OCW Help Please

[ashiha]

4 shot groups in each (loaded 4 in case of issues, didn't have any so just shot all)

These are 223 with IMR 4064.

Group 1: 22.5
Group 2: 22.8
Group 3: 23.1
Group 4: 23.4
Group 5: 23.7
Group 6: 24

Group 5 confuses me mainly. I'm not sure what to make of these results.

 

[DanSavage]

Did you shoot it round robin style ash?

 

[ashiha]

Yes sir. I set a new zero with a charge of 23.3 just before shooting this (to be in between and not have shots start flying too high). I also ran a boresnake through before each string.

 

[pell1203]

Perhaps running the bore snake through the barrel prior to each string was not such a good idea as it may have introduced an additional variable which could potentially make your results more difficult to interpret. After all, the rationale for shooting round robin is to minimize variability between groups but in your scenario every shot in the first group is made through a cleaner barrel than those in the last grouping.

Not sure what effect, if any, this may have had in your final results as I don't see a "classic" OCW pattern in your groupings. Hopefully others can interpret your results better than I. Have fun!

 

[ashiha]

Perhaps running the bore snake through the barrel prior to each string was not such a good idea as it may have introduced an additional variable which could potentially make your results more difficult to interpret. After all, the rationale for shooting round robin is to minimize variability between groups but in your scenario every shot in the first group is made through a cleaner barrel than those in the last grouping.

Not sure what effect, if any, this may have had in your final results as I don't see a "classic" OCW pattern in your groupings. Hopefully others can interpret your results better than I. Have fun!

That's the issue I had as well. It doesn't seem like a normal OCW result. This becomes particularly apparent at group 5 since it should theoretically have a higher POI than it does.

I guess I will do something along the lines of using 5 foulers at the start then shooting round robin without cleaning in between.

 

[Maelstrom]

Pardon my ignorance but what does OCW stand for?

 

[Thumper580]

To be honest you might want to try another powder better suited for 223. Maybe AA2230, TAC, XBR8208, IMR4895, 3031, etc. I've had really good luck with these powders in 223/5.56.

 

[MitchAlsup]

Pardon my ignorance but what does OCW stand for?

Optimal Charge Weight--it is a reloading procedure that seeks to find a charge weight that is least sensitive to everything that happens between reloading startion and when the bang happens.

 

[918v]

Yes sir. I set a new zero with a charge of 23.3 just before shooting this (to be in between and not have shots start flying too high). I also ran a boresnake through before each string.

Resetting your zero in the middle of an OCW test invalidates the test. OCW is more about POI shift than actual group size.

 

[richidaho]

? Ashih313 what software did you use to make the grouping data?

Rich L

 

[ashiha]

Resetting your zero in the middle of an OCW test invalidates the test. OCW is more about POI shift than actual group size.

It was reset before the test, not during. Zero before was set at a 21.3gr reduced load so I did a new zero first so that the shots wouldn't end up really high.

? Ashih313 what software did you use to make the grouping data?

Rich L

On Target