(Most have probably already seen much of this, but anyway...) In regards to my earlier post:
-With beer in hand...(not really)
Remington M7, 700SA, and M700LA fixture in use:
Winchester M70 fixture I just completed.
View attachment 7035255
The purpose for all this:
Watch an action being tuned up using the conventional practice once. These are just random videos that populated You Tube when I did a search. I chose them simply because they do a good job of demonstrating the process.
Cats head fixture dialed to the spindle and then go to work.
Here's ol Larry P. hard at it with some hand tools.
Ok, so most of us have been exposed to these two processes at some point. I have never cared for either all that much. There are a few things that work against you with both. 15 or so years ago I began playing around with this stuff on a vertical machining center. Over a weekend I bulldozed my way into a process that showed some promise.
We brought this to light in the spring of 2013 when LRI introduced the Group Buy here on The Hide. Thousands of actions have been tuned up since that time. That process used a vertical machining center fitted with a manual trunion table. Basically a sort of "ghetto 3+2" capability. It worked well and at the time nothing else came even close to the flexibility it offered. The Achilles heal became time/skill set. Setting the job up was faster than a lathe by over 3/4 of an hour. However the skill sets needed demanded that a guy be isolated from everyone else and not pressured. Demand for this stuff just drove us to solve it with a true 5 axis machine. The added advantage that I like is we are no longer tethered to setup tooling such as bushings and mandrels. Its a basic concept in machining to locate a part using qualified features on the actual part. Stacking things up to get a reading only promotes mistakes. (again, why a guy has to be left alone and contained in his own little "bubble" when doing this kind of work)
I'm pretty proud and excited about all of this. The intent from day one was to offer this stuff better and faster than anyone else. We now have that locked in pretty solid at the level we play at. All this work ultimately benefits the shooting community because now the work can be done much more affordably and with much more predictable results.
An example:
Over 40 actions were run here recently for one client. 10 of those were designated as 308 Winchesters. Random pieces were picked and those actions were lapped in. It never took more than 10 strokes of the bolt handle to show full lug contact. The threading program is designed so that pitch diameters can be chased .001" at a time for final barrel/receiver fit. That program required no editing for the run of 10. Last, all 10 of the actions headspaced within .001" of each other when completed. That part of the program was not altered as well.
.001" may sound like a lot but its really not. Not when you look at the whole package. There are 4 basic parts that influence this.
- Barrel chamber
- Recoil lug
- Receiver ring
- The bolt.
There's any number of ways to dissect this. One very easy way is to simply divide the tolerance over the number of parts. Done that way it means the 4 parts were held to within .00025" of print. There's any number of flaws in looking at it that way, but the end result is still the same; stuff is running very, very well.
Thanks again.
C.