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Making a Sharps barrel in my lathe

homebrew.357

Aluminum
Joined
Nov 4, 2013
Location
New Zealand
Hi, This is not C D or C N C stuff, I just made some add on bits to my lathe, pic816, so I could drill and rifle a " Black powder barrel "only.
Here`s how I did it. My lathe is belt driven and cuts metric and inch threads, the head stock bore is 38mm and at the back it has two bearing lock nuts screwed on, a bit of the thread for these was used to screw on my back barrel stock holder, pic817, with fore grub screws to centre the stock .
A flange was welded on with six even spaced holes for rifling register, pic818 . The fore jaw chuck centred the front end and this was how I held the barrel stock in the lathe. Homebrew.357. :)
P1010816.jpgP1010818.jpgP1010817.jpg
 
The barrel stock is set up true in the lathe and a light cut for register and faced of, ( pic 828, 829 ), this is done at both ends and the tail end is trued to, (pic 827, ) then the stock is removed for setting the gun drill guide ,:cool:, Homebrew.357.P1010828.jpgP1010829.jpgP1010827.jpg
 
Ok, The gun drill guide, this is made to fit in my angle bracket, made in three bits, the guide holder has two grub screws to hold it in place on the angle bracket. The drill guide body is a taper press fit in the holder and will not move, but the holder will move a bit in the angle bracket as the holes are over size, this is for lining up the drill guide true to the lathe axis with the guide stud . :cool:, The pic`s, Homebrew.357.
P1010821.jpgP1010822.jpgP1010824.jpgP1010823.jpg
 
My angle bracket is used to hold the drill guide and it is clamped in front of the fore jaw chuck with a packer, so it can be removed and put back in the same place. The guide stub is set true in the chuck , angle bracket clamped in with drill guide in housing and the two screws in ,but lose as the stub is pushed into the guide. Once the stub is in the screws are set tight, now the angle bracket is removed so the barrel stock can be set up. When barrel is set the angle bracket is replaced with drill guide in front with oil seal to stop leaks. pics, :cool: Homebrew.357.
P1010830.jpgP1010825.jpgP1010826.jpgP1010833.jpg
 
homebrew.357,

Thank you for this thread. I am waching it with interest and when completed I will copy it and archive it on my hard drive. This is something I and a friend have had interest in for quite a while.

Vlad
 
Hell then I`d better get it right, corrections, pic`s 825, 826 , the drill guide is on the wrong side of the bracket. pic 833, the angle bracket is pushed forward on to the guide stub and then it is clamped to the bed. now the guide housing screws are tightened so it stays lined up. Feew, I think all this typing is harder than making the barrel.:typing:. :ill: And I thought nobody was watching, well more to come, Cheers ,Homebrew.357.
 
Yes do keep up this thread... I was thinking it might be good to have a little OD stock do so if drilling wanders a skim might be taken between centers after ID is done.. Anxious to see how you produce riffling..Yes I did see the locating holes, good thinking.
 
Hi Guys, Yes the stock 1.240" and I need 1.220" at the breech, so where you start is the breech end, it`s spot on, but when you cut off the end bit to reveal the hole at the muzzle end it is a bit off centre, so yer, machine it true to the bore, you have tapered barrel, which is what I want.
Now, the gun drill is clamped into my X/Y vice on the lathe centre line. To mount the vice on my lathe I made up some ali blocks to fit and slide on the lathe bed ways and then the X/Y vice is bolted to this. A bracket is used to attach it all to the lathe saddle, vie under the saddle and a bent up bit is used to pull it all along, the bent bit is clamped with the following steady when it is screwed on. I hope this explains it all .:reading:. pic`s, :cool:, Homebrew.357.P1010836.jpgP1010834.jpgP1010835.jpgP1010837.jpg The arrows show where the bracket goes.
P1010838.jpg
 
So now I have drive to pull in the gun drill, but the drill must go in very slowly and on my lathe,(and most others)the finest feed is way to fast, so I had to find a way to gear it down. So a scrimmage in my comeindandy box I found two V belt drives, a very small one and a large one off an old washing machine. Now on my lathe a large gear driven by a forty tooth gear , so I changed it for a thirty tooth one. The large gear had fore holes , using two, I made up a bracket with the small V pulley on centre and two ali plugs to hold it in place on trhe large gear. An extension arm was made to hold the large gear and small pulley so it could be adjusted for gear and pulley drive. The large V pulley was made to fit on the gear box drive and with belt on and lathe gear box set at finest feed I got five turns of the chuck to 0.010 mm of in feed, I didin`t believe it, so checked three more times, :confused:. Just plain luck, the pic`s may help to show it,:cool: Homebrew.357.
P1010841.jpgP1010843.jpgP1010844.jpgP1010845.jpg pic 841 =forty gear to thirty. pic=843 all the bits for the big gear. pic=844, pulley bracket on gear. pic845=Extension arm on gear.
 
Things are ready to go, so mounting the gun drill in the lathe, from the back end, it is clamped in the vice at lathe centre height and the oil hose is connected . The following and fixed steadies are put on to keep the drill in line. The back of the drill guide housing is used to fit the plastic chip catcher, with oil seal , chip guide, drill seal ,and cap are fitted on to the drill, then drill is slipped in to the guide with seal holder, remember, oil is pumped in at 300 psi, you done`t want any leaks, :nono:
The chips and oil flow down to the tank, a fine mesh bit stops the chips and oil is returned to the tank. To start, drill is 1/16"from stock in the guide, lathe is started at 1200rpms, oil pump started, oil is going back to the tank, when all is running well the gun drill oil tap is opened and red tap is shut off. I get 300psi and the lathe saddle is engaged . I have a clear window in the oil pipe so I can see the oil and chips coming out, and they do, nice and fluffy. By the way, I changed the barrel steel, it`s 4140, recever as well, I listen to others how know more than me. :codger: , Homebrew.357.
P1010171[1].JPGP1010850.jpgP1010851.jpgP1010852.jpg
 
I like how you have that set up. Now I need a different lathe so I can try that myself sometime. :D

I'll also be interested in seeing your results.

Thanks,

-Ron
 
Hi Ron, Ok some more pic`s. The drill is very slowly going in and the chips are filling up in the filter , have to watch this, as when it gets full oil can over flow, so have to stop the drill and empty out the chips.:cool:, Homebrew.357.P1010858.jpg, Oil flow back to tank.P1010861.jpg, drill going in. P1010862.jpg, oil and chips flowing out. P1010870.jpg, This is what the chips look like, fluffy.
 
The results of two/three days of slow drilling and a big pile of chips is I have a bit of pipe ,with a .444" hole through it , so a bit of a clean up and then cut rifle it out to .458". :cool:, Homebrew.357.
P1010865.jpg, oil at 300psi. P1010863.jpg,Catcher full of Chips.P1010872.jpg, drill at last bit.P1010873.jpg, And I have a hole in a long bit of steel.
 
Thats some very good work , as well as the thought that went into the whole endeavour. How concentric was the hole in the opposite end ?
 
Hi, Yes Cutting off the back end reveals the out off round bit, my bit was about 0.038", I`m happy with that. Now the hole was .444" dia and not to bad, but I still gave it some passes with my home job reamer. I used an adjustable reamer, on the square end I tack welded a socket with a 1/4" drive to fit on an adapter in my rifling rod, lots of cutting oil and slow in feed did the job. Then a polish up with 600 grit paper on a wooden dowel. Came out nice, The pic`s, :cool:, Homebrew.357.P1010893.jpg, The homebrewed reamer. P1010894.jpg, ready to go.P1010895.jpg, doing the job.P1010898.jpg,P1010906.jpg There is the end result. :cheers:
 
Hi Guys, I forgot to say the reamer is only pushed through, but I guess you saw that. Now that I have drilled the bore with a new sized gun drill, I had to make a new body for my rifling cutter head, this is because the cutter assemble must be a snug fit in the bore so the cutter can not jump up and grab while cutting. I made it of silver steel and hardened it , all the old bits fit back in and the cutter is made from a t/c tipped saw blade, the t/c tip stays sharper and lasts a lot longer.
Will be looking at a rifling twist of 1-18", or close to it , I`m using bike sprockets to drive the rifling gear box, large one gives me 1-33.5" twist, and the smaller one gives 1-24.3", I will never get 1-18" with the back yard way I`m doing it, but if it`s close, will do, so a three inch one may do. The rifling will be a left hand twist,(I`m left handed),:rolleyes5:, six groves, 0.0065", bore, .445", groves .458". You are now where I`m at with this gun build, so it`s going to be slower, And I may have to have the breech block ,receiver assemble sent to a tool maker for a good job, there is no way I can do this with my limited tooling. And this gun is on my bucket list to shoot at the range, so it`s got be good. :cool:Hombrew.357. pic`s.P1010662.jpg Yep, rifling with bike bits.P1010910.jpg, New body and bits of rifling head.P1010912.jpg, Homebrewed t/c cutter.P1010913.jpg, Snug fit in bore.
 
How the cutter works.P1010914.jpg, Body with cutter in.P1010916.jpg, cutter, is pulled through left to rightP1010919.jpg.up for cutting. P1010920.jpg, down when going back through bore. Only very fine cuts are made and when you see fine chips , go through bore 25 times in all six groves, and start again till you get to .458" with the grove ID. Homebrew.357. PS, hey the All Blacks won!
 
homebrew.357,

This is a wonderful thread. When You have completed it I will copy it and archive it for my own use. This is something that I may try to do in the future.

What are you using as a pump for your cutting fluid when drilling? What do you catch the fluid in when the drill finally cuts through the far end of your barrel blank?

Vlad
 








 
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