Quote History Originally Posted By RattleCanAR:
Worked fine in my 1/9. I think it all depends on the barrel.
View Quote
<This. Not all barrels are exactly as marked. Depending on the manufacturer, twist rates can be +/- a little.
Many 1:9 barrels can shoot and stabilize 75/77 grain bullets, even though they are borderline not supposed to. Some 1:9's simply won't shoot them well.
All copper bullets, Barnes, GMX, etc. are considerably longer than their weight would indicate. Comparing them to a 62 grain M855 is probably not going to match up exactly. The bottom line is you are going to have to try them in your rifle to find out. I believe Barnes has twist rate suggestions included in their online reloading data base. I would check their first, before committing to a large purchase, after all, Barnes bullets are not real cheap.