Tumbling Problem with 147 gr. Lyman # 356637 Bullet

[eggman]

I ran out of the 147 gr. SNS Casting FP bullets I had been loading and picked up a bunch of local hard cast 147 gr. Lyman # 356637 bullets and am experiencing bullets tumbling and going through the target sideways as close as 15 yds. After reading posts on this forum of similar problems with lead 147 gr. bullets I went to virtually no crimp (just straightening out the case neck flair), not using my Lee Factory Crimp Die and going up on charge weight and down . My usual 147 gr. SNS load is 3.3 grs of 231 or HP-38 . I also tried 3.5 grs of Solo 1000 with the Lyman bullet which eliminated much of the tumbling but am still seeing it about 25% of the shots. I'm using a XDm 5.25 9mm Comp. but experienced the tumbling in my Glock 34 with a KKM barrel. My Lyman load manual shows an OAL of 1.058 for this bullet which is a shorter OAL than I use with the 147 gr. SNS FP . Has anyone experienced this problem with this bullet ? Oh... It measures the same diameter .356" as all the other lead 147 gr. bullets I've used with no problem.

Thanks,

Rodney

[robertbank]

Rodney I have experienced the same thing in my M&P. My M&P has a twist rate of 1 - 18 which is to slow for the Lyman 147 gr bullet. Mine were tumbling inside of 10 yards. S&W has since gone to a 1 - 10 ywist which will certainly allow for stabilizing the 147 gr bullets. Your problem will be either the twist rate is to slow to stabilize the bullet OR the sizing at 356. I suspect the bullets are sized to small. I size all my 9MM bullets .357. Check the twist rate of your guns. If they are slower than 1 - 10 then you have your answer.

The problem won'y go away driving them faster or slower. The bullets will just arrive at the target sooner.

Take Care

Bob

[eggman]

Thanks Robert I was hoping for a solution as I bought a bunch of these bullets but I'm thinking you are correct and I am wasting my time gettng these bullets to shoot .

Thanks,

Rodney

[DougCarden]

Check your bore in front of the chamber. My guess is you have some leading. A little bigger bullet would probably solve that, along with a little harder alloy.

DougC