140 ELD-M load data

[jkramlich]

Good evening everybody. I had a couple of quick questions as I am newer to reloading and only have experience with my 6.5 cm. I had a perfect load set up for .2 moa at 600 yards but as we all know with recent demands, I had to switch up my load. Before I was shooting 140 eld-m’s, hornady brass, CCi 200 primers, and 40.4gr IMR4350. I won’t get into head spacing, neck tension or bullet length. Well I now had to switch to 140 eld-m’s, Peterson brass, cci-200 primers, and still the same 40.4 of IMR4350. I had the exact same setup as the previous load, just with different brass. After going to the range today, I was shooting a consistent .1 moa at 100 yards. As soon as I moved back out to 600 yards I was shooting 3 moa with low sd’s. What I’m asking I guess is this: do I have to start from square one in order to regain that accuracy? If not, what am I doing wrong. Any input will be greatly appreciated!

 

[StrayDog]

Your 100y bugholes opened to 18" at 600y?!?

What were conditions like?
Scope used? Equipment? Barrel twist?
Did you add something to the muzzle--can or brake after shooting at 100y?

Something doesn't add up...

 

[jkramlich]

Your 100y bugholes opened to 18" at 600y?!?

What were conditions like?
Scope used? Equipment? Barrel twist?
Did you add something to the muzzle--can or brake after shooting at 100y?

Something doesn't add up...

I mistyped. It opened up to 2 moa 12” is still massive at that distance. 2 mph wind left to right. Vortex a razor gen 2 4.5-27x56. Rifle is a bergara ridgeback w/ triggertech diamond, factory 24” barrel w/ hellfire break. Everything was the exact same conditions before and after. I cleaned my rifle but then shot 10-15 rounds before going back out to a longer range

 

[DocRDS]

Something isn't right--Stray Dog is right--groups don't open up like that.

Thats too big to be a load issue

 

[jkramlich]

Any ideas what it could be?

 

[BigOldPhatboy]

Peterson brass is generally thicker than Hornaday. (less case capacity) Resulting in higher velocity when using the same charge weight.
Always start over when changing components.

 

[davsco]

after you cleaned the gun etc, did you go back and shoot at 100 yds with super tiny groups?

 

[huntnh]

How many rounds on the barrel? Was it super hot out mirage can do funny things that distance

 

[jkramlich]

after you cleaned the gun etc, did you go back and shoot at 100 yds with super tiny groups?

Yes after cleaning the barrel, I shot 10 into the dirt in order to flush away any excess lube. Then after those shots I was shooting 5 into the same hole at 100.

 

[jkramlich]

How many rounds on the barrel? Was it super hot out mirage can do funny things that distance.

I have exactly 658 rounds on the barrel. I have kept extensive research in a shooting binder. Yesterday it was 68 degrees f, 2-3 mph wind left to right, and around 62% humidity. After shooting each shot at 600 there was a bit of mirage but nothing crazy.

 

[davsco]

well that's crazy. maybe try 100, then 200 then 300 etc out to 600 and see where it falls apart. it sounds like it is b/c you did it before, but is your scope and eyesight powerful enough to get a solid sight pic at 600. any chance there were gusty winds out there but you were more protected at 100.

 

[DocRDS]

also is the spread vertical or horizontal or both.

My initial 'assumptions' that everything shooting wise being fundamental is that wind gives you left-right dispersion and load issues will contribute more to up-down dispersion. Its not 100% but at the gross level that may give you a clue.

 

[n0glock]

I just want to know where you got Peterson large primer brass and eldm’s to play with? if new Peterson brass what was your brass prep?