Building accuracy - Nemesis receiver project


PDA






Semmerling
March 5, 2009, 08:07 AM
http://i623.photobucket.com/albums/tt319/1M_GHOST/sercorrect.jpg

http://i623.photobucket.com/albums/tt319/1M_GHOST/Mini_logo_side_w-acc0032.jpg

The concept behind much of the Windrunner series is to eliminate the variables that, while individually can be small, when taken collectively, make up the majority of accuracy issues on any hyper accurate platform. Add allot of components, mate them, mount them, adhere them, bed them and attach them and the chances for complications, instability and the inability to provide ultimate accuracy becomes greater. Remove as many of these variables as possible, rule them out by initial design and production execution, simplify as much as possible while providing robustness, stability and ease of use and one should be moving in the right direction. Windrunners represent one example of what the final product of such an effort would be. It is a different platform altogether, having what some refer to as “monochasis”, and appearing stark in comparison to a majority of the other offerings. Some are uncomfortable with what appears to be a move away from the traditional “receiver in a stock” look. This is a real and completely understandable reaction and some of us have seen this before, in the earliest work of Stoner and decades later, in the world of sniping, with the Walther WA2000. As the traditionalist quite properly point out, there are a host of sniper rifles whose performance is nothing short of astonishing, especially in comparison to just a decade ago. They are, of course, correct. When I remember that when the optics were specified for the WA2000 (300 Win Mag), the effective range anticipated was thought to have been a then remarkable 600 meters! How things have changed and are continuing to change! The Windrunners are a great place to look at some of the current advancements and the Model 06 is the smallest Windrunner platform yet to incorporate those changes.

http://i623.photobucket.com/albums/tt319/1M_GHOST/both_cals_logo_side_056.jpg


The Nemesis receiver is completely produced by the Ives, Ritchie team. This is an important point, with the exception of raw steel, there are few deliveries of OPP (Other People’s Product) coming through the back door. Nemesis controls every set-up, every run, every inspection, every line test, every approval or dismissal, every assembly, every range test, everything. This makes for a hand assembled rifle that is truly custom made. The receiver starts off as an 18 pound block of 8620 steel alloy from Castle Metal. They come in looking like rows of perfect silver bricks. No matter, every one is loaded into aVF3 Hass CNC and all the sides are machined to square, again. Now they truly are rows of perfect square bricks. With that, the work begins. Everything will eventually locate from the concentricity of the initial ” bolt hole. The first operation is to drill four sets of holes; the bolt hole, both side of the stock holes, and the hole that will support the bipod assembly. All other holes and operations will co-locate from this set up. There are seven major set-ups to be applied to the receiver block. That eighteen (18) pound block will eventually have fifteen (15) pounds of material removed, leaving a three (3) pound masterpiece.


http://i623.photobucket.com/albums/tt319/1M_GHOST/IMG_1874-Copy.jpg

The next operation takes care of the front of the receiver. Working where the barrel will eventually slip in (and be properly timed) and the barrel nut will thread, the inside of the receiver is cored out and the receiver’s barrel head threaded -12. Then there is a tapping operation for the bipod pin. The bipod is one of the few products Nemesis buys on the outside. Nemesis utilizes Versa-Pod’s top quality pan-tilt sniper pod, the model 50. The Versa-pod bipod will eventually slip on to a custom pin that will go into the hole milled out of the lower front of the receiver in this operation. Next, the rear of the receiver is shaped and the cut-out where the bolt handle will eventually rest. That operation can be seen below.

http://i623.photobucket.com/albums/tt319/1M_GHOST/IMG_1891.jpg

Next, the receiver is turned upside down and the underside is formed and milled out. Preparation for the mating surfaces of the lower housing are all finished. Holes are drilled and tapped for the lower receiver as well as the trigger retaining bracket. The lowers that you see in the finished photos are newly redesigned and is executed in 536 investment cast aluminum. Those cast lowers are then resurfaced in house, holes tapped and galleys for the stock rods are cut, as is the relief for the Jewel triggers safety. The lower provides guidance and the structural support for the AR-15 style magazine release. The Jewel trigger is firmly attached directly to the bottom of the
receiver. The lower also provides the trigger guard for the trigger operation.

http://i623.photobucket.com/albums/tt319/1M_GHOST/IMG_1883.jpg

The sides are then attended to. This would include the pressure relief holes, bolt release mechanism and the hole at the front of the receiver that will support the “time locking” barrel nut. As mentioned, one of the most important design considerations in the whole Windrunner line is the removable barrel. The barrel is held to the receiver with the precision lock-up provided by the barrel nut. The barrel nut will eventually thread on to the receivers 1.290” diameter barrel housing tapped for - 12 thread. The design of both the barrel and the receiver provides for positive, repeatable timing when the barrel is slipped into the receiver. A spring loaded barrel nut retention button allows for the user to simple screw the nut down hand tight and have the nut held perfectly off of the face of the receiver every time. There is a positive sounding click or, if needed, complete silence as the device can be drawn back. The result is no wearing (the barrel nut stops 1/8” off the face of the receiver), no wear marking and silence and, as noted, absolute repeatability. The last operation to be done is side engraving. All the engraving found on the Nemesis is done in house. For Government and Police purchases, custom “Property” engraving is available.

http://i623.photobucket.com/albums/tt319/1M_GHOST/IMG_1880.jpg


The top of the receiver has the holes drilled to attach the picatinney rail to the top of the receiver. And with that, the milling is all done, and the receivers are given to Kerry Ritchie (Bill’s son) to have the EDM wire cutting done. The initial ” bolt hole is finished out to full diameter and the receiver lug path is cut all the way to the back. Durability is insured as the lug path runs the full length of the bolt galley path. When the wire cut work is completed the receivers come back to be heat treated. The receivers are brought to 40 Rockwell and the oil quenched and frozen. Then comes a honing operation to bring the receiver with of one thousands tolerance. Then each receiver is sent to final inspection. If passed, the receivers are cleaned and oiled and sent to be treated with black oxide. Tough stuff this! As it is a chemical impregnation, there is no change in the overall dimensions of the finished receiver. As many are aware, most coating wear off, well this one doesn’t without cutting/shaving/wearing material off as well. One Nemesis receiver has been assembled and disassembled more than 6.500 times and the resulting oxide shows a small wear mark, a polishing, with the vast majority of the oxide holding strong.

http://i623.photobucket.com/albums/tt319/1M_GHOST/IMG_1901.jpg

That completes the Nemesis receiver. To protect the threads of the receiver a custom Delrin cap is lathed out in house to screw over the receiver’s front. A Delrin cap is also provided to thread over the barrel end, allowing the barrel nut to thread right on it. A typical touch is that the barrel Delrin is also a bore guide for a cleaning rod. There is nothing like being able to clean and chamber and barrel that you can take off the rifle and get to work, all the guide and it’s a breeze. When both caps are used, the receiver and barrel are kept clean. The caps can be seen in front of the rifle below.

http://i623.photobucket.com/albums/tt319/1M_GHOST/both_cals_logo_side_043.jpg

http://i623.photobucket.com/albums/tt319/1M_GHOST/both_cals_logo_side_035.jpg


The receiver is now complete. Everything except the scope and trigger (a superb Jewel with a unique drop down safety) that attaches to it is made by Nemesis. Next up, now Nemesis makes a custom bolt.

If you enjoyed reading about "Building accuracy - Nemesis receiver project" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
gvnwst
March 5, 2009, 10:42 AM
Very cool, nice write up! I would love one of the rifles, but they are a bit out of my price range.

If you enjoyed reading about "Building accuracy - Nemesis receiver project" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!