Boat Tail Projectiles

[harleymac1]

I have never ventured into the rifle reloading world yet but a buddy just bought an XL650 and is reloading 5.56. He bought some 62 gr FMJ Boat Tails and says he can not find any reloading data. I told him I assumed that 62 gr is 62 gr whether boat tail of flat base but I also read somewhere that the BT might be longer than a flat base which would build more case pressure as it would seat deeper. Can anyone help us find the answer? He is using Hodgdon 335. I am heading to their website now to see what I can find but thought I would stop in here first and check.

 

[Robert Richardson]

Just load it for a 62gr. Boat tail or flat, doesn't matter.

 

[russc2542]

That's why you start working up a load from the low end and watch for overpressure signs. Brass wall thickness (and internal volume), brass hardness, machine tolerances/inaccuracy, bullet variation, temperature variations, etc all stack up.

 

[johntheplinker]

Bullet over all length in and of itself doesn't have much to do with pressure, bullet bearing length on the the other hand can make or break a safe load. Longer bearing length, more friction, more pressure.
From what I've seen boat tail bullets tend to have less bearing surface than otherwise identical flat base bullets.