22-6mm 85.5 gr Berger troubleshooting

EisenShift

Private
Minuteman
Mar 5, 2020
8
0
So question for the community. Obviously the 22-6mm is a wildcat. nearly zero load data out there. So when I work up my own loads I start way way low and creep upwards. The most useful start point I've found lately has been using 22 creedmoor data. However I've got 5 grains more capacity than the 22 creedmoor and I shoot competitive benchrest and like more of a case fill for consistency.

Quick rifle stats in case it matters: 30 inch shillen 1:8 twist barrel, savage target action, McRee G7 single shot chassis.

Also shots impact 300 yard target at 2650-2700 fps. I do not have muzzle velocity data at this time.

I know I can run up to 49 gr of h1000 before I start to see significant primer puckering. At that level I had a shot "disappear" fired and never made it to my paper targets. I've seen weird stuff so when doing these types of tests before so I cover my 100 yard board in fresh grid paper so I can see if i'm off by several feet in any direction from my center. I assumed I'd blown the bullet up and needed to back off.

I've since stepped down to 44 grains of h1000. But have still had odd flyers occasionally. And today at the range during a competition a few of the more experienced shooters noticed something dropping away and disturbing the grass by the 100 yard berm on most of my shots starting after the 5 shot. Which is when my SD always opens up from single digits until it climbs to about 40. Anyway one of the more experienced shooters shot my rifle a few times, and I saw the exact same thing, something appearing to drop away into the grass by the 100 yard berm, we didn't find anything when we went searching later but it was very clear. And the rounds aren't key holing and they all make it to the target but are sometimes an moa up or down and left or right from the others.

So here's my question. Am I still driving those bullets too quickly? What else could the visual anomaly we were seeing be? Do I drop down to 42-44 grains of h1000 well below my pressure limits? Or is their a slower/different powder I should be using for my specific application? Thank you in advanced for any assistance.
 
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What berger bullet are you shooting. I'm shooting 77 grain OTM berger with 51 grains H-1000 .10 jump at 3730 FPS with no issues i have used other berger bullets that were exploding mid air from to many fps I believe that is your issue u need a stronger jacketed bullet look at match grade bullets.
 
Hey Kody,

85.5 gr long range hybrid target. I deep cleaned and bore scoped the barrel at the end of July and had some fairly serious heat cracking so I think that was damaging the jackets. That barrel has been retired and I'll likely cut it in half to see how bad it actually is and have a good ready to hand example of barrel wear.

I also contacted Berger support and they have said the limit for any cup and core bullet is 3500 fps and 300,000 rpms. Going outside either of those and you may start seeing odd failures. so I've also transitioned away from the 22-6mm to a 6mm creedmoor at least for my target shooting needs.