Front Sight Base Problem

[Zakolev]

Hello, I'm new to the forum. I have been holding on to a (semi) sporterized 1903a3. I have decided to try and make something a little bit different out of it. There was a brief attempt in the 1920s by a Cavalry commander in the West to design a 1903 carbine. I believe two were built and recently sold at auction. I am going to try and see if I can gather the parts to make a 1903a3 based clone of that idea, though I may very well just end up putting together a 1903a3 based fantasy cavalry carbine as the original guns appear to have been built off of an earlier 1903 model.

The first problem I've determined is to be the front sight base. The gun came to me cut down by an inch and change. I have to cut it down further and then have it recrowned, a friend has said he can do that for me. However, I was wondering if anyone could come up with a way to instal an early model or later model 1903 type front sight base on a 1903a3 barrel that doesn't have the "cut out" area?

[Allen Humphrey]

Welcome. Sounds like a fun project for a barrel that has already been cut down. Since the barrel tapers to a bigger diameter you should have no problem turning a new surface to the correct diameter to mount the front sight base (to be clear, the part that mounts the front sight post, not the flip up ladder rear). Check page 12 of http://archive.org/stream/unitedstatesrifl00colvrich#page/12/mode/1up for dimensions. I presume your buddy is doing the barrel work on a lathe. You will have to mill a slot for the locating key, or come up with another method of securing it to the barrel (such as a set screw that would be hidden by the mating dovetail of the sight.

[Zakolev]

Allen,

Thank you so much for the info. Yes, he is going to do the work on a lathe, beyond that I have no knowledge of metal work, so I have no idea what else is going to be involved. Just to make sure that I'm giving him the correct information: (whatever length we decide to make the barrel) the end of the barrel will need to have a diameter .69555 and a .41 long tip with a diameter of .6455. The very top of the before the tip requires a small rectangle be maintained .92 long by .05 x .05 (I believe this to be the locating key). Followed by a pinhole reamed into that rectangle.) This sounds far more exciting than the divot I had hoped to drill into the barrel.

Considering that I am speaking to people who clearly have a much deeper understanding of this weapon than I do, I shall ask for any opinions on an appropriate barrel length? My understanding that the guns I had been inspired to build had been cut to around 20". Can anyone confirm this or would a different length (of at most 22") be preferable for a pretend cavalry carbine?

[Allen Humphrey]

Don't over think the metal work. It will seem pretty straightforward for a machinist. Provide him with the drawings (including page 25) and provide him with the front sight parts like shown in this auction http://www.gunbroker.com/Auction/ViewItem.aspx?Item=330721462 . You will need to buy a key and cross pin too. Lots of 1903 parts sources or auctions for those and pretty affordable. Do some internet research for pictures of 1903 front sights.

I can't comment on the barrel length as I really am not familiar with what you are trying to reproduce

[chuckindenver]

if you get the sight base to fit over the muzzle, in the correct place, then drill and tap a hole in the bottom of the dovetail on the base, go deap enough to drill a slight hole in the barrel, use a set screw to hold the base in place,
might want to high temp solder it in place as well.
done them before..a few times.