Raceway Reaming question.......

ultramagmed

ultramagmed

JKM
Gentlemen,

I,m getting ready to order a raceway reamer from Dave Kiff but, I have some questions before I do so.

1) Is .705 the most common diameter reamer to order?

2) What is the most common setup to ream? This is the big question. The way I see it (please correct me if I'm wrong) I would need to chuck up say for instance an old barrel shank, turn a shoulder and thread. Bore a .750 hole in it for the reamer to pass through, screw the action on and ream similar to chambering with some sort of pusher. Am I anywhere in the ball park here? Anybody have any pictures of their setup?

3) Can bushings be made for the mandrel out of old barrel stock, or would I be better off to buy the hardened and ground bushings from PTG?


Any and all opinions welcome.

Thanks In Advance,
Med.
 
Med,

1. To my knowledge, .705 is the "standard" if one is reaming a raceway for purposes of action trueing. That is the number I have heard, and that is what mine measures. I don't think this number is arbitrary, and was chosen because generally, it is of large enough diameter to clean up the existing raceway, but not so large that it removes material unnecessarily. One must (should) bush the bolt after this step, and to my knowledge, this is the primary reason for reaming the raceway, i.e., to facilitate a better bolt to bolt raceway fit.

2. I don't think you need, or better put, I have never heard of the necessity for a bored-barrel stub arrangement such as you describe. I ream as described by James Boatright in a past issue of Precision Shooting. Hold the action captive in something like a padded vise, drive the reamer with a hand-held drill, and use plenty of high quality cutting fluid. If I remember correctly, the pupose of using the hand held drill was it allows "float", i.e., the reamer follows the bushed pilot, and is not driven off axis by the pusher...pretty much the same theory as a floating reamer holder.

3. You can make your own bushings. I have made all of mine and they work fine. I used some stainless I had laying around. I bored the i.d. to a tight slip fit, and turned the o.d.'s down to a little bigger than my desired dimension. I then polished them down the last bit with abrasive paper.

This is how I do it, and my opinions. But I am not the font of all knowledge. I'm sure one of the real gunsmiths, who have far more knowledge and experience than I do, will step in and opine.

Hope this helps,
Justin
 
Med,

It was the October 2003 issue. Check with Precision Shooting. They may have a back issue, or be willing to photocopy the article for you.

Justin
 
reaming not always needed

I see little or no need to ream raceways. You can order a bolt from
pacific any diameter you want. Simply measure the ID's in your
action. The surface finish in a used action will be mildly burnished
from use. I purchase bolt bodies that are the same or .001 larger
and polish to fit. They can also be polished a little more in the middle
making them easier to operate. What you have in effect is min. clearance
at lock-up. If of course the forward support area is much larger than
the area at the rear bridge, reaming may be needed.
 
Bob Kingsbury said:
If of course the forward support area is much larger than the area at the rear bridge, reaming may be needed.
Click to expand...

Bob,

That is exactly the problem I have. I'm going to sleeve the bolt and I guess I could do the "Borden Bump thing so it will pass through the rear bridge and still lock up tight on the front surface but, I figured if I bought the reamer it could make life a little easier in the future when sleeving bolts. I then could cut both sleeves the same diameter. I'm just not sure what the best method is to ream the action.

Thanks for the reply,
Med.
 
Here is what I do and why

The problem that you have is that the Remington action is finished machined before heat treat and they are all crooked afterwards. I made a barrel stub that I screw into the action and chuck it up in the lathe. I drive the reamer with a low speed cordless drill, the lathe chuck remains still. The reason that I do this in the lathe is so I can use flood coolant and have easy access to remove the rear busing at the appropriate time. I have seen videos of people turning the action in the lathe and pushing the reamer with a floating reamer holder held in the tail stock. The problem with that is the set up is way too ridged to let the reamer pilot properly.
If you doubt what I say try this. If you do not have a reamer and bushings, turn a chunk of ground and polished drill rod or stress proof about 16” long between centers to just fit into your action. You want to do this between centers so you can let it cool and try the fit without affecting your set-up. You only need machine enough to fit into the action from the rear to clear the tang and fully engage the front bridge area. Machine a barrel stub mandrel in your lathe with a nice class two thread fit and a square shoulder for the front of the receiver to mate up against. You can do this in a three jaw chuck if you want because you are going to leave it in there. Screw the receiver onto the mandrel and slip your shaft into the receiver. Roll the chuck through by hand and observe the run out at the right end of the shaft. Not only will it be elliptical but conical as well. I have not found any floating tool holder that will absorb the result without stressing the part. But cut the short leg from a very long hex key and the long part chucked in your cordless drill motor will, and it only cost five bucks. Because you do not turn the stub mandrel with the lathe when reaming you can use it many times without worry about the set-up.

Play safe,
Nic.
 
Last edited:
Thank You Nic,

That is exactly the information I was looking for. I knew there are many ways to skin the cat, I just wanted to know the best way to go about it and why. Your theory make perfect sense and as soon as I get my reamer I'll give it a try (unless of course somebody has a better theory:D:D:D)

Just kidding,
Med.
 
You must log in or register to reply here.
Back
Top