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All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Topic started by: Bill G on August 10, 2015, 02:47:51 AM

Title: My atempt at chamber reamers
Post by: Bill G on August 10, 2015, 02:47:51 AM
With all the goings on today in regard to shooting slugs with air guns, it has become obvious that chambering is very important.  So I took notion to see if I could do my own and have had a few dry runs so to speak.  I just completed ,except for the hardening, tempering, finish grind and hand stoning.  Sounds like a lot but it really isn't that bad.  I managed to take some pics although they aren't the greatest.  I'll try to post them and give details about what we're looking at. 

First of all, this is much easier to do with a cutter grinder and proper tools. Well, I aint got no proper tools so I have to do with what I had.(that's the way we talk around here) :o ;D  The equipment that I had available to work with was an old but good 12"X36" Clausing-Coldchester lathe, my 5-C collets, hexagonal collet block,  Vertical milling machine, 3/16", 3 flute carbide endmill, various stones and grits of paper and various micrometers and such.  There have been plenty of how to's, so I'll probably shy away from that aspect.  This is not the way to do it but a way of doing it.

(http://i27.photobucket.com/albums/c179/BillGreathouse/20150810_000528_zpsvc2hys4g.jpg)
This is a .25cal chamber reamer.  The original target was to have a leade of 1.5* (3.0* included) and throat of .251.  I intend on press fitting the brass pilot after heat treat so that there is a soft pilot to ride on the lans.  This pilot is .2423 that could be tight could be loose but I expect it to grow a hair when it is pressed on and will be polished in after ward. 

(http://i27.photobucket.com/albums/c179/BillGreathouse/20150809_235700-1_zps6oeh4xx5.jpg)
Not a good pic but it gets the point across as to the form.

(http://i27.photobucket.com/albums/c179/BillGreathouse/20150809_235023-1_zpsx0ajb5ib.jpg)
Yet another not so good pic but the idea was to show the gradual tapper and the relief.

The final dimensions for this reamer are as follows:
throat .2506"
min diameter of leade in is .2418"
The angle is actually 1.15* (2.3* included) instead of 1.5* . Could have been tool flex but was more likely I can't see the compound graduations very well and kind of took a swing.  I indicated before I began cutting and it and was at 1.5*. Could have been a combination of the two. the leade length is .450" and the throat length is .250".  The pilot is .287"  With that info, I can easily judge the depth while using it.  There is approx. .008" remaining for the final grind and stoning.  I'll HT tomorrow when I get up and finish some time in the next few days.  Then I'll be doing a test cut on some 4140 and slitting it to see how good of a finish it leaves.

Until then
Bill     

       
Title: Re: My atempt at chamber reamers
Post by: Bill G on August 10, 2015, 03:00:16 AM
After thinking about it, I hope I put this in the correct gate. ???
Title: Re: My atempt at chamber reamers
Post by: HappyHunter on August 10, 2015, 07:48:55 AM
Very nice looking job, very nice indeed! 8)

I'm assuming it's made from some form of drill rod? (O1/W1/A1)

After LOTS of reading/watching videos, getting ready to tackle a reamer or three myself for the first time (.177, .22 & .25)...hope they turn out half as nice as yours. I "ain't got no proper tools" either. In fact, even less than you - no vertical mill, just a lathe w/milling attachment... :o. Think I have the process figured out, just had to get a little creative on how to go about it... ;)

Looking forward to your results!

Title: Re: My atempt at chamber reamers
Post by: Bill G on August 10, 2015, 08:40:01 AM
A-2.  I'll draw it back to 60ish were the toughness is highest. 
Title: Re: My atempt at chamber reamers
Post by: Rescue35 on August 10, 2015, 10:00:57 AM
Nice work Bill. I look forward to seeing the finish they leave.
Title: Re: My atempt at chamber reamers
Post by: Bill G on August 10, 2015, 11:05:34 AM
Thank you, Me too.  I'll tell you that I did cut some aluminum with it as it is.  The finish was quite nice but, as you know, aluminum isn't 4140 by any stretch.  The primary reason for cutting the Al was to deburr.  I first use a cemented carbide lathe bit to draw down the flutes then lightly stone.  My hands are usually numb so feeling burrs isn't something I can do anymore.  I have found that with A-2, I can use the tool in aluminum or brass at about 80ish rpm's once it is at depth, I stop the lathe with the break very abruptly. then turn by hand in the opposite direction bout 1/4 turn.  This seams to do a great job of breaking off those tiny burrs that I can't feel or see with out magnification.  Afterward, the reamer won't snag a cotton ball.  I have left all the flutes about .008" over center line to allow for plenty of material to grind.  The intent is to have a slight negative rake to assist in controlling chatter.  In the final grind, I will leave some of the flutes slightly above center line by like a couple of thousandths.  This should simulate a offset and un-uniform   angle between the flutes, which reduces chatter as well.  I've ground lots of tools in my career but have always disliked it.  This was fairly easy and if I had the right equipment, this would have been much easier.  If I had the right tools, the flutes would have been helical. I'll have to post some pics of some custom carbide dovetail cutter that I did for cutting the slides on a Glock for some custom sights that I made for a friend. another thread and another gate.  I hate grinding.
     
Title: Re: My atempt at chamber reamers
Post by: rsterne on August 10, 2015, 01:46:16 PM
Making your own reamer doesn't have to be that difficult.... Here is one of the first ones I made....

(http://i378.photobucket.com/albums/oo221/rsterne/Millenium%20Pumper/IMG_2872.jpg) (http://s378.photobucket.com/user/rsterne/media/Millenium%20Pumper/IMG_2872.jpg.html)

It has only a single cutting edge.... The pilot diameter slides easily into the lands, and the taper for the leade is 2* per side (4* included).... with the parallel chamber section about 0.002" over the groove diameter.... After turning to diameter, I milled a groove from the back of the pilot to long enough o protrude from the breech end of the barrel at full depth.... The groove is milled to the centerline on the side of the mill, and about 0.010" past the centerline on the end of the mill, which puts a slight rake on the cutting surface.... The deeper you go, the more aggressive the cut but the poorer the finish.... The material was O1 drill rod, hardened by oil quenching, and then tempered in the oven to a dark straw.... It works just fine at up to about 40 rpm.... but you do have to feed slowly, and withdraw and clean of chips frequently....

Bob
Title: Re: My atempt at chamber reamers
Post by: Bill G on August 12, 2015, 10:54:43 AM
Hey Bob, Did you do any polishing on the chamber after the ream?  I did see that one on your Hyabusa build it think.  This 6 flute reamer will end up at 0.0-.002 from center. and is only .030 deep on the flutes.  The relief at the back of the flute leave ~ .01 as a lip.  That gives some room for swarf but definitely require slow going and clearing.  I originally did my swagging dies with d-reamers and later with a reamer similar to the one you showed.  I am currently working on one that will be a .2435-.244 bore riding and place the knurl on it as you have drawn.  If that works out, I will likely make a die that is dedicated to making a single size bore riding with tail driving band.  The only altering of that bullet will be in the width of the band to adjust weight and or engagement very slightly.  The idea is that the knurled version could serve those with choked barrels and also allow for a much larger range in weight variations. This makes it good for those who aren't decided on what is best for their gun and are experimenting.  The dedicated die would be for a version of the Knurled bullet that is a proven performer.  You may be asking why bother with the dedicated version and the answer would be simply production speed.  The second operation just adds time, that is worth it for the versatility. The last reamer that I made as a test for a swagging die was was multi flute and seemed to work very well.  The previous reamers seemed to always leave a tiny bit of taper.  With the multi flute It will be made small as to allow allow for lapping and the final polish after hardening.  I am also going to make a tool holder for my quick change tool post that holds a collet.  This will allow me to dial indicate the tool to the center line of the work piece. Working in the tenths range with OLD manual equipment is definitely do-able but is sure don't make it as easy as a big-az Mazack turning center. If this reamer proves to be a good tool,  I will probably make them out of HHS and perhaps Carbide if it looks like this is something that I will be doing frequently. 

I have my own heat treat equipment which makes it a lot easier than the drill press method.  For 0-1 or even W-series carbon steel, I have a provision to keep them from warping.  In the top of the furnace, there is a vent hole.  I have made it so that I can put a collar on the shank of the reamer.  The shank it left long and cut off later to the proper length.  I use a piece of refractory brick that has had a hole drilled into it then split through the hole.  I heat the reamer to ~ 400ish degrees and dip it in an anti decarb agent that forms a sort of glass on it.  Then I program the heat profile and place the reamer through the hole and block it up.  Hit go and when the alarm goes off, remove and quench.  I keep the oil on a hot plate at 200*F.  The glass pops off in the quench and the reamer is a dull silver.  After the reamer is cool enough to touch and the heat treat furnace temp has dropped to the tempering temperature,  I hang it  bake in the furnace for about 30 min then remove and allow to cool to room temp.  I have double drawn O-1 but I don't see them lasting any longer.  Double drawing A-2 does seem to help, especially with not breaking, more than dulling. I tend to use A-2 because that what Is free to me.  I can have all the dropped ends That I want from work.

When I went through my apprenticeship 20yrs ago,  The guy that I was under made me take all my 1,2,3, blocks, toolmakers vise and sine bars home as well as my counterbores.  I had to make all of them.  If I had to order a reamer for a job and it wasn't a rush job, he made me make it.  Subsequently........  :-[ I don't like grinding even though I'm fairly good at it when I want to do it.   The right equipment make it far more pleasant also.  Here, I don't have the "right equipment".  If you were to ask Kieth, The guy who trained me, "the right equipment is in you &%!# head", he'd say.  He is right and the guys on this forum are proof.

Bill               
Title: Re: My atempt at chamber reamers
Post by: rsterne on August 13, 2015, 02:50:29 AM
Just a bit of 600 grit rolled up to smooth any roughness....

Bob
Title: Re: My atempt at chamber reamers
Post by: Bill G on August 13, 2015, 09:55:41 AM
Great.  That's kinda  what I had antisipated.
Title: Re: My atempt at chamber reamers
Post by: strever on September 06, 2015, 12:27:49 PM
Bob
are you making your own reamers now that Sean seems to have disappeared from here ?
do you know if there is anybody else we can purchase/acquire a reamer from ?





Making your own reamer doesn't have to be that difficult.... Here is one of the first ones I made....

(http://i378.photobucket.com/albums/oo221/rsterne/Millenium%20Pumper/IMG_2872.jpg) (http://s378.photobucket.com/user/rsterne/media/Millenium%20Pumper/IMG_2872.jpg.html)

It has only a single cutting edge.... The pilot diameter slides easily into the lands, and the taper for the leade is 2* per side (4* included).... with the parallel chamber section about 0.002" over the groove diameter.... After turning to diameter, I milled a groove from the back of the pilot to long enough o protrude from the breech end of the barrel at full depth.... The groove is milled to the centerline on the side of the mill, and about 0.010" past the centerline on the end of the mill, which puts a slight rake on the cutting surface.... The deeper you go, the more aggressive the cut but the poorer the finish.... The material was O1 drill rod, hardened by oil quenching, and then tempered in the oven to a dark straw.... It works just fine at up to about 40 rpm.... but you do have to feed slowly, and withdraw and clean of chips frequently....

Bob
Title: Re: My atempt at chamber reamers
Post by: rsterne on September 06, 2015, 01:51:10 PM
I do when I have to, but I don't sell them.... No idea if anyone else is making them....

Bob
Title: Re: My atempt at chamber reamers
Post by: Bill G on September 06, 2015, 02:11:47 PM
I'd be interested in doing it for hire after I prove to myself that they are functional.  I don't like selling things that aren't a good product if I have the doubt that they could be substandard.  I have a hard time staying on task when doing things for personal use.  My wife says I need to learn to say no (unless she is one asking) ;). So I haven't finished mine because I'm waiting to finish a couple of reamers that I'm doing for a couple of new swaging dies and punch profiles.  I figured that I'll do the heat treat as one batch and save the wear on the HT furnace.  Also have a friend that is wanting some trigger parts done. he'll be ready before me.   
Title: Re: My atempt at chamber reamers
Post by: strever on September 06, 2015, 03:15:07 PM
Bob
i am half way thinking of making one after watching Sean's videos & your post above
but of course it would be easier to get one from someone who is already experienced  ;D

Bill
would you think of making the D reamers or the multi flute ?

Dick


Quote from: rsterne
I do when I have to, but I don't sell them.... No idea if anyone else is making them....

Bob

Quote from: Bill G
I'd be interested in doing it for hire after I prove to myself that they are functional.

Title: Re: My atempt at chamber reamers
Post by: Voltar1 on September 07, 2015, 12:56:47 AM
Curious Bill, why lefthand cutting?
Title: Re: My atempt at chamber reamers
Post by: Bill G on September 07, 2015, 10:25:57 AM
LOL!!  No doubt.  That was the first one that I had ever tried and in my attempt to pay close attention to the details of the releif angles, flute depth and flute stager.... Well, I forgot to pay attention to what side I set my fixture up on. :-[ :-[.  I don't have a real tool grinder which is more intuitive IMO.  So this one will be for me and the rest will be for the right handed world.  It does make me laugh every time I look at that pic, even though it is an embarrassed laugh.  I have that one and a .357 done. I am making .257, 7mm, .30, .308, and .45X. Possibly one for .22cal. 

Bill