My thoughts:

Chamber neck .004" greater diameter than loaded cartridge neck.

Parallel-sided freebore of 0.5000" length.

Leade angle of 1.5 degrees.

Freebore diameter of 0.5110".

That ought to handle 570 grain GSC FN elephant busting solids at 2500 fps or 750 grain Hornady A-Max bullets at 2250 fps seated into the lands for 1000 yard targets, with the 500 Mbogo RIPoff (500 MR).

Sumbuddy there is who know better?

quote:

Originally posted by RIP:
My thoughts:

Chamber neck .004" greater diameter than loaded cartridge neck.

Parallel-sided freebore of 0.5000" length.

Leade angle of 1.5 degrees.

Freebore diameter of 0.5110".

That ought to handle 570 grain GSC FN elephant busting solids at 2500 fps or 750 grain Hornady A-Max bullets at 2250 fps

The 500a2 i am building matches everything but neck is i believe +.005 and freebore is .400. It fires 50 cal ap bullets ok. Haven't tried 750's. Have to wait till i get it mounted in the stock.
Dick

Ron,
at your suggestion, I took the 500jeffe to .850 total .5 free bore, .0350 lead

jeffe

quote:

Originally posted by jeffeosso:
Ron,
at your suggestion, I took the 500jeffe to .850 total .5 free bore, .0350 lead

jeffe

Jeffe,
Agreed, .350" is about the distance that the leade adds.

Bigholes,
Yep, .400" is the standard 500 A2 freebore, and even .300" of the parallel sided freebore is enough to handle the blacktip crimped on its cannelure.

If you want to seat the A-Max out as far as it will go and still leave shank for the neck to grip, you might need more throat, but you can make some serviceable loads with 750 grainers using the standard 500 A2 throat.