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XWrench3
07-23-2010, 06:38 PM
i just had a new barrel installed on my rem 700. no big deal there, except the nightmare of the process from the gunsmith i chose. anyway, i am curious if there is more than one angle that they cut into the rifling (to ease the bullet into the rifling), or if it s a standard one set degree (angle). the reasoning for my question is i wonder if it would lower pressure, or make a difference in life of the throat / bullet speed / and or accuracy. i have read that a longer leade (like weatherby rifles) will lower pressure and increase bullet speed, but i am not sure about accuracy. i know, it probably hardly makes any difference. but i am curious about it.

flounderman
07-23-2010, 07:38 PM
freebore allows the bullet to jump into the rifling . it has less resistance overcomming its inertia, so pressures don't peak as fast. if you seat bullets long enough that they are engaging the rifling, you will get higher pressures, with the same load. it has been my experience, experimenting with a target rifle, 20x scope, you get your best accuracy with the bullet just about, touching the rifling. as the throat erodes, you get more freebore and you have to keep seating the bullets out further to maintain your accuracy. depending on the particular rifle, you may not see much difference. every gun is different. a chronograph will open your eyes, a lot.

MtGun44
07-24-2010, 01:58 PM
Throats are highly variable! Understanding the throat on your rifle is fairly important
to load for it and help to extract the best availble performance.

HUGE topic, spend some time with the search feature here for cast, less for j bullets.

Bill

Dannix
07-28-2010, 03:23 PM
a chronograph will open your eyes, a lot.
How so? Lower fps, as the throat erodes which results in lower pressures?