High Pressure Flush System/High Speed Chambering Class

[Rustystud]

If all goes as planned, I will be teaching a 5 Day NRA Gunsithing class on Building and using a High Pressure Flush system for chambering rifle barrels at Trinidad State Junior College the week of June 7-11, 2010. If you might be interested please contact [email protected] or call 719 846-5541.

Nat Lambeth

 

[NesikaChad]

Hi Nat,

Here's a few pics of the one I build for Nesika. 600lbs of oil pressure is a beautiful thing. Just be sure to keep the fingers out of the way!

Good luck on your class.

Chad

 

[Rustystud]

Chad:

I am running Rustlic 255R cut 5:1. I can not run those kinds of presures in an open lathe. I am running from 35-125 psi. But it works very well.

I use the same Duff Norton Rotary Coupler that you have in your picture.

Nat

 

[NesikaChad]

That's a Dumore coupler. Carbide seals, 1800rpm capacity, and 2500lbs pressure rating. About $800 bucks.

The rub is the carbide seals. You MUST have clean fluid going through otherwise they'll erode quickly. I made those filter enclosures from scratch after a System One oil filter exploded on me (Christmas day, 2004 as I was chambering my Palma rifle)

In addition to those two filters there's a 3rd one that's not shown. A big, tall sock filter that is part of the pump. It gets the big stuff and these strained the itty bitties.


All the best,

Chad

 

[trueblue]

Impresive !

 

[squirrelduster]

I'm just learning but it looks like you push the fluid in the muzzle and out past the reamer. Where does the fluid go after it exits the chamber end?

 

[bigngreen]

A John Deere combine uses a hydraulic coupler like that on combines for a couple hundred dollars. They run at 1200rpm up to 3000psi with hydraulic oil. Thy last 1000's of hours.

 

[Rustystud]

Look up Duff Norton Rotary Couplers. Stainless Steel, grease fitting capible, bearings, and attaches straight or at 90 degrees. Comes in many sizes, pressure, RPM and temperature ratings. I think I paid about $180.00 for mine. You can find them on e-bay sometimes for $30.00 or less. Substantially heavier than nylon or plastic models I have seen.

Nat Lambeth

 

[NesikaChad]

I'm just learning but it looks like you push the fluid in the muzzle and out past the reamer. Where does the fluid go after it exits the chamber end?

That's exactly how it works. A variation that I also experimented with was in addition to the through barrel method, I had gun drilled reamers with delivery holes poked down into the chip gullets of the reamer. This is by far the best way I think as it ensures you have a way to positively evacuate the chips. Getting oil around the tight fitting pilot bushing can sometimes be tough with a HSS reamer. Carbide tools tend to use bushings with heavier wall thicknesses and can be fluted to allow for fluid transfer. I personally don't care for the carbide reamers. They are very, very unforgiving and it's another huge investment to buy an inventory of pilot sizes because they are not interchangeable with the HSS tools. (Cost me about a thousand bucks to buy all the HSS pilots from 17 up to 338 caliber in .0002" increments)

A set up like this requires a sump. Gravity has the oil make its way back to the sump where it's recovered and recirculated through the pump.

 

[J E Custom]

Chad:

I am running Rustlic 255R cut 5:1. I can not run those kinds of presures in an open lathe. I am running from 35-125 psi. But it works very well.

I use the same Duff Norton Rotary Coupler that you have in your picture.

Nat

I am in the process of building a low pressure system for the same reason (Open lathe)
and I bought the coupler and barrel attachment from Dave @ Pacific Tool and Gauge.

I am in the process of building the sump and drain pan and will let others know how well
it works when finished.

I realize it will not clear the shavings like the high pressure systems but hopefully it will
improve the process and reamer life.

J E CUSTOM

 

[Rustystud]

My system will clear 98% of all chips/shavings with simple flush. I runb a constant 35psi and back out .100 and flush with higher presure. I check for chip weld during the overall process. The coolant density is about that of whole milk. It has both cooling and lubricity. It is an extreme presure coolant. High clorine content you will be clean after using it. It flows around and under the pilot.

Nat

 

[adam]

Hey! I love it when work overlaps my hobby!
I have had some experience with the deep drilling and Machine tool customers at work. Feel free to PM me if you have questions, I'll try to share some practical experience that will save some money and improve results.

I have had some success selling these Magnetic filters to prolong the life of the high pressure filters, And remove some of the finer metallic particles without removing the lubricating properties of the oils.

Magnom Case Study: Gun Drilling Machine -


When filtering the cutting fluids used in this process, keep your micron rating above ~10um to prevent filtering out the larger sulfur and fatty acids commonly found in these oils. I would also recommend a series filtering arrangement with progressive filtration to minimize the annual cost of the consumables. There are a number of commercial products available which will duplicate the (impressive) arrangement that Chad machined for his filters.

The big machine tool guys will also try to maintain their oil temp to within a few degree's of ambient temp to control expansion and tolerance consistency. They do it with expensive chillers, however there are some commercial products that will do a good enough job for smaller operations.