10 shot load development, help me with the next step.

[bigdawg86]

Hey guys, so I am trying the "new" ten shot OCW test. I'm using Savage 110 Ultralite in 6.5 Creedmoor which has a 22 inch barrel. I was also shooting suppressed. Using the following charge weights of IMR 4064 below gave me the following plot line. The goal of this ammo is nothing crazy other than popping prairie dogs, coyotes, and varmints in general. I have a ton of these 95g VMAX laying around from when I thought I was going to build a 6.5 Grendel, but that didn't happen so I may as well use them. Same with the powder, using it because I have it.

1) 39.8 @ 2943
2) 40.0 @ 2923
3) 40.2 @ 2962
4) 40.4 @ 2994
5) 40.6 @ 2949
6) 40.8 @ 2994
7) 41.0 @ 3025
8) 41.2 @ 3082
9) 41.4 @ 3086
10) 41.6 @ 3086

My question is, while the top 3 charges look the most promising, how should I proceed from here in terms of charge weights? Should I shoot for groups using 5 charges of those 3? Or should I go to .1 increments? This is my first time using this method so curious on what would be best.

[NapalmCheese]

My not so expert opinion:

Load up 3 at 8, 9, and 10. Shoot for groups, calculate the centroid and group size. If they all shoot to about the same POI and about the same group size you're good to go.

Caveat, when I see a plateau like that at the upper end of the charge weights I usually associate it with hitting or going over max pressure. If not max pressure then at least hitting max 'efficiency' for that powder (that is more powder isn't likely to give you more velocity, until it does; and when it does it'll spike hard).

Edit to add: I don't like the 10 shot OCW and prefer to run something similar with 3 rounds per group calculating SD and ES for each group. From a stats point of view the flat spot at 8, 9, and 10 is meaningless if standard deviation for each charge is greater than 4. That is, if the SD is 10 at all three charge weights it could just be a fluke that they lined up that way.

[BajaJames83]

When i do load development i am more concerned about groups than velocity. Normally end up in thebmiddle somehwere but not always. I will say that rarely max velocity gives better gtoups. Load 3 to 9 of each and shoot some groups

[JackEllis]

When I do this, I usually shoot two rounds at each charge weight in case the chrono burps. That aside, I'd load 3 or 5 rounds at each of 8, 9 and 10, shoot them and pick the charge weight with the smallest group.

Being a crappy bench shooter, I'll usually load up five of the best round and go back another day to verify my initial results.

[bigdawg86]

I tend to agree about shooting 3-5 round groups, but decided to see if I can develop a decent load without wasting 50 rounds minimum. Ill load some up and shoot for groups hopefully in the next week or two. I tend to lean towards velocity SD more than groups (within reason) because at distance the changes in velocity will begin to be more influential.