Most of my shooting is done with 55 to 62 grain bullets, so a 1:9 seems to work for me.   How heavy before I need a 1:7?

The general rule is that you should be fine up to the 69gr stuff. Some people say their 9 twist barrels can shoot the heavier (like 75gr) stuff fine, and some can't. The only way to know for sure is to get out and try it with your rifle.

/thread.

No one can answer this but you and your rifle. Some say 69 some say 75. My Stag would shoot 75 all day without a key hole but yours may not. Just buy a few boxes of ammo and try it out to see what it likes.

Depends as stated before. My 6724 Colt was a no go on 75gr. It would keyhole them. It did very well with 68gr on down.

My 1/9 Bushy will shoot 75gr without a problem. My 1/9 RRA........not so much. Just try it. maybe it works, maybe it wont.

About 69 grs.

45-69 for most.

I have some Hornady #22793 75 GR BTHP MOLY Match bullets that I plan on shooting from the 600 yard line slowfire prone.  They are specifically labeled TWIST RATE 1-9".

I'm also going to work up some loads for some Sierra Matchking's, 69 GR. HPBT-MATCH, Sierra # 1380, that are labeled 7" - 10" TWIST BBLS ONLY.  Gonna try these at 200 and 300 yards.

If you reload, it opens up a lot of possibilities.

BTW, the deal about what weight bullet shoots from what twist barrel is really more that just about weight, it's about the whole cross-section of the bullet - it's length compared to it's diameter.  It is an estimation as to how fast you need to spin the bullet to stabilize it vs having it blow up in flight.

IIRC, that's the case with the tracer rounds used by the military- it's their length.

Thanks for all the input so far.    I'll keep it to 69 grain and under for now, but I'll eventually try some others to see how they do

I shoot the 62 and 69 BH in my SPR 20" 1-9..

Have not been able to make the 69 tumble but agree with Molon and trust his data. Anything 69 and over I would go with 1-7..