27/2020 at 8:13 AM, Batmo said:

3.0 grains of Sports Pistol is my standard load for all 147 grain coated bullets.  OAL may vary depending on bullet shape.  This load produces a powder factor of about 129.  For competition loads where a chronograph will be involved I load at 3.1 grains just to be sure I don't go sub-minor

Thanks for sharing, I am confused on the PF data. I did end up finding Aliant's data sheet for 147g and was starting just as you recommended with 3.1. I started with the following minus 10% which is your 3.1. 

9mm Luger

147 FP

Federal

1.08

4

Fed 100

Sport Pistol

3.5

890

 

I have not chrono graphed these yet just doing the math at this point to estimate PF which gives me an approximate of 118. FPS @800 X147 = 117747. I am shooting out of a 4" barrel for my IDPA weapon. I'm new to a lot of the PF requirements so wondering if I'm computing my "guestimates" incorrectly.  

 

Your math estimate is correct but without a chronograph achieving a correct PF is a guessing game at best.  Barrel length...bullet diameter...crimp....OAL and temperature are just a few things that would come into play in determining the numbers for estimating the PF from any particular fire arm.

Loading data is only a guide line and may not produce the same results with what you are shooting.  I found that 3.5 grains of Sports Pistol was a little hot in the pistols that I tested and settled on the 3.0/3.1 grain load. I found this load to be extremely accurate at 15 yards shooting my XDM 5.25 and a custom built 9mm 1911.  Good Luck with your future loads.

Edited November 29, 2020 by Batmo

[JPHoka]

3 hours ago, Batmo said:

 

Your math estimate is correct but without a chronograph achieving a correct PF is a guessing game at best.  Barrel length...bullet diameter...crimp....OAL and temperature are just a few things that would come into play in determining the numbers for estimating the PF from any particular fire arm.

Loading data is only a guide line and may not produce the same results with what you are shooting.  I found that 3.5 grains of Sports Pistol was a little hot in the pistols that I tested and settled on the 3.0/3.1 grain load. I found this load to be extremely accurate at 15 yards shooting my XDM 5.25 and a custom built 9mm 1911.  Good Luck with your future loads.

I've gotten some 3.1 at 1.110 loaded up for chrono testing. I'll start there and adjust. Thanks for all your input.

[Batmo]

12 minutes ago, JPHoka said:

I've gotten some 3.1 at 1.110 loaded up for chrono testing. I'll start there and adjust. Thanks for all your input.

That sounds like a really good starting point....adjust that by 1/10th of a grain at a time to find your sweet spot.  Make sure you "plunk" test OAL.  You should be good to go very shortly....Good Luck.

 

Edited November 29, 2020 by Batmo