New Primers = New Load?

[Lonestar1027]

So I have a load worked out for my 6.5 Creedmoor and it uses CCI BR2 Primers. I chose those primers at the time because I couldn't find the Federal 210M and wanted to get shooting. I have since found the federal primers and wanted to know if I needed to start load development again if I want to switch primers. Maybe bump it down a few .1gr's and see how it shoots? I know that it's dumb to mess with a good thing, but I've found myself trying to find that perfect load and I know that primers can have a big impact on SD/ES. I appreciate any feedback you guys might have

For reference:
Alpha 6.5 LRP Brass
40.6gr RL 16
Berger 130gr OTM
~2820 fps, SD ~8
No pressure signs, no issues

 

[ZiaHunter]

Wouldn't worry about it and just load them up.

 

[NGCSUGrad09]

Load up 10 of each type of primer and compare both accuracy and velocity. Then you'll know if there's a difference. I've had some that didn't matter, and others that it did.

 

[Greg Langelius *]

I consider this to be a new load; but so close, I would begin by confirming the existing load with a bracket of about .3gr up and down for comparison.

I even confirm loads when I get a new batch of powder before going ahead and cranking out a bunch.

Proper Prior Preparation Prevents Piss Poor Performance. (= the Seven-P's admonition...)

Greg

 

[Lonestar1027]

Thanks for the help gents. I'll load up 5 of my existing load +-.2gr to confirm SD/ES, Velocity, Accuracy(5@ 40.4, [email protected], [email protected]). Then I'll load up another 5 with the same loads and new primers to see if there is any difference. Comparing these 6 groups(3 with BR2, 3 with GM210M) I should hopefully be able to note any significant differences as well as verifying load data for the preferred load. I know this isn't a large enough sample size for actual statistical analysis, but I don't feel like loading up 60-120 rounds just for a primer change.

Second question- I am using Berger's 130gr AR OTM which is one of their Hybrid bullets. Because of the Hybrid design, I was under the impression that seating depth was not much of a tweakable variable. That is, testing for .040, .070, .10 etc off the lands for grouping like you would on a different bullet would not be necessary with this bullet. Load it for mag length-ish and go. Has anyone seen significant differences with seating depths and this bullet? What about experience with the other hybrid rounds(140gr) from Berger? I've only been reloading for the last 6 months so please forgive any false assumptions I've made.

 

[demolitionman]

I personally, would simply change to the primer you want. and adjust the load to the exact same velocity the other primer was shooting and drive on......maybe shoot 10 shots at a hundred yards and call it good. Load development sucks, and I'd rather be shooting steel at distance than f'n around trying to get a single digit SD's out of every rifle I own. Just my opinion.

 

[Tnc]

@Lonestar1027 I shoot the 130 hybrids as well. I tweaked seating depths and shrunk groups from 3/4 to just under 1/2 moa

 

[tnbowhunter]

I’ve swapped primers several times in my creedmoor load with Hornady brass because I was unable to find what I had been using locally. Out to 600 yards I’ve notived very little if any changes. I’ll likely chrono them eventually just out of curiosity

 

[OzTRG]

I tweaked seating depth with the AR 130gn OTM and was able to reduce group size by about 40%. You maybe happy with what you have as it suits your purposes.

 

[Lonestar1027]

@Lonestar1027 I shoot the 130 hybrids as well. I tweaked seating depths and shrunk groups from 3/4 to just under 1/2 moa

Perfect, I am right at 3/4 out to at least 600 yards. This is exactly the info I was looking for. Guess I'll get to adjusting my seating depth!

 

[flyright]

I've found that the FGMM's will pop out easier than BR2's in a gas gun with even semi hot loads. The FGMM's are a bit smaller diameter.