223 OCW test

[jpmimproved]

I chose to shoot three shot groups with the OCW method as you are not looking for group size as much as you are where the groups are centered. In particular, whether across a band of groups the vertical dispersion is similar or not. More often than not, I find that 5 shot groups, while they do open up, do not significantly change in the groups average position relative to the target. Also, it seems that you are looking for a pattern across the array of groups, not how well each load groups, when performing the test. When I start testing seating depth, I intend to use larger group sizes.

 

[jsthntn247]

Water line looks good and less horizontal than the 23.4 charge. And yes 24.8 or 25 just might answer all the questions.
LitLBoy
PS What makes 24 a scatter node?
Thanks

If you don't know this, why respond to a question about OCW? That's how these threads get cluttered up with BS and the OP has a hard time finding the real answer.

 

[LitLBoy]

jsthntn
Read it all. I ADMITTED my mistake in my second post.
LitLBoy

 

[USMCDOC]

For my purposes this would not be very valuable as the groups were only three shots each, despite lots of groups, the range was restricted to 100 yards and velocities were not measured. In my thinking 69 grain bullet loads for a .223 with a 1-8 would be intended for ranges up to and including 600 yards; at that distance velocity spreads would be a consideration. Many tight 3 shot groups have been fired at 100 yards but have had considerable velocity spreads. A .1 grain powder charge increment is .4 percent of a 24 grain charge and might not affect much of anything.

If possible testing at 300 yards and even better at 600 might be more definitive.

1) Have you ever tried to shoot the SIE 69 MK at 600 yards?
2) the 223 case is small enough that One Tenth increments are enough to cause drastic differences!


As for testing, i have found that using a Ladder Test is best for finding the max pressure. Then use the data from the Ladder to point you in the right place to find that OCW load. It has been working for me.. i now have 4 working loads for .223 and i didn't use more than 40 bullets of each kind total to find those screamers!

 

[Clancy]

I’ve done ladders, OCW and the “cortina.” The Cortina is the only one that hasn’t lied to me.