Headspace question

[shamrocks]

I'm rebuilding my Inland barrel/receiver with correct parts and today when putting a Inland bolt in and checking the headspace I had a problem. The bolt will not close on the field gauge as is correct, but it will not close on a go gauge without forcing it and I haven't encountered that before. Since it should close on the go gauge, is this going to be a safety problem? If so , I do have a couple other bolts (Underwood and Standard Products) that I tried and gauge correctly using both gauges.:yikes:

[Mike in NC]

Shamrocks,

Not closing on a go gauge can present a function problem at the very least. There is some variation in the case length of different manufacturers of carbine ammo. With cases at or near the maximum length you can have problems with chambering ammo. Make sure the front of the chamber is clean and the front of the bolt is clean of any debris. Worst case is you might have to look for another Inland bolt and save the "long" Inland bolt for a carbine that has headspace problems with too much headspace.

[shamrocks]

Thanks Mike. I 've been experimenting a little here. Put a shell in the chamber by hand (no housing or hammer or firing pin so it's safe) and worked the slide. It may just be okay afterall.......when releasing the slide from full back it goes fully closed in battery and ejects the round when I pull it back, but if easing the slide forward it stops.
Didn't make it to Raleigh..had a family emergency but that tool worked like a charm installing the sight. Thanks again.:super:

[us019255]

Thanks Mike. I 've been experimenting a little here. Put a shell in the chamber by hand (no housing or hammer or firing pin so it's safe) and worked the slide. It may just be okay afterall.......when releasing the slide from full back it goes fully closed in battery and ejects the round when I pull it back, but if easing the slide forward it stops. ...


The potential problem still exists. The carbine headspaces on the mouth of the cartridge. If a longer round is forced into battery, the bullet will be crimped tighter into the cartridge. This will raise the pressure, possibly enough to cause a failure. My bottom line: don't fire until the headspace is within specifications. You might fire 10,000 rounds with no problem or you might have a problem with the first round.

[shamrocks]

Mmmmm...that makes sense. I may try another Inland bolt or use one of the 3 other makes I have that do headspace if I decide to shoot it.

[shamrocks]

Mmmmm...that makes sense. I may try another Inland bolt or use one of the 3 other makes I have that do headspace if I decide to shoot it.


If I try another Inland bolt should it be the circled OI marked one for this period or AI? The more I read the more confused I'm getting.

[Mike in NC]

Shamrocks,

Let us know the approximate serial number of your Inland ane we will let you if a round bolt is correct. Without checking my references, I would say the transition happened in the mid to late spring of 44 with serial numbers in the 5 million range. Just going from memory on this.

[shamrocks]

oops, sorry I think I mentioned it in another thread. It's 495520x which I think is right around a alot of changes.

[lbelflowers]

Is this a new barrel and old receiver?What type of gauges are you using? It seems odd that a barreled receiver(if it is an original mate) would not close on a go gauge. The only reason I would see,is a short chamber(and that comes with a new barrel). Its hard too speculate without it being in hand, try your other bolts,especialy the flat ones if you have any.

[shamrocks]

I have three other bolts that do fine. One flat IBM and two round underwoods that work. I also took a flat standard products out of another carbine and it worked. Not sure about new barrel or not as I bought it as a barrrel receiver already together and the barrel date (2-44)matches the serial number apparently. I can use any of the other bolts, I just wanted to put the corect Inland bolt in it.

[lbelflowers]

If you are working on making it as correct as possible,then find a flat OI bolt with number 2 or 3 would be close to correct. Your serial number puts it close to the transition period I believe.

[bruce381]

If it will NOT close on a go gage then when fired and force of slide it MAY push cartridge to deep and riase pressure so yes close on go is correct way to go.
bruce