M1903A4-gery Build

[95chris]

Made some progress on the stock today. Slowly removing wood from both locations the recoil lug (carried out first) and receiver flat have made contact when fitted. As expected, the clearance between the rear tang and stock decreased so that was also worked on to maintain that ~0.010" of relief.

With everything still tight, I checked the force needed to separate the stock and and the barrel at the muzzle. It barely took any force, I could separate the two by pushing against the barrel with my thumb while holding the barrel with my other hand. If I had to guess it probably took less and pound of force. Also used one of those luggage scales for travel and it had similar results (I'm aware they're probably inaccurate to a degree).

I decided to inlet the length of the barrel and noticed it was still making contact at the previously pictured location near the chamber, probably due to the fitting of the receiver flat. Those were relieved and by following Claven2's advice on lowering the receiver flat to increase pressure and by removing small amounts of material, I was able to achieve a pound of force on the scale to separate the two. I'll be continue this process while marking the flat and lug to ensure they remain seated.

Of course I can't make a post without asking a few questions so here goes! FYI, the bedding at the muzzle has not been touched up to this point.

From the tip of the stock, how much of the barrel is supposed to make contact with the stock to create this pressure? The number I saw online is one inch The picture on the right shows where the contact points are at this moment.

I can continue working on the flat but if too much of the forward length of the barrel is contacting, should I relieve those areas to stay within that one inch point of contact?

Cheers.

 

[purple]

About an inch of barrel/stock contact area is desirable at the forend tip.

Before removing any more wood, I'd check the fit of the upper band with the action installed and the guard screws drawn up tight. Does the top of the barrel make contact with the upper band? If there is no contact, good. If there is contact you can either remove some wood from the forend tip (but this will decrease barrel/wood pressure there), or you can grind away some of the upper band surface to get clearance between the barrel and the upper band.

As you have found, when the receiver flat is lowered further in the stock, the amount of barrel/wood pressure at the forend tip will increase. This should also tend to increase clearance between the top of the barrel and the upper band. Take note: I'd previously mentioned 5-7 lbs pressure at the forend tip, but checking my original M1903 - 03A3/A4 tech manual shows 4 lbs pressure at the forend tip. Not a huge amount of difference though.

All things being equal, if there is clearance between the upper band and the top of the barrel, the forend tip could also be shimmed to increase pressure at the forend tip. With a full length military stock, contact/pressure at the forend tip is also desirable to eliminate the possibility of the stock warping and binding aginst the barrel over time.

In fitting a number of new GI stocks I've found that minimal wood removal is required at the forend tip, but stocks can be different, and this is a commercial repro stock.

You should also verify that you are using a 03A3 front guard screw, rather than a M1903 guard screw. The 03A3 screw is 1.015 OAL while the M1903 screw is shorter (.0922 OAL). The screws are interchangeable, but the 03A3 screw allows more penetration of the receiver. The longer 03A3 screws should not be used on an M1903 receiver because they may bottom out in the blind hole for the guard screw.

 

[95chris]

About an inch of barrel/stock contact area is desirable at the forend tip.

Before removing any more wood, I'd check the fit of the upper band with the action installed and the guard screws drawn up tight. Does the top of the barrel make contact with the upper band? If there is no contact, good. If there is contact you can either remove some wood from the forend tip (but this will decrease barrel/wood pressure there), or you can grid away some of the upper band surface to get clearance between the barrel and the upper band.

All things being equal, if there is clearance between the upper band and the top of the barrel, the forend tip could also be shimmed to increase pressure at the forend tip.

I did this check with and without hand guard ring, no upper handguard (if I need to just say so) and there's a pretty good gap in both scenarios.

To be honest, I'd be happy to shim the fore end tip to achieve the required pressure. I can always come back and try it again in the future or on a proper GI stock. I'm guessing I would need to shim it just have enough to have a gap when the upper handguard is installed. A quick search online mentions 0.025" would be O.K to go with. Would feeler stock similar to the attachment be used? Can be easily cut to length and has various sizes.

You should also verify that you are using a 03A3 front guard screw, rather than a M1903 guard screw. The 03A3 screw is 1.015 OAL while the M1903 screw is shorter (.0922 OAL). The screws are interchangeable, but the 03A3 screw allows more penetration of the receiver. The longer 03A3 screws should not be used on an M1903 receiver because they may bottom out in the blind hole for the guard screw.

Looks like I have the shorter M1903 screw.

I should really find one of those tech manuals for myself.

 

[purple]

A quick check of several 03A3s and 03A4 shows .020 clearance between the top of the barrel and the upper band.

The handguard should be fitted after everything else is satisfactory.

If shimming the forend tip is necessary, different thicknesses of wooden shims can be tried until desired forend tip pressure is established. When it's right, the shim should be glued in otherwise it may dislodge from recoil. People often try shims of various thicknesses to see how a rifle shoots with different forend tip pressures.

The receiver flat can also be shimmed to check for differences in accuracy as a result of different pressures at the forend tip. The stock area behind the recoil lug acts as a fulcrum when shimming under the tang to increase forend tip pressure and/or to gain clearance between the top of the barrel and the upper band.

I have a spare 03A3 front guard screw. PM me your address if you want it. As you can see, the 03A3 guard screw hole is drilled right thru the receiver ring which allows for the longer screw.

 

[95chris]

Decided to try out and see what the shimming the fore end would look like in the current setup. In the end, it required 0.042" to reach that 0.020" clearance. This created a few issues:

1. Contacted is made on the upper right side of the barrel. Looks to be a slight curve towards the end of the stock which curves to the left.
2. The barrel is pushed upwards to the point where it locks up the hand guard when fitted.
3. That's a lot of shims!

So decided to go back into adjusting the flat. By sloooowly removing material, the pressure at the front had increased with noticeable difference. With the puller I achieved roughly 4~ lbs of force. Believing there's a margin of error in the tool in addition to defining how much it "feels" to pull. I added a 0.02 shim at the muzzle. With tape is should come around to 0.03". The tape used is glass cloth type tape that can handle temperatures to 392 F / 200 C. Should be good for test firing for now until I make a proper wood shim. I've read others have used plastic, leather and just a strip of metal so I think I'm good for the mean time.

This all done while making sure the other areas of the receiver remained in contact, which they did. The barrel channel required minimal relieving so that the contact point remained at the muzzle tip only. There is plenty of room between the barrel and upper band. I also ended up cutting the rear bushing with a jeweler saw and using a punch to open it up a bit.

The rifle up to this point.

Will most likely tackle the buttplate next while looking for solutions on other issue, such as:

• Dejeweling the bolt
• Blueing or parkerizing the bolt, bushing and bands that were mentioned before. Maybe coating the bolt will hide the jeweling?

I have a spare 03A3 front guard screw. PM me your address if you want it. As you can see, the 03A3 guard screw hole is drilled right thru the receiver ring which allows for the longer screw.

EDIT: Attempted to send one, but your inbox is full.

 

[tiriaq]

The bolt could be de-jeweled by polishing it boot black style with fine abrasive cloth strips, then blasting and parking. Blasting alone might be enough. Residual swirls might or might not be left.

 

[purple]

Decided to try out and see what the shimming the fore end would like in the current setup. In the end, it required 0.042" to reach that 0.020" clearance. This created a few issues:

1. Contacted is made on the upper right side of the barrel. Looks to be a slight curve towards the end of the stock which curves to the left.
2. The barrel is pushed upwards to the point where it locks up the hand guard when fitted.
3. That's a lot of shims!

So decided to go back into adjusting the flat. By sloooowly removing material, the pressure at the front had increased with noticeable difference. With the puller I achieved roughly 4~ lbs of force. Believing there's a margin of error in the tool in addition to defining how much it "feels" to pull. I added a 0.02 shim at the muzzle. With tape is should come around 0.03". The tape used is glass cloth type tape that can handle temperatures to 392 F / 200 C. Should be good for test firing for now until I make a proper wood shim. I've read others have used plastic, leather and just a strip of metal so I think I'm good for the mean time.

This all done while making sure the other areas of the receiver remained in contact, which they did. The barrel channel required minimal relieving so that the contact point remained at the muzzle tip only. There is plenty of room between the barrel and upper band. I also ended up cutting the rear bushing with a jeweler saw and using a punch to open it up a bit.

The rifle up to this point.

Will most likely tackle the buttplate next while looking for solutions on other issue, such as:

• Dejeweling the bolt
• Blueing or parkerizing the bolt, bushing and bands that were mentioned before. Maybe coating the bolt will hide the jeweling?

EDIT: Attempted send one, but your inbox is full.

Jeweling can be removed with a polishing wheel being careful to stay away from the rear of the bolt lugs. Or there's the shoeshine method with a strip of emery cloth.

Vulcan refinishing does a very nice job of parkerizing. The bolt, bands and other stock metal on an 03A4 were originally blued, but many were parkerized in the repair/overhaul process.

One last check on the bolt; always verify clearance between the rear face of the safety lug and the receiver. Hard contact here will enable the safety lug to act as a recoil lug.

The action will tend to settle in a new stock during firing, so the guard screws should be tightened between shots. My PM box has some room now.

 

[95chris]

The bolt could be de-jeweled by polishing it boot black style with fine abrasive cloth strips, then blasting and parking. Blasting alone might be enough. Residual swirls might or might not be left.

I'll look into those options for the bolt. I have some Micromesh paper up to 12000, maybe those will work?

Jeweling can be removed with a polishing wheel being careful to stay away from the rear of the bolt lugs. Or there's the shoeshine method with a strip of emery cloth.

Vulcan refinishing does a very nice job of parkerizing. The bolt, bands and other stock metal on an 03A4 were originally blued, but many were parkerized in the repair/overhaul process.

One last check on the bolt; always verify clearance between the rear face of the safety lug and the receiver. Hard contact here will enable the safety lug to act as a recoil lug.

The action will tend to settle in a new stock during firing, so the guard screws should be tightened between shots. My PM box has some room now.

See, this why I love communities like this. I never heard of Vulcan Refinishing during my search online. I'll be glad to help out local Canadians when I can. With that said, if things were originally blued, I may keep it that way. Thanks for the heads up on the safety lug and guard screws.

 

[tiriaq]

I'd be inclined to start with 220 grit. You don't want to have swirls showing through the finish.
Parking is easy to do at home. If you want bluing, use the hot water system. Hot caustic blue is very effective, but is nasty. Strong boiling caustic solution is dangerous.
With careful prep and degreasing, you could probably get away with a good cold blue. Blast and cold blue looks pretty good, appearing very much like park.
I expect that the Dulite bluing process was used on the original blued parts.

 

[Claven2]

The bolt could be de-jeweled by polishing it boot black style with fine abrasive cloth strips, then blasting and parking. Blasting alone might be enough. Residual swirls might or might not be left.

He could also wire wheel the bolt with a medium coarseness wheel on a bench grinder. In the end though, the bolt should be either blued or parkerized.

 

[Claven2]

I'll look into those options for bolts. I have some Micromesh paper up to 12000, maybe those will work?



See, this why I love communities like this. I never heard of Vulcan Refinishing during my search online. I'll be glad to help out local Canadians when I can. With that said, if things were originally blued, I may keep it that way. Thanks for the heads up on the safety lug and guard screws.

The barrelled actions were always parkerized, but some parts (like the bolt) left the factory blued over a freshly machined surface. If it were me, I would see if I could wire wheel the jewelling away, then degrease and hot blue the bolt (use a gunsmith for hot caustic bluing). It should turn out fine.

If thought so the prep work, most smiths won’t charge much to just dip your bolt in a caustic blueing bath when they do their next blueing job.

 

[95chris]

Thanks for the info everyone, I fired off an email to Vulcan Gun Refinishing. I'd like to blue the bolt and parkerize the barrelled action in addition to the attachments such as the bands, scope rings and mount. Was the magazine cutoff switch, butt swivel blued or parked? Few images online of actual A4's show both. Picked from a bin and installed perhaps?

Just checked the gap between the rear face of the safety lug and receiver. A generous 0.062" gap is present.

I also fitted the upper hand guard, ring and bands see how it all fits. I'll have to relief the hand guard ring a little bit, it moves but just slightly. The upper handguard seems to push down on the barrel and is a bit tight. A bit similiar to my M1903 but that's probably from age.

I guess everyone likes photos right? I believe the rifle is an all original RIA M1903 from 1913, low serial number. No rebarrel or extra arsenal stamps, and markings all seem to point to 1913 such as the steel code on the bolt itself. Sling is from Turner Saddlery. Haven't disassembled it but don't feel the need to.

So tempted to add the scope... In time.



That reminds me, I should remove that key at the front used for the sight base.