M1 Carbine barrel installation

To the proficient and knowledgeable, could one of you tell me how to measure the draw on an M1 Carbine barrel installation? I took my carbine with a new barrel to a gunsmith and asked to have it installed. Also installing the front sight and the gas valve. When I got the gun back the barrel was still .025 from tick mark to tick mark. This also made the front sight out of alignment. I was told to just adjust the rear sight and it would be good to go. I was under the impression you lined-up the tick marks so everything was timed and square. I took the barrel back off the receiver and then hand tightened it and measured mark to mark. It measured .230, which is about 29.3 degrees. Can this be reinstalled to the marks. If I reinstall it the headspace will be reduced by .00044 if my calculation are correct.

Thank you,

Hobberdobber

The marks aren't always correct. If you do it with an angle meter, you'll get a correct TDC on the front sight and rear sight. I've played with the marks until frustrated, and when I used an angle meter, the problem was solved. The book shows using a pair of square blocks, I had no success with that either. Headspace will have to be measured after assembly to be sure. You may have to ream with a pull through reamer after.

have yet to find a carbine that the witness marks wernt good yet,..
i would find another gunsmith for sure.

I had problems with some Chuck. The barrels were separate from the receivers and they didn't always come correct. Just what I found. A few were out by quite a bit. Replacements? I don't know how they determine where to mark them if they are a replacement.