I’m scratch building an under-hammer rifle.

[Secesh]

I have put several kits together, years ago but this will be my very first scratch build. I’m gonna do everything myself except install the breech plug in the barrel but I have a very important question to ask the professionals here…

I do know the correct placement and size of the ignition hole in the barrel is very critical. I was planning to use a standard flintlock plug with no bolster. Nipple will be installed directly into the barrel as per an under-hammer design.

Exactly where should I drill the ignition hole? Should the hole be drilled just ahead of where the plug threads kiss the inside edge of where the bore begins?

Many thanks for the help!
farmer

 

[billraby]

Congratulations on being done with the kits! A whole new world has just opened up. I have never built a percussion rifle. Guessing that the threads on the nipple are NOT longer than the thickness of the barrel wall. So what I would do is drill a clearance hole so that the edge of the hole is just very slightly in front of the breech. Then use a bottom tap to cut the threads only deep enough for the threads on the nipple. If threads go past the nipple you have a great place for fouling to build up that will be impossible to clean.

 

[DuncNZ]

One of the reasons for an under hammer rifle is the flash goes directly into the powder charge for faster ignition , I'd say the nipple should be placed enough ahead of the breach plug so as to not interfere with the flash

 

[tallpine]

I assume you are building an H & A underhammer. The position of where the hammer lines up with the nipple is going to determine where the nipple hole will be drilled. This is the way I did it. I took a 1/4 inch rod, ground a tapered point on one end and cut it off to an over all length of 1/2 inch ( the length of the nipple without the threads). I then Superglued it into the hammer, make sure it is straight. Hold the trigger down and let it lightly strike the barrel.This will give you a mark that will locate where you need to drill your nipple hole. Check it and double check it, you are only going to get one chance to get it right. This has worked for me, I have done two like this and both came out dead nuts. A little heat on the hammer and the Super glue will turn loose. I hope this makes sense, if not PM me.

 

[Secesh]

I assume you are building an H & A underhammer. The position of where the hammer lines up with the nipple is going to determine where the nipple hole will be drilled. This is the way I did it. I took a 1/4 inch rod, ground a tapered point on one end and cut it off to an over all length of 1/2 inch ( the length of the nipple without the threads). I then Superglued it into the hammer, make sure it is straight. Hold the trigger down and let it lightly strike the barrel.This will give you a mark that will locate where you need to drill your nipple hole. Check it and double check it, you are only going to get one chance to get it right. This has worked for me, I have done two like this and both came out dead nuts. A little heat on the hammer and the Super glue will turn loose. I hope this makes sense, if not PM me.

Excellent idea, I’m going to give that a try.
Not an H&A rifle, I’m making all parts, what few there will be, hammer, springs myself except the screws, barrel etc. I’m not quite set up for that.

Cutfinger,
I’ll probably need to pay close attention to the depth of the plug compared to the position and throw of the hammer so that I don’t drill too short of the bore?

I’m going with a Rice .50 cal. 1 1/8” across the flats barrel so I should have plenty barrel wall where I can keep my nipple threads out of the chamber.

What diameter flash hole do you guys suggest?

farmer

 

[Colonial Boy]

Farmer,
As you’re making everything I suggest that you determine where the nipple will be first, then make the hammer to suit.

 

[Secesh]

Solid advice and ideas from everyone so far!

 

[22ceejay]

You can also use an old nipple, grind/file off all the threads down to the shoulder. set it on the barrel flat (upside down of course) and simply lower the hammer down on the nipple, make sure you get it centered, mark around it, then drill and tap. I have built several, it works for me. Have fun!

 

[unclelouie]

I have put several kits together, years ago but this will be my very first scratch build. I’m gonna do everything myself except install the breech plug in the barrel but I have a very important question to ask the professionals here…

I do know the correct placement and size of the ignition hole in the barrel is very critical. I was planning to use a standard flintlock plug with no bolster. Nipple will be installed directly into the barrel as per an under-hammer design.

Exactly where should I drill the ignition hole? Should the hole be drilled just ahead of where the plug threads kiss the inside edge of where the bore begins?

Many thanks for the help!
farmer

just finished a underhammer using a Arkansas under hammer action from Pecatonica. I used a William Large 40 inch 47 caliber barrel. use the long nipple if using a 1 inch barrel. made the stock and forearm out of walnut. I made my bullet mold using a 45cal mold. made it to .465 diameter. bench rest at 50 yards using NMLRA target, it shot a 49 3x on the first target using 65gr of 3f, second target shot a 50. weighs 10 lbs. it's my new bench gun. best action i have found found.

 

[Secesh]

just finished a underhammer using a Arkansas under hammer action from Pecatonica. I used a William Large 40 inch 47 caliber barrel. use the long nipple if using a 1 inch barrel. made the stock and forearm out of walnut. I made my bullet mold using a 45cal mold. made it to .465 diameter. bench rest at 50 yards using NMLRA target, it shot a 49 3x on the first target using 65gr of 3f, second target shot a 50. weighs 10 lbs. it's my new bench gun. best action i have found found.

I look around the Pecatonica website pretty regularly but I’ve never seen an Arkansas action. Is it a new design they’ve added?

 

[user 34300]

I have built several under hammers and a side hammer, all my own lock designs. As for threading the nipple into the side of the barrel....Some will say that is not a good idea. I have done all but one that way. The tap drill hole goes all the way in to the bore. The nipple rests right on the powder. There is no flash hole. Making a flat bottom hole with threads to the bottom is impossible with common tooling. IF you tried and got close you would still have fouling fil the gap. The center flash hole might be 1/16" ? My method of skipping all that make the most sure fire and shortest lock time ML I have ever fired.

It is not a bad idea to buy a nipple with extended treads that fit the full length of the barrel wall.

These are pistols, if the nipple came out the risk is less. Consider all cap and ball revolvers have the full nipple face on the powder charge. And, the nipple is pointing at your face.

You can use a patent breech arrangement. I did just that on an under hammer target pistol. I used the conical breech and small flash hole. I am sure it is stronger but it also clogs with with fouling after a while. Tradeoffs......

 

[Secesh]

just finished a underhammer using a Arkansas under hammer action from Pecatonica. I used a William Large 40 inch 47 caliber barrel. use the long nipple if using a 1 inch barrel. made the stock and forearm out of walnut. I made my bullet mold using a 45cal mold. made it to .465 diameter. bench rest at 50 yards using NMLRA target, it shot a 49 3x on the first target using 65gr of 3f, second target shot a 50. weighs 10 lbs. it's my new bench gun. best action i have found found.

unclelouie,

I just educated myself. Finally found the Arkansas action. Nice, stout looking design! How well does it perform for you? It looks like something I’d be interested in.

farmer

 

[Secesh]

just finished a underhammer using a Arkansas under hammer action from Pecatonica. I used a William Large 40 inch 47 caliber barrel. use the long nipple if using a 1 inch barrel. made the stock and forearm out of walnut. I made my bullet mold using a 45cal mold. made it to .465 diameter. bench rest at 50 yards using NMLRA target, it shot a 49 3x on the first target using 65gr of 3f, second target shot a 50. weighs 10 lbs. it's my new bench gun. best action i have found found.

Unclelouie:

I have looked into this action (I wasn’t aware of it prior to reading your post) and I like its design and the solid cast steel frame. I am of the understanding that it will accommodate up to a 1 1/4” barrel, my question is if the frame or receiver were mated with the 1 1/4” barrel, what size nipple would need to be used?

The reason I am interested in this action is the solid and stout frame that would definitely ennance accuracy. It would definitely be more stout than anything I could produce and would go farther in accomplishing my end goal of building a very accurate rifle. The only detraction I see when looking at the action is the hammer symmetry (I hope no one takes offense to that comment, it is merely an opinion) as I would prefer to see more of a graceful transition from the axis of the hammer to the nipple. Otherwise, I love the design.

Any insight you would have would be greatly appreciated.

farmer