A slower powder will have more muzzle pressure, so that's a possibility. I would bet it's on the other end. Not enough pressure to expand the bullet and seal the bore, gas cutting the base.Klem wrote:As I said earlier in the thread, my usual sub load is the 220SMK and this was shooting fine on the day. I have been shooting Blackout since 2011 and trialled a number of heavy bullets for subsonic (220SMK, 240SMK, 220Sierra RN, 220Hornady RN, 210Berger, 220Outlaw State SN, 220 Blackout Bullets HP, the 200Lapua and a few light bullets with Trail Boss for non-cycling super-quiet). This is the first time I have seen any go unstable.bearcatrp wrote:Have any other sub rounds you can try to see if they are doing the same thing? the hornady 190 subs are out now so should be easy to get some. I know your hand loading these but a commercial round could help figure this out if your barrel is bad.
Nosler replied again saying they have seen this instability on two occasions;
1. When a muzzle device interferes with the gasses surrounding the bullet on exiting.
2. When slow powder does the same.
I have been using H4198 but will try a faster powder.
If they are having enough problems to flag "muzzle devices", I think that bullet is barely stable unless there have been a lot of people with threads not concentric with the bore.
Interested to hear what happens.