barrel threads

T

timgd

New member
I recently purchased mod. 1898 30-40 krag and after getting it out of the 10 day wait I noticed that the sights did not look centered on the top of the barrel. After removing the stock I found that the alignment marks on the barrel and receiver don't align. My question is are the threads std. rt. hand or left. Or is the barrel run in to far or not far enough. I know I will have to check head space but what else should I check?
Thanks for your help.
 
Might have been an ineffective attempt to correct excessive headspace issue.
Simply turn, grind, file a wee bit off the back of the barrel and "screw it deeper".
 
Krag threads

Krag thread is right hand, square thread, 10 threads per inch.
Correcting this issue can range from easy to challenging.
A must is a proper action wrench to avoid damaging the receiver and a good barrel vise.
If screwed in too little it is an easier fix than screwed in too far.
 
threads

Barrel has been screwed in past the mark ,slight but very annoying when using the iron sights.I think it is a replacement carbine barrel on a rifle receiver,I wonder if a shim on the barrel would be all right or does that cause other problems?
 
Most barrels are theoretically torqued to 75 to 100 ft-lb. Some benchrest guys who switch barrels for different classes torque from 20 to 30 ft-lb.

It's possible the barrel was removed or replaced, and whoever did the job just cranked it in as far as they could.

You could try backing the barrel off a turn, then tightening it until the witness marks line up. If it's over 40 ft-lb and the headspace is within limits, I'd shoot it. If it's less, you'd have to make a judgement call.

The "correct" solution, assuming no headspace issues, is to cut the barrel tenon back to allow for a spacer washer .100" or so thick that will allow for proper torque.

Many people will suggest cutting the tenon and turning the barrel in another thread, then rechambering, but this only works in a few cases. Any extractor cuts will probably be too shallow, barrel furniture won't line up, etc.
 
How far past is it?

10 tpi, .100" per turn, you would have to be .07 of a turn to move it from minimum to maximum headspace. 25 degrees. Bet it isn't that far off.
If, as TRX said, you could line up the witness marks and it hold, it will probably shoot just fine.
 
I don't think its off more than 2-3 degrees,I will try to find a barrel wrench and vice and try to re torque the barrel. I looked at Brownells and the wrench and vice is kinda pricey for a 1 shot deal. Maybe I can borrow 1.
 
Not easy, but you could make a thin washer from STEEL shim stock. I have done it and it works. You can get shim stock down to .0005. Some guys just stipple the back of the barrel. I never did that. I consider that a half #$$%^ fix. Anyway, it does not sound as if it is too bad.
 
Krag barrel shimming

US Krag original barrels have no shoulder to pu a shim against.
If the barrel is a replacement which has a shoulder against the receiver, a shim can work.
Pics would help.
 
"...find a barrel wrench and vice..." That'd be a barrel vise and an action wrench. Said wrench needs to be the proper one too. It's very easy to twist a receiver using the wrong tool. Requires a very solid work bench too. Everybody forgets the bench.
Brownell's Universal Action wrench might do. Isn't cheap for a one time job though. $109.99.
 
Do they even make a Krag wrench?

Krag receiver is cylindrical in front of the complicated magazine well.
You might could grab it with a barrel vise type clamp but would have to be careful not to squash it against the barrel shank.
There used to be a lot of Krags gunsmithed, have the methods been lost?
 
This is a Krag Action Wrench sitting on top of a Brownells barrel vise.

Bill Jacobs

IMG_2665.jpg
 
threads

I thought about clamping the barrel in my six jaw chuck and locking the spindle but that still leaves the problem of grabbing the receiver. Bill how does your wrench work, it is not obvious to me?
 
The wrench fits through the receiver. It can be turned with a large Crescent wrench. I bought it from Numrich when I had a Norwegian Krag in for barrel setback. I had to mill a modification into the wrench for the Norwegian. As mentioned above, the Norwegian Krag has Left Hand threads! Failure to remember that can ruin your day.

A lathe chuck will not hold a barrel tight enough for removal. Neither will a vise with wood blocks in many cases.

Bill
 
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