load changes for longer barrel length

[SJshooter]

I've reloaded for a few years now and do a little f class comp, I reciently up graded to a savage mod 12 benchrest and can't find any info on load data changes for longer target barrels. Thanks for any info anyone has.

[boomtube]

"can't find any info on load data changes for longer target barrels. Thanks for any info anyone has."

That's easy; there isn't any.

Whatever works best (velocity) in a short barrel will work best in a long barrel, peak pressure occurs within a couple-three of inches of bullet travel.

[BigSkyGP]

Standard load work up, look for pressure signs, as you increase the powder charge with a given case, primer, and bullet.

I nearly blew up my 6.8 using the load I worked up for my 18" barrel in my 24" barrel. It ended up being the powder, I even went below the minimum recommended charge for that powder, and still had excessive pressure. I ended up changing to a more friendly powder. I use the load for the 24" barrel in the 18" barrel now, not a problem.

You have a valid question, and there is concern. Pay attention, have good shooting!

[436]

I'd have to agree with the others here... Unless you know someone shooting your barrel length and cartridge that has a proven load, and the ability to chronograph it; well you’re going to be pretty out I the cold. Best bet would be to make your next large investment in equipment a chronograph... If you’re going to shoot “long range” competition of any type you’re going to need one anyway for a myriad of reasons.
Good luck.
436

[davewilson]

i'm with boomtube on this one. the powder selected has everything to do with getting the bullets started into the lands. peak pressure occurs at the end of the bullet engaging into the lands. pressure then keeps dropping as the bullet goes down the barrel. this thing of using a slower powder for longer barrels is horse hockey!

[805_Sniper]

I agree. Look closely around the primer pocket for signs of excessive pressures. If the firing pin is starting to make significant primer indentations and rings are visible around the outside of the primer, and your bolt begins getting sticky start backing off the powder, before a serious accident occurs. Chronographs are also a great tool that will let you know when you start approaching unstable conditions/pressures. If your shooting F class distance, you should definitely invest in one...