Any BMG 50 shooters here?

[bluechip]

I recently bought a BMG 50 in target form, McMillan action, Lilja barrel, etc. and something seems odd about the seating depth. I bought several target loaded cartridge's from a known reloader all with different seating depths and they start at .125 off the lands and wind up at a whopping .425 off the lands. He said (the reloader) a 50 sometimes likes a bit of a 'jump', but almost a half inch? I would think the same principles apply to the 50 cal. as they do for the shells I am used to, so does anyone here have any experience with seating depth on the target style 50?

 

[Lee Martin]

Between dad and I we have three .50 BMGs. His two are homebuilt on Martin actions, mine is the State Arms shown below:



As expected, we've found seating depth depends on the bullet and chamber specs. I've heard of guys jumping them 0.200" - 0.300" but we've never gone that far in ours. With 750 gr AMAXs the State Arms likes touch pouring 215.0 of H50BMG. But switching to the Barnes 800 gr solid I jump them 0.050" over 225.0 of US 869. BTW, my barrel has a hybrid chamber.



When you get into load tuning, start at touch and work back in 0.020" increments. You'll soon find what the gun likes for that bullet/powder combination.

-Lee
www.singleactions.com

 

[bluechip]

Lee, my sample bullets were loaded by a guy that seems to know his 50's, he gave me five different samples, well, sold would be more accurate ($600 for 100 rds.) all A-max at different depths except for some solid brass ones. I had to take one apart to figure seating depth and there was 240 grains of a very course rod powder in it. My barrel has a .554 neck and I plan on turning the cases to .549-550 after firing, sound right?