1896 Sedgley sporter with head-space issue.

[spentprimer]

The SAMMI SPECS for the .25-35 rim thickness is:.063"-.010'. Rim thickness for the .30/40 Krag is: .064"-.010". Rim diameter for the .25-35 is: .506" -.020". Rim diameter for the .30/40 Krag is: .545" -.010".

Now for something else to measure. The SAAMI SPECS for the depth of recess for the rim in the chamber is: .063" minimum and .070" maximum. This dimention would be equal to any recess for the rim in the barrel plus the recess on the bolt head. Assuming Zero clearance between bolt and barrel, if there is a gap this too must be added.

I hope this didn't muddy the waters. :)

[CEH]

I spent some quality time with the Sedgley yesterday and discovered the following;

My Foster "Go, No-Go Gauge" does not extended into the shoulder area of the chamber. See photo. The bolt won't close on it. I think that rules out shoulder interference. Yes? No? The rim on the gauge measures .063" and a new case (Winchester) measures .059". I get about 3 or 4 more degree of bolt rotation on the case vice the gauge. My bolt face recess is .056", less than that found by "spentprimer" in his recent timely post.
Following "gunboat's" and "butlersrangers" lead I blued the aft face of the bolts locking lug and guide rib. Nice full contact patch on the guide rib and just a hint of contact on the fore lug. Bolt was striped of firing pin, extractor and cocking piece. When closed on an empty chamber the bolt has less than .001" of movement. I say < .001 because I can feel movement but am not really seeing it. I blued the bolt face rim also and found no contact there after cycling the bolt several times.
I inspected the bolt's guide rib to see if there has been any modifications. "Matsenshooter's" suggestion. Photos attached. It appears original to me.

So it still appears to me to be an issue of the bolt face recess. There is no recess on the barrels face. The rim of the case sits proud there. Seems to me that increasing the depth of the bolt face recess is the path forward. The bolt locks as smooth as silk and I'm hesitant to mess with the locking lug and guide rib to move the entire bolt aft. Photo of bolt in the receiver is with the "Go Gauge" in the chamber. The bolt is hard against it in the photo----so nearly 45 degrees more rotation to lock up.

Chuck

[madsenshooter]

Hmm, vertical line on the guide rib went away, must've been a reflection. Only cure now is a chamber reamer, one that has flutes on the rear that also cuts the rim seat into the breech face, like the one I have pictured. I'd think any 25-35 reamer would have them. As you know, you only need a little bit. The chamber reamer would probably be easier than cutting the face of the hardened bolt, but one of them has to be done. Don't forget a handle for the reamer!

[butlersrangers]

CEH: The simple problem is your bolt and action combination do not have sufficient headspace to accept a .059" thick factory rim or the "Go" gauge. I would consult a qualified gunsmith. I believe it would be easier to gain a few thousandths of an inch at the barrel breech by slightly recessing the rim into the chamber, than it would be to grind the hardened surface of the bolt face. However, this is my hunch and beyond my capabilities. (I guess R.F. Sedgley set the rifle up with some thinner rimmed ammo).

[spentprimer]

Another option which you may or may not like. I don't know how much you are going to shoot the Krag, but, if you have a lathe nearby. Chuck the cartride cases in and remove a couple of thousands from the leading edge of the cartridge rim. This would mean that these are the only cases that will headspace properly with this rifle and be a problem in other guns. You might not even need a lathe, a drill press might work just as well with a file and a steady hand.

:)

[gunboat57]

I agree that letting a qualified gunsmith examine your rifle is a good idea. If he suggests cutting the chamber a few thousandths deeper to meet the SAAMI spec, you could let him do it...

OR

You could rent a finish reamer and extension handle from www.ReamerRentals.com which is somewhere out on the west coast I believe. For less than maybe $50 you could deepen the chamber yourself. Cut a little, clean, check with Go gage, cut a bit more. It sounds like you're familiar with the process of doing careful fitting.
One thing you'd probably have to do is do a good chamber cast to determine what pilot diameter the reamer needs to have.

By the way, I've heard that the proper heat treatment of the Krag bolt head was absolutely critical. I'd be reluctant to do anything that might alter the temper or maybe cut through a hard skin and expose softer material beneath.

[CEH]

Ok. Guess I'll bite the bullet and run her into a gunsmith. Thanks for the help. I'll let you all know how it turns out and the ransom I'll pay.

[Top Dean]

I see all of the things the guys are saying to do but I have a very siple question to ask, based on a picutre you posted. have you cleaned your rifle and ammo. You have a pictue of a round sitting on top of the bolt and it seems to have a lot of rust on the casing. you did state you have had the rifle for 20 some years and you have never fired it. Just a questions as only a small amount of rust would stop the rounds from seating correctly.

[Michael Petrov]

Another option which you may or may not like. I don't know how much you are going to shoot the Krag, but, if you have a lathe nearby. Chuck the cartride cases in and remove a couple of thousands from the leading edge of the cartridge rim. This would mean that these are the only cases that will headspace properly with this rifle and be a problem in other guns. You might not even need a lathe, a drill press might work just as well with a file and a steady hand. :)

I have done this many times over the years and works just fine. Just remember to take off brass on the front side. You can do a little bit at a time until one fits then set up for the rest.

For what it's worth the ONLY thing Sedgley is the barrel and Sedgley did not put it on that action.

[CEH]

Good question Top Dean. I'm taking a lot of the photos with the camera on the macro setting. It tends to make thing look bad. Take a look at the shell casing in the bolt face and you will see a finger print on the case. In normal lighting it's barely viable. One photo of the rear sight seems to show rust but none is there. But before I spend a weeks wages at a gunsmith I'll plan on cleaning it and checking again.

Thanks, Chuck