I just bought a real nice 95% + condition remington 700 bdl in 243. The rifle's action has no prefix in the serial number. The way i understand this is an older receiver. Maybe from the 60's. I was doing a bit of reading and read were the scope mounts of today will not fit properly on the older receivers. Something about needing shimmed from the back to the front?? This rifle i bought already has a 2 piece mount, so maybe i dont need to worry about any of this. I bought the rifle for 350 bucks and of course i bought it for the action and bdl bottom metal. I hope this turnes out to be a nice rem 700 receiver. any thoughts on the scope mounts?? Thanks lee