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Need veloicty data !
- Thread starter Rimdenter
- Start date
Reason I'm asking i put on a new Keystone Accuracy barrel today 25" medium Palma. Match chamber run it in with Wolf Target 100 rounds then I put 7 brands 10 shots each through it the avg. Veloicty drop was 2-9 fps over my 18" Proof, target was 320 yds. Faster the bullet better the group . The Midas plus shot worse then my super Red Hawk at that range with a 4 power burris.
The Rws 100 shot a12" group
The Eley black box shot just under 10"
It had a es of 19 sd was 6 ?
SKRM had a es of 28 with a sd of 8 shot just under 9"
SKLR had a es of 21 a sd of 5 put all 10 under 7"
SKPLUS es 25 sd of 8 put all 10 in 8"
Now heres the kicker
SK HVM es 35 sd 10 put 8 on a 3.5x3" group 2 rounds 2" up all 10 on a 5.5x3" group the rounds avg. 183 fps faster then everything else what gives is this a possible sign of improved gyroscopic stability? The numbers yall have posted are very close but im not seeing this major reduction in the additional 7" of extra barrel im running. What I'm seeing is the ammo running 1234 fps groups better. Will see how it fairs next week at 600.
The Rws 100 shot a12" group
The Eley black box shot just under 10"
It had a es of 19 sd was 6 ?
SKRM had a es of 28 with a sd of 8 shot just under 9"
SKLR had a es of 21 a sd of 5 put all 10 under 7"
SKPLUS es 25 sd of 8 put all 10 in 8"
Now heres the kicker
SK HVM es 35 sd 10 put 8 on a 3.5x3" group 2 rounds 2" up all 10 on a 5.5x3" group the rounds avg. 183 fps faster then everything else what gives is this a possible sign of improved gyroscopic stability? The numbers yall have posted are very close but im not seeing this major reduction in the additional 7" of extra barrel im running. What I'm seeing is the ammo running 1234 fps groups better. Will see how it fairs next week at 600.
It may not be possible to have a basic answer that applies across the board for any ammo in barrels of different lengths. The results other shooters get for a particular lot of ammo in the barrel on their particular rifle may not be the same as others.
There are at least two general problems worth noting. One has to do with the barrels themselves, the other with the ammo.
Bores are not identical simply because they have the same length. They vary between manufacturer and even between each other on identical models. Bores vary in ways including not only length but also bore diameter consistency through the length of the barrel (tighter and looser areas), bore concentricity consistency, and rifling consistency and wear. Even different chambers have a role in how bores respond to ammo.
The result is different barrels of the same length may shoot the same lot of ammo with different results in terms of accuracy and MV, including ES and SD. Different lots of the same variety of ammo may shoot differently in the same barrel in terms of accuracy and MV, including ES and SD. Across different barrels the results are even more complicated.
The bottom line, quite literally, is that the length of the barrel and the name on the ammo box are not criteria by which barrels and ammo respond in a reliably similar or universal way.
could just be your rifle like that lot of ammo
i would wager that 4 more 10 round groups from each all end with very similar results down range
how were you cleaning between ammo types? did you clean? fire 20-30 before shooting groups? or just switch ammo and have at it
True that,but the tell all MIDAS and ELEY with the low ES. SD'S got their butts out shot this lends to a long range stability issue due to veloicty. I'll be setting up at 600 next week I'll clean and run in between ammo will see what happens.
Yep, I've seen some interesting groupings happen during my 200 yard mornings.
With the chronograph out front, my results showed that specific muzzle velocities produced tighter clusters.
Same mv's, even with different brands of 40 grain cartridges, produced more consistent trajectories.
Benchrest competitor looked at my chrony numbers and target results for those runs,
and commented that that particular bullet weight/range of mv's must be a good fit to the barrel harmonics and exit timing.
With the chronograph out front, my results showed that specific muzzle velocities produced tighter clusters.
Same mv's, even with different brands of 40 grain cartridges, produced more consistent trajectories.
Benchrest competitor looked at my chrony numbers and target results for those runs,
and commented that that particular bullet weight/range of mv's must be a good fit to the barrel harmonics and exit timing.
Has to be harmonics ,the Lapua stability calculations show their ammo running at best in untuned rifles 225 yds.for a avg. MVS of 1065 at muzzle. I was astounded the SK ammo out shot the $15.00 a box bullets I might look at pushing hand loads up some in velocity if these groups hold at 600. To see where the sonic transition starts breaking the spread down. Maybe it can be corrected with higher spin rates ? I might need to put the 3 g 9 twist back on and blast the 600 yard line with it to build a solid baseline.
It's Friday...slow morning at the office. 
I've found that the transition from super-sonic to sub-sonic with the 22lr has little or no effect on my results.
Doesn't matter 50 yards, 100 or 200 yards, the transition causes almost no pitch or yaw with the short, stubby 22lr.
I've sent similarly made cartridges from Eley, one sub-sonic, the other super-sonic and the results were almost identical.
50 shot clusters and the spread was the same. It would appear cartridge quality has more effect on accuracy than the transition.
The 22lr is not a long, slender, needle nosed, tail heavy bthp, where the shift in center of pressure unbalances the projectile.
The other thing to remember, the 22lr goes subsonic before it hits 50 yards. I've found that cartridge defects are responsible
for the majority of accuracy problems that most shooters will blame on the transition. Get in the habit of visually inspecting
the ammunition before chambering, it'll make the correlation to poor results extremely apparent.
I've found that the transition from super-sonic to sub-sonic with the 22lr has little or no effect on my results.
Doesn't matter 50 yards, 100 or 200 yards, the transition causes almost no pitch or yaw with the short, stubby 22lr.
I've sent similarly made cartridges from Eley, one sub-sonic, the other super-sonic and the results were almost identical.
50 shot clusters and the spread was the same. It would appear cartridge quality has more effect on accuracy than the transition.
The 22lr is not a long, slender, needle nosed, tail heavy bthp, where the shift in center of pressure unbalances the projectile.
The other thing to remember, the 22lr goes subsonic before it hits 50 yards. I've found that cartridge defects are responsible
for the majority of accuracy problems that most shooters will blame on the transition. Get in the habit of visually inspecting
the ammunition before chambering, it'll make the correlation to poor results extremely apparent.
So heres the deal just ran velocity curve data on
ELEY TENEX. H1096 l1077 avg 1085 es19 sd 6. Drop at 320 yds h 138.6" L 143.44"
SK HV h1263. L1231 AVG 1247 es 32. Sd 10.5 drop at 320 H 116.36" L 119.27"
SKHV AVG. DROP 2.91 WITH ES OF 32 AND A SD OF 10.5
ELEY AVG. DROP 5.08 WITH ES OF 19 AND A SD OF 6
Long story short I'm sacrificing 2.17" of mathematical accuracy at 320 yds by saying a lower es and sd is a proven winner when that's not the case when veloicty and stability at longer yardage have proven this between these 2 rounds.? Much more testing is required.
ELEY TENEX. H1096 l1077 avg 1085 es19 sd 6. Drop at 320 yds h 138.6" L 143.44"
SK HV h1263. L1231 AVG 1247 es 32. Sd 10.5 drop at 320 H 116.36" L 119.27"
SKHV AVG. DROP 2.91 WITH ES OF 32 AND A SD OF 10.5
ELEY AVG. DROP 5.08 WITH ES OF 19 AND A SD OF 6
Long story short I'm sacrificing 2.17" of mathematical accuracy at 320 yds by saying a lower es and sd is a proven winner when that's not the case when veloicty and stability at longer yardage have proven this between these 2 rounds.? Much more testing is required.
Is velocity the deciding factor? Is figuring out the difference in elevation relevant? Look at the Eley force in this chart. The number under the ammo lot number is the group number. Some data is missing in velocity column due to um well accidents happen....
How does force make groups smaller then the velocity vertical should be?
Attachments
That spreadsheet......
Any chance you could pull a pivot table off of that comparing ES and SD in relation to barrel length? I know not scientific but....
I have determined veloicty and stability are the key factors I have viewed this several times theres a point veloicty overrides a wider es the very reason SKLR out shoots most ammo I wont get to try the SK HV till this weekend at the long target it shot very good at 330 , but the 180 fps increase made it peel right 3-4 inches more then the LR the Lapua ballistic chart contradicts that it actullay computes less drift then the 1080 plus and this isnt the case it could be error generated since my barrels are right hand twist and you have to enter negative data for this.
Absolutely thats what I see but the Lapua program says no ? But I do know this your automatticly giveing up 2 " of vertical group to a lower 1080 veloicty ammo with 1/2 the ES I saw that on paper and the math backs it up. At 320 yds
I haven't shot over a chrono. Drop says SK long range match is running 1120fps out of my 18" barrel.
Stre-lok says published is 1109fps.
I was getting 1230fps out of pistol match special. It was within .1-.2" of the long range match. Published is only 955, but I don't know what barrel length they use.
Stre-lok says published is 1109fps.
I was getting 1230fps out of pistol match special. It was within .1-.2" of the long range match. Published is only 955, but I don't know what barrel length they use.
I'm not convinced on the higher velocity part being more accurate yet. The stability part I'm totally convinced. The higher velocity maybe makes enough stability difference?
In the cold below -10⁰c i had a ammo that fell apart but the high velocity version stabilized.
1-16 is very marginal for stabilizing a 22lr bullet so.....
What I'm saying Is at this point I'm not convinced its the velocity that gains the accuracy rather the additional stability gained by velocity.
In the cold below -10⁰c i had a ammo that fell apart but the high velocity version stabilized.
1-16 is very marginal for stabilizing a 22lr bullet so.....
What I'm saying Is at this point I'm not convinced its the velocity that gains the accuracy rather the additional stability gained by velocity.
More so stability I truly believe, but if you can add controlled veloicty you automatically reduce group size the arc decreases therefore your allowable room for error increases while maintaining equal accuracy.
I'll have to look on my charts in office I saw 1118 yesterday twice on duplicate shots once 1115 duplicate a 1108 and something else it was 74.5 degs. Yesterday the ES was 15 with a sd of 6 for 10 shots
so did the match/low velocity just drop below the barrels harmonic speed preference and the high velocity dropped down into it?
The denser air requires more spin for stability so I think with that bullet it was borderline stable when warm then combine higher air density and lower velocity it became unstable. 12"+ groups at 50 yards. The HV version of that bullet is 150 fps faster and grouped 2-3" when cold. Both ammo group just fine in warm weather. As in fine for what they are. Federal target and auto match.
I had one other ammo start to open up in the cold weather as well but not keyhole. Cci sv
Then I have other ammo that is running slower yet in the same cold and maintaining precision like before. Sk/Lapua
That spreadsheet......
Any chance you could pull a pivot table off of that comparing ES and SD in relation to barrel length? I know not scientific but....
The problem with in comparing those things in this spreadsheet is that different ammo is used in different guns. Like in a 3" barrel from a pistol, one typically rather cheap stuff rather than match grade ammo. Whereas for many of the longer rifle barrels, quality match grade ammo is used, so ES and SD can't really be compared well. But if I take something like Winchester SuperX that's fired in various pistols and rifles to get a good variation in barrel lengths, one can see that there really no correlation evident. And that's what I'd expect since ES's and SD's of MV values are really nothing more than a measure of cartridges performance relative to each other out of a particular barrel.
I'm attaching to excel files with the extension changed to PDF that I can upload it here. So, you'll need to change the extension back to .xlsx to open it in Excel.
Thanks! I agree 100% we would also need to know lot# etc.
I like looking for averages. I am in the process of testing for groups and velocity spreads with a 3 different eley ammo and 2 sk maybe 1 more wait and see.
I have a IBI at 26" then plan on doing 24,22,20 be doing 50, 100, 200, 300 yds
Looking at my data, a good batch of Eley Tenex can get you single digit SD's and ES's in the 20's. The better Eley Target ammo looks like SD's in the mid to low teens with ES's around 60 (a little better if one is only looking at 10 shots) and Eley Match looks very similar to Target. The SK Long Range Match and SK Rifle Match have produced some good number too where they're almost the same getting single digit SD's and ES's in the 20's to low 30's (the Long Range Match better numbers than Rifle Match). If you don't want the pricey Tenex, you might take a good look at SK's Long Range Match as it appears better than Elely Target and Eley Match as far as the numbers I've collected (it's right there with CenterX). As a disclaimer
, you know it'll depend on good the particular lots you happen to test. Have you tried the Eley past 300 yds ?Looking at my data, a good batch of Eley Tenex can get you single digit SD's and ES's in the 20's. The better Eley Target ammo looks like SD's in the mid to low teens with ES's around 60 (a little better if one is only looking at 10 shots) and Eley Match looks very similar to Target. The SK Long Range Match and SK Rifle Match have produced some good number too where they're almost the same getting single digit SD's and ES's in the 20's to low 30's (the Long Range Match better numbers than Rifle Match). If you don't want the pricey Tenex, you might take a good look at SK's Long Range Match as it appears better than Elely Target and Eley Match as far as the numbers I've collected (it's right there with CenterX). As a disclaimer
I have found the same. I also do not find a distinct relation between group size and velocity at long range. Sooo the quest continues.Looking at my data, a good batch of Eley Tenex can get you single digit SD's and ES's in the 20's. The better Eley Target ammo looks like SD's in the mid to low teens with ES's around 60 (a little better if one is only looking at 10 shots) and Eley Match looks very similar to Target. The SK Long Range Match and SK Rifle Match have produced some good number too where they're almost the same getting single digit SD's and ES's in the 20's to low 30's (the Long Range Match better numbers than Rifle Match). If you don't want the pricey Tenex, you might take a good look at SK's Long Range Match as it appears better than Elely Target and Eley Match as far as the numbers I've collected (it's right there with CenterX). As a disclaimer
Only did 200. Not very good. 5"+ at 200. So far the only correlation between 200 yd groups and anything is base to ogive measurements. My rifle likes long ammo.
my Tenex is short.I was gonna say you'll proably hate it at 300 yards I shot some at 320 it really sucked had a awesome es 15 sd was 6Only did 200. Not very good. 5"+ at 200. So far the only correlation between 200 yd groups and anything is base to ogive measurements. My rifle likes long ammo.
Oh well, I went out today to get some Labradar velocities in my Vudoo V22 with Lapua Center X. I thought I could get data even without an external mic but it was not to be, even on the most sensitive setting. I guess I'll order that darn mic or an inertial trigger.
ETA - Appears the consensus of LR users is to get the inertial trigger.
ETA - Appears the consensus of LR users is to get the inertial trigger.
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