How is any sporterized rifle with a 2 piece scope base accurate?

[RD57]

My technique is to loosely install the two piece base just so it has a little/minor freedom of movement. Install the lower ring to the bases. Place my lapping rod on the rings and then do a lower ring alignment so there are no apparent gaps between the lapping rod and rings. Install the top rings and torque to specs. The stainless lapping rod aligns the rings very well. Now you can sight down the bore and adjust the windage (Leupold dovetail) over the top of the lapping rod for course adjustments. Since the bases were installed with wiggle room you'll be able to see and measure with a feeler gauge if the bases mate to the receiver correctly. If not then you can shim or glass bed the bases to the receiver. Using a lapping rod to align rings, especially with turn in bases works great and doesn't pose the risk to damaging a scope either by scratching or torqueing the tube. With a picatinny base I install the lower rings on the base in the desired location with just enough tension to hold them in place. Put the lapping rod in the lower rings, install the upper ring and torque to spec. The rings are in the best alignment they'll ever be in, now torque the rings to the base. You'll be surprised to see how little ring lapping is required if any.

 

[ntsqd]

Average aluminum (aluminium?) can is about .003" thick and likely getting thinner as mass production technology allows. We've used them to set-up an ACVW's transaxle R&P diff carrier bearing per-load in the desert. Can't see why they wouldn't work for this either. Maybe not to prettiest way to get it done, but functional.

FWIW the 'tool' that I used to turn in front rings was a ~12" long piece of Ø1" wood dowel. It didn't risk marring the rings like a metal bar could. Good or bad method didn't matter, it's how my bosses wanted it done. We had this one lbs OD green can of what claimed to be "Breech Grease" (or some wording similar) that we used to lubricate those dovetails before turning them in. Agree, turning them in dry is not a good idea.

Can also bed the rings, but discussing that is a whole new thread all by itself.