Which Charge Weight would you pick based on these results?

[Sooner Sniper]

Working on initial load development for a new rifle. Barrel has a little over 200 rounds down the tube. My current thinking is to run seating depth tests with 41.0 gn and 41.8 gn loads. In a previous test I tested 40.9 and 41.0 loads and the ES/SD results were almost identical to the 41.1 gn load shown here with slightly lower velocities. I didn't have a lot of time yesterday, so I wasn't able to let the barrel cool down as much as I would have liked which likely effected the group sizes in the later groups as the barrel and the can were getting pretty warm. All groups are 5 shots at 100 yards with virtually no wind measured with Ballistic X. All test loads were seated .005 off the lands with Berger LRHT 140s. I'm curious which loads others would choose and why if they are different from the ones I'm planning to use. The extra shots between targets 8 and 9 are sighters. Thanks in advance for your thoughts!

 

[Emerson0311]

I’m not seeing any real differences, once you do bigger sets of data. Adding in your comments about barrel heat opening things up; I would pick 41.8 and do a slow 10 shot group on paper at 300. Data collection at 100 is where I do Rimfire. 300 paper shows differences better for centerfire. Also, very slight variations in position often obscure load differences on target.

 

[whatsupdoc]

Terrible target to use for testing, different aiming points will affect your
groups. Some are dots some are triangles. Also you are shooting out your point of aim
add two clicks of elevation for testing.

 

[wpeach1912]

All of those groups and SDs look like they’ll be plenty good for hunting and practical shooting. Probably fine for PRS as well. You aren’t likely going to make significant gains by shooting another 1-200 rounds trying to find the “perfect” load. I’m usually a fan of 41.3-41.5 grains of H4350 with a 140. That has consistently worked over like 5-6 barrels

 

[Doom]

Your charge increment of -0.1 gr is real tight and doesn't really correlate with the variations in point of impact. It looks like you have some variations due to moving from target to target. You also didn't mention if you shot round robin or not.

I would actually pick #5. The group size isn't the reason. The POI of 4 and 6 is the same and #5 group isn't bad and shift in POI is probably shooter. The SD's are good. Comments on the type are target above should be considered as a possible issue.

 

[Sooner Sniper]

Thank you for the replies. I wasn't actually too concerned with the group sizes in this test so much as finding a node where the SDs and ESs remained in a tight window.

 

[Baron23]

Personally, I would go for #4 based on group and I would discount ES/SD with such small data set.

In the past, I've had super ES/SD with initial 5 shot LD testing that increased quite a bit with larger data sets.

Also, personally I'd also look at something around 2,750 fps and see if you have an accuracy node (and I hate using that word "node") down there also.

Take it with a grain of salt...I'm not one of the reloading experts on this site.

Cheers

 

[straightshooter1]

Working on initial load development for a new rifle. Barrel has a little over 200 rounds down the tube. My current thinking is to run seating depth tests with 41.0 gn and 41.8 gn loads. In a previous test I tested 40.9 and 41.0 loads and the ES/SD results were almost identical to the 41.1 gn load shown here with slightly lower velocities. I didn't have a lot of time yesterday, so I wasn't able to let the barrel cool down as much as I would have liked which likely effected the group sizes in the later groups as the barrel and the can were getting pretty warm. All groups are 5 shots at 100 yards with virtually no wind measured with Ballistic X. All test loads were seated .005 off the lands with Berger LRHT 140s. I'm curious which loads others would choose and why if they are different from the ones I'm planning to use. The extra shots between targets 8 and 9 are sighters. Thanks in advance for your thoughts!

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You're increments of .1 grs is too small for that size of cartridge, IMHO, making really hard to see what'd really going on unless you had a much longer string of POI's. For the future, I'd suggest .3 gr increments for that many POI's. With that said, I'd suggest you retest 4 through 6 . . . even #7 to see if there's anything there can can repeat. I think there might be something there.

What I like to look for in a series of groups is where the center of the mean average is at a pretty consistent position.

 

[BobinNC]

No Caliber listed: But I assume it's a 6.5 Creedmoor.

No Barrel length listed, so it's hard to know if these velocities are good, bad or indifferent.

No purpose or mission for the load listed so it's hard to just pick one load for an unknown purpose. PRC use, or Punching paper & Steel, or Hunting, or what have you.

Shoot and See target are terrible for recording groups IMHO. If you have an in-home printer try some of these: Free Printable Targets

The 41.7- 41.9 Grain range of H4350 is a known accuracy node with 140 grainer's in many a 6.5 Creedmoor. BTW

 

[Sooner Sniper]

You are correct. It is a 6.5CM. 26" Krieger MTU. Mostly shooting steel out to 1200 yds.

 

[Kadams1563]

I would actually go lower and see about a slower node from 2750-2820

And your speeds are smoking on the top end. When I was shooting 6.5 creed with a 26” barrel I was dumping 42.3 of H4350 and still below 2850.

 

[Sooner Sniper]

I’m in Colorado so I have a bit thinner air up here

 

[Sooner Sniper]

Probably should have added that all loads were weighed on an A&D and were dead nuts on the stated charge weights.