Range Report Opinions appreciated on OCW test. 147gr/Peterson/H4350

[Breacher]

I picked up a new rifle and figured it would be a good time to switch over to Peterson brass from Hornady.

Rifle - Accuracy International AT 6.5 Creedmoor w/24” barrel.

Bullet - 147gr ELD
Powder - H4350
Case - New Peterson SRP
Primer - Rem 7 1/2 BR

All rounds were shot round robin style with a Labradar chronograph at 100 yards. One group only registered 2 of the 3 shots fires but is marked on the target. I kinda wished I would have loaded up some higher charges and I still may. How are you guys reading these targets node wise? Thanks for any assistance.

 

[47guy]

i would shoot 42.3g and see how it grouped if it grouped close to 41.7 and 42 id play with seating a little with the 42g load and be done.

 

[Stpilot12]

Agreed.. Something around 42 +/- .1 maybe, should put you in the middle of a node. With my Tikka I ended up with 42.4 RE16/147 in Lapua brass. 42.3 and 42.5 shot nearly identical speed and groups. 42.7 went to shit..

 

[Breacher]

My Tikka liked 42.9 with hornady brass and 147’s.

I think I’ll start at 41.8, 42.0, 42.2, 42.4, 40.6 and see how that goes.

 

[BearNaked]

yup. that is what I would do. just watch for pressures.

 

[EXTREMEPREJUDICE]

Interesting that charge weight 40.5 had the greatest ES and largest SD number but the most precise group?

 

[Breacher]

OCW round #2
I do not have any chrono data for these unfortunately. Called flier on 42.4 load I’m thinking about try 42.3 or 42.4 with some OAL variations currently in 0.028 off the lands with a COAL of 2.880 in AI mags.

What do you guys think?

 

[ken4570tc in WY]

What distance were these shot from?

 

[BearNaked]

I would say get some velocities at 42.4 and verify that it was truly a flier. Read the numbers and if they are a below 10 on the SD, you are good to go. adjust seating depth to tighten up the groups if needed.

 

[Breacher]

What distance were these shot from?

100 yards.

I’m out at the range all week for work so I’m going to try to get some 42.3gr loads with varying OAL over the chrono soon.

 

[Subwrx300]

I'd reshoot 42.0-42.4 at .1 intervals 5-shots each at 200-300 yards on calm day (if possible). This will do several things: show better precision of average group size, better SD/ES accuracy, and show relative impact from group to group.

Shoot them all at the same level if possible (ie 4 pasters set on a flat line so you can see vertical shift between group centers.)

I think you will find that 42.1-42.2 is the sweet spot.
I am a bit surprised at the difference between 42 #1 and #2. But this is why 3 shot groups are next to useless. I try to shoot a minimum of 4 shots during load dev to weed out false positives and get SDs that are a bit more valid.

 

[Breacher]

I went with .010,.020,.030,.040 and .050 off of the lands.

 

[ken4570tc in WY]

100 yards.

I’m out at the range all week for work so I’m going to try to get some 42.3gr loads with varying OAL over the chrono soon.

As was suggested by another post to this thread, I'd move the target out further. They all look to be about the same elevation. I'm not seeing the characteristics that would be an indicator of a decent node. Remember, finding an OCW node is trying to locate a range of charge weights that give nearly the same elevation/velocity, picking the charge weight in the middle and tinkering with other variables to tighten the groups and yielding a very forgiving load that will have a minimal change in POI while reducing the occurrence of fliers.

 

[Maxduty]

Given the info above, I'd go 42 and play with the seating depth. That was a good group with a single digit ES.

 

[Seymour Fish]

As was suggested by another post to this thread, I'd move the target out further. They all look to be about the same elevation. I'm not seeing the characteristics that would be an indicator of a decent node. Remember, finding an OCW node is trying to locate a range of charge weights that give nearly the same elevation/velocity, picking the charge weight in the middle and tinkering with other variables to tighten the groups and yielding a very forgiving load that will have a minimal change in POI while reducing the occurrence of fliers.

Agree, and add the bbl may speed up at 100 reds and throw this attempt off. Would fire form the remaining brass shooting steel for fun, then tune

 

[tnichols]

Interesting that charge weight 40.5 had the greatest ES and largest SD number but the most precise group?

I’ve witnessed this on the low node as well. Great in close, but a fair amount of vertical at distance.

 

[Breacher]

I’m going to use some of the fire formed brass and do the 10 round test with a H4350/RL16 and 140/147 ELD’s. I’ll report back when I get time to make this happen.