Where to go from here...

[S3th]

(update on post #10)

6.5 Creedmoor - H4350 - 140gr ELDMs

I just got access to a range (two hours away) that extends to 1,000 yards + purchased a range finder. Should I load up five-shot groups at 42.0-43.4 and go shoot at say 300 or 600 yards? Or should I run to a local range and shoot groups at 100 yards? Or should I run a seating depth test at 600 yards? This new range opens up a new world of load development for me. Typically, I just do load development at 100 yards.

Below is a pressure test I ran on a fresh barrel and fresh brass.

 

[rustyinbend]

Until you've got your 100-yard reference load ... distance shooting shouldn't be the priority IMHO. The high node (43.3-ish) is interesting, but that's some damn high velocity for 6.5-CM. Are you seeing pressure signs like cratered primers or a heavy bolt at that speed? I'd be loading for group testing at around 41.7 and see if you get tight groups and low SD's just above 2700 fps ... but that's just me. Over 2800 is really hot for 6.5-CM ... at least so far as I've discovered in my Tikka T3x TAC A1. My reference load there is 43.4gr of Winchester StaBall for around 2660 average fps ... and SD's of 5.5. That said ... wherever you want to shoot ... JUST DO IT !!!

 

[nn8734]

6.5 Creedmoor - H4350 - 140gr ELDMs

I just got access to a range (two hours away) that extends to 1,000 yards + purchased a range finder. Should I load up five-shot groups at 42.0-43.4 and go shoot at say 300 or 600 yards? Or should I run to a local range and shoot groups at 100 yards? Or should I run a seating depth test at 600 yards? This new range opens up a new world of load development for me. Typically, I just do load development at 100 yards.

Below is a pressure test I ran on a fresh barrel and fresh brass.

View attachment 7761641

At Which charge weight did you see your first signs of pressure, if any? What brass are you using?

 

[Cascade Hemi]

How long is the barrel?

 

[S3th]

Until you've got your 100-yard reference load ... distance shooting shouldn't be the priority IMHO. The high node (43.3-ish) is interesting, but that's some damn high velocity for 6.5-CM. Are you seeing pressure signs like cratered primers or a heavy bolt at that speed? I'd be loading for group testing at around 41.7 and see if you get tight groups and low SD's just above 2700 fps ... but that's just me. Over 2800 is really hot for 6.5-CM ... at least so far as I've discovered in my Tikka T3x TAC A1. My reference load there is 43.4gr of Winchester StaBall for around 2660 average fps ... and SD's of 5.5. That said ... wherever you want to shoot ... JUST DO IT !!!

Yeah, maybe I will start at 41.6 as my barrel should speed up.

At Which charge weight did you see your first signs of pressure, if any? What brass are you using?

Peterson, 43.0-43.4 were just slight ejector marks. I likely wouldn't run a load above 43.0.

How long is the barrel?

26"

 

[impactaddict]

I think the answer is going to lie somewhere with answering the question, what are you wanting to do with the load once its finished. If its shooting steel targets then the thread below should provide some answers.

https://www.snipershide.com/shooting/threads/how-does-being-in-a-“node”-actually-matter.7035382/

This one too...

Are Velocity Flat Spots a Myth?

Controversial topic here. Are velocity “flat spots” based on powder charge a myth?

www.snipershide.com

Tl;DR - pick a speed you like (140gn 6.5mm is generally ~2750). tune with seating depth, shoot.

 

[nn8734]

Yeah, maybe I will start at 41.6 as my barrel should speed up.

Peterson, 43.0-43.4 were just slight ejector marks. I likely wouldn't run a load above 43.0.

26"

Gotcha. I’d run an OCW at 100 yards topping out at something like 42.7 with the expectation you would see a stability node somewhere between 41.2-42.5 grains.

 

[Cascade Hemi]

If it is a fresh barrel you're wasting your time. Load a minimal load and shoot 100 to 150 rounds before load development. Ideally over a chronograph so you can see the velocity change.

 

[OREGUN]

To answer your question, do load development at 100 if it’s the most convenient. Tiny groups at 100 don’t suddenly open up at distance (by themselves. There’s always an element of poor zero, scope tracking/level issues, poor fundamentals, etc.). Sometimes load development issues can be easier to see at 300 but not at the cost of 2 hours each way to do it. 600 yard load development will be an excerise in frustrations as outside factors will cloud the data unreasonably.

Find a powder range that gives you the speed you are happy with and then do a seating depth test. Bear in mind that the barrel will likely speed up a little as you exceed 150-200 rounds fired. The best charge weight may need to be backed off a bit when this happens to stay at the optimal speed but if you seat to the longer side of your seating depth range, your seating depth shouldn’t need to be adjusted as the initial throat erosion takes place. You can absolutely get load development largely completed in those first 200 rounds without having to redo everything. Your SD/ES data will likely come down a bit once you are using once fired brass If you are watching that too.

 

[S3th]

5 shot groups at 100 yards.

Rifle definitely shoots better than me; no reason all groups can't be smaller than 0.5 MOA. I'll probably load up 41.7 and 42.1 and go shoot at distance. Might even do a seating depth test on both of those loads but I feel pretty dialed in (with any load I use, to be honest).

This was with factory brass. Once I bump the shoulder 0.002", continue to fireform, and seat with a CPS I am sure I can reduce my SD/ES.

 

[nn8734]

5 shot groups at 100 yards.

View attachment 7762381

Rifle definitely shoots better than me; no reason all groups can't be smaller than 0.5 MOA. I'll probably load up 41.7 and 42.1 and go shoot at distance. Might even do a seating depth test on both of those loads but I feel pretty dialed in (with any load I use, to be honest).

This was with factory brass. Once I bump the shoulder 0.002", continue to fireform, and seat with a CPS I am sure I can reduce my SD/ES.

Nice graphic, looks like you’re getting there.

Controlling seating pressure consistency and inner neck diameter (and to an extent, interference fit) is the way to reduce SD/ES

Couple thoughts:

1) 5 shots is an inadequate sample size for purposes of inferring population attributes like SD - you really need a min of 30 rounds, same load for the numbers to be stastically significant.

2) Dont get wrapped around the axle when it comes to having a super low, single SD unless you will regularly be pushing the rifle through the transonic zone of the bullet or doing BR/1000m F-class (not saying you are atm, just mentioning)

 

[S3th]

Couple thoughts:

1) 5 shots is an inadequate sample size for purposes of inferring population attributes like SD - you really need a min of 30 rounds, same load for the numbers to be stastically significant.

2) Dont get wrapped around the axle when it comes to having a super low, single SD unless you will regularly be pushing the rifle through the transonic zone of the bullet or doing BR/1000m F-class (not saying you are atm, just mentioning)

Yeah, absolutely. Not really concerned about achieving single-digit SD/ES like I can with 6BR. However, I do believe I can get them down from where they are today. More data to be collected as you mentioned.