300 win and 215 bergers load development

[Joefrazell]

No I didn't. I shot 77.5 gr of retumbo at .040" and the group opened up more. I'm about out of retumbo so probably will wait on continuing the load for it.

 

[wildcat455]

Ok well I have a pound of it to try, one of my 300 Win Mags is a Sendero like yours. My Base to rifling lands measurement is 2.900" for reference. I will be using Winchester brass, which differs from your Hornady brass. If I find something that works, ill post it up here.

 

[Joefrazell]

Ok well I have a pound of it to try, one of my 300 Win Mags is a Sendero like yours. My Base to rifling lands measurement is 2.900" for reference. I will be using Winchester brass, which differs from your Hornady brass. If I find something that works, ill post it up here.

I think my overall lent is like 3.72 and that's a .010 jump. They fit in the mag with maybe .020 to spare. Are you going to try h1000 and retumbo?

 

[wildcat455]

I usually don't even use COAL, (Cartridge OverAll Length) but I went and measured mine for comparison and I am at 3.680". About .040" shorter than yours, mine also with a .010" jump to my lands.

My load stuff might not help you, running different brass and having such a big difference in our chambers. I would have thought they would have been a little closer. I think you will end up with a little more powder to get your pressure/speed up than what I will use.

Yeah, been fiddling with my H1000 load on the 215 Bergers. Got a couple more tests to run with the H1000 anyway, then i'll be cleaning the barrel to finish up load development with RL 26, clean again and work on Retumbo.

 

[Joefrazell]

I think I drank too much beer last night. Not sure where I came up with 3.72. I guess I probably missed the 6. It's actually 3.672 lol. Our chambers are pretty close.

 

[wildcat455]

LOL!
That puts you more in the neighborhood then. Your lands are somewhere around .008" closer than mine, depending on how you initially measured your distance BTL, (Base To Lands) and any differences in the meplait and ogive on the different bullets we used to get the COAL.

In that case it'll probably take you less powder to get to pressure/velocity than me, given slightly smaller chamber and the lower volume of your Hornady brass. 74 gr of H1000 would be a good starting point for you, I think. I hit right at 3000 fps with 75.5 gr in unfired virgin Winchester brass, I have to re shoot it in fired brass, then I can mess with seating depth to see if it tightens things up. Already sub MOA with the magneto speed attached to the barrel, my precision is off of course, but the accuracy is there, so we'll see.

 

[Joefrazell]

I wanna see some groups when you get time to post if you don't mind. Yeah I've got just a little h1000 ad will probably test 73.5 and 74.5 of powder with the same seating depth.

 

[wildcat455]

Ok. Got a new pound of H1000 and this one is considerably slower than the previous pound. Making another powder weight adjustment and ill have the groups up after that .

 

[Rick Richard]

Mine likes 75 grains of H1000 with the 215. I am about .030 thousands off the lands.

 

[Clint Butler]

As soon as my rebarrel gets done I look to forward to loading some 215's in front of some H1000.

 

[Jeremy338]

Berger 215 20 off
Fed 210 m's
73-74 gr 4831sc
26" barrel
73 should run 2950
74.5 in my proof runs 3050

 

[Joefrazell]

I bought some h1000 today so I'll work up some loads soon. Probably 73gr. to 77 gr. and see how it goes. Hopefully I can get 2900-2950. More speed is always better

 

[Jeremy338]

When I switched to a non mag primer and to 4831sc I gained 100 fps. All my buddies that run the 300wm and 7wm use 210m's and 4831sc. Seems like 73 in the 300 over 210's or 215's and 64 in the 7 over 180's is the sweet spot. 210's and 180's we jam 10 thou

 

[4mattmyers]

Berger 215 20 off
Fed 210 m's
73-74 gr 4831sc
26" barrel
73 should run 2950
74.5 in my proof runs 3050

mine likes the same load