Headspace gauge confusion

Hope someone has an answer for me because I am confused. I ordered Clymer headspace gauges from Brownells. Put in the go gauge and it wouldn't chamber. Tried the no-go gauge and of course it wouldn't go either. Maybe I don't understand this whole headspace thing, because I can be dense. If the go gauge won't chamber wouldn't it stand to reason that it would be very difficult to chamber a regular case? If I am not getting it please someone edify me as to what is up. It chambers a round very nicely and smoothly without a hitch. Could there be the remotest possiblility that I have two no-go gauges that are mislabeled? I'd appreciate any help you guys can give. Thank you, Mike :confused::ugh::(

Is the barrel new? Indexed properly? I've got one that closes kinda tight on the go gauge, but chambers a round no problem. Shoots fine. Others will be more of a help than me on this one. Good luck.

id really need more info on your rifle, serial number, make, barrel, date ect.
but try this.
remove the cocking assembly from the bolt, then install the bolt sans the cocking assembly, load a live factory round in the magazine. feed the round from the magazine into the chamber.
it should feed easy, and smooth, bolt should close all the way with no problems,
if the bolt closes hard, then your chamber is still short...if it feeds easy, then your good to go..
headspace gages go, not go or no go, and field reject...
however, i have noted a differance in newly made gages.

Thanks for the replies. Serial #3706446, barrel is 6/43. They appear to be a match by the info found on this website. Bolt appears to be SC as well. Only thing not origial is stock which was refurbished at Red River Arsenal. It chambers a loaded round very smoothly without a hitch. I tried the quick and dirty method a member told me last week, where you put thicknesses of cellophane tape on the cartridge on the primer end till it was really hard to push the bolt down with a finger. Per his direction it checked out just right at 2 layers of tape. But I wanted to be sure so as not to hurt me or the gun. Now I'm just confused. Is there a different manufacturer than Clymer that I could go to? Thank you, Mike

Mustang you might want to move the cutoff to the center position, withdraw the bolt and manually slide the go guage under the extractor and then reinsert the boltand try it again.

The dimensions in inches should be stamped on the side of the guage. Why don't you post them for both guages on the off chance you got the wrong guage.

Regards,
Jim

i just had this same issue with a Clymer gage.
a rifle that i just rebarreled, and testfired, sent the fired case with the rifle, owner called me and said it wont close on a Go Gage..i asked who,s gage...Clymers..
i said, you looked at the fired case with the serial number on it right??yes...then shoot the rifle and enjoy..

Mustanggt

Gages

When specifications are drawn up for a cartridge, there are dimensions for this cartridges and there are tolerances for these dimensions, a minimum and a maximum. The US Military wants to be sure that their weapons will chamber all cartridges with in this tolerances range. Sam wants to be sure that his firearms will chamber the largest cartridge that will be available.. Sooo, the GO gage is made to the dimensions of the maximum cartridge. The head space gages go up from there in 0.001” steps.

Actually most ammo is in the mid-range of these tolerances, so you can have a rifle, such as yours, that will not close on a GO gage and will chamber a round. This can cause problems only if you run across cartridges that are at or over the max dimensions. If you can tolerate these restriction, you are OK. Just be certain of your ammo.

When barrel were being made for the M1903 they are made with the chamber not fully completed, usually referred today as ‘Short Chamber’, so that when fitted to a receiver, with index marks lined up, the bolt will not close on a GO gage. So that the chamber can be deepened, slightly, until the bolt closes on the GO gage but not on the NO GO gage. This is so to allow for variations in wear and manufacturing tolerances of each individual receiver. Given the pre-WW I drawings provided by Colvin and Viall, this has been a standard manufacturing procedure since at least 1916.

Given the number of rebuilt M1903s I have encountered and heard/read about with the same problem you described, not all US Ordnance rebuild facilities followed their own procedures as well as they might have. I once spoke with a E-6, that as a PFC had worked at the US Army depot just outside Tokyo. He told me that the Finial Inspection, consisted of running five dummies thru and a headspace check with the NoGo gage only.
He said this was during 1954-55 and was mostly Small Arms from Korea. This discussion came up after I encountered some M1903A4s with the problem you described.
Some were straight from the crate after rebuild, some were in use, this was in Viet Nam.

I know a lot of people that would be very happy with your problem (very tight head space). You just must be certain your ammo will chamber. A case gage (I use a Wilson and a Forster-Appelt) is a great help here.

I have three sets (Go, NoGo & Field) of 30-06 headspace gages. I tested these gages by trying them in one rifle and carefully noting were the bolt stopped. The bolt closed on all the Go gages. As near as I can tell,, these gages are all the same. The gages were a set by Wilson, that I had purchased new in !958, a GI set, of one manufacturer that were new when I ‘acquired’ them, only used in this test, and a set by Forster purchase about twenty years ago, about the time this test was made.

As long as the bolt will close on the cartridges you wish to fire, head space is not all that important, 0.002” to 0.003” one way or another does not make that much differences. While in the Army we ran a test on how much excessive headspace GI ammo will take, we were up to over 1/8” headspace before we started getting rupture (blown out a the base) cases, we got separated cases before then but these are not dangerous( no gas to the rear) just an annoyance. Note,, this was with standard GI ammo, not reloads. Reloaders can figure out many ways to take a firearm apart,, no mater what the headspace is.

As long as it chambers the ammo you wish to use,, shoot it.

45B20

JGaynor and Chuck, Thanks alot for your advice. I took out the bolt and slid the go gauge under the extractor and slid it home. Sucess!!! No go wouldn't go!!! So now as Chuck said shoot and enjoy which is what I plan to do this weekend!!! 45B20 thanks to you also. Very interesting info. A whole lot to learn.

Mustang ..Glad we could help! Good shooting :beerchug:

Regards,

Jim

I'll give a report about my range experience this weekend. Thanks again, Mike