300 Winnie 215 Berger bullets Magnum Powder

[BEEMAN]

I'm also at 79 gr of H1000. Gets me just under 3000 FPS with a 26" Brux. As mentioned work up to this slowly.

 

[Shane Lindsey]

Are these new cases? Standard or long. If standard, I would load them all with the 77gr load to fireform and let the barrel speed up.

I found a great load with N570, ADG, and 215 Bergers only to have to back it down after all the cases were fireformed and my barrel sped up. Had the same issue on another 300 WM with H1000. Let your cases grow, then tweak it.

 

[bergara0256]

They're standard cases, they have been fired once. I fired all of them at a lower charge for the first round.

 

[DustThroughaFan]

Are these new cases? Standard or long. If standard, I would load them all with the 77gr load to fireform and let the barrel speed up.

I found a great load with N570, ADG, and 215 Bergers only to have to back it down after all the cases were fireformed and my barrel sped up. Had the same issue on another 300 WM with H1000. Let your cases grow, then tweak it.

Where did you start with the n570? I've got a pound to try but data isn't readily available. 215's, fed.215m and Norma brass.

 

[Shane Lindsey]

Where did you start with the n570? I've got a pound to try but data isn't readily available. 215's, fed.215m and Norma brass.

With Norma cases, start about 76gr and work up. I think you will end up around 79 or so. I had to back mine down for the second firing. I was sad, becasue I was seeing some good velocities without pressure on virgin cases. Norma did better in mine than the ADG. About two more grains before pressure. My COAL was about 3.65". I think I was able to get about 5 firings on the Norma before pockets got loose.

 

[MagnumManiac]

I run old Winchester and old/new Lapua for precision, but do use Remington brass for hunting/precision.
All of my brass gets fireformed during hunting, or seating depth testing. Have had excessive pressures running loads from new brass in once/twice fired cases…so don't do that.
I hunt with new brass when stalking game, but not for LR.

Cheers.

 

[xsn10s]

Without seeing your brass or knowing what loads got you to pressure before I'd just keep going up a half a grain until you see pressure. Here's my buddies rifle shooting a 208 ELDM. He still wasn't seeing pressure but like the load so he left it alone.

Sorry I forgot to put in data for this picture. Factory 26" Rem 700 LR. 2880 fps with a 208 ELDM. Your rifle has a low round count and may need 100 more rounds to be shot before you see an increase in velocity. If it were me I'd shoot the most accurate load you have for another 100 rounds. Your brass should be fully formed in 2-3 firings and the barrel will be closer to being broken in. Even at 2700 fps the 215 gr Hybrid is a formidable round out to 700 yards. I'd even get a box of 208 ELDM's to break the barrel in and conserve the 215's.

 

[DustThroughaFan]

With Norma cases, start about 76gr and work up. I think you will end up around 79 or so. I had to back mine down for the second firing. I was sad, becasue I was seeing some good velocities without pressure on virgin cases. Norma did better in mine than the ADG. About two more grains before pressure. My COAL was about 3.65". I think I was able to get about 5 firings on the Norma before pockets got loose.

I've got a load with magpro, a 212eldx, win lr and r-p cases that just did the same thing. Could have been tempature also. It's a little warner now than when I first loaded it. Shot it out to 1k and it did good but I tweaked seating depth a little (.003 shorter) so I loaded three more to verify before I loaded a bunch. All had pressure and about a 60fps increase in velocity. Backed off 1gr and it was good. Group opened up a little but it's still under half moa.

They shot good, the bolt just clicked a little. Every time.

 

[Shane Lindsey]

Virgin cases?

 

[Shane Lindsey]

For the tow belted mags I loaded for (300 WM amd 7 Rem Mag). ALL have done this.

 

[DustThroughaFan]

Virgin cases?

Once fired. I think. Even so they were not fired in this chamber. Holdovers from my last barrel. Both were/are saami chambers but the current barrel was throated specifically for the 215's.

If I had it to do over I'd do the mk248mod0 chamber or the broz reamer.

I played with the 215's and magpro a little when I first got this barrel and had them over 2900 comfortably but I didn't have many of them. Picked up 500 so I'm about to start in on them again.

It's a 26" Bartlein 5r medium Palma.

 

[BPollard]

This is my recipe in my CA Traverse 300 WinMag. 215 Berger 71.5H1000 3.54"

 

[K.E.C.]

I'm still tweaking mine, I'm thinking of going to N570. I have been using H1000,
Settled on 77.6 avg 2920, CCI250 max box length 3.590. 215's Hybrid.

 

[Mooseknuckles]

I have been running 215s for a while now. I settled on a very accurate load. I'm running Norma brass, 77.1 grains of h1000, cci250 primers. The bullets are seated at 3.701. My velocity is 2945. This is out of a trued Remington 700, 26 inch Bartlien barrel and silencerco harvester 300 suppressor.