Question for those that have way more experience in this than me, but we know that in a semi-auto of similar barrel length that you won't get as high of velocity #'s with the same ammo as in a bolt gun.
However do you also expect to see significantly more spread and standard deviation?
So I've had a JP supermatch barreled upper (had two in fact) neither have ever impressed me with accuracy. To be fair to JP, if you dig deep in the manual, they state that these are not designed for max accuracy, but more for reliability (perhaps maybe "supermatch" is not the right name for them then).
The accuracy issues seem to be just flyer related, it will stack 3-4 rounds and throw a couple badly, like 1" off at 50yds. I thought I've noticed shooting it that it seemed like perhaps the ignition wasn't great (weak cycling/sounding loads etc.) as the primer hits were not nearly as deep as my CZ or 10/22s. I know AR22's can be trigger picky, so I've tried 3-4 with no real difference, aside that a hiperfire would not even get ignition. Now that I have a garmin chrono for my centerfires I thought I'd do an experiment.
I took 4 different ammo choices: Tac 22, Eley Precision Benchrest, and 2 lots of SK Long Range. I ran 50 rounds of the same lot through both the JP and my CZ 457 with the chrono and compared #'s, same day, same range, same bipod/rear bag etc. I fully expected velocity out of the CZ to be higher, but the JP was also ~2x worse on spread and standard deviation as well. Tac 22 was by far the worst, some of the lowest velocities on those out of the JP were not even 900fps. The weak cycling from those very soft rounds also caused the next round to be a flyer (I can only assume because it changed the cycling speed). It got to the point where you could basically look at the chrono and call shots as good or flyers.
Lots of things jump out at me here, none of which are good for the JP and accuracy. First the average velocity across all four varied only 17fps for the CZ but almost 60fps for the JP. Both Standard Deviation velocity spread was basically 2x in the JP what the CZ was. Obviously this lot of Tac 22 is not good, and part of why I used it here was I know it's not consistent, but even so we can see the JP #'s are way worse than the CZ.
However do you also expect to see significantly more spread and standard deviation?
So I've had a JP supermatch barreled upper (had two in fact) neither have ever impressed me with accuracy. To be fair to JP, if you dig deep in the manual, they state that these are not designed for max accuracy, but more for reliability (perhaps maybe "supermatch" is not the right name for them then).
The accuracy issues seem to be just flyer related, it will stack 3-4 rounds and throw a couple badly, like 1" off at 50yds. I thought I've noticed shooting it that it seemed like perhaps the ignition wasn't great (weak cycling/sounding loads etc.) as the primer hits were not nearly as deep as my CZ or 10/22s. I know AR22's can be trigger picky, so I've tried 3-4 with no real difference, aside that a hiperfire would not even get ignition. Now that I have a garmin chrono for my centerfires I thought I'd do an experiment.I took 4 different ammo choices: Tac 22, Eley Precision Benchrest, and 2 lots of SK Long Range. I ran 50 rounds of the same lot through both the JP and my CZ 457 with the chrono and compared #'s, same day, same range, same bipod/rear bag etc. I fully expected velocity out of the CZ to be higher, but the JP was also ~2x worse on spread and standard deviation as well. Tac 22 was by far the worst, some of the lowest velocities on those out of the JP were not even 900fps. The weak cycling from those very soft rounds also caused the next round to be a flyer (I can only assume because it changed the cycling speed). It got to the point where you could basically look at the chrono and call shots as good or flyers.
| Ammo | JP AVE | CZ AVE | JP STD | CZ STD | JP Spread | CZ Spread |
| Tac 22 #4 | 986 | 1102 | 30.7 | 16.3 | 138 | 80.6 |
| Eley BRP | 995 | 1109 | 12.8 | 5.8 | 57 | 26.6 |
| SK LR #6 | 1026 | 1110 | 13.8 | 7.1 | 50 | 21.7 |
| SK LR #4 | 1044 | 1119 | 13.8 | 7.4 | 69 | 31.9 |
Lots of things jump out at me here, none of which are good for the JP and accuracy. First the average velocity across all four varied only 17fps for the CZ but almost 60fps for the JP. Both Standard Deviation velocity spread was basically 2x in the JP what the CZ was. Obviously this lot of Tac 22 is not good, and part of why I used it here was I know it's not consistent, but even so we can see the JP #'s are way worse than the CZ.
