need barrel reaming advise

[w4zmb]

Hey Everyone,

I just ruined another barrel. It's a .58 bore X 40" when done, or was going to be. (Actually I will save it with a liner if I can buy one somewhere) I'm still crying & whining a little when I think about it. Real discouraging.

The spiral reamer I bought left a distinct spiral chatter that looks surprisingly like rifling, one spiral for each of the teeth of the reamer. Didn't seem to make any screaming sounds or much noise so you'd notice.

It is held in a 1/2" pull tube with a light tap fit into a bored socket in the tube, the reamer turned down to fit and held with one 3/16 roll pin.I was taking about a .005 cut.

The drilled hole was half way decent, done with a standard twist drill on a long 1/2 bar extension with about 50,000 ins and outs. Really wasn't too bad, took about 2 1/2 hours and came out about .030 off center in 41". At least it was cheap!

The reamer tube has 4 holes drilled around near the shank of the reamer for oil to come out.The tube has a close fit to the drilled bore size, bushed up close to the drilled bore size to hopefully direct the oil forward toward the reamer.

I used soluble oil squirted down the tube and was always trickling out the end and used air occasionally to blast the chips out. I checked it several time and didn't seem to be clogging.

I'm using a 17" X 54" LeBlond lathe turning 131 RPM and .008" per revolution. Seemed about right but maybe not.

What am I doing wrong?!?!

Next thought I'd go the tried and true route of using an old fashioned square bit reamer.

I'm getting ready to finish my wood backed  square bit barrel reamer tomorrow. I've been reading all of the posts & info I can find about it.

 Its made with a 3/8" X 8" HHS lathe tool bit tapered on a belt sander and wood tied with a string. I'll experiment on this barrel.

I think I know enough to get into trouble, but would appreciate any hints & tricks in making and using it from  anyone that may be willing to lend a bit of experience. My head is starting get a flat spot from beating against the wall.

Also would love to discuss gun-drilling  (another tragic story) Sort of takes that sharp edge off the fun at $130 per broken drill. Makes a person want to say bad words, I'll tell you.

Any advice would be really nice & merciful!

Thanks,Steve

[billd]

Take this for what it's worth, I never made a barrel.....but I would think a pull reamer would be better.

Bill

[Carper]

The softer the barrel the better the luck you will have with the homemade square reamer. When I was a little boy I helped my grandpa redo three Honaker rifle barrels for a friend of his.  We actually drilled them up using about the same rig as you described. The inside of the bore was rough as can be. We had a square reamer with the cutting side being a piece of file riveted to the square body backed by shim of hickory held in place with a leather washer. I reamed them by hand using a old drill motor with the barrel held in a post vice. It took about all day..... for each barrel. Using lard for lube it was a long , nasty day. But the old barrels came out  smooth and fairly consitant in diameter. It took about three times as long to ream them as it did to rifle them. Years later I tried to take a CVA barrel up from 45 to fifty something using the same method, I was a week getting it reamed and it never looked real good but it shot just ok. Now I just buy a smooth bore from one of  folks making barrels and cut my own rifles at whatever caliber it comes.  Getting your bore consistant and smooth , I think is more or at least as important as doing a decent job of cutting the rifles. As far as accuracy is concerned. I have cut some bad looking rifles that shot great.  Go figure.     Good luck    Johnny

[w4zmb]

Thanks for the feedback.

I forgot to mention this is 12L14 leaded cold rolled so it is pretty soft stuff. I know a spiral gun reamer would be quicker, but I'll try anything.

BTW it is a pull type reamer.

[Steve Bookout]

Steve, that new long bit you're making should work just fine provided you don't turn it too fast.  On my wooden bench we're lucky to get 60 rpm.  If you have the rear end tapered a bit, you can ream both forwards and backwards without it grabbing on you.  Used to use hog lard for lubricant, but Dan Land gave me a gallon of peanut oil, so I started using that.  Works just fine and never needs flushing in my experince, but then again, I never use electricity to forge, bore, ream, and rifle a barrel.  Good luck with that armoury reamer.  Cheers, Bookie

[Acer Saccharum]

I have never done the reaming before, either, so take what I say with a grain of 2F.

I thought the bore would be reamed out with two or even three reams of successive sizes. It does not surprise me that your first reaming would have rings, as it's taking a pretty heavy cut, and you don't have high pressure coolant flushing the chips out. Some of those chips are bound to score the hole. A next size ream of .002-.004 larger would generate very fine chips and likely take out the rings.

Tom

[Don Getz]

Reaming is probably the most important element in making a good barrel.   When I first went into the business we played
with reaming for a long time in order to get it done well......it's not easy.   You must get the correct RPM, feed speeds, and
load on the reamer correct before it will work right.   We ream about .010 on a ream.   Our drills are about that, .010, under the finished bore size...............Don

[rick landes]

I have re-read you statement about the flutes of the reamer leaving "rifling" marks. Are you powering the lathe when you are pulling the bit out of the material? If so stop the power and pull the reamer. I have not used any reamers with less than 8 and normally 12 flutes to ream a piece, however to pull the reamer out under power will leave mark in the bore for each flute.

The material has some degree of give/support as the reamer turns mostly from the chip being cut and spiraled back. This ends when the motion is reversed.

Reaming is best done at a lower speed with a controlled or steady feed a minimum. Variation will show up.

I hope that is of help. Just a final note. Good reamers are very expensive and also very sharp. Care must be taken when pulling them from the tube or box these were shipped in or you will have 8 to 12 nicely spaced cuts on your hand. Do not ask me how I know.

[Dphariss]

I would pull ream so the chips are going back out the reamed portion of the barrel with oil holes in the tube the reamer is welded to.  It should make enough pressure to wash the chips away from the reamer.

I would run the reamer much slower with less feed. About 1/2 what you have in each case. My smaller LaBlond has at least 4-5 speeds slower than 130 and feeds to about .003 per rev maybe less. Would have to go look. Loading a reamer too much, or a drill for that matter is going to cause problems so slow feeds will usually make for a smoother hole with more uniform dimensions.

I would use a straight flute reamer.
Generally in reamers speed is bad unless reaming a hole in a lock plate where it can be run about the speed of a drill.
Drilling a barrel blank requires high speed, low feed and lots of oil at pressure to blow the chips back down the hole. Oil hole is at the cutting end of the gun drill. Single flute with a flute pressed into the tube full length.


Dan

[Clowdis]

I would agree with most of what Dan said above, especially the straight flute reamer and slower speed. Chip loading is the key to keeping the chatter down along with a rigid setup which it sounds like you have. The one thing I'd try is a higher chip loading and the best way to get that is with a higher feed rate in your case. Slower speed will help some but crank the feed up instead of down. You might give the folks at Pacific Tool and Gauge 541 826 5808 or JGS 541 267 4331 a call and see if someone will talk to you about chip loading on bore reamers. Sometimes it's best to go to the people who make the reamers and ask them what's best. Sometimes they'll even take a minute to help.
Blair

[Dphariss]

I would agree with most of what Dan said above, especially the straight flute reamer and slower speed. Chip loading is the key to keeping the chatter down along with a rigid setup which it sounds like you have. The one thing I'd try is a higher chip loading and the best way to get that is with a higher feed rate in your case. Slower speed will help some but crank the feed up instead of down. You might give the folks at Pacific Tool and Gauge 541 826 5808 or JGS 541 267 4331 a call and see if someone will talk to you about chip loading on bore reamers. Sometimes it's best to go to the people who make the reamers and ask them what's best. Sometimes they'll even take a minute to help.
Blair

You could be right on the feed but I would think something under 1" a minute would be better than over.
When chambering barrels too much speed will flute a chamber faster than anything else and the feed must be slow at the final cuts to assure headspace is maintained.
The reaming machine at Shiloh when I was there was built from an old lathe and would do 2 barrels at a time. But I don't know the feeds or speeds but it was not very fast. Nor were the bores in the middle of the blank, exactly, at this time so the barrels were not rigid so the bores could align with the reamers as I recall. Since the bores were often .010 or more off center at the muzzle there had to be some way to keep the reamer true in the drilled hole.
Dan

[Clowdis]

Dan,
Like you I used to make some barrels. I did a lot of .58 caliber musket barrels that I sold in the N-SSA. I still have the drill and 4 flute reamer I used but the equipment is long gone. But also like you I can't remember the speed or feed for the life of me. But, I think the reamer was a JGS and that's where I got the info on speeds and feeds.

[w4zmb]

Hello All,

Just want to let everyone I appreciate you for taking the time & bother to share your good advise!

Just got back from a unexpected trip. Didn't mean to take so long to thank everyone. Glad to be home again for sure.

Haven't had a chance to try the old style square reamer yet, but will soon.

Sounds like maybe I didn't load the reamer enough, I was worried about chips jamming up. Must be a "sympathetic" shatter causing the spiral, its just too deep and even for score marks.

Its actually a beautiful thing. Too bad I don't want it. If I were trying to do it on purpose  I could never do it for a million bucks.

Slower RPM and play with the feed some. Maybe pressure coolant would be good.

Probably switch to a straight flute reamer. Should I use a tapered pull type or off the shelf push type chucking reamer?

Especially, Don Getz, you use .010' cut on the reamer, so that's something I'll do next time. Thanks for that!  I was reaming about .003- 004" at most.

Don, could I please ask you what type of reamer you found works best as far as straight/spiral, push or pull type? Do you use pressure coolant? Any advise would be wonderful.


Thanks again everyone!

[huntinguy]

For us the standard rule is .001 to .0015 feed per flute. Speed is not the friend of a reamer but is must be fast enough to cut. Soluble oil does not lubricate as well (okay, some of the new stuff isn't bad) as a good sulfur based oil.

.005 to .0075 per side (small bores less, big bores more) on a reamer will be enough material to stabilize it. Too little material and the reamer will float and gall and all kinds of other bad stuff. Too much and the reamer will pack and burn, or cut oversize.

You didn't say if this was a rifled barrel to begin with, or I missed that part. If it was, and if it was button rifled you may not have taken enough material out to remove the compressed area from the button, hence you are seeing the rifling.

If you started from a blank and used a two flute drill, chances are that rifled the barrel and the reamer followed.

I am a fan of core drills and multi reaming, each reamer will straighten out the errors of the prior reamer. I like to prebore about one or two diameters of the reamer, .001 to .002 smaller than the reamer, before sending it in the hole. Keeps things straight and gives the reamer a good start before it is influenced by its cutting edges.

Make sure you get a staggered flute reamer. Not all of them are. Keeps harmonics down (chatter and rifling).

(ya know, there is nothing keeping you from honing or lapping out the barrel you have to remove the light marks inside. Just a thought to save the barrel you have.)