What would you do next?

[shaneroyce]

I'm curious how you'd move forward with determining a load for a new rifle that I purchased...Christensen Arms Mesa 6.5 Creedmoor.

Background...I've been loading about a year for 6.5 CM and 7mm RM. I put together 5 different loads (4 shots each load) for my 6.5 CM and headed to the range. All loads are seated .060" off the lands at 2.250" COAL. All loads are Hornady 143 ELD-X over H4350 with Hornady brass and CCI 200 Large Rifle primers. I shot all 5 loads at 100 yards with the following results:

40.0 grains: .500 moa
40.5 grains: .656 moa
41.0 grains: .375 moa
41.5 grains: 1.00 moa
42.0 grains: .438 moa

All groups were shot cold bore with full barrel cool down between each group. There was ZERO pressure signs at any load...even the 42.0 which is .5 over max.

I would typically take my next session to the range at 300 yards and shoot my best grouping load, within a node of good grouping loads, at different seating depths to see if the load holds it's accuracy at range. In this case, I see that as my 41.0 grain group.

My question is really two-fold. First...before settling on which group to work with, would you continue to go up in powder charge above 42.0, until pressure signs begin, to see where the max load is for this rifle?

Second...if seating depth makes no difference to the group size at 300 yards, where would you want your bullet seated...where it's at, closer to the lands, or further from the lands?

FYI...this will be like all of my rifles...a hunting rifle that I also shoot year round for fun.

Any other thoughts or advice would be appreciated. I look forward to hearing from you all! Also...feel free to be critical of my process if you see a significant issue. I should add that I have no chronograph and no access to one in the near future.

 

[JJMoody]

Developing a new load, I'm trying the Berger seating depth test, followed by charge weight testing for nodes. So far, I've determined that the eldx s I'm shooting like between.010 and .050 jump and I'm also a crappy group shooter at 100 yds. Both pieces of info are equally relevant and unequally frustrating.
I might just run out to longer ranges and run the 42 grain load til all the brass is fired, get really good data on drops, get to know the rifle, then tweak if needed. If I find something that shoots well in a hunting rifle, I quit messing with it. If you want to change something, I'd start with a seating depth test.

 

[shaneroyce]

Would you shoot both the 42.0 and 41.0 at longer ranges to see if one held accuracy better? If they both held accuracy similarly, would you choose the higher velocity load or stay below the Hornady book max? Also...Hodgdon lists the max with that bullet and powder at 41.8 grains. Do you see any reason to continue to go up in powder charge?

 

[Rflamm250]

I would back up to at least 300 and stay around the 41 grain but try .02 above and below. And also try .030 off my lands. The mesa rifles are known to start stringing when heated if you do not have them bedded. They only bed the recoil lug from the factory and its usually not pretty. I got mine consistently under.3" but I had to bed the whole receiver to get it.

 

[shaneroyce]

First of all...sorry for the typo in the original post. My COAL is 2.825"...not 2.250" I'm .060" off now. I was thinking of going to .040" off and .020" off to see what it liked better. Maybe .030" off instead of .040" & .020" would let me see if closer was better without shooting as many groups? I also though trying .2 above and below would be wise. Thanks for the info. Keep it coming!

 

[Rick Richard]

I load until I see pressure signs and then back off a couple of grains. That way I know where max is with that recipe. I then load a couple of grains below max in half grain increments. Once I see a good group, I begin tweaking with seating depths. I also test with a chrono and look for low ES and SD. That way I am assured down range accuracy will be more consistent. Trust me, a chrono is a MUST for long range load development.

Good luck!

 

[Rick Richard]

First of all...sorry for the typo in the original post. My COAL is 2.825"...not 2.250" I'm .060" off now. I was thinking of going to .040" off and .020" off to see what it liked better. Maybe .030" off instead of .040" & .020" would let me see if closer was better without shooting as many groups? I also though trying .2 above and below would be wise. Thanks for the info. Keep it coming!

Follow the Berger method. It will save you a bunch of time and money. These guys know what they are doing and I find their method is spot on in most cases.

 

[dok7mm]

Before I start ladders or start load work-up, I always use fully formed brass to do a pressure test, as Rick said. Then, I'll load a series to within 1 full grain short of where pressure signs began. This way you won't loosen up your primer pockets prematurely.

 

[Aoudad shooter1975]

Id shoot the 41 grain load...I'm not a max load guy though...I usually do whatRick Richard does..unless I stumble on to a load that just works...which I have done before. the last load work up I did on my 33 nosler.. the 2nd load I tried shot so good I didn't mess with it--and I know I could probably coax another 50-100 fps out of the load to the next good shooting node.

 

[Alaska_Guy]

Depends on your shooting distance. My old man was of the impression early on to load as hot as he could get while still obtaining good groups. The issue he had on a black bear was the bullet fragmented apart when he shot it at 100 yards. It took about 5 shots to kill that bear. He was using Accubonds. He now loads in the middle of the range as most of his shots are 100-200 yards and he doesn't need the extra velocity. If you were taking shots at long range then I would say load it hotter.

 

[Joefrazell]

I'd load I'd load 40.7, 41 and 41.3 and shoot at 300. Make sure they all group close. Then stick with 41 if all goes well

 

[Deviant]

I start every new rifle with 60 rounds of moderate break in loads to fire form the brass and break in the barrel. Then I load up a ladder test that goes above max and stop when I see pressure signs. I use a chronograph and would definitely put it at the top of your purchase list as you can learn a lot with it. After the ladder/pressure test I perform the Berger seating depth test to find the sweet spot. If I'm not happy I switch powders and start over. This has worked very well for me but the most important thing for me is low SD and consistency which is impossible to determine without a cronograph.

Al