I bought a older CPA (1996) a few years ago  and have never really been satisfied with it's accuracy. My latest thoughts are centering on the 15 inch twist of the barrel and the bullets that I've been using.
All of the bullets that I've been using are 1.5 to 1.6 inches long and weigh from 205 to 209 grains. I've been trying to hold my lead mix to between 1 in 20 to 1 in 25. I do weigh my bullets and sort them by weight to within 3 tenths of a grain.
As far as my powder I use Alliant 300 MP at 14.5 grains.
I'm not too bad of a shot. I win my share of shoots at my local club. But we're talking muzzleloading rifle, bullseye pistol, small bore silhouette, and anything else we might think of. But I just can't seem to get consistancy with this cast bullet stuff.
I've been looking at this lately and think maybe I'm using too long a bullet for that rifeling.
Can I get some ideas from you guys?

Thanks,
Kcajeel

I'm in a kinda similar situation - .30-20 (meaning .308 groove), 15 inch twist barrel.  And to make it worse, I shoot BP in it - which means my MV is subsonic.
I decided upon a 150gr bullet as optimal, but I also shoot the 308403 Pope bullet (at 170gr), which might just be on the ragged edge of stability:  It still shoots well at 100m (didn't try it yet at longer ranges), but if you look carefully at the targets, you can detect some tipping - sometimes.  So yes, I'd think your bullets might just be a smidgen too long for that 15-twist barrel.  And a bullet is better off overstabilized than understabilized IMO.

Bullet design plays a big part of it and you failed to mention those specifics so there is no way really to provide an honest answer. Unfortunatly you are going to end up with just personal opinions with no bases to form it on.

And John, I don't know enough about bullet design to describe the bullets.

That lenght bullet will be well stabilize, what ever it's design, in a 15 twist.

Frank

A 15 twist barrel cannot stabilize a 1.5 or a 1.6 length bullet as was noted in the original post and for someone to say it will is simply nothing other than a false statement. Kcajeel are your bullets. 1.115 and 1.116, 1.050 & 1.060 or 1.005 and 1.006 in actual length.

JLouis

Greenhill formula for 32 caliber, 15" twist bullet length should be 1.043"
1.5" would not stabilize at that slow a twist.

CF best go back to the original post where it was stated 1.5 and 1.6. in length. There is now way they would stabalize nor would they be able to match the weights he stated. How anyone here can continue to provide this sincere gentleman any means of honest and positive information and direction without knowing all of the intricate specifics is simply beyond my understanding. It all appears to me as soley being based on assumptions up to this point but maybe I am missing something and if so I apologize but please take the time to point it out to me so I don't inadvertently make the same mistake twice.

JLouis