[ultramag44]

I would like to add that I believe there is
a small recoil lug under the reciever attached by a screw. Your rifle is an "E" if the serial number ends with the letter E. Kirk

The "E" will be a prefix, not a suffix. The letter being a prefix was a mandate of the GCA of 1968.

There are several features of E guns that are different from D guns. BUT, not all the changes were applied @ once. Stocks of D parts, like un-counter bored barrels, wood stocks, etc, were used untill depleted. Early E's were polished, very late guns were dull finished. Some E's were not D&T'ed on top of the receiver, but most were. Some E's were fitted with side bases for a receiver sight, barrel blocks and a front sight block. Others were D&T'ed for ALL the sight options, but not fitted with blocks, mounts etc.

My E is D&T'ed for ALL the sight options, but not factory fitted with blocks, mounts etc (threaded plugs are in all the holes). The muzzle is counter bored, highly polished finish, Marksman stock. The stock has the 2 tuning screws in the front.