PRIMERS???

[ropeNshoot]

Working up a new load for my rifle:
.300wm
26" Bartlein 1:10" twist
Blueprinted Rem 700 action

Load:
Hornady brass (twice fired in this rifle with old load)
H1000
Berger 210VLD

My old load was 76g H1000 with 212 ELD-X and shot very well but just wanted to try Berger. So I backed off to 74g and did Berger's seating depth test at 200yds. .010" off the lands shot < .75". I repeated that twice. Now for powder charge testing with Magneetospeed V3. 74, 74.5, 75, 75.5, 76, and 76.5g of powder. Did this twice to verify results and something strange happened. Here are the chrony results from both ladders working from low to high charges. The first ladder is the left column and second is the right.
2798 2787
2832 2850
2876 2838
2866 2854
2861 2894
2909 2908

After the first ladder I thought I knew where I wanted to be. 75.5-76. Then I shot the second and the numbers got weird. Im using an RCBS chargemaster that has always been reliable and I am very meticulous about my loading practices. The only thing I can think of is the primer. I'm using Winchester LRM primers. Sorry to make you read all of this to get to the brand of primer but do you think that's what is causing the erratic velocities?

 

[BallisticsGuy]

There's nothing erratic in there. If you thought the velocities would be exactly the same then your expectations were out of line with what the universe allows. What it looks like to me is you've got possible highly consistent points at 74, 75 and 76 grains even with a change of primer.

 

[ropeNshoot]

That was the same primer in both ladders. Would another brand of primer help smooth that out?

 

[L.Sherm]

That was the same primer in both ladders. Would another brand of primer help smooth that out?

I've never had good luck with win. primers. A primer change can really tighten up E.S and groups, it's worth a try.

 

[Wolf76]

I'm a federal 215M guy. Never had good luck with win primers except with handguns

 

[Smokenaces]

+1 on Federal. I'm running them and the H1000 in my 300 RUM. If you have access to a beam scale, run a ladder off it and compare your numbers to the chargemaster data. I found RCBS varies on charges. My Scott Parker tuned Lyman is the go to scale!

 

[ropeNshoot]

BallisticsGuy,
I've read your post several times and I think I didn't understand what you said. I was looking where I wanted my results to be and not where they really were

Tried five this afternoon at 76g with CCI 250 Primers. I was surprised see that velocities were around 2850 with an sd of 25 and es around 43. I was hoping they would be faster.

I loaded a whole nother ladder with the cci's....

I haven't shot them yet but according to the last two tests, I could run 75.5 with the win's and rock on

 

[ropeNshoot]

Both of the rounds at 75.5 with win primers landed within a half inch laterally and that was certainly my error. The numbers are good on those and I'll probably try them again anyway and work from there

 

[WestCo]

Might try 210M primers, they worked wonders for me in both 300 WM and 30 Nosler as far as a more consistent velocity and low ES

 

[ropeNshoot]

I'll certainly try to find some. Been using what I've got on hand

 

[bob4]

I have certainly have had a primer change make a difference. Let me just add that Federals don't always win out but trying a few different is never a bad idea.

 

[CUTTER1]

Have had to go to Federal primers long ago, only exception is small rifle there Remington 71/2 and hand guns I use several brands depending on caliber!

 

[Mike AVM]

I switched to Federal after 3 WLRM no-fire's. My loads shoot about the same though I've definitely seen some ES drops and group size changes with a change in primers. I changed to a Federal GM215M in a 270 load that uses RE23. The ES dropped in half but it's still shooting the same size groups at 0.5-0.7 inches. It's worth a try.

 

[caveman4867]

I shoot a weatherby 7mm mag,and i load all my own ammo.I use nothing but rem 9 1/2 magnum primers.Weatherby brass barnes 140 gr bullets and H1000 powder.The cats meow.