300 WM ES spread issue

[ruggedtraditions]

I am having trouble with tightening up the extreme spread on a new Bergara HMR in 300wm. I am getting an occasional wild swing on velocity and fliers out of the group. Groups are decent 3/4-1 moa but not great
Gun has 100 rounds through it now. I have several other guns I have worked up loads into the single digit ES and I would like to get the ES single digit since I want to shoot this rifle 1000yds+

Load Data
212 ELD-X (almost identical results with 208 eldm)
New Nosler brass (also tried with some fire formed and was nearly same velocity avg but had big spikes too)
CCI BR2 primers
78.3 gr H1000 (weighed on a chargemaster that I am very careful to watch for consistency)
neck tension .0025 set with redding bushing die and finished with a sinclair carbide mandrel

I did a depth tested from . 010 off to .080 and landed on .050 off being the best group
I ladder tested up to 78.3 with no pressure and it grouped the best

Velocities taken using Magneto speed V3

I have not tried other primers yet, but I think that will be my next step. Magnums?

First Pictures are from Fire Formed Brass and my ladder test the

Second set is from trying out some new nosler brass tonight
The fire formed brass ES of 17 isnt terrible, but I just dont have the confidence in the consistency. And the ES of 37 on new brass is alot

Any ideas and suggestions? Or should I just stop worrying and Load them up and start shooting and having fun again haha

 

[ruggedtraditions]

I am also thinking about dropping down the charge and hitting a lower velocity. I started here since my Remington 700p liked this range

It seem like most guys in that 2980ish range

Is anybody having better accuracy and es at a slower velocity? I would rather chase consistency and accuracy then speed at this point i think.

 

[Alabusa]

I have 2 nodes with mine. One ar 76.3gr and one at 77.8 gr of H1000. Both are half minute loads. The lower one has single digit sd & es #s. The higher one runs in the low double digit #s.
Components are:
Nosler brass
Winchester LRM primers
Berger 190 VLDs
H1000

 

[mudpig]

Have you tried to anneal the necks???

I'm working a similar combo right now.
212ELD-X
Win Brass
Win LRM primer
H-1000
Two nodes I'm working right now 77.0gr & 78.4gr.

 

[ruggedtraditions]

Thanks guys

what velocities are you guys seeing at those charge weights?

I have not annealed yet Fired brass is only once fired and the other is new nosler brass
Getting an annealling setup is on my short list though I just bought tons of brass for all my guns so I could get away from having to do it until after the 2nd firing hopefully

I am confused by the one spike in velocity on my loads last night its only 2 rounds in a ten shot group with out those 2 its an ES of 17 and SD of 7 Thats why I am wondering if magnum primers would be a better choice. I have always ran br2 primers in my 300 with good luck until now

 

[supercorndogs]

People used to load brass many times with out annealing, and still do.

I would have to wonder about you load development process first. Is the the info posted what you used to decide on your charge weight?

 

[mudpig]

28 inch barrel. Getting approx. 2950 with 77.0 and 3040ish (can't remember right now) with 78.4. Loaded to 3.600 long. That's .010 off the lands. With that much powder the magnum primer might give you more uniform ignition. I have not tried standard primers as these are working great and I might hunt with this load in freezing temps.

Have you checked for burrs on your flash holes???

I uniform primer pockets and deburr all flash holes on my brass. ES on both loads is around 12.

 

[FLIGHT762]

Yes, try the Magnum primers and see what that does to your E/S.

 

[shoot4fun]

I am 100% in the camp with @FLIGHT762 on this one. Magnum primers all the way.
The primer is having to light a fairly long column of powder, slow powder at that, and magnum primers should be much more consistent in getting that ES down.

 

[ruggedtraditions]

Thanks guys I will load some up with some federal 215M primers I have and give that a shot.