03 How to mount barrel with no witness mark?

[Sgt USMC]

I have a 03 Springfield that was stolen and recovered by a fisherman who found it in a stream, in Montana. It was then returned to the original owner by the local Sheriff's office. The original owner's friend ,"cleaned it up" and in so doing eliminated the witness mark. I bought it at a local gun show for $25.00 and was going to turn it into a lamp. On one of my trips out of state I took it to a gunsmith friend, who built weapons for the Marine Corps museum. He said to rebuild it and supplied me with all new parts. My gunsmith passed away a few years ago and I'd like to put this together as kind of a tribute for all the time he spent teaching a poor young Lcpl how to fix broken weapons. That being said I've searched a few forums and have some ideas, but I wanted to see what the experts here have to say, about mounting a barrel that does not have a witness mark on the receiver.

My second question is ; Does anyone have the a diagram with dimensions for where a Hatcher hole should be machined?

This weapon as been drilled and tapped for a Lyman peep sight and has no collector value other then the story that came with it.

Thank you for your time and knowledge, Semper Fi!

[lyman]

you can use the extractor cut,

using a barrel vice, and receiver wrench tighten it up, and insert a bolt with extractor to see if it clears,

maybe use a feeler or a piece of tape or 2 on the top and bottom of the lug to make sure it is centered

[fguffey]

That being said I've searched a few forums and have some ideas, but I wanted to see what the experts here have to say, about mounting a barrel that does not have a witness mark on the receiver.

Do you have a receiver with no barrel? Do you have a barreled receiver with a mark on the barrel and no mark on the receiver? Does your old barrel have sights? Does your new barrel have sights? Do you have an extractor cut on your old barrel? Do you have an extractor cut on your new barrel?

F. Guffey

[John Beard]

As lyman pointed out, you can use the extractor cut for indexing in lieu of a witness mark. If the barrel is good and tight and the bolt with extractor will fit, then you're good to go. Unlike an M'03-A3, the M1903 rear sight is mounted on the barrel. So the front and rear sights will align regardless of receiver indexing.

Good Luck!

J.B.

[fguffey]

As lyman pointed out, you can use the extractor cut for indexing in lieu of a witness mark. If the barrel is good and tight and the bolt with extractor will fit, then you're good to go. Unlike an M'03-A3, the M1903 rear sight is mounted on the barrel. So the front and rear sights will align regardless of receiver indexing.

If aligning the witness marks/extractor cut was all there was to it then you have a do it yourself project. Life has not been fair to me because all of my rifles have chambers. I do not care where all of those marks align I have to determine the length of the chamber. With 03 variants I have found chambers that were short and the barrel mark passed the receiver mark. On others I have I have had barrel marks not make it to the receiver mark.

That is the part of life that is not fair but if you are lucky the chamber will be go-gage length and THE MARKS WILL ALIGN; and you did not learn anything.

F. Guffey

[lyman]

If aligning the witness marks/extractor cut was all there was to it then you have a do it yourself project. Life has not been fair to me because all of my rifles have chambers. I do not care where all of those marks align I have to determine the length of the chamber. With 03 variants I have found chambers that were short and the barrel mark passed the receiver mark. On others I have I have had barrel marks not make it to the receiver mark.

That is the part of life that is not fair but if you are lucky the chamber will be go-gage length and THE MARKS WILL ALIGN; and you did not learn anything.

F. Guffey

I think you are overthinking the original question,

[fguffey]

I do not care where all of those marks align I have to determine the length of the chamber.

I think you are overthinking the original question,

I do not want anyone to think I am desperate for attention but the op is a Sgt USMC, If there is something I said he did not understand he can ask for help. I could start asking you what you think but to be honest I do not care.

I understand I wasted my time explaining how much trouble a member of this forum had trying to find information, methods and techniques on measuring the length of the chamber from the shoulder to the bolt face. There is no other way for me to explain I have three different methods and none of them include a head space gage. The man had 20+ head space gage, he handed me the box, I told him there was not a gage in the box that would indicate the length of the chamber from the shoulder to the bolt face in thousandths.

I did offer to modify one of his go gages to a 'go to infinity gage', all he had to do was shorten the length of the chamber .0025" to get the chamber down to go-gage length. I offered to size cases by increasing the length of the case from the shoulder to the case head .0025 but he wanted a go-gage length chamber. That is when I offered to measure the ability of his bolts to off set the length of the chamber, he had 100+. I promised him he did not have a bolt that would change/shorten the length of the chamber .0025".

Again, I am not interested in what you think, I am interested in what the OP thinks. And then there is that thing about me and Marines, it all started in 1954, a story you do not have time for.

F. Guffey






Sgt USMC is offline

[lyman]

I do not want anyone to think I am desperate for attention but the op is a Sgt USMC, If there is something I said he did not understand he can ask for help. I could start asking you what you think but to be honest I do not care.

I understand I wasted my time explaining how much trouble a member of this forum had trying to find information, methods and techniques on measuring the length of the chamber from the shoulder to the bolt face. There is no other way for me to explain I have three different methods and none of them include a head space gage. The man had 20+ head space gage, he handed me the box, I told him there was not a gage in the box that would indicate the length of the chamber from the shoulder to the bolt face in thousandths.

I did offer to modify one of his go gages to a 'go to infinity gage', all he had to do was shorten the length of the chamber .0025" to get the chamber down to go-gage length. I offered to size cases by increasing the length of the case from the shoulder to the case head .0025 but he wanted a go-gage length chamber. That is when I offered to measure the ability of his bolts to off set the length of the chamber, he had 100+. I promised him he did not have a bolt that would change/shorten the length of the chamber .0025".

Again, I am not interested in what you think, I am interested in what the OP thinks. And then there is that thing about me and Marines, it all started in 1954, a story you do not have time for.

F. Guffey






Sgt USMC is offline

I stand by my comment,


have a great night Guffey

[gjungle56]

If a 1903 barrel with rear sight on, simply screw barrel on until the rear sight base, with ladder off or aside, is parallel with receiver bottom. If no rear sight, I align to front sight or it's key much like a Garand. Do not tighten using rear sight base as a point to wrench from. Hatcher holes vary a bit but ones I've put in are 1.000" from receiver face, .690 up from receiver flat and 7/32 dia. A carbide end mill works very well in a mill. For what it's worth, I never trust witness marks.

[Sgt USMC]

Thank you everyone for your responses! Since the receiver was already drilled for a Lyman peep sight, I didn't see any reason to machine the barrel for the rear sight base of the 03. The barrel is a new, in the cosmoline, 03A3 SA dated 8-44 (old DCM stock) The new barrel has the front sight post. I have all new internals the only original part I will be using is the receiver. As I stated it does not have a witness mark on the receiver. It will be an 03 receiver with all A3 parts. S/N 852xxx
20200402_150513.jpg Originally I was going to machine a "T", that would fit the front sight post. I would use a spirit level on the "T" and on the receiver rails and a plumb bob to check my work. But I thought their might be a better way hence the reason for my post.

In regards to the Hatcher hole; What I wasn't sure of is, did they originally drill from the #30 hole on the right side through to the left side, as a pilot hole and then enlarged it from there

Thank you again for your responses, it is much appreciated!!

[John Beard]

If your barrel has no rear sight base and you plan to use a Lyman receiver sight, then you have an alignment challenge. Unless the front sight is aligned directly above the top center of the receiver, you may have a large windage offset in the Lyman sight. As I recall, the extractor cut in the barrel is a little wider than necessary to accommodate tolerance stackup. So you can't use that reference for tightening the barrel. You, therefore, need to observe carefully when tightening the barrel to align the front sight with the top center of the receiver.

Good Luck! And stay safe!

J.B.

[lyman]

interesting,

when I read your post I thought you were mounting a 03 barrel to an 03 receiver,

in that case, you can clamp a flat bar to the front of the barrel near the sight, and make sure it is perpendicular to the post,

and then install your rear, and mount a level to the arm the aperture is mounted to,



or just do a trial and error

[fguffey]

SGT USMC, I will tell you I am not the expert but if I was involved I would screw the barrel into the receiver first. After screwing the barrel into the receiver I would check the alignment; in the perfect world the shoulder at the end of the threads will seat against the receiver with the extractor cut aligned.

And then it is time to think about it; I would strip the bolt, back the barrel out and then chamber a minimum length/full length sized case. After closing the bolt I would screw the barrel in until the shoulder at the end of the threads contacted the receiver or until the shoulder of the chamber contacts the shoulder of the case.

Because I am not the expert I would not start this job without a feeler gage nor would I start with a case that is minimum length/full length sized. Because? The threads on the barrel and receiver are 10 per inch keeping up is easy.

And then there is the length of the chamber from the shoulder of the chamber to the bolt face. Because I am not the expert this stuff does not drive me to the curb. In the perfect world the go-gage length chamber will be .005" longer than a minimum length/full length sized case; meaning I want to know the length of the chamber from the shoulder of the chamber to the bolt face, If the bolt closes on a minimum length/full length sized case you will not know the length of the chamber.

F. Guffey

[fguffey]

meaning I want to know the length of the chamber from the shoulder of the chamber to the bolt face, If the bolt closes on a minimum length/full length sized case you not know the length of the chamber.

This does not mean I do not know nor is it implied I can not measure, I would not waste my time asking the experts.

F. Guffey

[lyman]

you know most folks would install, check headspace, ream if needed , and go shoot,,,