Help with load development target

[XTR]

I can usually figure these out, but this one is kind of puzzling to me.

5 different loads, shot at 300 yards. I have to think the low shot in the second group is a flyer. Where is the node?

(ignore the holes in the bottom, those are sighters on the target behind it.)

 

[BoydAllen]

First off, why are you testing at 300 yards? Secondly, are you shooting over some sort of wind flags, arrayed between your shooting position and the target? Third, what are the loads that you tested? Because wind can cause vertical, as well as horizontal bullet displacement, it is difficult to pin down your node, but the upper left group looks promising. There is a thread about testing loads for long range at 100 yards. I think that that procedure would be the best place to start, including the addition of flags, and additional notes as to loads, and velocities.

 

[XTR]

It was calm today. I shoot my OCWs at 300 yards, it usually works for me. After I test at 300 I take my loads to 600 yards and shoot 10 shot groups to confirm that they are working for me. If I can get a good day I'll take them to 1000 and do the same thing. ORSA is 25 minutes away, and I shoot a 308; I'm not worried about wearing out my barrels. This test just didn't give me the clearest of answers. I will probably take #1 and #4 back to 600 and see how they group.

The loads are all .3 grains apart lowest on the left. I'm shooting 200 Hybrids from an F-TR rifle (new barrel) off of a bipod.

The load on the left is the load I was using in my last barrel. I shot a similar test with it earlier this week and the results seemed to say I could look higher.

 

[dmoran]

My input is: you have good accuracy and promising potential. The lack of POI shift and positive vertical aspects of all 5 increments, tells me all 5 increments are in a good accuracy zone. And suggest to take it out to 600 or 1000 to find the true node center. Many times I have seen how the shorter distances do not tell the truth for long range loads that need to be taken to the intended distances to find the truth.

Going backwards to 100yds, as was suggested above, would be just that: going backwards and starting over - IMO. You have accuracy established with positive vertical as is. Pin-pointing the best vertical and least POI shifting is all that is needed to finish, that the intended target distances will tell the truth. Any thing found at shorter distances would just have to be confirmed at the longer intended distances, so why start over? Just continue on is my advise....

Good Luck
Donovan

 

[6BRinNZ]

XTR - are you using SRP brass?

 

[XTR]

XTR - are you using SRP brass?

Winchester large rifle primer brass

 

[6BRinNZ]

ta - asked because I tried load dev with SRP and came away scratching my head...ended up not going down that track as much as I would like to.

FWIW I thought groups 4, 5 looked promising with a seating depth tune for shape.

 

[fm1947]

#4

 

[dalej]

Between 4 and 5. Tweak seating depth to fine tune.

 

[dcali]

The size of the groups and the uncertainty of their centers dwarfs the size of the vertical change, so I'll go out on a limb and say that it's impossible to tell. Which might be another way of saying "there isn't one".

 

[Lapua40X]

I don't think you have enough data to make a rational judgement here. IMO, trying to find a node with three shot groups at 300 yards is fantasy; too many statistical possibilities. If the low shot on #2 is a flyer then we could just as easily call any shot in any group a flyer.
I don't see any reason not to use 300 yard data in this type of test, but I"d recommend you use a minimum of five shots to get a better idea of how those pills are actually performing when they leave the muzzle.

 

[Ledd Slinger]

I only work with triangle shaped groups when possible. They seem to tune in better than vertial or horizontal groups. I don't even mess with groups that give 2 together and a flier. The 2 and 1 groups are hard to find a node that is forgiving.

As far as 300 yards testing goes...good way to do business. I do initial testing at 100 yards to find powders a rifle likes, but the 100 yard tests mean nothing to me if they won't perform at 300 and beyond. For fine tuning, I use 200 yards as a minimum, during as calm a day as possible. If your groups are tight at 200-300 yards, you can guarantee they'll be ragged holes at 100.

 

[barefooter56]

XTR,
# 1 has the least amount of vertical. That is the one I would go with as long as it met my requirement for velocity. Very good "water line" !!!