Your opinion on load development

[300 RUM]

I would like to get some opinions here.

First the targets below are 1/2 moa X rings and 1 moa 10 rings etc. for a simulated F-T/r class target, they were shoot from the prone position at 200 yards. One load use has a .040 jump and the other load used has a .030 jump (same powder charge) Lapua brass, CCI # 2 primers, each target is marked accordingly.

So when you view the targets you will see some tighter grouping with the .040 jump over the .030 jump. On the .040 jump target you will also see 3 shoots scoring 8's and 2 shots scoring 9's. When I view these targets and do a comparison I favor the .040's jump target over the .030.

And here's the question. Do you agree/think that the obviously missed placed shoots were a result of a "bad hold" and due to recoil differences or such, or is it something else?

 

[jlow]

To my untrained eyes, seems like there is some vertical stringing on both groups. Do you have MVs?

 

[300 RUM]

To my untrained eyes, seems like there is some vertical stringing on both groups. Do you have MVs?

Actually both the .040 and the .030 had a great SD the .040 was 7 and the .030 was 8, extreme spreed for both was 20fps give or take.

 

[jlow]

That is indeed very nice – congrats there! I think the problem with these “fliers” is that we all (at least the mortal one of us) seem to get them but figuring them out seems to be the holy grail. Sorry can’t be of much help. Would also like to hear from the experts.

 

[jp]

is the top target turned same way as shot?

 

[fredhorace77]

if the top (.030) jump target is indeed sideways in the photo..i favor it more...i personaly would try a load with .025 and .020 jump and see what they do...as a general rule of thumb with my rifles i find that if i get vertical stringing in a target i usually give it more powder if i can and also play with the seating depth...personaly when i see horizontal stringing in my groups i normaly can attribute that to wind...

 

[K22]

The shots in question for the .040" jump could very well be due to shooter error since as you know, making the slightest error shooting prone off a bipod can induce this kind of error. However I think it's difficult to draw conclusions on load comparisons when not shooting off the bench with as much control as you can acheive to minmize as many variables as possible.

I'm no expert but I'll share my procedure. I do all my load development off the bench with as stable of shooting platform as possible. My initial testing consists of 3 shot groups to narrow the field but before I adopted a load, I shoot three - 5 shot groups on different days from a slightly fouled barrel. Sometimes I'll shoot another group or so if I suspect a flyer was due to my error but normally it becomes obvious which load is going to work and which isn't by examining the clustering. If I see my shots going awry (without being called) during practice (shooting off the sticks) under field conditions, I'll sometimes go back to the bench (which I hate ) to verify it's me, not the load.

P.S. I wouldn't be surprised if a longer jump yielded better accuracy for some rifles. I have one 223 that prefers a .020" longer jump than my other six 223s.

By the way, very nice shooting.

 

[300 RUM]

is the top target turned same way as shot?

The top target is rotated 90 deg off it should be 90 counterclockwise

 

[300 RUM]

The shots in question for the .040" jump could very well be due to shooter error since as you know, making the slightest error shooting prone off a bipod can induce this kind of error. However I think it's difficult to draw conclusions on load comparisons when not shooting off the bench with as much control as you can acheive to minmize as many variables as possible.

I'm no expert but I'll share my procedure. I do all my load development off the bench with as stable of shooting platform as possible. My initial testing consists of 3 shot groups to narrow the field but before I adopted a load, I shoot three - 5 shot groups on different days from a slightly fouled barrel. Sometimes I'll shoot another group or so if I suspect a flyer was due to my error but normally it becomes obvious which load is going to work and which isn't by examining the clustering. If I see my shots going awry (without being called) during practice (shooting off the sticks) under field conditions, I'll sometimes go back to the bench (which I hate ) to verify it's me, not the load.

P.S. I wouldn't be surprised if a longer jump yielded better accuracy for some rifles. I have one 223 that prefers a .020" longer jump than my other six 223s.

By the way, very nice shooting.

All initial tests were done off the bench, I started with .010 jamb to .040 jump and with each increase in jump the groups became better. I did not try a .050 jump yet.

I shoot the two groups prone just for the sake of it.

 

[300 RUM]

Ok went back to the range this morning to see if I found a good seating depth or not. On the newly posted target you will see 2 three shot groups and 1 labeled "warm-up", then 3 shots aiming for the center and 3 shots aiming for a additional 1/2" dot. This target shot prone just as described on my original post.

Great results, although I have 2 shots touching and one to the left on each, there was no elevation change on either group and POI was dead nuts for POA. One group is .486 and the other is .354, I will consider this GE (Good Enough) for now.

Further analysis of my shooting position I will say the flyers on the original posted targets were due to a harder hold against my shoulder causing an indifference in recoil.