1903A3 Conversion to A4 Sniper Variant

I was at a gun auction when a lot came up for bid that nobody seemed interested in. It was an assortment of 1903A3 parts that included a stripped receiver, four stripped bolts, and a number of internal parts. There were a few half-hearted bids and it looked like it was going to sell for $75. It struck me that the receiver alone was worth more than that so I placed a bid for $100 and won the lot.

The parts languished in my shop for a couple of years waiting for some 1903A3 Springfields to come in needing work or replacement parts. Those jobs never appeared and this last winter I decided building a 1903A4 Sniper rifle would be a fun project. A brief history. The M1903A3 was America’s last general-issue bolt-action military rifle.

The A2 variant released in 1942 is defined by its more simple rear aperture sight that replaced the more complicated M1905 ladder-type rear 1903A3 barrels come up on the auction sites regularly. This one was the perfect match for my Remington receiver. sight. The A3 also had less finishing with a rough, Parkerized finish and many used a two-groove barrel. The U. S. Army used the M1903A4 as their sniper rifle during WWII.

Being a variation of the M1903A3, the only difference between receivers was that the model and serial number on the receiver were split on M1903A4 to make room for the scope mount. The Redfield scope mount removed the A3 rear peep sight and instead used a Weaver 2.75x scope. Remington tested A3 receivers and those closest to ideal specifications had a quality barrel installed to become an A4 sniper rifle.

The M1903A4 was a relatively accurate rifle with an effective range of about 600 yards despite the limitations of a low-powered optic with a narrow field of view in the Weaver scope. Since I already had at least one of the major components, and the original A4 sniper rifles really were rebuilt Springfield 1903A3 rifles, I might just as well build a sniper rifle that wouldn’t cost me an arm and a leg. I’m full of fantasy thoughts like that. The first step in the project was to determine what I had and what I needed.

As it turned out I could put together a receiver, bolt, and trigger with the parts I had on hand but would have to find a stock and handguard, all the stock hardware, A barrel vise and action wrench from Brownells are used to install the barrel. The extractor on the bolt must fit into the extractor cut on the barrel and headspace adjusted.

a barrel, the scope base, rings, and scope. It all seemed simple enough. Little did I know I might as well have been searching for and funding an expedition to find the Holy Grail. I’m sure I am not the only one to have experienced sticker shock at the prices firearms and accessories are bringing today. Anew pistol grip 1903A3 stock alone will set you back $250 and since I’m a cheap SOB, I knew immediately my work was cut out for me.

I love to cruise gun auctions and online auctions looking for deals and projects so it was simple to add the 1903A4 parts I needed to my saved searches on Gunbroker.com and Proxibid. Part by part, I started accumulating what I needed. First was a Remington barrel that someone had managed to reblue without buffing A Dremel tool with a diamond cutter was used to grind through the case-hardened receiver ring so it could be drilled and tapped for the scope mount. off all the lettering.

Then I came across a scant grip stock that was well used and abused but was still serviceable. I picked up all the other small parts from Numrich and assembled them into a complete rifle. The stock was really dirty and even still had quite a bit of Cosmoline in the barrel channel and some of the receiver cuts. I scraped the Cosmoline out in big greasy globs but the stock still looked like it had seen every beach and swamp on every island of the Pacific War in WWII.

A stiff nylon brush, some Dawn dish detergent, and a couple of hours in the bathtub had the built-up dirt pouring out of the cracks and crannies of the stock and down the drain. After giving it 24 hours to dry, I smoothed out the roughest spots with sandpaper and gave it two coats of boiled linseed oil cut 50/50 with turpentine. The tur- American Gunsmith Reader Services 1.

pentine allows the oil to penetrate the wood and promotes faster drying of the oil. A Google search found an original style base, rings, and scope for $375! Considering that the market for these can’t be very large and that With the iron sights removed, the bolt replaced or modified, and the scope mounted our run-of-the-mill A3 has become a replica of the 1903A4.

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I didn’t want to pay it but I do think it is fair. In my relentless searching of auctions, I came across an old Weaver J2.5 scope with a 3/4" diameter body that I was able to buy for under $50. Further searching found a Chinese-made original style base and rings for just under $100. The build was pretty straightforward with the most difficult jobs being the removal of the original 03A3 Far With its 3/4-inch diameter finding a correct scope to fit the rings is a challenge.

I found this Weaver J2.5 power on Gunbroker. The bolt for the conversion can be purchased from Numrich Gun Parts or you can modify a standard bolt to clear the scope. rear sight and drilling the receiver to mount the scope base. The rear sight was riveted to the bridge in two places and no amount of beating on it would move it in the dovetail. In the end, to remove the rear sight, I had to drill through both places where it had been riveted to the bridge so it could be drilled and tapped for the scope base.

The receiver ring presented a very different problem. When the receiver was heat-treated it was left harder than woodpecker lips. Brand new number 31 drills wouldn’t even scratch the surface of the receiver. I was ready for this problem and there are two ways of dealing with it. The hardness is confined to the outer surface of the receiver ring and it can either be annealed with a torch to soften it or you can use a diamond grinding point with a Dremel tool to grind through the surface hardening.

I had a Dremel and a diamond point on hand and chose to grind through the hard surface and then drill and tap the receiver as normal. I ended up with a pretty neat copy of the 1903A4 sniper rifle as used during WWII at a cost far below what an authentic one would be. I am looking forward to a lot of fun days at the range with this, sniping paper targets left and right and hopefully putting a lot of little holes in very small groups. AG