so i have a Bravo Company 14.5" middy, and have been reloading at a case length of 1.750" and a overall length of 2.250". ive seen some conflicting information in the books, some say to go with 2.260". so i had my jump measured, and also a friends, and the rifling was really far in apparently. anyone have any experience with these barrels and bores, and any opinions on what OAL i should be going with? whats too long?
I have been using an OAL of 2.232 ~ 2.235 with 55gr fmjbt projos. I have had good luck with that OAL.
I have a Bushamaster Carbine. I dont have any experience with BCM.
O.P. what bullet?
Originally Posted By 506thCurrahee:
whats too long?
When it won't fit in the magazine, chamber or hold the bullet (usually in that order).
Unless you are loading one of a small number of bullets made to be single loaded for long range AR competition you aren't going to get a bullet anywhere near the lands. That is the nature of the beast with a 5.56 chamber. Just load to mag length and call it a day.
This idea that keeps floating around that you have to load near the lands to get decent accuracy is a misunderstanding. Unless you are shooting benchrest competition it really doesn't make enough difference to matter. Find a bullet and powder combo your rifle likes at mag length and that's it. BCM makes military grade rifles with CL bores so expecting very much better than MOA is unrealistic anyway.
Originally Posted By 506thCurrahee:
so i have a Bravo Company 14.5" middy, and have been reloading at a case length of 1.750" and a overall length of 2.250". ive seen some conflicting information in the books, some say to go with 2.260". so i had my jump measured, and also a friends, and the rifling was really far in apparently. anyone have any experience with these barrels and bores, and any opinions on what OAL i should be going with? whats too long?
BTHP bullets have the greatest variation of length from bullet to bullet due to the nonuniform meplat. So many people load magazine length bullets to an average COAL of 2.25 inches to insure reliability of feeding. I have one commercial magazine that chokes on a cartridge loaded to 2.26 inches.
I usually load bullets that seat sufficiently deep out to 2.26 inches and let the longest sneak out to 2.265 inches, and that's where I draw the line. 2.27 inches will drag in a USGI magazine, and I don't want feed malfunctions due to length.
As the reloader of your ammunition, you have to decide. You'll find that light weight bullets can't be loaded out to 2.25 or 2.26 inches as they barely engage the case neck. The usual rule of thumb for insuring good neck tension is 1 to 1.5 diameters of the bullet bearing surface engaging the case neck. That means some bullets simply can't be loaded out past 2.22 inches or so, or even 2.21 inches in for the tiny bullets.
