Lambeth/Kiff Micrometer Adjustable Reamer Stop

[Rustystud]

For those who cut their own chambers The Lambeth/Kiff Micrometer Adjustable Reamer Stop make Chambering much easier and faster. They are available from MidwayUSA, Pacific Tool and Gauge, and Nat Lambeth, (919)556-0554 or [email protected] They come as an 8 piece set, 1 micrometer dial, a short and a long, Adjusting collar and 5 bodies from .750 through 1.750 in length. It make the reamer become a micrometer, the reamer itself is the pinion, the colar and the tendon face become the anvils. The dial is marked in .001 increments. With this tool you don't have to keep track of tail stock position. Works great with or without a flush system. Can be used with a hand driver.

Rustystud

 

[Ronin]

Rusty

I see the advantages of using this with a throating reamer to cut a specific throat length, but would there be any benefit to using this tool over a tailstock mounted dial guage for normal chambering?

I ask as I am collecting an inventory of "must haves" for doing my own chambering work.

Ronin

 

[Rustystud]

Advantage of the MARS

Ronin:

I assume you cut chambers and are familiar with the process. Let me ask you a question. When you use a indicator measuring off the tail stock and ram what happens to your refrence point if /or when you move the tailstock when cleaning your reamer? The MARS makes the Reamer and the barrel become a Micrometer. The collar on the MARS becomes one anvil and the back of the tendon becomes the other anvil. The reamer is the pinion. The MARS can be set to bottom out short of the desired chamber depth. So multiple measurements and the dreaded going to deep can be prevented. One can measure with the action screwed down on the barrel with the go gage installed. when bottomed out one can measure the gap between the action face and the barrel shoulder. It gives rock solid reference that can be measured with feeler gauges. I can usually cut a chamber with only two stops for measuring. I hope this has answered your question. If not I will be glad to work with you until you understand how it works. Steve Acker did an article in the Home Shop Machinist Magazine last Feb/March 07. The MARS has a Micrometer Dial that is marked in .001. The dial and collar jam together locking. Each body length and there are five different boddies allow for .750 of adjustment With the incorporation to the long and short collars. MidwayUSA has a picture on their web catalogue.
Nat Lambeth

 

[Ronin]

Nat

I am at the beginning of a long journey into doing my own barrel work, I am familiar with the principles and techniques of chambering but have not done so yet in practice.

I asked the question as a layman, not out of any critisism for your idea.

I posted as I am currently collecting items I need to stock my own home workshop and had settled on using a clock mounted on the tailstock spindle to measure the final cutting distance after checking as you described with action, headspace guage and feeler guages. (as per John Hynants text in precision rifle barrelling)

It never occured to me that the MARS tool could be used replace the dial test indicator (clock) in the final stages of cutting the chamber.

Would I be right in thinking that one could use the MARS in the closed position and chamber until somewhere near - measure using the action, HeadSpace guage and feelers and then dial in the necessary depth to be cut into the mike on the MARS to provide a simple finish depth cut?

Thanks for bearing with me!

 

[Rustystud]

Use for the MARS

Ronin:

No offence taken, I just wanted to know your experience level. The MARS is put on the reamer and affixed with a set screw. You use the appropriate body and collar to get the headspacing depth within the adjustment range of the MARS. PT&G reamers have a line marked on the reamer showing a zero headspace. The MARS is placed (bottomed out against the reamer shoulder)on the reamer and set to cut short of the desired depth. Maybe .050. The a measurement is taken and the MARS is adjusted to the desired headspacing. The final reaming is done and then checked again. You can cut your chamber dead nuts on the mark with as few as two measurments. It is a real time saver. I use a high presure flush system and ream at high speed in the headstock. I can cut a 308 chamber after set up in 10 minutes or less. The larger the case the faster cuting speed can be used.

Nat

 

[Ronin]

Nat

thanks for bearing with me, I understand perfectly now and see the benefits!

Could I ask if you use a roughing reamer and then a finish reamer or just chamber with the finisher?

 

[wnroscoe]

I've spoken with Rustystud (Nat) several times. He's very knowledgeable about the whole machining, gunsmithing thing and is very generous with this knowledge. He's one of the persons that has pointed me in the right direction in the area of rifle building. Nat is GTG.

 

[Rustystud]

I do all my chambers with finishing reamer.

Ronin:

Since I use a high pressure flush system and ream at high speed I chamber with a finishing reamer. My barrels and reamers never even get warm. I am running 15 gallons of Rustlic 255R through my barrel under 10-125 psi. I cut .100 back out .020 let it flush, cut anther .100 and repeat the process. I pull out about twice during the entire operation checking for chips in the neck shoulder area. When I get to the last .050 I cut and flush about ever .010. Since I use a MARS I cut my pressure down cutting the final .050 but I check for chips every .010. This method prevents any chip rings in your chamber. It takes very little chamber polishing, chamfer the mouth and your done. I just did a .308 in a Broughton barrel Sunday. I ran my lathe in both directions at 600 rpms for 5 minutes in both directions warming the berrings. I dialed in the barrel with with .001 indicators off a tight fitting PT&G bushing and range rod. I dialed in the barrel until the needle was staying constant on a single tick mark. My lathe is proper aligned and level. I still use a floating reamer holder. I cut the chamber and inserted the same bushed range rod and put an intrepid .0001 indicator on it and another on the chamber wall just inside the tendon face. Both indicators showed less than .0002 TIR. Yes, 2 tenths. It can't get much better than that with a manual lathe due to bearing runout.

Rustystud

 

[Rustystud]

William your chack is in the mail.

One advantage with the MARS it can prevent you from undercutting a chamber. Thus having to set back a barrel.

It also allows you to remove the Reamer and clean and inspect it without loosing your point of reference.

I cut chambers for 40 years without a MARS so it definately can be done.

I have not undercut any barresl since I started using the MARS.

My chambering time has been cut in half and maybe 90 percent in some cases.

Time is money when you do piece work to make a living.

Most of the advice that I give comes from the mistakes I have made in the past.

Rustystud