Help load development

[Liberator]

Might try annealing your necks. Most of those problems were solved for me doing that on a regular basis.

 

[cjuve]

I struggled with the same thing with the 156 in. .264 win mag. could not get them to shoot until they were on the ragged edge of pressure then they shot sub 1/2 MOA, lots of 2 shots in 1 hole then a flyer. Primer pockets in Winchester brass would not make it 3 firings. I scrapped the 156 and am now working on 140's but kind of running into the same issue. I got Jameson brass on the way we will see if I can revisit some of those hot loads.


What is your velocity with your current load?

 

[ShtrRdy]

I just went through a long drawn out frustration with the same sort of thing on a new barrel for my 22-250. A few excellent suggestions I got were:
1. Try another scope of know good functionality. While you're changing scopes make sure the rail/base is attached well to the action.
2. Check out the action seating onto the stock/chassis and re-torque Action Screws to the correct torque. Make sure the recoil lug is firm against the surface on the stock/chassis.
3. Give the barrel a good cleaning. Are there any heavy copper or carbon fouling?
4. When firing shots for a group stay in position and fire at least five rounds to better understand if the weapon system is tending to put more shots in one spot or if they're scattered.
5. Have a gunsmith give it a good look-over. My GS suggested recutting the crown to rule out that possibility, so we did.
6. Try a different bullet. Use good quality bullets.
7. Try a different powder.

Doing all of these steps, for me, helped give me confidence that the equipment was basically good and so I worked harder on finding a load. I think I found one but I have a couple more step to prove it to myself. My next step is to shoot a few groups at 100 yards and see if it holds up. Then I can take it put to longer distances.

 

[sedancowboy]

Shoot more than 3 shots in a group and you might learn more. I know how frustrating this can be.
Try 6 shot or even 10 shot groups see if you have 2 distinct groups or a scatter.
I practically wore a barrel out and finally changed bullets to Bergers and the problem went away.

 

[sveltri]

Thank you all for the advice. I have literally done everything suggested so far. What I find most boggling is how consistently the groups look like this despite all the variables. Velocities I recorded Saturday were: Berger 156 H1000 59 grn 2980, 2983, NR; 59.5 3004, 3035, 3008; 60 3047, 3035, 3030.

 

[ShtrRdy]

Thank you all for the advice. I have literally done everything suggested so far. What I find most boggling is how consistently the groups look like this despite all the variables. Velocities I recorded Saturday were: Berger 156 H1000 59 grn 2980, 2983, NR; 59.5 3004, 3035, 3008; 60 3047, 3035, 3030.

What does a group look like when you fire 5 or more shots without breaking your position?

 

[nmbarta]

Most 3 shot groups that are 1 moa will have two that are close pretty often. Thats just a probability thing. 1moa guns are occasionally going to shoot a 1/2 or even smaller group, also probability.
Lots a factory rifles that shoot just like that, and won't do any better regardless.
It's possible your chasing the dragon buddy.
If it's something in your form, you can figure that out if you have access to a rifle with proven accuracy. If it is you, you get to go back a revisit your loads.....the joys of figuring things out after all your efforts.

 

[nmbarta]

Another thing I like to do when I'm getting frustrated with my shooting is to have a friend load my rifle for me. I have him randomly load it, sometimes there's one in it, sometimes there's not. It makes it easy for me to spot my own mistakes. It's fun little drill, that is more effective than dry firing alone.

 

[DENRIK89]

Charge weights? I pressured out @ 57.8gr H1000 with the Berger 140s going 3100 24" Christensen. Accuracy was 1 grain under that

 

[DJ Fergus]

Charge weights? I pressured out @ 57.8gr H1000 with the Berger 140s going 3100 24" Christensen. Accuracy was 1 grain under that

This was exactly along with what I was thinking. Alot of good suggestions were made. I've often saw the same thing as the OP is seeing. Pressure it up until just under max, or near max and the flyer goes away. I'm not saying that it happens in every situation but I've saw it happen several times. If it doesn't go away, then go to just a bit faster powder and try to find a node just below max for that powder.

 

[sveltri]

Charge weights? I pressured out @ 57.8gr H1000 with the Berger 140s going 3100 24" Christensen. Accuracy was 1 grain under that

Berger 156 H1000 59 grn 2980, 2983, NR; 59.5 3004, 3035, 3008; 60 3047, 3035, 3030. No heavy bolt lift, no extractor marks. Most of my shooting is at 7500'.

 

[sveltri]

What does a group look like when you fire 5 or more shots without breaking your position?

I haven't tried that yet.

 

[DENRIK89]

Berger 156 H1000 59 grn 2980, 2983, NR; 59.5 3004, 3035, 3008; 60 3047, 3035, 3030. No heavy bolt lift, no extractor marks. Most of my shooting is at 7500'.

I'm at 6500'. Something as small as dimpled/flat primers could be a big indicator. I've seen chambers that were a little on the rougher side grip the brass and give little to no bolt thrust so the heavy bolt and Ejector marks don't show until well into the danger zone

 

[DENRIK89]

Berger 156 H1000 59 grn 2980, 2983, NR; 59.5 3004, 3035, 3008; 60 3047, 3035, 3030. No heavy bolt lift, no extractor marks. Most of my shooting is at 7500'.

Next I would guess inconsistent neck tension, after the second firing on brass, I couldn't cure until I started anealing every second firing and setting neck tension with a mandrel (never had to with other chamberings). All personal experience I had with my prc. Best of luck man