Renovating a Rolling Block: last time (6/10 issue), Coffield made a forearm and installed the sights. This time, he relines the barrel and modifies the breechblock.
I won't deny the importance of projects like that and I'll admit they can be really satisfying. Maybe it's just my age (really old!), but at this point in life I also value just havin' fun with my guns and my gunsmithin'. Sometimes, my projects don't have to "make sense," they can just be fun!
Building a 19th century military-style carbine is just such a fun project. Starting out with a 30-year accumulation of rusty parts and pieces of various Remington Rolling Block rifles, I'm in the process of putting together a military-type carbine.
Since the project started, I've had a couple of folks who just couldn't understand why I would "waste" my time and my parts on something like this when I could use the same components to build a long-range black-powder cartridge rifle for serious competitive shooting.
They're right, I could do that. However, I really don't have a desire to do a lot of "serious" shooting anymore. I just want to have fun and a day spent at the local range poppin' metal plates with my buddies with a carbine like this sure sounds like a blast to me!
If you want to make your Rolling Block into a rifle capable of extreme accuracy at long ranges; go for it! A lot of the techniques and procedures I'm using with this carbine can be employed on your project as well. The important points to keep in mind on any project are to turn out a good piece of work and to enjoy the work while you're doin' it. So ... let's get rolling on the carbine!
In the early parts of this series, I built a buttstock and forearm from a blank. The walnut blank was obtained from Boyds Gunstock Industries, Inc., 25376 403rd Ave., Dept. SGN, Mitchell, S. Dak. 57301-5402, telephone 605-996-5011. You may not be aware of it, and I sure wasn't, but Boyds offers good solid walnut blanks at a very reasonable price.
For about 50 bucks, you can get a good piece of wood that's fine for a project like this or for your first attempts at making a stock. Sure, you can pay a lot more for a fancier piece of wood, but if you're not an accomplished stockmaker, you might want to hedge your bets and keep your investment on the low side for your first few stocks. I'd not cut a stock from a blank since gunsmithing school, so I sure didn't want to risk screwin' up on a high-priced piece of wood. The Boyds stock blank was just the ticket.
In building the carbine, I used a variety of components from some other rifles. The buttplate is from a U.S. Trapdoor Springfield, as is the barrel band. The barrel band spring is from a Mauser and the rear sight from a modern Italian-made replica Enfield muzzle loader. I also picked up some modern replacement screws for the Rolling Block from S&S Firearms, 74-11 Myrtle Ave., Glendale, NY 11385, telephone 718-497-1100, www.ssfirearms.com
With the carbine stocked and the sights installed, the next step is to install a Redman.44 liner I obtained from Brownells Inc., 200 South Front St., Montezuma, Iowa 50171, telephone 800-741-0015. If you don't already have a Brownells gunsmithing catalog, give 'em a call and order one. It's an essential resource for anyone doing gun work either as a hobby or professionally.
Before installing the liner, I took a long hard look at the breechblock. There are two reasons for this. First, the breechblock is important relative to headspace and any modifications to it should be done before the liner is installed, chambered, and headspaced. Second, the breechblock is currently set up with a significantly over-sized firing pin.
The current firing pin measures about .109" in diameter. While that was just fine back when blackpowder cartridges were used, it would not be suitable for any smokeless powder loads. Most modern centerfire firing pins have a tip that measures about .075" diameter. While I do plan on shooting some cartridges loaded with blackpowder, I will also most likely use some smokeless powder loads as well. For that reason, I need to modify the original firing pin and have it conform to modern standards.
Also, the hole for the firing pin in the breechblock has eroded. It's oversized even for the .109" diameter firing pin. As best I could tell, it measures about .125". That definitely needs to be reduced. Can you imagine what would happen if you fired the rifle with a .075" firing pin? You could almost bet on having a pierced primer and the release of gases in your face! Definitely not something you want.
In addition, the face of the breechblock was moderately pitted. While this alone would not necessarily prevent using the breechblock, it sure as the devil made it look bad! Since I had to bush the firing pin hole, I figured I might as well go ahead and remove as much pitting as possible. By using a fairly large bushing for the firing pin, I could basically kill two birds with one stone; I'll be able to use a smaller diameter firing pin and get rid of a lot of those ugly pits.
There are a number of ways you can bush a firing pin in a Rolling Block. The easiest method is to just drill out the firing pin hole, tap it, turn in a screw, cut it off flush, and then drill it out for the smaller diameter firing pin tip. That is definitely the quickest and easiest method.
There are a couple of problems with this procedure. First, you end up with a bushing that is fairly small in diameter. At most, it would be about a quarter-inch in diameter. If you have significant pitting or erosion on the face of the breechblock, the small diameter plug might' not cover or remove all of it.
Also, when you thread the breechblock and turn in the screw, you'll generally see a trace of the Thread at some point around the side of the screw plug once it has been cut off and filed flat with the face of the breechblock. To me it just doesn't look right.
The British, when working with the old Martini single-shots, would cut a dovetail across the face of the breechblock and slide in a dovetail filler. Once that was in place, it would be drilled out for the smaller diameter firing pin. The, filler was held in place by the dovetail itself and a small lock screw.
This is a darn good method, but you normally need a mill to cut the dovetail. One other positive aspect of this method is that you can remove the dovetail at a later point if needed by just removing the retaining screw and driving out the dovetail filler.
Probably the most common procedure is to use a lathe and bore out the face of the breechblock around the existing firing pin hole. A plug is then turned on the lathe to fit this new hole and soldered in place. The plug is later faced off and drilled for the firing pin tip. My only concern with this method is that you normally are relying only on solder to hold the plug in place, though you certainly could use pins or screws to help secure it.
I opted to go with the British method. I really liked having the option of being able to remove the dovetail filler if needed. Also, it's a method I've never seen used on an authentic U.S. military firearm so it will be just one more indicator to someone in the future that this isn't an original Remington or U.S. government issue firearm.
The first step was to cut a half-inch dovetail across the face of the breechblock. This was perhaps a bit larger dovetail than absolutely necessary, but I wanted to clean up as much of the breech face as possible. I used a dovetail cutter I purchased from Brownells for this. In cutting the dovetail, I first used a 3/8" end mill to remove most of the metal. I then followed up with the dovetail cutter.
Doing it this way meant the dovetail cutter was basically just removing steel from the "points" or edges of the dovetail. This significantly reduced the stress on the dovetail, cutter.
If you try to cut the entire dovetail without first using an end mill, you will often break or damage the dovetail cutter. Those things can be darn expensive, so I'll do all I can to reduce the stress on 'em as much as possible. By the way, I cut the dovetail to a depth of .100". That should be of more than sufficient depth for strength.
After cutting the dovetail, you'll notice that the firing pin hole went from a small round to a large oval. Actually, it was oval all along. Because it was so much smaller, it just looked more round. Keep in mind, the firing pin is at an angle to the face of the breechblock. It's not perpendicular at 90 [degrees]. The angle is much closer to 75 [degrees].
If you want to check that out, just put an angle gauge on the face of the breechblock and insert a long straight piece of metal that fits into the firing pin recess. With these two items in place, it'll be very evident that the angle is a lot less than 90 [degrees].
This can cause some problems centering the hole for the firing pin tip but I'll go into that in more detail later. It's a good idea to check the angle, no matter what type of single-shot you're working on. I've known of a number of folks who ran into trouble because they assumed the firing pin was at a 90 [degrees] angle when it wasn't. It pays to check it out!
After cutting the dovetail, the next step was to make the filler for the dovetail slot. I initially cut a small piece of l/4"-thick steel just a hair over 1/2" wide and about .890" long. The length is not critical, but there's no need to make it any larger than necessary. All you're doing is addin' work to the project if you make a dovetail longer than needed.
When cutting out the dovetail filler block, I tried to make my sides as straight and true as possible. Having the sides and corners at 90 [degrees] will definitely make the layout and cutting of the dovetail points easier. It'll also make it a lot more likely to have the front and rear sides of the dovetail perfectly parallel.
I should also point out that my dovetail cutter was designed to make a dovetail with 65 [degrees] edges or angles. Cutters are available for all sorts of angles. It's not really all that important as to what angle you use for your dovetail. Just make sure your filler matches that angle!
Once the dovetail filler was made by hand filing it to shape, I fitted it to the breechblock. Again, you want this to be as close a fit as possible. Ideally, you should have enough resistance that you have to tap it into place when it is fully seated.
My filler was by design too thick, as it was made from 1/4" thick steel and my breechblock dovetail was only about .100" deep. I cut down the thickness by about .100" in my mill. I then put it back in the breechblock and used files to finish taking it down flush with the face of the breechblock.
I had to be careful to avoid cutting the breechblock as I did this. I just wanted to remove material from the filler rather than the breechblock. If anyone ever tells you it's no longer important to know how to work with files when gunsmithing, you can be darn sure they don't know what they're talkin' about! If you're doing serious gunsmithing as a hobbyist or as a professional, you'll constantly have to use files. We may live in an electronic age, but you still have to know how to use your hands and basic hand tools to do a lot of gun work.
With the dovetail filler flush with the face of the breech-block as well as dressed off even with the sides, the next step was to install a small screw to help anchor it in place. I opted to use a standard 8-40 plug screw. Again, that should indicate to anyone in the future that this definitely wasn't an original 19th century gun. The standard 8-40 plug and sight base screw is a 20th century development and is found only on modern firearms.
In positioning the screw, I put it partly on the edge of the dovetail filler. This made it virtually impossible to move the filler without first taking out this lock screw. Yes, you could still beat out the filler but you would ruin the breechblock, the filler and the lock screw if you did!
By the Way, before you drill a hole for the lock screw, be sure to place a machinist clamp on sides of the breechblock to prevent any side to side movement of the dovetail filler. Any time you are drilling two separate pieces of metal at the same time, you'll want to have both pieces firmly secured so nothing can move. If you don't do this, there is a darn good chance your dovetail filler will move when contacted by the drill bit.
Once the filler block was completed and secured with the lock screw, the next step was to drill a hole in the filler block for the firing pin. I had already turned down the tip of the firing pin to .075". Traditionally, you turn a plug that fits the firing pin hole and then solder an appropriate size drill bit for the firing pin hole in the plug. The plug is then turned under power and you drill out the new firing pin hole. It works but I wanted to try something a bit different.
Because the firing pin is at an angle to the filler block and not at 90 [degrees], I first used a carbide bit to cut away a portion of the rear of the filler block where it would later be drilled. I was basically making a large center punch mark.
I did this so the drill would not "walk" or move off-center when it was turned. I've seen this happen several times and it leads to the firing pin striking the primer off center. If it's bad enough, you'll end up with misfires. The bottom line is you want your firing pin to strike as close to dead center in the primer as possible.
I initially took a 1/4" diameter piece of steel rod and turned it down to match the outside dimensions of the firing pin body. I then drilled through the length of it with a #55 drill, which is about .052" in diameter. Once this was done, I had a centering sleeve for my drill. I then set this up in my drill press and using a new, sharp #55 drill, drilled a hole through the filler block in the breechblock. This new undersized firing pin tip hole was drilled from the back side of the filler block.
I then, removed my sleeve from the breechblock and reversed the breechblock in my drill press vise with its face up. The #55 drill was still in the drill chuck and was used to align the chuck with the firing pin tip hole in the filler block.
When that was done, I replaced the #55 drill with a #54 drill bit and opened up the firing pin tip hole. I repeated this using progressively larger diameter drill bits until I had a firing pin tip hole that would easily accept the .075" tip of my firing pin.
When fitting the firing pin, you want it to move freely in the breechblock and through the filler block. At one point, I coated the firing pin tip with machinist layout fluid to see where I was getting contact or rubbing inside the breechblock.
A bit of work for a few minutes with some needle files and my firing pin was soon moving freely. The important thing to remember here is to work carefully as you remove metal from the filler block. You don't want the firing pin tip hole to be any larger than is necessary to allow movement of the firing pin. If the hole is too large, you may have the primer flow back into the breechblock when the cartridge is fired. That's bad and can definitely lead to a ruptured or pierced primer.
After fitting the firing pin, I checked for protrusion. With a centerfire cartridge, you generally want to have protrusion of about .060" to .065". After thinning and shaping the tip on the Remington firing pin, the protrusion was right at.063" and required no further adjustment.
With the breechblock work done, I moved on to the barrel I removed barrel from the receiver in preparation for lining. If you haven't already done so, make darn sure your barrel index marks are deep and readily visible before you pull the barrel. I definitely don't want to install the barrel after lining and chambering and have the darn sights canted off to the side. Again, check the index marks before pulling the barrel.
Once the barrel was off the receiver, I took another look at the two screw holes for the original Remington rear sight. I decided to go ahead and plug those holes. I took two pieces of mild steel rod about 1/4" long and fitted them in the holes.
Then, I used the flat face of a ball peen hammer to swage the rod down into the holes. The mild steel will swage very easily and quickly fills the holes with a nice small mound of steel above the surface of the barrel. Then, I filed the two mounds down flush with the surface. After that was done, the locations of the holes were hidden quite well. Hopefully once the barrel is blued, it will be even harder to spot the original screw locations.
In order to install the Redman liner, I needed to drill out the bore. The bore is basically .445" diameter while the liner measures .586". I'll use a piloted drill to open up the bore. Unfortunately, the pilot of the drill is just a bit small and is not a sliding fit in the bore. An easy way to deal with this is to just make a sleeve from a .44-40 cartridge case and place that over the pilot. When I later reverse the barrel in my lathe and drill from the breech end, I'll have to make a slightly larger sleeve from a.45-70 cartridge to center the pilot in the chamber which is, of course, a much larger diameter than the bore.
The barrel was set up in my lathe using a four-jaw chuck. A dial indicator was used to center the barrel as accurately as possible. Rather than use the dial indicator on the exterior of the barrel, I installed a snug-fitting plug gauge and indicated off the surface of the gauge. The bore is often not concentric with the exterior of the barrel, and especially so with older guns like this. The bore on my barrel was considerably off-center.
Any misalignment between the barrel and drill will result in an oversize hole for the liner. I wanted the liner to be as close a fit as possible, so I took a few extra minutes to set the barrel up as carefully and as accurately as I could using a dial indicator.
After that was done, it was just a matter of drilling out the barrel. Keep in mind you always want to use lots of cutting oil when drilling out a barrel. Cutting oil is much cheaper than the barrel drills, so don't be stingy with it.
Also, be sure to clear the chips from the drill frequently. If the chips are allowed to pack up in the drill flutes, it'll cause friction inside the barrel and generate heat, which can damage the drill. Packed chips can even jam the drill inside the barrel causing all sorts of problems, including breakage of those expensive drills.
The last step will be to chamber and install the liner. While it's possible to install the liner and then chamber it, I prefer in this case to do the chambering before installing the liner in the barrel. This will make headspacing much easier. I used my Manson Precision chamber reamer to cut the chamber to full depth. A wood plug was then installed in the chamber to seal it from epoxy.
While there are a number of makers of chambering reamers and headspace gauges, you would be hard-pressed to find anyone who makes better reamers than Dave Manson and his crew. I've been using Dave's products for many years, and have always been delighted with the results. If you ever need a reamer, by all means, contact Dave at Manson Precision Reamers, 8200 Embury Road, Dept. SGN, Grand Blanc, MI 48439, telephone 810-953-0732. He offers great products at a fair price and fantastic service.
I turned the barrel into the receiver, using those witness marks that are so important to align it. I also took the time to apply some release agent to the breechblock, as it will later be locked up against the liner and may come in contact with some of the epoxy.
I cleaned the interior of the barrel with alcohol to remove all traces of cutting oil and any other contaminants. The exterior of the liner was also cleaned and then it was coated with Loctite epoxy. Even though I had five minutes before the Loctite set up, I didn't waste time. I had everything prepared so there was no lost motion or wasted time.
When mixing the epoxy, I used some Brownells black epoxy dye to color it. There won't be much of a seam between the liner and the barrel, but having the epoxy dyed black will help a bit in making the liner a bit less obvious.
The epoxy-coated liner was inserted from the muzzle and pushed through until it protruded just a bit from the barrel breech. At that point, the excess epoxy that had been pushed through was cleaned up with alcohol soaked patches. The Wood plug was also removed. The Manson .44-40 "Go" headspace gauge was then inserted into the chamber. The breechblock and hammer were placed back in the receiver.
I carefully closed the breechblock and locked it in. place with the hammer. Then, I applied pressure on the muzzle end of the liner to force it back against the face of the breechblock. By doing this, I had set the carbine up with the proper headspace. It was all very quick and very easy.
The breechblock was closed and locked on the Go gauge. If you're careful and don't move the liner, you can double check by removing the Go gauge and inserting the No Go gauge. When you do that, the larger No Go gauge should prevent the breechblock from fully locking up.
Once the epoxy had set up, I once more checked the headspace just to make sure. If by some crazy chance anything was wrong, I could always heat the barrel up with a torch and move the liner back just a bit to correct the problem. With this final check completed, I cut the excess liner off from the muzzle and used my Manson tool to crown the liner and barrel.
I had used this tool before when I cut the.45-70 barrel. As I said then, this is the absolute finest hand crowning tool you can find anywhere from anyone. It's an amazing tool that gives you results you could only duplicate on a lathe, yet it's a lot quicker and easier to use.
The next time we get together, I'll modify and fit the extractor, make some repairs to the action, and do some work on the metal finish. The exterior of receiver is especially rough, and it'll take a major effort to get it lookin' good. However, we're on the downhill side of this project and it won't be much longer until this little puppy is ready to go to the range.
Until next time, good luck and good gunsmithing!
SGN GUNSMITHING PROJECTS
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|Title Annotation:||Reid Coffield|
|Date:||Jul 10, 2011|
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