Hey guys I was wondering if someone could tell me what is a fairly normal velocity spread for 9mm hand loads. I'm using a sr9 with 124g plated RN and 6.1 AA#5 with a 1.160 OAL and today at the range with a caldwell chronograph I was getting a spread of 47, 59, 49, and 80. All 10 shot strings. Velocity was all in the 1000 range with lowest at 957. Being semi new to reloading and very new to chronographs I figured I would ask the experts. Also I must mention that I can never get my lee seating die to reproduce exactly so some are seated at 1.159 and some at 1.160.5 but most are 1.160. Are these spreads somthing to worry about? Thanks guys.
Handload velocity spread question.
- Thread starter DTOM47
- Start date
Western powder 5.0 p24 has aa5 124berry start=5.6, max=6.3 oal=1.160
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Lee 2nd p509 shows copper plated aa5 at start=5.0, max=5.8 oal=1.060
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Did you watch for pressure as you worked up to the 6.1gr?
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You listed 47, 59, 49, 80. Are these groups sizes at 4.7 spread or 4.7 from bulls? Not sure how to take those references. But the answer is look for consistency. Lots of possibilities on flyers (numerous headstamps, seating to oal vs ogive, bullet tensions, etc, etc).
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What distance did those numbers occur?
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Lee 2nd p509 shows copper plated aa5 at start=5.0, max=5.8 oal=1.060
-
Did you watch for pressure as you worked up to the 6.1gr?
-
You listed 47, 59, 49, 80. Are these groups sizes at 4.7 spread or 4.7 from bulls? Not sure how to take those references. But the answer is look for consistency. Lots of possibilities on flyers (numerous headstamps, seating to oal vs ogive, bullet tensions, etc, etc).
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What distance did those numbers occur?
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Hey qrz, the max from the new western powder sheets say max is 6.4g for 124 berry plated RN. I did work up from the very min load and 6.1 was the load that would fully cycle and hold open slide on last shot. The spreads I listed were taken from my chronograph it's referring to the spread between min velocity and max velocity in a 10 shot string. For example if the min velocity was 950fps and the max velocity was 1000 fps the spread would be 50. Distance of chronograph was about 12 feet from muzzle.
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g.willikers
New member
Those are large spreads.
If my reloads get those, I know it's time to slow down and pay more attention to what's going on.
Sorry not to be more help, but the cause(s) is going to be hard to figure from long distance.
The devil is in the details.
You might want to re-read your reloading manual for a better understanding of those details.
Probably good advice for all of us, come to think.
If my reloads get those, I know it's time to slow down and pay more attention to what's going on.
Sorry not to be more help, but the cause(s) is going to be hard to figure from long distance.
The devil is in the details.
You might want to re-read your reloading manual for a better understanding of those details.
Probably good advice for all of us, come to think.
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Hey unclenick you are close. The standard deviations are 14.88, 17.04, 26, and 11.14. (Not in order by how i listed the spreads) OK g.wilikers that's what I was kinda wondering if I had a problem with my loads. Also FYI federal factory was at a 27 spread and winchester was at a 42 spread on 10 shot strings. So a little lower than mine haha. I guess back to the drawing board.... 
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ok on your 6.4. I listed 6.1 and gave the 5.0 edition reference to eliminate any confusion. Ok on your spread explanation. I think you can narrow that deviation by tyring things like same headstamp brass separating, deburring primer pockets, measure bullet and case to get a consistent tension, separate your bullets into mini-lots to get a consistent oal (ogive related). Number your casings in the powder ranges and then compare fired cases in inspection for pressure variants. If that doesn't work, shift to x-treme fmj's and repeat.
OP, if you want to be precise, you have to use the same head stamp case, and weight out each powder charge, and weight and measure each bullet diameter, and measure each OAL, and case length, and record all that stuff. But for pistol, inside of 40 yards, it will be way more accurate than you are anyway, so it doesn't matter. Tight spreads are less than 5 fps with the right powder and good quality bullets.
When testing AA#5, just to give you some idea,
15 shots per string, per test (several tests per cartridge)
.357 Mag ES 35-50fps
.45 ACP _ES 24-42fps
.44 Spec _ES 26-43fps
.45 Colt __ES 40-60fps
I would suspect your 9mm loads should fall somewhere in-between. The more shots the better for getting a better feel of ES and SD. That's why I choose 15 rounds per load test. You'll note your SD is approximately 1/3 of your ES (sort of rule of thumb). That is why I pay more attention to the ES. For pistol/revolver, I like my ES to be <= 50. Less is always better (0 would be great! Actually less the 20 is very good) . Some powders are better than others. The lower the ES, the more 'potential' for accuracy follows. As noted above 'consistency' of the process all enters in to the final ES value (powder charge must be the same, crimp same, case grip on bullet, case volume, primer same) . Then of course the gun itself can introduce error too.... <sigh>
15 shots per string, per test (several tests per cartridge)
.357 Mag ES 35-50fps
.45 ACP _ES 24-42fps
.44 Spec _ES 26-43fps
.45 Colt __ES 40-60fps
I would suspect your 9mm loads should fall somewhere in-between. The more shots the better for getting a better feel of ES and SD. That's why I choose 15 rounds per load test. You'll note your SD is approximately 1/3 of your ES (sort of rule of thumb). That is why I pay more attention to the ES. For pistol/revolver, I like my ES to be <= 50. Less is always better (0 would be great! Actually less the 20 is very good) . Some powders are better than others. The lower the ES, the more 'potential' for accuracy follows. As noted above 'consistency' of the process all enters in to the final ES value (powder charge must be the same, crimp same, case grip on bullet, case volume, primer same) . Then of course the gun itself can introduce error too.... <sigh>
Hey guys thanks for the replies! I am by no means trying to get my deviations down per say, rather I just wanted to make sure they were not "out of the norm" because there was an issue I needed to adress. I for sure am not the most accurate guy on the block with a pistol. So if I'm understanding this right I should be ok with the results from the load I developed? Thanks again for your responses.
shootniron
New member
If you have a standard deviation of 22fps...you are fine and actually doing quite well. Don't pay a lot of attention to the those that claim to be doing better, consistently. A few actually do load more consistent ammo...but it is a VERY FEW. Apparently, a lot of fisherman, must shoot...based on a majority of stuff posted on gun boards.
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DTOM47,
For long range shooters velocity variation affects vertical point of impact (POI) on the target enough to matter and most of the guys shooting 1000 yards try to get the extreme spread down to about 10 fps if they can. But at short ranges (≈100 yards for a 1 moa rifle and 25 yards for a 4 moa pistol) the bullet doesn't have time for the difference in drop on the target due to normal differences in velocity variation to be discerned from random grouping error, even shooting from a machine rest.
Example:
Pistol. 148 grain 0.358" Lead Wadcutter.
700 fps
25 yard drop = 2.3 inches
50 yard drop = 9.4 inches
750 fps
25 yard drop = 2.0 inches
50 yard drop = 8.2 inches
So, a 0.3 inch error or 1.15 moa at 25 yards, hard to tell from the 4 moa group. At 50 yards a 1.2" drop, or 2.3 moa, which begins to grow the 4 moa group more oval. If you were using a bullet with a higher MV and higher ballistic coefficient than the wadcutter, you'd have less error from a 50 fps spread, though. The target velocity wadcutter is a good worst case for velocity variation sensitivity.
For a rifle shooting a 175 grain 30 cal Sierra MatchKing bullet:
2500 fps
100 yard drop = 2.9 inches
300 yard drop = 29.2 inches
1000 yard drop = 518.4 inches
2550 fps
100 yard drop = 2.8 inches
300 yard drop = 28.1 inches
1000 yard drop = 494.7 inches
So velocity variation vertical errors of:
100 yard error = 0.2 inches or 0.19 moa
300 yard error = 1.1 inches or 0.53 moa
1000 yard error = 23.7 inches or 2.26 moa
The worst handgun velocity variation I've heard of was on another board where a fellow using powder too slow for his bullet weight was getting variation 27% of maximum from a 1⅞ snubby. He had a peak of about 650 fps and a bottom of about 475 fps, representing a 1.9:1 difference in muzzle energy. This was due to inadequate and therefore irregular ignition of the powder causing the bullet position in the barrel at the pressure peak to be different enough to produce that result. A longer barrel wouldn't have shown it nearly as much.
He had three options.
1.) He could improve the load by going to a magnum primer, carefully trimming all his cases to exactly the same length and using a Redding Profile Crimp die to give him the highest bullet pull, and putting a polyester pillow ticking tuft over the powder column to keep it over the primer. Then he'd have to work the load up over again as these steps would increase pressure.
2.) He could go to a heavier bullet and just deal with the added recoil and hope the POI didn't rise too much for his fixed sight picture.
3.) He could go to a faster powder and just accept a lower peak velocity of about 600 fps, but one that was more consistent.
For long range shooters velocity variation affects vertical point of impact (POI) on the target enough to matter and most of the guys shooting 1000 yards try to get the extreme spread down to about 10 fps if they can. But at short ranges (≈100 yards for a 1 moa rifle and 25 yards for a 4 moa pistol) the bullet doesn't have time for the difference in drop on the target due to normal differences in velocity variation to be discerned from random grouping error, even shooting from a machine rest.
Example:
Pistol. 148 grain 0.358" Lead Wadcutter.
700 fps
25 yard drop = 2.3 inches
50 yard drop = 9.4 inches
750 fps
25 yard drop = 2.0 inches
50 yard drop = 8.2 inches
So, a 0.3 inch error or 1.15 moa at 25 yards, hard to tell from the 4 moa group. At 50 yards a 1.2" drop, or 2.3 moa, which begins to grow the 4 moa group more oval. If you were using a bullet with a higher MV and higher ballistic coefficient than the wadcutter, you'd have less error from a 50 fps spread, though. The target velocity wadcutter is a good worst case for velocity variation sensitivity.
For a rifle shooting a 175 grain 30 cal Sierra MatchKing bullet:
2500 fps
100 yard drop = 2.9 inches
300 yard drop = 29.2 inches
1000 yard drop = 518.4 inches
2550 fps
100 yard drop = 2.8 inches
300 yard drop = 28.1 inches
1000 yard drop = 494.7 inches
So velocity variation vertical errors of:
100 yard error = 0.2 inches or 0.19 moa
300 yard error = 1.1 inches or 0.53 moa
1000 yard error = 23.7 inches or 2.26 moa
The worst handgun velocity variation I've heard of was on another board where a fellow using powder too slow for his bullet weight was getting variation 27% of maximum from a 1⅞ snubby. He had a peak of about 650 fps and a bottom of about 475 fps, representing a 1.9:1 difference in muzzle energy. This was due to inadequate and therefore irregular ignition of the powder causing the bullet position in the barrel at the pressure peak to be different enough to produce that result. A longer barrel wouldn't have shown it nearly as much.
He had three options.
1.) He could improve the load by going to a magnum primer, carefully trimming all his cases to exactly the same length and using a Redding Profile Crimp die to give him the highest bullet pull, and putting a polyester pillow ticking tuft over the powder column to keep it over the primer. Then he'd have to work the load up over again as these steps would increase pressure.
2.) He could go to a heavier bullet and just deal with the added recoil and hope the POI didn't rise too much for his fixed sight picture.
3.) He could go to a faster powder and just accept a lower peak velocity of about 600 fps, but one that was more consistent.
g.willikers
New member
While most of my pistol shooting is of the fast and furious variety, I do like to be able to hit a clay bird at 50 yards with my loads.
Never know when ya' might have to shoot an apple off someone's head.
As long as the loads are well within the range of safe loads, those velocity spreads won't be of concern.
It's only when the loads get to maximums, with no room for error, that even relatively small deviations can get dangerous.
It does pay to know what's what at all times.
So, worry less and shoot more.
That will be more productive.
buck460XVR
New member
My question would be, how was the accuracy at the distance you were shooting? So many folks put so much concern on velocity that they forget about accuracy. Was just reading another thread somewhere where the OP was not interested in anything more than "meh" accuracy as long as he was getting the highest velocity he could get safely. While I agree that there are a multitude of reasons for velocity spreads, I think that the OP should be satisfied with his, considering they are probably just range fodder. I doubt if someone using standard plated bullets, is looking for the highest velocity consistency and accuracy within the normal distances a sr9 is used. So many plated bullets are inconsistent enough(size and weight) to create even more of a spread than the OP is experiencing, even when loaded to the highest degree of handloading. Add a powder thrower to the mix(some are better than others) and I'm surprised the OPs numbers are as good as they are.
Thanks buck. Maybe I was a little unclear in my post or maybe the other posts got slightly off topic but I was not concerned with my velocity per say but since I am new to the whole works I just wanted to make sure it was fairly normal and I wasn't going to get into any danger areas. Thanks again guys I feel pretty confidant with my loads now.