http://vishooter.home.att.net/ra_serialization.txt

The serialization chart on the above captioned site is the best one available. The author has attempted to account for scrapped receivers and to rationalize the upper limit of the "third s/n block" with the serial numbers of the rifles known to exist in the real world.

Ordnance placed two orders for A4's, one for 20,000 rifles and the second for 8,365. Production on the second order commenced before the first order was finished so for all intents and purposes it was one continuous process controlled primarily by the availability of scopes.

Specific serial number ranges for various rifle models were assigned by ordnance. When production on the second A4 order commenced using numbers starting at 4,000,001 (as instructed) Remington determined that regular A3 production had already run into that portion of the range. A leading "Z" was added to the serial of each of 3000~ duplicate A4 Receivers and a new block of serial numbers started at 4,992,001 to complete the reamainder of the second order. (NB A4 and A3 production was performed in separate areas of the Ilion plant. Also thoughout 1943 Remington was producing an average of 50,000~ A3's a month!)

On an otherwise original rifle barrel dates serve only as a general guide. Lower serial numbers will have earlier barrels. Things get less clear as you get toward the middle of the serial number range. The lack of scopes meant the rifles couldn't be finished, shipped and billed. Finally ordnance directed Remington to maintain an inventory of 1000 completed rifles on hand awaiting scopes (a month later the quantity was bumped to 2000). These instructions caused certain month's component production to increase dramatically (September barrels for example).

Springfield Arsenal sent several thousand "C" stocks for use on early rifles.
Thereafter M1903A1 ("sorta C") stocks were supplied mainly from contractors such as Keystone.

Scants started to appear on original rifles (in the first order) in the fall of 43.
Over time the use of scant stocks seemed to increase.

Regards,

Jim