338-378 range report

[dgr416]

My.pet load for my.accumark. 338-378'weatherbys yep I have three of them .It like 250 grain nosler partitions with.109 grains of reloader 25 with federal 215 primers .I.have shot 1/4 inch groups with it at 100 yards and under an inch.at 300 yards with it .I.am.fixing.to try 250 grain serria and lapua 250 grain .My.rifles hate hornady bullets they don't shoot good in any.of my 338 rifles !

 

[Scratch]

el matador

Is your rifle a Weatherby Accumark? And at 3.90" COAL are you single feeding?


Thanks

Scratch

 

[Scratch]

el matador

Okay, I read another one of your post and found you are shooting a 26" Accumark.
I'm assuming that you are single feeding it at 3.90" COAL ? That case is pretty full at 115 grains plus.

Thanks Again

Scratch

 

[el matador]

Correct. At 3.900" they won't fit in the mag. I'm impressed with the velocity I'm seeing here but I do think my pressure is getting up there. If the accuracy is there at 117 to 118 grains it'll be a fairly warm load and my brass may not love it. Time will tell.

I have some of the 285 grain ELD Match bullets loaded up at 3.800" that I'm going to test shortly. If I can find accuracy with these at ~3000 fps I'll be very pleased since it would be a little easier on my brass and my shoulder.

115+ grains of powder is a compressed load. With the length I'm loading to I think you'd max out around 120 grains.

 

[Scratch]

el matador

Since your single feeding your rifle wouldn't help with pressure to load at longer COAL?
I just measured my rifle chamber and with the 300 grain OTM it measured 4.30" COAL with the freebore would it help to load them at 4.00" or 4.10" that still allows more then .338 of the bullet in the neck. Maybe you have already tested this. I was just curious.
Let us know your findings with the 285 grain ELD

Thx

Scratch

 

[el matador]

That's an interesting thought, Scratch. I know the long freebore helps reduce pressure in the Weatherby rifles, but seating the bullet out further should also reduce pressure. I don't know exactly where the tipping point would be - the length where pressure starts going up because you're too close to the lands. Might have to experiment a little with that. To be clear, I have not seen any of the telltale pressure signs yet with the 300 grain Bergers. No sticky extraction, no marks on the case head, no obvious primer issues. All I've seen is that the edges of my primers are a bit less rounded than my 250 grain Accubond loads. I didn't notice much difference in the primers between 116.0 and 118.0 grains of powder. I guess I just assume the pressure is getting up there due to the high velocity.

If I do find good accuracy with the Bergers I'll dedicate a batch of cases to this load and see how many firings I can get.

 

[Scratch]

el matador

I do know that weatherby brass is very good stuff. I have 378 Weatherby Mag loaded with 270 bullets and 115 grains of H-4831 at 3100+ and I got 9 0r 10 loads before the brass started to come apart.

Scratch

 

[el matador]

I made it out to the range again today. The 200 yard range was closed due to recent heavy rains so I was stuck shooting at 100. Today I was hoping to find accuracy with my 117 to 118 grain loads of RL33 with the 300 grain Bergers.

117.0 RL33 shot into about 1.5", Avg velocity 2960, ES 24
117.5 RL33 shot into .920", Avg velocity 2971, ES 38
118.0 RL33 shot into .725", Avg velocity 2982, ES 18

I've heard that these big slugs take a while to settle down and 100 yard results may not tell the whole story. I'm seeing good enough accuracy that I'll continue to fine tune this load and test it at 300 yards. I'd also like to shoot on a warm day to see if I see any pressure signs. I thought I saw a couple of very faint ejector marks at 118.0 grains. Something else: The 117.5 and 118.0 groups went into the exact same spot. The 118.0 group literally fits right inside the 117.5 group.

I also tested some of the Hornady 285 ELD Match bullets today. I shot groups from 115 to 118 grains:

115.0 RL33: Pretty tight left to right with almost 2" of vertical. Avg velocity 2948, ES 38
116.0 RL33: Vertical string 1.75". Avg velocity 2966, ES 38
117.0 RL33: .75" horizontal, 1.9" vertical. Velocity: 3022, 2995, 3000
118.0 RL33: .25" horizontal, .650 vertical. Velocity: 3023, 3000, 3031

Interesting that the last 2 groups had near identical velocity. I'm getting a higher ES than I expected and I'm not sure why. The 118.0 group was about as tight as this gun has shot so I'm very happy with it despite the ES of 31. I'll test another batch of these, focusing around 118 grains and maybe varying seating depth a bit. The vertical spread correlated very closely to the changes in velocity. If I can get the ES down with the Hornadys they might shoot extremely well.

All of my loads today used HBN coated bullets. Both of the bullets I tested liked the 118 grain charge of RL33. I'm going to dedicate about 25 of my brass to these RL33 tests and see how many firings I can get before I lose the primer pockets.

 

[Scratch]

el matador

Thank you for the update. Did you keep your COL at 3.90" for the 285 ELD-M.
I'm curious if your ES would be lower with a CCI-250 primer? The reason I mention that is I have read others report their ES dropped when going to the CCI from the F215.

Thanks

Scratch

 

[el matador]

The ELDs were loaded to 3.800", and the Bergers to 3.900". I'll probably play around with the seating depth next time. Might have to try the CCI 250s, thanks for the tip. I've heard that the Fed 215s are the hottest you can get, so I figured they'd be best for the 378 case. Luckily the CCIs are easy to find!