Originally Posted by azsugarbear
Many of us shooting the 270AM and 277AM rifles ran into problems using the longer/heavier .277 wildcat bullets in Lilja 3-groove barrels. After about 350-400 rounds down the tube, these bullets began to break apart before reaching the target. The problem was primarily with the bullets. The 3-groove barrels have a lot of contact with the bullet jacket. The heavier/longer bullets have a lot more bearing surface. When you combine that with a slightly thinner jacket, you get a recipe for disaster. We needed a heavier jacketed bullet (not available yet), or a shorter bullet (lighter) to reduce the bearing surface to solve our problem. The other solution might have been to switch to more grooves in the barrel. A quick search will turn about several threads on this problem that began occuring approx. two years ago.
I should emphasize that this situation with the .270 Allen Magnums was the exception rather than the rule with 3-groove barrels. Other calibers fair very well. It shouldn't be a problem in a 30 cal, unless you start shooting 240 gr. bullets with thin jackets. :-)
Also wasn't there a problem with twist rates being to fast ?
Some were trying to use fast twist like (1 in 7 or 8) and these are very hard on bullets even in
6 groove barrels at the velocities some of the wildcats achieve.
The best advice I can give is to talk to Dan Lilja and tell him what you are going to expect out
of your rifle (Velocity) and let him recomend the proper twist and groove style that is best.
J E CUSTOM