Please tell me about the cross bolts/lugs on 1903 A3

[bushmaster1313]

Local gunshot is selling a Remington 1903 A3 with a very smooth action.

But instead of cross bot heads that look like this picture



there are what look like nails without the flat head (this image from internet)

Information

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[browningautorifle]

Those are pins, threaded rods that are screwed in and cleaned off...late stuff. Very nice though.

[Rick the Librarian]

Pins were used on late Remington M1903 and early M1903A3s from about late 1942 to mid-1943, in an attempt to save time, materials and labor. It was discovered that the stock with pins didn't hold up to hard use as well as stock bolts and they were restored to production about mid-1943.

[firstflabn]

Rick, I've long wondered what was the basis for the pins deficiency conclusion. Have you seen a primary source? I can't help but notice that both you and Poyer use the passive voice (it was discovered/it was found), instead of saying "so-and-so made a decision based on..." Of course, Poyer goes even further, claiming the pins actually weakened the stock.

Having worked in materials testing and having read several Ordnance Dept test reports on other subjects, I understand the lengths they went to in developing physical tests that would produce valid results. Lacking such a report - or a credible account of one - I'm not quite ready to be convinced - especially by mushy language (plus it's out of character for you - we're spoiled).

I'm too lazy to disassemble, so anyone have an empty stock to measure the shelf dimensions? Isn't it about 1/2" high and 1-1/4" deep? With that info, I'll try to crunch some numbers.

[emmagee1917]

You do not want to fire rifle grenades from these stocks . For normal civilian use , they're fine .
Chris

[Johnny Peppers]

The pins/screws show up again in very late S-C stocks. Whether S-C went back to them, or was just cleaning up left over stock at the end of the contract I do not know.

[Rick the Librarian]

Being compared to Poyer ... that's a low blow!!

Poyer isn't the only source that claims that pins didn't hold up. Most other M1903 sources agree. As for "primary" sources, I couldn't tell you. However, if stock pins were working (which required much less in the way of labor and materials) why would Remington go BACK to stock bolts?

I would not have a problem with using a "pinned" stock for the occasional shooting I (or probably most of the folks on this forum) do. For heavy day-to-day use or firing rifle grenades (which was one of the major uses M1903s continued to be employed after the M1 Garand became top dog), I'd look for another stock.

[browningautorifle]

I'd look for another stock

You'd have to, because yours would be split.

[firstflabn]

Being compared to Poyer ... that's a low blow!!

I thought you'd enjoy that. Hope you noticed the actual compliment later (kiss and make up time - I may need you sometime).

So, the answer is: there's nothing beyond speculation as to the reason for the decision. Might just as easily have been superstition or bad assumptions if no tests were done. 'They musta had a reason' is fairly weak. What matters is whether they were right or not.

I wish they had tested, as they had plenty of stocks in new condition - plus - they had piles of sophisticated lab gear to play with. Coulda had a field day carefully breaking stuff.

I'd be interested in the results from sticking a pressure transducer between the receiver recoil lug and our dear little stock recoil shelf and take firing measurements - both with the recoil bolts properly tensioned and then with them a bit loose. That would tell something about margin of safety - both in resisting shear on the sides and crush at the front edge.

Previously I calculated recoil from firing a rifle grenade. That came close to 5.5x larger than firing M2 Ball. Unless someone can show where rifle stocks regularly failed after firing their first (and only) grenade, then it becomes clear that there was plenty of safety margin designed in.

Fatigue is another possibility, but even more difficult to test for, even before considering that wood fiber is not homogeneous like steel, or ceramic, etc. Variability in critical stock dimensions, wood density, are also possibilities. That just leads us back to my original point, so I won't belabor it.

One last shot at Poyer - his idea (or whoever he got it from and didn't bother to mention) that the stock pins actually weakened the stock is ludicrous. A back of the envelope calc tells us that if you simply drilled a 1/16" dia. hole where the front pin goes - and left it empty - you would reduce the area resisting recoil forces by somewhere around 1/2%. Other complexities factor in, but that's not a bad proxy for loss of strength.

If Poyer was no more discerning than to propose that the loss of well under 1/2% of bearing area was meaningful, his entire assertion loses credibility. If, however, he was relying on an official document, it has remained elusive. That's why I tried to dump it in your lap. I'll wait patiently (unless I can come up with something snarky to say in the meantime).

[Rick the Librarian]

I wish John Beard would jump in - he may have more details. I wouldn't say the replacement of pins by bolts to be "speculation", though. However, if you want "primary source" quotation, I probably don't have it.