Help with .300wm Load

[PingGong3]

I am trying to develop a load for a .300wm Christensen Arms Mesa Rifle and can't get it to shoot with a sub 2moa.

This is my current proponents:
205 Berger elite hunters
H4831
ADG brass never fired
Expander mandrel, the pressed for consistent neck tension
Seating depth .080 off the lands (tried right off the lands and same result)
Federal 215M primers

Powder charges:
71.8
72.0
72.2
72.4
72.6

All of them are garbage with random fliers. I've never had this big of an issue with a lid development. We have checked the scope mount and rings. I'm going to try a load I made for another rifle later to see if it does any better.

 

[cabelasken]

Try some other bullets at different weights. I've had good luck with H-4831 and IMR 4350.

 

[Rick Richard]

Berger 215 and H1000 or Hammer Hunter 166 or 188. If you can't get a nice group with any of these, then you should question your rifle.

 

[Longtine88]

I would check for any stock touching barrel, action bedding issues, scope rings mounts, etc before I'd question the recipe.

Got to be the rifle dude.

 

[PingGong3]

That's what I was thinking but I was really hoping y'all would find something with my load data. I'll go see my gunsmith next week.

 

[ShtrRdy]

What does the following mean? Particularly the "pressed for"?

Expander mandrel, the pressed for consistent neck tension

 

[PingGong3]

I expanded the neck out with the mandrel to get all deformities out and just expand the necks. Then I ran them through my bushing die so all neck tensions would be the same.

 

[ShtrRdy]

Thanks for explaining your neck process. Personally I would run the necks through the bushing then use the neck mandrel. Or, since it's new brass run it over the mandrel only.

Something you might try differently is space the powder charge weights further apart. Since you're using around 70 grains of powder space the powder charges 0.4 or 0.5 grains apart. You can cover more powder charge weight .

 

[Lefty7mmstw]

sounds like the bullet isn't tough enough for the barrel with the random fliers... switch brand...
I had the same issue with a Brux bbl'd 7rum... she would tear up Sierra and Berger match pills and toss random fliers or just plain loose a pill...
I went to the 175 eld-x and the bull stopped cold...
if that isn't enough try a flat base pill like the 180 Hdy interlock or the 200 gr flat base pills pills from Sierra, Nosler, or Speer...
a mono like Barnes could even be your huckleberry
as to charge weights in a 300win... a grain or two on initial work up... 1/2 to 1 gr looking for top if I even bother; most times I land close enough not to care

 

[PingGong3]

Thanks for explaining your neck process. Personally I would run the necks through the bushing then use the neck mandrel. Or, since it's new brass run it over the mandrel only.

Something you might try differently is space the powder charge weights further apart. Since you're using around 70 grains of powder space the powder charges 0.4 or 0.5 grains apart. You can cover more powder charge weight .

I'll give that a shot. I'm not showing any signs of pressure so I think I could take it up to 74gr and be fine.

 

[cape cove]

Just my take but I find, as ShRdy posted that your powder charges are very small. There wasn't a full grain window in your entire ladder.. JMO

 

[gbett308]

Change the primers if you have them to spare, WLRM and even large rifle primers CCI #200 or Fed 210 have worked for me.

Maybe check bullet weights and brass weight for consistency or case lengths.

Definitely make sure your rifle is good to go first...

 

[str8meat]

I have 2 browning a bolts, medallion and stainless stalke. Both shoot sub moa with either 185 Berger vld or classic hunters 78 grains h1000 3050 fps. 210 Berger vld hunting with 75.5 h1000 2850. Might be the powde.

 

[WYMIKE]

Lapua brass, FED-215M, Vihtivouri N568 powder, Berger 215 bullets, Every piece of brass is cleaned, trimmed, annealed, primer pocket checked, and flash hole checked. Bedding is marginal but gun seems to be performing in my CA Mesa .300 WM with good 3/4 MOA accuracy or better out to 950 yards.