Load Accuracy

[Jimbuck]

We are reloading 9mm. Using 115 grain Hornaday Round Nose, 4.2 grains of Bulleyes with Federal Primers. From two guns (Sig 229 and S&W 9 compact) they shoot consistantly low. This was from two shooters. Any ideas? Not enough powder? Crimp not right? They all case guage fine and there are no FTF issues. Thanks,

 

[mike_in_md]

Good groups?

 

[Biggfoot44]

What load are the sights calibrated for ? Do these guns shoot to same POI with factory 115fmj ? As a rule of thumb , it the (presumably fixed) sights are aligned for 124gr , 115 will group low ( and 147gr high).

 

[Magnumite]

This a POI condition, not accuracy. Accuracy is misused in shooting but is used to indicate group size in shooting jargon. Accuracy is actually a measure of repeatability to a level of precision. Precision is how finite (or in shooting, how close a group of shots are together) a measurement or distribution is.

I use virtually the same load (4.2 BE, 115 grain bullet) different components. The load chart indicates it is not real fast. This load also shoots higher, consistent with slower velocity for same bullet weight.

The others have posted good thoughts on what are your sights regulated for and how does this POI compare with factory loads in same bullet weight? I would suggest the comparison be made with factory ball in 125 grain weight.

 

[Jimbuck]

Thanks all. Will do somemore testing. The groups were rather large (6 inches) at about 10 yards.

 

[Jimbuck]

These are standard sights, not having any adjustments made. Not sure what they are set for at the factory.

 

[mike_in_md]

Thanks all. Will do somemore testing. The groups were rather large (6 inches) at about 10 yards.

That would be a 15 inch (terrible) group at 25 yards. I recommend shooting from a bench rest supported position to try and eliminate as much human error as possible if you haven't done that first and shoot for groups (aim at the same spot for all shots). I'm guessing that if you haven't benched the gun, that the group is likely based on the expertise of the shooters and that low POI could be related to their skill. One possible explanation is jerking the trigger and related flinching. With that said, 10 yards is not very far away. May I ask how many inches below point of aim the shots are going?

FYI. I use Bullseye 4.5 gr powder at 1.120 OAL for my 9mm Beretta 92FS and that gets me about 1180 FPS with very good accuracy. My reloading manual says 5 gr powder for that OAL does 1180 FPS, but my 92FS flings them at almost 1300 FPS so I had to adjust accordingly. This is probably because my 92FS barrel is not a factory barrel, it's a 1/32 twist Match KKM barrel. I'm going to bring my Glock 19 to the range later today and chronograpgh it with the 4.5 load to compare the difference. The real reason I'm going to the AGC today though is to chronograph my 9mm reloads using Unique and HP 38 powder since I have very little other pistol powder laying around and want to conserve my remaining Bullseye powder for 45ACP and 38.

 

[trickg]

Posting so I can follow this thread. In my experience, Bullseye has been a wonderfully accurate and consistent powder, although to be fair, I've never used it in 9mm - only .45 and .38 spc.

 

[Biggfoot44]

As sugguested try some quality factory 115 and 124 for group and POI. From your prefered braced or supported position to minimize human variables.

 

[mike_in_md]

Posting so I can follow this thread. In my experience, Bullseye has been a wonderfully accurate and consistent powder, although to be fair, I've never used it in 9mm - only .45 and .38 spc.

My most accurate 9mm load was using Bullseye and a Sierra bullet. I have a 50 yard target from a ransom rest with a 5 shot 3/4 inch group. Is that good enough?

 

[trickg]

My most accurate 9mm load was using Bullseye and a Sierra bullet. I have a 50 yard target from a ransom rest with a 5 shot 3/4 inch group. Is that good enough?

Daaaaaang - that's more than good enough!

 

[Melnic]

FYI. I use Bullseye 4.5 gr powder at 1.120 OAL for my 9mm Beretta 92FS and that gets me about 1180 FPS with very good accuracy.

Same here. This is pretty much what I target for my 9mm using CPRN and the same OAL. My chrono said average 1150FPS from my Walther P1

1125-1150 was about what Federal factory 9mm was doing in my P1.

But even when I ran lighter loads, I did not notice as much drop at 10 yards as you are reporting.

 

[mike_in_md]

FYI. I use Bullseye 4.5 gr powder at 1.120 OAL for my 9mm Beretta 92FS and that gets me about 1180 FPS with very good accuracy. My reloading manual says 5 gr powder for that OAL does 1180 FPS, but my 92FS flings them at almost 1300 FPS so I had to adjust accordingly. This is probably because my 92FS barrel is not a factory barrel, it's a 1/32 twist Match KKM barrel. I'm going to bring my Glock 19 to the range later today and chronograpgh it with the 4.5 load to compare the difference.

I'm back from the range. I took my 5 gr Bullseye load using a Zero 115 FMJ. It was 1290 FPS with the Beretta 92FS match gun and 1191 FPS in my factory unmodified Glock 19 for the same load. I was using Tula Primers. For HP 38 it looks like 4.65 gr gets my Beretta 92 with KKM barrel to 1180 FPS for 1.125 OAL and for Unique it was 1175 FPS at 1.120 OAL using Zero 115 FMJ bullets, 5.5 gr powder, and Tula primers.

This goes to show that every gun is different and it seems barrel twist, barrel length differences, as well as bullet and primer used have a very significant impact on speed. A chronograph is very useful for working up loads. In my case I am trying to duplicate recoil management as best as possible between powders. The groups were all about the same, but not a surprise since I used the same bullet.

 

[Jimbuck]

Beside Ranson, are there any other pistol rests?

 

[Pinecone]

Not as good as a Ransom rest, there are the ones that work like a front rest and bag for a long guns.

http://ads.midwayusa.com/product/51...-_-pf_ci_google-_-pf_ci_google-_-pf_ci_google

http://www.brownells.com/shooting-a...e-rests/bullshooter-pistol-rest-prod9688.aspx

http://www.mtmcase-gard.com/products/shooting/shooting-rests.html

 

[mike_in_md]

I have a Caldwell Hammr Ransom rest clone, but they discontinued making them in 2008. It users Ransom Rest grip inserts. Midway use to sell them for $165, but I probably got the last one. I paid $32 new from Midway on a clearance sale. It works almost as good as a Ransom Rest and in some ways better. You may find a use one for sale.

 

[Magnumite]

Didn't Caldwell or somebody come out with a less sophisticated rest several years back?

 

[Blacksmith101]

Jimbuck

The first thing I would recommend is to establish a baseline using a variety of factory ammo. Decide what your test methods will be, number of rounds, distance, position or supported, etc. Then fire enough targets to figure out what is "average" for you and record the data and file the targets for reference. Do this for a variety of commercial loadings from several manufacturers (the same bullet type and weight from different makers may shoot differently). Once you have an established baseline you will be able to judge if your loads shoot better or worse and as you refine your loads will see the differences.

 

[Biggfoot44]

Mechanical rests have the advantage of not getting fatigued, an important factor if testing a bizillon rounds.

A decent shooter can aproach , if not match, a mechanical rest using sandbags or whatever, for a few groups while fresh.

Experement a little to discover what rested and/ or braced position works well and copnsistantly for YOU. Use raw 5 shot groups to make relative comparisons. A rule of thumb is in circulation that the best 3 out of 5 from braced/ rested handheld will be reasonably close to 5 round group size from a Ransom.