Don't think I'd use a bonded bullet for varmints. Depending on your definition of what a varmint is and the ricochet factor. Sort of depends on the velocity as a deer bullet also.
Hate to say it here but best load in my 44 contender is the 200 gr Barnes XPB. Plenty of speed and very accurate with a healthy dose of W296. Whitetail hammer!
I see that this cartridge is available in the new NCH. In the handloading book they have OAL at 2.25". First I've seen anything about this. Is this the 22 Nosler necked up for AR use?
I've been using a 50 cal CVA the past few years, Accura MR. With Shockwave bullets and Blackhorn 209 powder you can cover 3 shots at 100 yds with a quarter. Never fails to put at least 1 whitetail in the freezer every year. I had been using a 45 cal TC omega but just couldn't get it to be...
I use Aero M4E1 uppers so that's not an option. I have just found though that during resizing the shoulders were being pushed back way too far. I adjusted the die for .004 and they seem to feed fine. That's not going to help the primer pockets though.