Man, that's a tough one. The only thing that comes to mind is that the alloy might be a little soft for my own rifle in that caliber. At least, with that powder charge. Are you sure you haven't messed up the base of the bullet in that soft alloy with your seater? Well, I guess you have a project anyway. Good luck, and sorry I don't have more than condolences.

Bullets keyhole due to not being stabilized properly by the rifling.  Factors that influence this are bullet length, bullet diameter (relative to groove diameter), rate of twist of the barrel, and velocity.
* rule out bullet diameter- Douglas is .321 groove
I'd guess the bullet length in conjunction with velocity has a stability factor not conducive for a 1:15
Do some calculations ... (You need to Login or Register to view media files and links)
(You need to Login or Register to view media files and links)

Velocity (V) (feet per second): the velocity of the bullet. The higher the velocity, the more stable the bullet will be.

Length of Bullet (BL) (inches): overall length of the bullet. The longer the bullet, the more difficult it is to stabilize.

Very nice . I do not think the 1:15 twist is an issue either.
For example , my .223 1:9 twist barrel will not stabilize a 62 gr. 223 bullet , it will stabilize a 55 gr. bullet . My .223 rifle with a 1:7 twist rate will stabilize the heavier bullet . Both bullets are the same length . So here we are talking purely about bullet weights of the same length bullets . Current and past knowledge has told us that a longer and heavier bullet will usually do better with a faster twist rate . The Saeco bullet is about 1/8" longer than the Hoch bullet and both are the same weight 200 gr. Both bullets cast around .322-.323 should be fine for the Douglas .321 groove diameter .I'am trying to wrap my mind around conventional wisdom here with no clear answer . So the only thing I'am left with is FPS, or pure bullet speed or lack of bullet speed. So back to the reloading bench . There is no reason that this Saeco bullet should not stabilize ! I just need to find the variable that is missing here . The Hoch bullet is great, but I have to say the Saeco base poor casts so nice, you have to work a little harder casting with a nose pour mold . Thanks

Have shot that bullet in my Helm.  Has fifteen inch twist. Similar powder charge. 

Shoots good with 16-1 thru 60-1. 

Key holing? 
Hard to believe. Barrel heavily leaded? Squirrel storing nuts in barrel? You cast real crummy bullets?  

      Joe. 



       

Dave ... Opps!
This is the Powley Calculator for lead though I have used the posted one for lead...
(You need to Login or Register to view media files and links)

Other good stuff ... (You need to Login or Register to view media files and links)

Brudford01,

I forgot to mention the alloy of my bullets are 20-1.

Bob

Bruford, here is an earlier thread I started when I was experiencing the worst tipping using Fg with that bullet in my rifle.  Maybe it'll be useful to you.

(You need to Login or Register to view media files and links)

Chris.