PaoloAR15. Here's something you can pass along to your friend at the range. It was written by Dick Culver.
The question is often asked "how do I know if the M1D I want to buy is a genuine sniper rifle, and not a back room ‘put together’?" The answer(s) has many "what ifs".The judgement of what does and does not constitute a genuine M1D depends primarily on experience and the use of a little common sense.
First let’s crank in what we know about the "real" M1Ds. We know that they were developed to allow their construction at the Depot (or lower) level, and to circumvent the "heat treat" problems associated with drilling and tapping the M1 Receiver for the G&H "lever-type" mounts. Unfortunately this also makes it more easily fabricated in someone’s shop or garage "armory". While some of the rifles may well have been assembled in the field under less than optimum conditions, the smart money says that most were assembled at a major Army rebuild facility.
Those that were made (for instance) at Springfield Armory were quite probably WWII rebuilds. The ones that I have encountered were built/rebuilt (probably) at Springfield Armory in the very early 1950s (prior to Springfield having their rifle production line setup for producing the "Post WWII" M1s in the 4,2XX,XXX serial number range). These rifles usually have an early 1950s barrel (1951 is a common date, but not definitive) and will be appropriately refinished (if the rifle needed refinishing, some did, some didn’t). SA usually replaced the old stock with a new walnut number with a cartouche located in a spot that would be naturally hidden by the leather cheek-piece. Usually the cartouche is an "SA" over a letter or letters, such as "RA" or "F" with a sort of ¾ open bottomed box around the stamp... I have also seen early 1950s era Springfield Armory rebuilds that were NOT "Ds" with the same cartouche. Rifles rebuilt in the 1960s usually have the electo-pencil markings on the right receiver leg, and were furnished with stocks displaying the standard DAS cartouche (adopted in late 1953).
The WWII rear sight will (usually) be replaced with the T105E1 version. In addition to the replaced rear sight, all of the WWII corrections will (most probably) have been instituted, such as the "relief" cut in the OP rod having been performed and the rifle being completely refurbished and refinished. The rifle will probably have a "high hump" gas cylinder lock, and will have a new (or refinished) gas cylinder that has been subjected to (dipped in) the potassium (or sodium) dichromate finish. It will no doubt, have the cruciform or "cross slotted gas cylinder lock screw" installed. If the conversion was done far from "chimney smoke" as the old saying goes, some of the normal "upgrades" may not have been accomplished. I would also not be too surprised to see a legitimate M1D with a lock bar rear sight or with a single slotted gas cylinder lock screw (there are a few die hards that feel that the single slotted screw is more conducive to "gilt edged" accuracy than the "poppet valve" type).
If the rifle was a "used" M1D (as opposed to one of the CMP rifles that are virtually unused with new leather cheek pieces), the leather cheek piece will no doubt be stained dark, and the brass screws will have been installed to hold the cheek piece in place on the stock. You can expect a bit of verdigris (green stuff) to have formed around the brass eyelets where they come in contact with the leather (a conscientious soldier would have kept the leather well rubbed with neatsfoot oil – which will also eventually cause the leather to turn dark. Most of the M1Ds sold through the CMP come with "brandie, brand new cheek pieces"). The rifles that were returned U. S. Lend-lease will probably show lots of wear to the finish and to the bore.
A rifle used in the Korean fracas would have probably been issued with the M-2 bell type flash hider, whereas the ones used into the 1960s may well be fitted with the T-37 Prong style. Even though the T-37s were technically available before the end of the Korea (Jan. ’53), don’t forget, it takes a while for new equipment to filter down to the troops.
Trigger guards may be either of the stamped or milled variety, and I have seen both on legitimate M1Ds. A "D" is correct with either the M82 or M84 scope, but the M84 is far more likely. A "put together" D will probably be fitted with an M84 as they are far easier to find.
One of the real "tip offs" is to pull the operating rod handle to the rear and read the writing on the side of the barrel. The normal everyday issue barrel will have the drawing number on the side of the barrel followed by the date. If the "D" you are looking at has a "drawing number"on the SIDE of the barrel, BEWARE!! Real "D" barrels have their drawing # on TOP of the barrel, not on the side. M1 D drawing numbers will have a "555" as a part of the number, and the barrel will have a small ordnance wheel stamped on the barrel just aft of the drawing # and slightly lower (this can vary, but the small magic wheel will be there). Unfortunately, you probably won't be allowed to "pull the handguard" unless you have money in hand - BUT before you actually fork over the cash, by all means, look at the top of the barrel. The quick and dirty trick however, is to check for a drawing number on the SIDE of the barrel - if it IS there, chances are that the rifle ain't an original D! Mine has a series of "Ps" (some right side up, and some upside down) on the side of the barrel that can be seen by retracting the op rod, along with the barrel date - but NO drawing number!
A certain amount of the ability to discern a fake M1D from the "real McCoy" is akin to witchcraft, it takes a bit of "bat wing" and "eye of newt" – they just "feel" right. On the other hand, there are some extremely "good" producers of scarce goods out there, and some of the fakes almost impossible to tell from the original! And of course, that’s part of the problem, there WERE no true originals, unless you count the "tool room" models put together at Springfield from scratch in WWII.
Your best bet of course (unless you had a crooked Uncle who liberated one from the Korean War) is to acquire one with a CMP pedigree – this removes all the mystery from the equation. If you find one that looks right, contact an experienced M1 Collector to take a look at the rifle before you mortgage the farm to pay for your treasure.