My Adjustable Barrel Lapping Tool
I’ll not try to make the case here for why the bore of many modern barrels (especially target guns) can be made much better by lapping. I’m sure you’ve heard enough about the benefits as well as the hassle of doing it the usual way.
My approach requires no heat on the barrel and most shooters will have very little if anything to purchase to get this done. A bill of materials will follow.
Essentially, I compress a soft lead ball between two washers and mounted to a hickory ramrod. A threaded stud (same thread as ramrod end cap) runs through the center of the ball. Then tightening nuts on each side off the washers compresses the ball (while it is in the barrel) until it is forced into the lands and grooves. This is easier to do without the breech plug in place but is not that difficult to do from the muzzle if you plan ahead.
Most people don’t have all-thread studs lying around that match the female thread of their ramrod so I usually find a bolt of suitable length and cleanly remove the head so I have a stud. You will want enough length to bottom out in your ramrod and lock in place by making a double nut locknut so this doesn’t come unscrewed while using. A small washer goes on next and this should be a tight fit to your threads to keep lead from squeezing through. If you don’t have a tight washer, drill out an undersized washer to make the close fit.
Next you push your center drilled, soft lead ball, conical or round fishing weight on the shaft to the washer. Another snug washer goes over the ball followed by a nut which will compress the lead. At this point push the back of the ramrod through the muzzle and out the breech. You want to have the ball part inside the barrel with the nut outside the muzzle so it can be tightened while you or a helper holds the ramrod at the breech end to keep the ball from turning in the barrel. You want to slowly compress the ball since the stud you made is possible to strip if over tightened at once. I just stripped a thread on one I’ve been using for years and had to replace it yesterday. My new one was from a drawer pull knob and Phillips button head which I decided to leave on until it gets in the way.
Anyway, when your lapping rod moves freely through the barrel, give another half turn on the nut to expand the lead more. It is a good idea to mark your ramrod so you know when you are about to hit the breech plug threads and stop your stroke before your rig leaves the rifling. It isn’t a bad idea to index your lead ball to the front sight or top flat in case the lands and grooves are not a perfect match. That way you can remove the rammer and line it up the same way when you reinsert it.
What to do with a closed breech without removing the breech plug. We start out assembling the same way but we remove the rammer before we try to insert the tool. In this case rather than an all thread stud I suggest using a bolt and leaving the head on since it will give you something to pull on in case you push it too deep.
At this point I would secure the head of the bolt with bailing wire or good braided nylon line. An alternative to this would be a fender washer that you have installed between the head of the bolt and the nut you will be tightening so that the head is retained and the washer can’t go into the barrel. The above is just in case since accidents can happen. With care you may not need this since you just tap the head of the bolt with a hammer and pull it back between tightening the nut. I only pull out far enough to reach the nut with a wrench. Use oil at this point to make sliding the lead in and out easier until you have good lands and grooves formed.
Once you see good grooves on the lead ball go ahead and extract the tool and attach securely to your ramrod. This will reverse the ball in the barrel but this seems to make no difference as far as lapping. You will have to remove the rammer each time you want to tighten the nut and expand the ball. Just take it slowly so it doesn’t swell so much it won’t force back in. You can try marking the ball so you can always line it up with the same land in the barrel. That may not be necessary with machine rifled barrels.
Back in the day we used to ball burnish the barrel without compound or just drop a little fine dust in the barrel. In recent decades I have used the adjustable tool described above for a number of strokes with only oil, but then add a little compound meant for polishing wheels to buff out knife blades or other metal. If you don’t have an abrasive stick on hand but do gave some silver polish or compound for your automotive finish, those will also work to smooth out that bore. As the lead wears I tighten the nut a smidgen to improve the fit.
In conclusion, you don’t have melt lead in your barrel and i find it useful to be able to adjust the fit of the lead ball part of this tool. You don’t have to use an abrasive but it speeds things up. If you have a friend who is a mechanic they likely have some very fine valve grinding paste if you want to remove metal quickly.
I normally lap barrels when taking a break from stock carving or cleaning up castings for a new rifle. I’m in no hurry and don’t use such heavy abrasives. Lapping is something you can do while watching TV since it requires no thought once you get going. If you have questions please let me know. I be been making these for about 19 years and was preparing a video this week but had to stop before finished because of holiday stuff.
B.O.M.
1- wooden ramrod with a female threaded metal end cap.
1- soft lead ball the size of your barrel or smaller and center drilled to accept a stud that will screw into your ramrod.
1- all thread stud or a bolt that fits your ramrod threads.
4- nuts to match the threads on the stud or bolt.
2- washers that are a very close fit to the OD of your stud or bolt.
Some gun Oil
Optional - Abrasives
I’ll not try to make the case here for why the bore of many modern barrels (especially target guns) can be made much better by lapping. I’m sure you’ve heard enough about the benefits as well as the hassle of doing it the usual way.
My approach requires no heat on the barrel and most shooters will have very little if anything to purchase to get this done. A bill of materials will follow.
Essentially, I compress a soft lead ball between two washers and mounted to a hickory ramrod. A threaded stud (same thread as ramrod end cap) runs through the center of the ball. Then tightening nuts on each side off the washers compresses the ball (while it is in the barrel) until it is forced into the lands and grooves. This is easier to do without the breech plug in place but is not that difficult to do from the muzzle if you plan ahead.
Most people don’t have all-thread studs lying around that match the female thread of their ramrod so I usually find a bolt of suitable length and cleanly remove the head so I have a stud. You will want enough length to bottom out in your ramrod and lock in place by making a double nut locknut so this doesn’t come unscrewed while using. A small washer goes on next and this should be a tight fit to your threads to keep lead from squeezing through. If you don’t have a tight washer, drill out an undersized washer to make the close fit.
Next you push your center drilled, soft lead ball, conical or round fishing weight on the shaft to the washer. Another snug washer goes over the ball followed by a nut which will compress the lead. At this point push the back of the ramrod through the muzzle and out the breech. You want to have the ball part inside the barrel with the nut outside the muzzle so it can be tightened while you or a helper holds the ramrod at the breech end to keep the ball from turning in the barrel. You want to slowly compress the ball since the stud you made is possible to strip if over tightened at once. I just stripped a thread on one I’ve been using for years and had to replace it yesterday. My new one was from a drawer pull knob and Phillips button head which I decided to leave on until it gets in the way.
Anyway, when your lapping rod moves freely through the barrel, give another half turn on the nut to expand the lead more. It is a good idea to mark your ramrod so you know when you are about to hit the breech plug threads and stop your stroke before your rig leaves the rifling. It isn’t a bad idea to index your lead ball to the front sight or top flat in case the lands and grooves are not a perfect match. That way you can remove the rammer and line it up the same way when you reinsert it.
What to do with a closed breech without removing the breech plug. We start out assembling the same way but we remove the rammer before we try to insert the tool. In this case rather than an all thread stud I suggest using a bolt and leaving the head on since it will give you something to pull on in case you push it too deep.
At this point I would secure the head of the bolt with bailing wire or good braided nylon line. An alternative to this would be a fender washer that you have installed between the head of the bolt and the nut you will be tightening so that the head is retained and the washer can’t go into the barrel. The above is just in case since accidents can happen. With care you may not need this since you just tap the head of the bolt with a hammer and pull it back between tightening the nut. I only pull out far enough to reach the nut with a wrench. Use oil at this point to make sliding the lead in and out easier until you have good lands and grooves formed.
Once you see good grooves on the lead ball go ahead and extract the tool and attach securely to your ramrod. This will reverse the ball in the barrel but this seems to make no difference as far as lapping. You will have to remove the rammer each time you want to tighten the nut and expand the ball. Just take it slowly so it doesn’t swell so much it won’t force back in. You can try marking the ball so you can always line it up with the same land in the barrel. That may not be necessary with machine rifled barrels.
Back in the day we used to ball burnish the barrel without compound or just drop a little fine dust in the barrel. In recent decades I have used the adjustable tool described above for a number of strokes with only oil, but then add a little compound meant for polishing wheels to buff out knife blades or other metal. If you don’t have an abrasive stick on hand but do gave some silver polish or compound for your automotive finish, those will also work to smooth out that bore. As the lead wears I tighten the nut a smidgen to improve the fit.
In conclusion, you don’t have melt lead in your barrel and i find it useful to be able to adjust the fit of the lead ball part of this tool. You don’t have to use an abrasive but it speeds things up. If you have a friend who is a mechanic they likely have some very fine valve grinding paste if you want to remove metal quickly.
I normally lap barrels when taking a break from stock carving or cleaning up castings for a new rifle. I’m in no hurry and don’t use such heavy abrasives. Lapping is something you can do while watching TV since it requires no thought once you get going. If you have questions please let me know. I be been making these for about 19 years and was preparing a video this week but had to stop before finished because of holiday stuff.
B.O.M.
1- wooden ramrod with a female threaded metal end cap.
1- soft lead ball the size of your barrel or smaller and center drilled to accept a stud that will screw into your ramrod.
1- all thread stud or a bolt that fits your ramrod threads.
4- nuts to match the threads on the stud or bolt.
2- washers that are a very close fit to the OD of your stud or bolt.
Some gun Oil
Optional - Abrasives
