Adjustable Reamer Stop

Jud96

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Michigan
I wanted to start this thread to share with you all the adjustable reamer stop I made. This whole project began when I was considering my options for how to control the depth of my reamer on my lathe. My lathe doesn't have .001 graduations on the tailstock, and my tailstock is round so attaching an indicator or something similar to precisely measure depth wasn't simple. Then I saw a post about an adjustable reamer stop and I decided to make my own version that I thought would be simpler and work with a wide array of rifle chambering reamers and a variety of reamer holders. It kills two birds with one stone, gives me an accurate way to control reamer depth and is another layer of protection so I don't ream too deep!

I made this reamer stop so it will work with everything from 223 Remington up to 338 Lapua without needing separate length stop collars. The reamer shank passes through the body of the reamer stop and there's a 10-32 set screw to lock the stop to the reamer. The reamer shank then goes into your reamer holder so the stop has no influence on the reamer other than to act as a stop. The "lock nut" is engraved with .001 increments and each revolution is .025 with every .005 having a longer line. The body of the reamer stop is threaded most of the way and it has a flat milled on top with a reference line running the full length so you have a lot of adjustability for different length reamers. I also added a 10-32 brass set screw to the "stop collar" to prevent the collar from accidentally coming loose or possibly over tightening when it's pressed up against the barrel tenon. The threaded body is also counterbored to allow more rearward travel of longer reamers so the stop is able to be adjusted far enough out to still work with setting headspace.

I CNC machined every part so I can make many of these fast and repeatable if I decide to do that. This reamer stop is a simple 3 piece system that has been working well so far. I don't get to chamber on the clock at work, so I gave it to our chambering guy and he's used it to chamber about 10 barrels so far. It's nothing new, but I think it's a great tool for chambering and in my opinion a simplified yet still affective piece.

Pictures show the reamer stop in action, it happens to be upside down in the first photo because I wanted to show the brass set screw that prevents the stop collar from moving unexpectedly. The second photo is the reamer stop without a reamer but has a 0.437 pin gauge in it I was using for checking the through hole dimension. The third photo is showing the stop collar adjusted towards the end of its travel, the counterbore in the the body of the reamer stop, and the 0.4375 reamed through hole. The final picture is the adjustable reamer stop before it has been engraved and with it attached to a reamer. Let me know what you guys think and if you have any questions, opinions, or any input I'd appreciate it. Thanks!

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I've gotten some interest in these and I'm planning to make a run of them. I'm thinking I'll start out around $125 for the reamer stop. The other popular adjustable reamer stop available is $225, but it's more pieces than mine. Thoughts?
 
I've gotten some interest in these and I'm planning to make a run of them. I'm thinking I'll start out around $125 for the reamer stop. The other popular adjustable reamer stop available is $225, but it's more pieces than mine. Thoughts?

I have the one with many pieces as you mentioned. Your price is very reasonable. If I were looking for one, I would definitely get yours for the limited cartridges I do. Maybe offer quantity discount, so users for a cartridge can set one and forget.

Other cartridges I do, I just run the reamer slightly deeper and adjust shoulder and tenon face for final HS and clearance, but for the 223 that I do for the TX JRs, which I do at least ten in a batch, the reamer stop is invaluable.

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Good luck on your venture on this great tool for chambering.
 
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I have the P.O. Ackley style stop sold by PTG ($175)- I like the design in that the reamer is held independently in a holder, and the breech stop acts as a lock nut with the micrometer section. No need to mess with an allen key to tighten/loosen a locking screw for each adjustment.

https://pacifictoolandgauge.com/4483-thickbox_default/p-o-ackley-micrometer-reamer-stop.jpg

When time permits, I'm going to try to re-design the stop collar somehow to facilitate the flow of cutting oil from the flush system through it- as is, when I get close to depth I need to turn it off when reaming then stop the lathe, back it out, turn the pump back on to flush the chips, then stop it again for the next pass.
 
I have the P.O. Ackley style stop sold by PTG ($175)- I like the design in that the reamer is held independently in a holder, and the breech stop acts as a lock nut with the micrometer section. No need to mess with an allen key to tighten/loosen a locking screw for each adjustment.

https://pacifictoolandgauge.com/4483-thickbox_default/p-o-ackley-micrometer-reamer-stop.jpg

When time permits, I'm going to try to re-design the stop collar somehow to facilitate the flow of cutting oil from the flush system through it- as is, when I get close to depth I need to turn it off when reaming then stop the lathe, back it out, turn the pump back on to flush the chips, then stop it again for the next pass.
The advantage of my design is the reamer shank is held directly by the reamer holder, and not a separate holder that then goes into the reamer holder. There's no possibility of tolerance stacking with the reamer being held by a separate piece vs being held directly by the reamer holder.

Also, the set screw is only there to prevent the stop collar and adjustment ring from moving unexpectedly or tightening up when the stop collar makes contact with the barrel. With my reamer stop adjusted and set screw locked down, we're able to cut consecutive barrels back to back and maintain headspace within .0005 without ever adjusting anything the entire chambering process. We chambered x10 barrels all for our actions and chambered for 223 Wylde the other day and the reamer stop was never adjusted after the first barrel and all barrels headspaced within .0005 of one another.
 
With my reamer stop adjusted and set screw locked down, we're able to cut consecutive barrels back to back and maintain headspace within .0005 without ever adjusting anything the entire chambering process. We chambered x10 barrels all for our actions and chambered for 223 Wylde the other day and the reamer stop was never adjusted after the first barrel and all barrels headspaced within .0005 of one another.
Understood. I can see that advantage when you're barreling multiple precision machined custom actions where the boltface to receiver ring dimension is not a variable. For most of us, that type of repeatability isn't applicable. Should sell a ton of them at that price point...
 
I like that shooters/reloaders/GS are always looking for a way to build a better "Mouse Trap" to speak of.
I have been asked several times from shooters that want to start getting into chambering their own barrels and possibly start a small GS Shop.

"What equipment/tooling/ machinery do we use. I always start out telling them that the Machinery is "X "amount of $$, but the Tooling "Y" amount is probably more $$$. We have a modest GS Grizzly G0824 with DRO. This machine has a 2" Bore and already comes with a built in Outboard Spider, has a Steady Rest and a Tail Stock has a Hub to use a Torque Wrench. Besides all the tooling we also use a Viper Chamber Fixture and a Manson Floating Reamer Holder with a Micro Adjustable Reamer Stop Kit - (MARS Kit). This Kit can also be used with PT&G Throating Tools.
We are also mentoring "Young Ambitious Tomorrows SHOOTERS".
There are several processes to chamber a barrel with using an Outboard Spider, Viper Chambering tool, Steady Rest. It all comes down to a concentric chamber.
I like the way Jud96 is trying to make something that works better and less expensive.
 
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