Pictures of Jerry Keefer's mill fixture for building scope bases on the action

B

Boyd Allen

Active member
He asked me to post these. I had mentioned in a previous thread that some smiths build bases directly on an action. He Does, and I only have one question...how much?Comment?
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Decent set-up.
Wrong sine plate for mill work--and it's hard to see much detail as to precision of the set up.
If everything is indicated in properly should be good to go.

Rich
 
I guess I have to question using the outside of the action as a reference point in relation to the inside. I may not be seeing something here but wouldn't a mandrel in the action be a better starting point. That is after all what positions the barrel.

5C collet spinneror divideing head with matching center, a cutter or two with the correct angles and your off and running.

Jerry's way will get the bases in alignment with each other but not with the barrel. I think you can do both.

Just thinking out loud but it would be a fairly simple fixture to make that had v-blocks mounted on each end of a plate. Clamp that in a vise, lay the mandrel in the v-blocks, level,clamp the mandrel down and go to work. That would take care of two problems at the same time. Put feeler gages under one side of the plate and you have a angled base.

Dave
 
Jig

IF I said IF the bore of the barrel is running true with the outside of the barrel and he indicates the barrel in, he doesn't have a problem as far as centering the bases with the bore (windage)---as long as everything is indicated in properly.
I noticed the holding across the loading/ejection port too--my concern was will the holes drilled and taped for the bases, be perpendicular to the bore holding it this way---then I thought well, it really doesn't matter if they are off a little because the bases are machined in place--if the holes are off alittle it won't matter the only thing that matters is the position of the bases themselves and since they are cut in place--it'll work.
Like I said, I can't see everything---but I think he is fine as long as everything is indicated in.
I agree Dave, a couple of dovetail cutters would be alittle easier but his way will give him a dead nuts angle too.
If he is just clamping the barreled action in place and clamping across the port and having at it, I don't have confidence that the set up is that precise and that the bases will be running with the bore.

Rich
 
Fixture

Rich;

I milled the V-block out of a large block of aluminum. If I recall, the raw block was about $100. from MSC. There is of course recoil lug clearance milled into it and the action screws secure the action from the bottom. It has bolt patterns for Win. Rem. Savage rifle and Savage 10 Muzzleloaders. The top plates are just some added insurance.
The sine vise is a large Suburban making the set up quite accurate, rigid, and quick to set up.. The cutting forces are minimal on the aluminum blocks, and vibration is non existant. This is really the easy part of it all. Calculating and milling the action radius to each block is more time consuming.

Take Care

Jerry
 
If he took a clean up cut on the outside of the action I would feel better. I'm probably slitting split hairs here but I would be concerned about tolerances stacking up with all the different setups. The block gets moved two times and the sine plate gets moved once.

A 1" 90 degree double angle cutter would make short work out of cutting weaver style bases. No sine bar needed. A 60 degree dovetail cutter for the 1/2" dovetails. Kelbly style

Appears to be factory barrel. Doing it my way would require pricing in barrel removal.

Then something else to think about, how many different ways are there to cut the radius on the bottom of the bases to fit different actions?


Dave
 
jigs

Hi Jerry,
I could not tell if you were using the action screws or not but if you are you are certainly good to go!!
As long as your indicated in properly, your there.
I have a suggestion---looks like you have a decent shop---you could cut your stock in lengths and bore the correct diameter(for specific actions) in your stock in the lathe ---split it---you have a surface grinder and probably a cut off wheel for it--and you can make multiple base blanks at once--you may have thought of this already but it could save you some time cutting the radius on the mill.
Either way, good job.

Rich
 
From My Point of View........................................

Your pulling a cylindrical piece of steel (that isn't round or consistant in diameter) into a "V" block (your stressing the action).

The only for for this set-up to work would require the action to either have the O.D. trued either by turning or grinding while on an arbor through a trued bolt bore.

While the barrel O.D. may be straight the bore doesn't run concentric to the O.D.

I'd agree with the included angle cutters. #1) Every time you re-position the set-up your building in error which has to be compensated for. #2) this set-up isn't condusive to cutting bases with built in taper ( 10MOA, 15MOA, 20MOA...........)
 
I disagree, I don't think he's stressing anything---he using the action screws and the plate across the port for extra clamping---he would have to REALLY crank that plate down to induce any stress.
There is a couple of good ways to check the bore in his set up and get it pretty much dead nuts--see if you can think of it.
He may not be offering tapered bases--just regular old everyday bases.

I make multiple parts all the time-- many ground to .0002 tenths tolerance--figure out a good repeatable set up, work clean,no burrs etc. and repeatability is not a problem.
Is there a better set up for ease of machining ---I think so---but what Jerry is doing will work fine--it's all in the indicator!!
Rich
 
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AJ300MAG said:
Your pulling a cylindrical piece of steel (that isn't round or consistant in diameter) into a "V" block (your stressing the action).

The only for for this set-up to work would require the action to either have the O.D. trued either by turning or grinding while on an arbor through a trued bolt bore.

While the barrel O.D. may be straight the bore doesn't run concentric to the O.D.

I'd agree with the included angle cutters. #1) Every time you re-position the set-up your building in error which has to be compensated for. #2) this set-up isn't condusive to cutting bases with built in taper ( 10MOA, 15MOA, 20

Yes Sir; Everything you say is exactly correct for long range ultra precision rifle. I am a pistolsmith who enjoys reading and studying the machining practices of rifle smiths. Some of the techiques riflesmiths use are very applicable to precision pistol smithing. Some of my customers(who hunt) from time to time request scope mountings, and when mis-aligned holes and out of square actions were encountered, I came up with this fixture to machine blank blocks right on the receiver. It does correct factory mass production errors to the degree that it greatly compliments a 150/200 yard deer rifle, but it would be completely inadequate and poor workmanship for your type of work..I didn't have an adequate cutter at the time the pictures were taken, hence the set up, you are right though, it works better and faster with the cutter...

Thanks for looking..

Jerry
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He's violating one of the basic principals of machining.

Kinda like a 4 legged stool with one leg too short. He's pulling the action down into the "V", either distorting the action, the "V" block or both. Kinda building in the inaccuracy your trying to eliminate. Only way to resolve that issue would be to to shim the action. Remember .001" error at the action can result in a 1" error at 100 yards.

Results will be as inconsistant at best.
 
You have got to be kidding!!
I use V-blocks everyday ---I use them to hold parts in the lathe sometimes--the workpiece is mounted in the V-block and the v-block is clamped to a faceplate--one example.
I use them on the mill, I use them for precision grinding on the surface grinder----.0002 tenths tolerance.
I use them in the Ram EDM and Wire EDM.
I use them on the CNC grinder--all precision work!!
I use them in the machining center for certain setups.

Honestly, if you made that statement in any shop I EVER worked in they would laugh you out the door.
I don't know what kind of machining you do but if you don't use v-blocks your pretty darn limited.

Respectfully,

Rich
 
Rich............................................

Your using "V" blocks on surfaces that have been previously machined. BIG difference between that and holding on to an object with unsymmetrical cut outs and then being ran through a heat-treat process. To call an action warped is an understatement.

I've been involved in machining for darn near 30 years, have been down the "splitting tenths " road a time or two (O.D., I.D., surface & jig grinding along with thread grinding. Not even counting the time spent making EDM electrodes and laps that were held within 10ths..........) BTDT.
 
Jerry

Not dissin your work, looks like your doin a heck of a good job. Sad thing is that in this day and age quality has taken a back seat to the profit margin.

There's more than one way to skin a cat..............................................

Neither is wrong as long as you end up with a nakid cat :)
 
Rich

With all due respect your missing the point. Setting a piece up in V-blocks and working on the outside is one thing but when your original reference point is internal. How can a V-Block clamped in a vise that doesn't have a swiviel base, with a sometimes crude piece of round stock clamped in it be called precision. Yes Jerry can do exacting what he says he can but from the perspective of BR shooting it won't pass muster and if it was explained that way in any good machine shop, it wouldn't pass muster there either. We do everything using the bore of the action as a reference point. That is the criteria that is used by all accuracy smiths. There are machinists and there are Riflesmiths. One removes metal and the other knows where and why to remove metal to make an accurate rifle.

Jerry

I'm not picking on you it just about perspective. Yours is different than ours. If I was doing nothing but factory deer rifles I would probably do it your way only without the sine bar. As a matter of fact I probably have at one time or another. I make a lot of custom bases around here so I feel your pain.

Dave
 
set ups

And I said there are a couple of ways for him to check that bore with the set up he has and get it dead nuts if he wants to---an indicator is a wonderful thing and I'll bet good money, what he is doing is far better than most factory bases that are installed and it sounds like he is not looking at the BR community for his work.

No matter what any one thinks, outside of building a fine custom action, rifle work is VERY basic machining---no smoke and mirrors.

I served my apprenticeship in a tool room that was considered one of the best in the PM industry--again all close tolerance work.
When I started, over 30 years ago, I was trained by some very skilled talented men who could do more with a bridgeport and a bastard file than most people would believe.
There is most always a set up or a way to skin the cat--you just have to do it enough to start thinking in that vane.
Are there better, easier, faster ways to do what Jerry is doing---like I said before YEP!! BUT he can do a darn good job with what he's got.
I understand your point Dave about working off the bore and I agree that's what should be done and if you thought about it for awhile you may see how Jerry can do that with his set-up.

Again, maybe not the best set up but certainly can be accurate and I'm sure plenty good for a hunting rifle.
 
Two things.............................................................

Take the barrel off an action, make up a tapered arbor with .0005" press fit that fits the bolt bore. Grind the action between centers, hold your taper end to end within a couple of tenths. Let me know how much steel you had to grind off until you had clean-up.

Heck this is easier for ya............................
Mount a barreled action into Jerrys "V" block. Place the set-up in a vise leaving the front action screw accessible. Place a dial indicator on the top of the barrel and on the side of the barrel at the muzzle. Loosen the front action screw, get back to me with the amount of movement on the indicator dial.

I served an apprenticeship as a machine builder. Not only did I make parts and pieces I had to put them togeather and build a machine that actually worked. I worked with "the best of the best", difference being I actually learned something from them.
 
Jerry

As a toolmaker by trade I always believe, that taking a reference point directly from the main crucial area (in this case the inner of the action) and do all the cuts on one setup will minimise the room for an error.
However, it doesn't necessary mean that an equal precision work can't be achieved by doing it otherwise, where it can't be mechanically done on one setup alone.

Jerry you must be a brave man to post your pics and ideas here. Next time you wanna post some picks and ideas, smear yourself naked body with a honey and sit on the top of ants nest. The result will be the same, as they all will come at you, just to have a bite of you.

Shoot better
Peter
 
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PPP MMM said:
Jerry you must be a brave man to post your pics and ideas here. Next time you wanna post some picks and ideas, smear yourself naked body with a honey and sit on the top of ants nest. The result will be the same, as they all will come at you, just to have a bite of you.

Shoot better
Peter
Click to expand...

I've learned my lesson.
 
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