Got a question for the esteemed gunsmiths here

[MBTcustom]

I have a project rifle I'm doing for a member here.
This is a mauser action being rebarreled to a wildcat with a semi-heavy contour barrel
I have procured a folding three leaf rear sight, and banded front sight from the good folks at NECG.
I got to looking at this build and stroking my chin whiskers, and thought about how unique it would be to dove that rear sight into a quarter rib.
I am actually pretty smitten with the idea. A little 50 LPI, a little hot blue?

Now, who here has made a quarter rib for a barrel, or knows where to read about it?
I know Brownells sells quarter ribs, but sure as shootin the one that has been discontinued is the one that would work best. Besides, I really want to do this myself.
Thoughts? Suggestions? Rotten fruit?

[No_1]

I like that idea and to take it one step further how about adding Ruger style ring grooves in the sides of the quarter rib just in case the owner wants to use a LER scope on the rifle.

[MBTcustom]

The scope is going to be mounted on the receiver in the traditional fashion.
But without the scope, this rifle is going to look really striking. You have to be careful with features like this. They can look like complete dog manure if you execute them in the wrong way, or they can turn a bunt into a home run if you do it right.
This is an example of WTH was he thinking?!?:
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=355003406
Kinda "gee wiz" but well executed:
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=355317983
Shut up and kiss me:
http://www.gunbroker.com/Auction/ViewItem.aspx?Item=355729605
Yep, picture #3 is extremely well done and you can see it even in the fuzzy picture.

I'm wanting to get some of that style on a Mauser, and the stock on this rifle would totally pull it off. Only problem is, I dont really want to sit there for 20 hours with a needle file, lamp black, and a visor making it happen.
I just want to hear from somebody who has done this and see if there's any slights I might not be thinking about.
If I had a CNC lathe, I would just input the barrel taper into cad-cam and turn a cylinder, and then cut a 1/2" slice out of the middle of it to get the rib. Not having access to such sweetness however, I'm trying to see how they did it in the old days.

What I have brewing in my head is to use a ball mill to get a channel sarted down the middle of a strip of steel, and then make a disk scraper to widen the channel and make it fit the rifle. Still very time consuming.

[Junior1942]

Man, I love the cartridge trap on rifle #3. If a person could make those out of aluminum or even HDPE to sell for $50 or so he'd get rich.

[MBTcustom]

Hey jr.,
Couldn't you substitute by drilling 4 holes in your stock, dropping in the shells and laying a strip of duct tape over the holes?
That'd go pretty well with your screwdriver handle.:kidding:
Sorry buddy, couldn't help m'self LOL!

[Nobade]

My boss figured out a nifty way to make light tight quarter ribs on the Bridgeport. It's kind of involved to explain but if you are interested, PM me and I'll try to describe it.

-Nobade

[country gent]

The big thing is the barrel is a taper and that has to be matched the radious you need isnt a constant but changing with the barrel taper. Get the radious close turn a mandrell that matchs the barrel taper from brass and then lap the radious on the quarter rib to that. That will get you very close to a perfect match. Work in a figure 8 stroke and rotate mandrell 180 degrees to do a final finish. The rest is simple mill work above the radious. You might want to consider making a parrallel with the matching taper for setting up in mill with. A small block with the hole pattern for the rail tapped in it makes getting it set up and easier to work also. Bolt the rib down and you can work 5 sides all at once to the holes and radious. Just my thoughts

[waksupi]

Tim, any time I did something like that, I had the barrel maker do it. One of my .358 Win. have a Bauska barrel, tapered octagon with integral front sight ramp. I have seen other barrels Les had cut ramping such as you talk about.

[Junior1942]

Tim is a dirty bird :-)

[Cap'n Morgan]

I never made a quarter rib, but I did make a 1/8th picatinny-style base which matched the barrel profile. Not hard to do when you have acces to a CNC mill and 3D CAD/CAM. In your case (I'm guessing you have a Bridgeport of some sort) I would tilt the head at an angle and use a 3/4" or thereabout endmill to cut the concave profile. The more the head is tilted the more "hollow" you'll get - it will not be a perfect radius (until you tilt the head 90 degrees), but you can come pretty close. The radius should match the smallest diameter of the barrel, that way the edges of the rib will make full contact with the barrel.

If the barrel is not a straight taper, but has a slight concave curve, you can bend the rib to follow the barrel contour after milling the channel and then mill the top of the rib flat afterwards. You can then use the tilting head trick to cut a slightly hollow profile here as well. If you use a modified endmill running it at a high feed on the last cut to produce a nice semicircle pattern.