barrel length and reloading ?'s

[aldar]

when looking at my reloading manual's, all the tested loads were shot through either a 22" or 24" barrel. I'll be shooting in a 26" barrel. Having the longer barrel, does that automatically mean higher velosity's and pressures? if it does, by how much? would the max loads listed for a 24" barrel be less than a max load for a 26" one, or are they the same? should I just begin at the suggested starting loads or can you move up a couple of grains as a starting point? did'nt find these answers in either manual

[beemanbeme]

No to the greater pressure; possibly to the greater velocity.  Only by shooting your rifle over a chrony will you know.  Just use the receipes in the load books with a normal work up and then chrony your best load.  I'm gonna guess that 2" of barrel is gonna have little effect on your velocity.  As far as reloading safety is concerned, ignore the barrel length.

[Castaway]

As stated, in general velocities will go up with longer barrels.  There are exceptions though.  Big pistol bullets launched at sedate velocites in rifles (45 Colt factory loads) sometimes  slow down due to the increased friction when they are shot through longer barrels.

[Lone Star]

...Having the longer barrel, does that automatically mean higher velosity's and pressures? if it does, by how much?

The maximum pressure developed in a rifle cartridge occurs in the first few inches of bullet movement, so the max pressures won't be affected by barrel length.  Muzzle pressures will be affected and the shorter the barrel the higher the muzzle pressure - but all that really means is that the report will be louder with shorter barrels.

The velocity difference between a 24" and 26" barrel depends on many factors, including the cartridge capacity and bore size, and the powder and bullet used.  For typical rifle cartridges, the difference is usually between 15 and 30 fps per inch.


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[Castaway]

Lonestar, well said.

[aldar]

thanks guys, I think I understand better now. A max load is a max load, no matter the barrel length! change any components in a recipe, back down and work the load up.