03A4 Original Bolt vs. 03A3 Reciever - should A4 Bolt close in unmodified A3 reciver?

[Col. Colt]

Trying to put together the parts to make a faux A4, using an 03A3 reciever. Bought a "maybe" replica A4 bolt - which fit and worked well overall but would not close completely in the A3 reciever when mounted in a genuine A4 stock.

All the "gurus" online told me that an 03A4 sniper bolt would close fine in an unmodified 03A3 reciever, even though, for some reason, all Real 03A4s have a definite notch cut down into the reciever for the bolt root that 03A3s (and 03s) do not have.

So I found a "real" 03A4 bolt to try and, guess what? It won't close completely in the unnotched, stock 03A3 reciever, either. It is close, and the trigger drops the firing pin - and it is probably even safe - but it does not look right compared to a normal, non-scoped 03/03A3.

Those of you with both - could you switch bolts, check and chime in here? It needs to be a verified original M1903A4 Sniper rifle bolt, and do make sure if it does not close all the way that it is not interferance with the stock cut, but actually stopping the bolt root on the top surface of the reciever directly behind the reciver bridge and that is keeping it from turning all the way down into lock. You might have to remove or at least loosen the stock to be 100% sure it is not the bolt handle touching the stock.

All the world wants to know - is the bolt handle notch cut into every 03A4 a functional necessity for full lockup? Or just an extra, unneeded step taken during wartime?? CC

PS - If it is shown to needed, everyone making faux 03A4s should know that - and specs provided from an original A4 reciever to make an accurate milling cut. CC

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[Neal Myers]

It sounds to me like all the advice you were given is correct.

Yes, any bolt should function in any 03/03A3/03A4 receiver. When the 03A4 was developed, first the bolt handle had to be changed to clear the scope. Then, it was found that the bolt wouldn't close fully (& safely) because of stock interference with the handle, so the notch had to be routed. If all your components are really "genuine", the handle will drop into the stock notch without interference.

Replacement 03A4 stocks by Springfield Armory & Keystone usually had the bolt handle notch routed by the arsenal, so slight variations will be found.

Compare what you have with these photos:

[Mike D]

I have an original bolt in my clone. In the first two photos you can see how much the bolt closes when it is locked all the way down. I notched the stock, myself, and it does not contact the bolt. The bolt is in excellent, original condition and headspaces great in this receiver/barrel. I have shot the rifle maybe 40 rounds.

When I later learned that original A4 receivers were relieved where the bolt closes, I inspected. My bolt shows a very small mark where it contacts the receiver. Check out photo 3. I do plan to file this area to avoid further contact.

I have a second original A4 bolt, that I will test also, and get back with you on that.

It would be my guess, with manufacturing tolerances varying, some bolt/receiver combos would be OK without the milling, and some not. Instead of changing the bolt manufacturing process, the receiver milling was the easier solution. Mill 'em all and avoid any "possible" problems.

Mike