Build a roller

[mdeland]

Well things slowed down a bit so back to work on the roller. It doesn't look like I will have it done for this years caribou and moose hunt but will keep pecking away at it anyway as time allows.
Laid out and turned the eccentric on the mock up block to fit the new extractor tonight. It could be done with an old barrel root if I had one but the action came to me barreless. This will allow a closer fit anyway as I can swing it up to the breach face and scribe around making a very close fit in the barrel and I will have it to fit any more I come across in the future.
After getting the pin hole cut and snugly fit in the mock up block I turned a pin to the diameter of the extractor hole and cut a center in it. I then parted it off , dressed it up and used it to locate the center of the eccentric by gluing it in the correct position after laying it out on the mock block face.
I then used a wiggler in the tail stock drill chuck to center it in the lathe four jaw chuck. Now it was set up to turn the eccentric the depth of the extractor thickness.

Turning completed and the center disk removed.

Here are the blocks compared. I have to mill away the front section of the mock block for clearance against the barrel root so it can swing up and cam the extractor into correct position just as the action block does.

Here the two blocks are pinned together so you can see how it works. The top half of the mock block is gone so I can perfectly fit the ring ejector to the barrel face as it swings into correct position on it's eccentric seat.

I will have to locate top dead center and drill a stop pin to properly locate the extractor claw on the barrel face. It came out within .002 of the same height as the action block so was pleased with the accuracy. Mike D.

[mdeland]

Any one notice I have the extractor in bass ackwards in the last picture. I just noticed myself and had a good chuckle! Couldn't figure out why it looked so strange for a minute there.
Ah well, I'll get it the right way around in the gun. Mike D.

[mdeland]

Some may wonder why the ring extractor is set up on an eccentric rather than just rotating about the pin. The eccentric gives the extractor more mechanical advantage to lift a reluctant case from the chamber. No doubt this is military thinking which this particular Rolling block model was designed for. I can see no reason for it in a sporting gun and makes them a pain in the butt to fit as one must make a separate block to get a good fit other wise your doing it blind behind the regular breech block even with an old barrel root as a guide.
Close fitting extractors have always been one of the things I look for in a well fit up gun. Usually if they are well fit so will all the other parts of the gun be on a custom build. Mike D.

[mdeland]

Here are a couple of better shots of the two blocks pinned together with the extractor properly orientated.
Thinking on it a bit more while examining the extractor I can see the genius in the eccentric design in that it pulls the case head more to the rear before beginning its arc downward. Some one had their thinking cap on when coming up with this design.
The mock up block was fit snugly to this action but probably won't fit them all so it could be made less wide and a spring washer added to keep the extractor snug against the opposite receiver wall when fitting up.

Mike D.

[mdeland]

The original circular extractor is set up to act as a spring washer but I decided to make mine full thickness around the entire perimeter as it does not have to spring around a rimless case head while seating the the current 45-70 chambering. Mike D.

[Lumpy Grits]

THX Mike-I really do enjoy your builds and appreciate the time it takes for the pictures and write up.
Gary

[mdeland]

Thanks for the come back Gary. I hope to stimulate conversation and interest with pictures and discussion as this is just one way not "THE" way to do a job and it sure is helpful to me to pick up new ideas and methods from other folks doing the same kinds of stuff in their home machine shops. Differing thought and approaches makes this stuff fun to do as a good idea is like seeing a gold nugget in a stream bead and I keep finding them from all sorts of people.
Actually I think this is the first eccentric I have ever cut in over thirty years of working on guns if I remember correctly and it was interesting to do.
Steve Crawford sure hit on a good thread subject. I've heard a bunch of good ideas already. Mike

[Ken Heier]

You are a clever lad around machinery, Mike

Leonard Geiger (designer of the RB action) was a genius of gun design who is little known; the whole thing looks so deceivingly simple until one really gets into it. Rider at Remington helped refine it further.

Ken

[Steve crawford]

Mike

I have enjoyed watching your work. I will never have the skill to do any of the work you do. Thanks.
Steve

[mdeland]

I'm always fascinated at how these designs come together. Do folks just get an inspirational vision or is it an accumulation of mechanical ideas picked up along the way and adapted to suit a design need ? Probably both are at play to one degree or another.
One thing I have noticed over time is that I personally have never had an idea so good it could not be improved on.
I'm not at all sure that is the case with folks like Paul Mauser or John Browning! Mike D.

[mdeland]

Finished up the fitting block tonight so now it's back to working on the extractor. It needs the claw to be shaped yet from the extra steel I left on top and then the counter bore, rim seat cut in. After fitting to the barrel it will be hardened and have the temper drawn.
As often happens in gun work the part to make the part is harder to make than the part............................... er, ah, I thinks that's how it goes. I guess in this case to fit the part.

New extractor fits up pretty good so far. Hope I don't screw it up some where along the line.

Lot of material to be removed and as the new 45- 70 case head is much larger than the original, that was set up for 7 x 57 Mauser, the claw will be shorter in height.


The fitting block and new extractor in place for fitting into the barrel yet to be screwed in place. I may need to remove a bit more of the block top to get the full extractor profile scribed unto the barrel face before cutting it in.
Mike D.

[mdeland]

This is what the fitting block should look like when it is completed and functional. Works like a champ and will make all subsequent fitting both easier and more accurate than trying to just duplicate a factory extractor slot. You can see all the way around as the extractor is filed into the barrel slot and taking it slow with Swiss files ought to be able to get a good fit.
We'll see if my theory holds true as I'm not there yet but to this point it's looking good.

Preliminary lay out cuts. Now it's try and fit repeatedly until the extractor face is flush with the breech block face and bottom of the seating slot.

It's about half way seated at this point. Hard to to as it is both raising on the eccentric and rotating forward while matching up to multiple compound angles. Try and fit often is the only solution if one wants a close fit.

I leave the action wrench on as it has to come off repeatedly to get at the compound angles with the files.
Mike D.

[mdeland]

Finished up fitting the extractor last night and will harden it tonight if all goes well. Next is turning the barrel half round if I can pull the trigger on deciding how I want to do it. I'm between level half round, tapered half round or leaving it octagon and draw filing off about an 1/8 inch the full length. Man what a job that will be!
Not going to save much weight either way. The best weight reduction was cutting it off to 28 inches.

[Lumpy Grits]

Damn good thing I'm not closer to you-------
I'd be in your shop, and bug'n you for info all the time--------
I've learn'd much from you
Gary

[mdeland]

That would be fun Gary, Gabbing about gun stuff is just plain interesting! I keep getting the slap your forehead ( why didn't I think of that) moments as well! No end of the things for us yet to be learned!