22 Creedmoor 77gr Sierra TMK aren't making it to the target

[Iron Worker]

Shooting my 22 Creedmoor today in the hot NV desert. I was experiencing terrible, mysterious groups (Oblong holes) and missing shots at 100 yards, but only with Sierra 77gr TMK bullets. Hornady 62-grain ELD-VT bullets shot well. The 85.5gr Bergers did okay. I fireformed some 53gr V-max (22/250) they did fair, but made it to kick up dirt at 300yds.
I never had this problem in the wintertime with these bullets? 8"twist 3,425 FPS. I just bored-scoped the BBL; it needs cleaning, but the Carbon ring was minimal. I was worried that my BBL was shot.

 

[stello1001]

What's the speed on 77TMK vs 62 VT?

 

[spife7980]

How many rounds? My most recent 22 creed 7 twist is ghosting 90smks at 600 rounds.

 

[Iron Worker]

What's the speed on 77TMK vs 62 VT?

62 gr is an average of 3,740 FPS

 

[supercorndogs]

How many rounds? My most recent 22 creed 7 twist is ghosting 90smks at 600 rounds.

I had a 7 22-250 that did the same with 75 and 80 a max by about 700. At that point it had to stay squeaky clean for bullets to hold together with any consistency. It is what pushed me back to 6mm.

 

[tekmann2377]

Tougher bullet or less velocity. I shoot the 80 ELDX and keep velocity to the 3250 range to avoid this.

 

[supercorndogs]

I was shooting them about 3200 out of a 26" barrel.

 

[Ronin22]

Are 22CM barrels beginning to shoot out by 500rnds, or jackets coming apart?

 

[spife7980]

Are 22CM barrels beginning to shoot out by 500rnds, or jackets coming apart?

My first shooting noslers was good to 900 rounds. This second shooting sierrra is done at 600, but I also shot a match with it and that likely contributed to its downfall. Im not going to start developing a new bullet for a couple hundred rounds tops, so for me shot out and missing bullets is the same.

 

[supercorndogs]

Are 22CM barrels beginning to shoot out by 500rnds, or jackets coming apart?

Fast twist high speed 22 cal has always been pushing the ragged edges of what bullets can take. Several of us talked quite a bit about it years ago when a handful of us build 22-250s and the like with 7 and 8 twist barrels. Those discussions and warnings were rehashed when the 22 creed came out. More overbore equals more power but also more problems.

.308. 8-10k rounds
6.5 creed 3-4k rounds
6 creed 1-2k rounds
22 creed ??? rounds

6-700 rounds doesn't suprise me from one that wasn't babied.