Average "As Issued" GI M1903 Springfield Headspace Readings? Throat Depth?

[Col. Colt]

Update. Finally had to take the plunge and put my original, still in the cosmolene and wax paper wrapper original C-3940 Breech Bore Gauge to work doing what it was built for! After cleaning the new (67 year old!) Breech Bore Gauge of old wax paper and hardened grease in my gunsmith's solvent tank, I checked the breechbore reading - which was roughly 2.5-2.75, if you were to try to be precise. If this is indeed a new (or nearly so) 10 of 1942 SA barrel (reads a "1" at the muzzle") it confirms that by October of 1942 the throat/leade of M1903 barrels was being cut deeper than the pre-war barrels. I had heard that this was believed to be necessary due to variations in ammo types and quality. By the way, my Canadian Ordnance supplied gauge measured perfectly to the gauge blueprint!

So the throat at the rifling is certainly not the problem with the bolt lift.

Last night I did try a US Arsenal "U.S. Rifle, cal. 30 M1903 A1 Complete Profile of Chamber Gauge" from my US Armorer Tool Collection in the barrel, and it did not seat all the way down flush with the barrel entrance. So something about the chamber neck, then? Next to clean/polish the neck area of the chamber. My gunsmith didn't like the idea of using scotchbright (TM), as he advised it "scratches". He sent me home with 0000 steel wool, and directions to wrap it around a .30 caliber brush and have at it, liberally using oil/lubrication. So we will advance cautiously, and use the Scotchbright as Option #2. We will report back as soon as we have done so. CC

[Premod70]

Possible fractured case neck remaining in the chamber? An inspection of the fired cases should show "shiney" where there is a restriction or a step if there is a obstruction.

[Col. Colt]

The cases did show a little "shiny" around the bullet end of the neck - we'll see what vigorous cleaning of the neck area brings. Thanks for the thought - it is certainly possible. CC

[John Beard]

John, Care to let us know how many a "substantial quantity" is? Heard the number is quite large and varied.

Please pardon my tardy reply. I was on vacation.

I don't know the exact quantity. I try not to ask too many questions when I work at the CMP. I can only say that the number we have processed since January is greater than 100, but less than 200. Others remain to be processed, but I would guess that the quantity is only a few hundred at most.

I am informed that the Army has no more M1903 rifles available. And no significant quantities of foreign-aid M1903 rifles are known overseas. So, the only remaining source of M1903 (and M1917) rifles are those being turned in from American Legion and VFW posts. And that trickle is very slowly drying up.

Hope this helps.

J.B.

[Randy A]

Starting in 42 the new barrels had a deeper bullet seat, apparently there had been reports of bullets sticking in the bore after a GI had chambered a round and then decided not to shoot. Upon extraction, it would pull the bullet from the case, leaving it in the bore. This poses a problem when people try to TE one of the newer barrels, they appear to be worn more than they are. I have the excerpt from the Depot rebuild manual that explains it all. PM me your email and I will send it to you, I consolidated all of the information on Bore gaging on a word doccument. I can't get it to photobucked or I'd post it here.

[Col. Colt]

More related info. This may be old news to some, but it is new to me. I just finished gauging another Springfield M1903 at my favorite gun shop, Serial No. 851,xxx, with an 8 of 29 SA barrel installed, R-AP rebuild mark on standard S stock, NS Bolt - all in all a pretty nice gun. It appeared to possibly be a possibly little to unused Greek return - had the punch/alteration to the floorplate. Park was kind of mottled, - possibly Greek. Anyway, it measured 1.5 at the Muzzle, and a 1 on the Breech Bore Gage!! Newish barrel - which may be why they wanted $1200 for a rebuild!

Point being, the throats indeed seem to have changed, Wartime vs. PreWar. Both barrels seemed to be new or very nearly so. Different Breech Bore Readings, with the WWII barrel throat startingout 1.5 bigger. A sample of two isn't much, but I found it interesting. Now to polish my chamber....... CC

[Randy A]

Here is where I saw it,,,, looking at the date on the thread, it's been a while ago. Take note of Bill Ricca's post, it explains it all.

Sorry,,, that happens once in a while

http://www.milsurps.com/showthread.php?t=7708&

[PhillipM]

Here is where I saw it,,,, looking at the date on the thread, it's been a while ago. Take note of Bill Ricca's post, it explains it all.

No link and send me the documents of the throat being changed, I'd like to read them over.

[Randy A]

Bill posted them on a forum a few years ago, the link on my post above has it. I'm not sure what/ where he found the doccuments, but they are pictured on it also.