Is this jig accurate or can you do as good as a gunsmith with it?

quote:

Originally posted by Wildlife Artist:
Is this jig accurate or can you do as good as a gunsmith with it?

Probably?

quote:

Originally posted by Wildlife Artist:
can you do as good as a gunsmith with it?

You should be able to do as good a job as a gunsmith who uses one himself, provided you have a similar level of experience in setting it up as he does. But if you are wanting to compare the results between the use of the fixture and an experienced gunsmith who uses a milling machine to do the job, I'm thinking the experienced gunsmith and the milling machine will win.

quote:

experienced gunsmith who uses a milling machine to do the job, I'm thinking the experienced gunsmith and the milling machine will win.

Every time.

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Originally posted by D Humbarger:

quote:

experienced gunsmith who uses a milling machine to do the job, I'm thinking the experienced gunsmith and the milling machine will win.

Every time.

Exactly,

I assume you are asking about B Square's $100 drill and tap jig and not their cross bolt drilling jig.




I have the Wheeler Engineering $50 imitation drill and tap fixture. I have done ~75 Mausers with it, one Arisaka, and I can't remember what else.

A) To drill and tap a receiver for scope mounts with the vertical mill, it take me the better part of an hour, while thinking, and doing arithmetic. There is a big risk I will make a mistake.

B) To drill and tap a receiver for scope mounts with the fixture and a drill press, it takes me 10 minutes, and no thinking required. There is little risk I can make a mistake.

Fixture accuracy:

Often I am at the range helping guys who have sight problems. A common problem is that the gunsmith they trusted drilled off center 0.2".

The Wheeler fixture usually makes the holes line up well enough that the scope can be sighted in [better than some WA state gunsmiths], but does not guarantee that the scope in the middle of it's range will be on the paper. The final accuracy of scope mounts is added when I fixture [not the drill and tap fixture, but a scope with rings in the same plane] the mounts and glass bed them to the receiver. Then the scope in the middle of it's range will be on the paper. And the mounts will be in the same plane so no one should be tempted to wreck the Weaver rings with lapping.

I made one using the B square's as a pattern when I was in gunsmithing School. Been using it ever since for the last 14 years, works just fine with a drill press or milling machine.

One of the beautiful things about using a milling machine for drilling and tapping receivers, besides the precision with which you can place the holes, is being in a better position to act if and when a drill bit or tap breaks. It makes it a whole lot nicer when your machine is already dialed in on the hole.

Hmmmm interesting replys.

There is a local gunsmith but he is so backed up it will take a while to get it done.

I have three rifles that I need to drill and tap.

I was hoping to do as much of the work on these rifles as I can just for the satisfaction of it. I have a drill press. I'm not trying to be cheap with them just learn with out making a mess. These actions are really nice.I can imagine the feeling that you would get looking at a rifle that you put together yourself.

I have found some really nice bolt handles with a pear shape but I need to drill and tap and put the scope on them so I can get the angle correct which is another issue.

tnekkcc:

"Fixture accuracy:

Often I am at the range helping guys who have sight problems. A common problem is that the gunsmith they trusted drilled off center 0.2"."

That is a helleuva lot of error. That is more than 3/16" but less than 1/4". Maybe you got the decimal point in the wrong place?

If there is a "gunschmidt" out there that is that far off we need to put out a contract on him.

quote:

Originally posted by mad_jack02:
I made one using the B square's as a pattern when I was in gunsmithing School. Been using it ever since for the last 14 years, works just fine with a drill press or milling machine.

There are those that have advanced in the last 14 yrs and there are those who have learned nothing new.

quote:

Originally posted by Wildlife Artist:
I have three rifles that I need to drill and tap.

I was hoping to do as much of the work on these rifles as I can just for the satisfaction of it. I have a drill press. I'm not trying to be cheap with them just learn with out making a mess. These actions are really nice.I can imagine the feeling that you would get looking at a rifle that you put together yourself.

You have 3 really nice actions that you need to drill and tap for scopes. You want to do these yourself and that's great, however, you need to know that drilling and tapping an action can, without warning, turn to shit real fast so you need to be prepared for when it happens.

Wear safety goggles and use "carbon" taps for the job because they are probably the easiest to break into pieces with a hammer and a punch when you break the tap off in the hole. Pull the barrel off the action and drill the front hole all the way through before tapping it. If you don't have any experience tapping a blind hole, now would not be the time to learn.

Drill a hole and tap it before moving on to the next one. Don't go and drill them all first and then come back and tap them. That would be a quick way to lose your zero which could bind the tap, causing it to break.

I would recommend practicing drilling and tapping into a scrap 3/8 inch thick piece of steel, using the same size taps you will be using on the actions, so you can develope a feel for the cutting action of the tap. Buy plenty of taps and use a good sulfer based tap lube. Good luck!

I have in my shop an action that someone tried to D&T themselves. They drilled two sets of holes. The frist was off to the left of center by a good amount. It was also, unbeknownst to the driller, right smack on the face of the lug seat. His second set was properly placed (fore & aft anyway) but he drilled to within .100" of perforating the chamber. So, now, his DIY project is junk! Action ruined, barrel ruined. the best part was when i removed the action from the stock, the barrel unscrewed. A novel takedown methid relying of poor inletting to keep the barrel from unloosening.

Hello,
Most drill press's run to fast for metal and are next to impossible to get square with the table. A milling machine is 10 times more rigid than a drill press. If a gunsmith misses a hole by .200 he missed counted a turn. A digital read out is the only way to work nowadays.

quote:

Originally posted by J_Zola:
Hello,
Most drill press's run to fast for metal and are next to impossible to get square with the table. A milling machine is 10 times more rigid than a drill press. If a gunsmith misses a hole by .200 he missed counted a turn. A digital read out is the only way to work nowadays.

The drill bushing and tap bushing get the alignment so well, that the drill press does just fine. The drill bushing touches or nearly touches the receiver.
On the mill, the #31 drill sticking out of a chuck 1.5" for a 6-48 tap is so compliant that a short fat starter drill is needed.

What does that mean?
A drill press, drill jig, and a #31 drill is stiffer than a mill, a mill vise, and a #31 drill.

The drill press can be slowed down by moving the belt on the shims, but for a #31 drill, ~1500 rpm is about right for 4140 tool steel.

I spray [with a plastic plant spray bottle] a 15:1 water:Cool-Mist coolant on the drill as I go. This makes the drills last a long time.


A big jug like this diluted 15:1 will last a long time, , unless you decant and sell it in little bottles to muzzle loaders


Don't have Simple Green Degreaser in a spray bottle unlabeled near an unlabeled spray bottle of diluted cool mist, or rust under the mill vise can result


I put Tap Magic on the tap.
The drill and tap jig with tap bushing on the drill press is much nicer for keeping the tap aligned than some limited range spring loaded tool in the mill pushing down on the center of the tap holder.

Another nice thing about those jigs is that they keep the action welders in work!

Seriously, we learn to use the tools we have (been tellin' my wife that for almost 30 years).

If you're careful a lot can be done with simple tools, but for this job I'd rather use my Bridgeport and DRO.

quote:

Originally posted by Toomany Tools:
Another nice thing about those jigs is that they keep the action welders in work!

Seriously, we learn to use the tools we have (been tellin' my wife that for almost 30 years).

If you're careful a lot can be done with simple tools, but for this job I'd rather use my Bridgeport and DRO.

Yeah, I used to make a good deal of money fixing the buggered holes people made using those jigs. Either enlarging them to 8x40 or welding and re-drilling.

They are a real gunsmith's best friend, lol.

Thanks to all that have replyed.
Some of have got me gunshy about doing it myself and some have encouraged me.

Obviously you pays your quarter and takes your chances. Setup either way will make or break your success. Question I have, since they weren't mentioned is what is the opinion of those experienced with them of the Foster Jig sets?

The Forster jig can be as bad or worse. If you are drilling the receiver you are relying on the fact that the barrel is screwed in straight. How many Rem 700's do you hear about people paying to have the receiver threads recut becuase they are crooked? A lot!

But hell, they cost $300 you can pay a smith to D&T a lot of receiver for that kind of money.

You know, the Forster Jig can also be a wake up tool...If the rear hole is obviously going to be off center, time to stop and see what's up..

The trick to using these jigs is to know if the action in question is true enough. If the reference surfaces are where they should be, then they do a fine job of locating the holes, guiding the drills and guiding the taps.

quote:

Originally posted by JohnD:
The trick to using these jigs is to know if the action in question is true enough. If the reference surfaces are where they should be, then they do a fine job of locating the holes, guiding the drills and guiding the taps.

And the average hack is equipped to know this, how?

quote:

Originally posted by Westpac:

quote:

Originally posted by Wildlife Artist:
I have three rifles that I need to drill and tap.

I was hoping to do as much of the work on these rifles as I can just for the satisfaction of it. I have a drill press. I'm not trying to be cheap with them just learn with out making a mess. These actions are really nice.I can imagine the feeling that you would get looking at a rifle that you put together yourself.

You have 3 really nice actions that you need to drill and tap for scopes. You want to do these yourself and that's great, however, you need to know that drilling and tapping an action can, without warning, turn to shit real fast so you need to be prepared for when it happens.

Wear safety goggles and use "carbon" taps for the job because they are probably the easiest to break into pieces with a hammer and a punch when you break the tap off in the hole. Pull the barrel off the action and drill the front hole all the way through before tapping it. If you don't have any experience tapping a blind hole, now would not be the time to learn.

Drill a hole and tap it before moving on to the next one. Don't go and drill them all first and then come back and tap them. That would be a quick way to lose your zero which could bind the tap, causing it to break.

I would recommend practicing drilling and tapping into a scrap 3/8 inch thick piece of steel, using the same size taps you will be using on the actions, so you can develope a feel for the cutting action of the tap. Buy plenty of taps and use a good sulfer based tap lube. Good luck!

great post, malm.. thanks for explaining this out and being very helpful!!!

quote:

And the average hack is equipped to know this, how?

That's my point. If you don't know that, it's a crap shoot. And if you can't figure out that much, a milling machine won't help, because you need to do the same cogitating to get the milling machine set up for the job.

I am suspicious that there are gunsmiths that posted on the thread that finds center by indicating on the outside of the Mauser receiver or a vise fixture that positions from the outside of the receiver, and yet these same guys are tying to look down on someone who uses a drill and tap fixture that indicates center off a bolt bore mandrel.

Just a suspicion

So what the hell is that supposed to mean? What is correct and what is wrong. If the bolt bore is off, so are the threads and the barrel. If the two are not concentric or parallel then what one do you use?

Don't you want the mounts parallel to the barrel anyway .. and not the receiver

quote:

Originally posted by rem721:
The Forster jig can be as bad or worse. If you are drilling the receiver you are relying on the fact that the barrel is screwed in straight. How many Rem 700's do you hear about people paying to have the receiver threads recut becuase they are crooked? A lot!

But hell, they cost $300 you can pay a smith to D&T a lot of receiver for that kind of money.

quote:

Originally posted by tnekkcc:
I am suspicious that there are gunsmiths that posted on the thread that finds center by indicating on the outside of the Mauser receiver or a vise fixture that positions from the outside of the receiver, and yet these same guys are tying to look down on someone who uses a drill and tap fixture that indicates center off a bolt bore mandrel.

Just a suspicion

Who are you referring to? I re-read this thread and I didn't see one post by anyone saying they find center indicating off the outside of the Mauser receiver. I'm suspicious of folks who read what isn't written.

quote:

Originally posted by Jim Kobe:
So what the hell is that supposed to mean? What is correct and what is wrong. If the bolt bore is off, so are the threads and the barrel. If the two are not concentric or parallel then what one do you use?

The bolt bore is the starting point for other reference.
The threads, receiver face, and inner stop ring are trued with respect to the bolt bore.
The barrel is then mounted with those three things tracing back to the bolt bore.
The bore of the barrel should be centered with respect to the barrel threads and shoulders, which makes it true to the bolt bore.
The scope mounts should then be in a position that can be referenced back to the bolt bore of the receiver.

quote:

Originally posted by Westpac:

quote:

Originally posted by tnekkcc:
I am suspicious that there are gunsmiths that posted on the thread that finds center by indicating on the outside of the Mauser receiver or a vise fixture that positions from the outside of the receiver, and yet these same guys are tying to look down on someone who uses a drill and tap fixture that indicates center off a bolt bore mandrel.

Just a suspicion

Who are you referring to? I re-read this thread and I didn't see one post by anyone saying they find center indicating off the outside of the Mauser receiver. I'm suspicious of folks who read what isn't written.

Wespak,
The were many postings about drilling and tapping on the mill, and few pictures or detailed instructions.
I can only be suspicious of the techniques used by these posts, as they have not really said anything.

I would like to see a detailed procedure for how they are getting more accuracy with a mill.
I would like to see their tolerance stack up calculations.
Show me the math.
Define your process.

I have done it both ways and I think that the jig is better.
I am open to learn new things, if we can get the information in an apples vs apples format.

I have the tools and the will to calculate and measure to compare the two techniques if we find out what they both are.

quote:

Originally posted by tnekkcc:


The bolt bore is the starting point for other reference.
The threads, receiver face, and inner stop ring are trued with respect to the bolt bore.
The barrel is then mounted with those three things tracing back to the bolt bore.
The bore of the barrel should be centered with respect to the barrel threads and shoulders, which makes it true to..........the bolt bore.

You are assuming that all these steps have been taken when in reality they rarely ever are on factory rifles. That's why, except for mounting sights on barrels, did I use a jig.

You ask how things are done, well, when I blueprinted a receiver I trued everything to the bolt bore including the exterior of the action (surface grinding). Thus I could index of either a mandrel or the exterior of the action.

One of the problems of using a forster jig is that the barrel may be pointed off in one direction and when you drill receiver holes they are aligned in that direction. Now you go to mount your factory bases which are sculpted to match the receiver in parallel yet the mount holes in the receiver are now at an angle.

I like how so many ask how things are done, does a plumber get on line and tell how to fix a sink? Amazing how many think they are owed a detailed description from someone whose livelihood hinges upon their knowledge of these arcane secrets.

quote:

Originally posted by rem721:


You ask how things are done, well, when I blueprinted a receiver I trued everything to the bolt bore including the exterior of the action (surface grinding). Thus I could index of either a mandrel or the exterior of the action.

You correct that that will work and is not an out of control process, but we don't yet know that it is better.
I have been truing actions to the bolt bore since the first barrel I ever pulled.

I have seen barrels where the threads are angled to the barrel. So, if we heeded the advice of those that say, "don't you want the holes lined up with the barrel anyway"; we would be in a pickle later on if we elected to rebarrel the rifle.

quote:

Originally posted by tnekkcc:
If someone is implying that their technique is better, shouldn't they have something to back it up?

tnekkck,

I can understand the need for a fixture. Not everyone has access to, or, the know how in using the precise capabilities of a milling machine. And for those folks, what choice do they have.

Like I said in my first reply, the person using the fixture can, with equal experience, do equally as good as job as a gunsmith can if he himself is using a fixture. But in a contest between a skilled user of fixtures and skilled gunsmith/machinist on a milling machine, the skilled gunsmith/machinist would likely win.

Myself, I use a mill because, among other things, it is the gold standard for placing holes precisely where they are needed.

And like I implied earlier in the discussion, if you break a drill bit, or, God forbid, a tap in a paying customers receiver, you won't have to be standing around with your thumb up your ass wondering "what now".

Speaking soley from experience, for an experienced gunsmith, dialing in a receiver on a milling machine is a breeze. With experience comes speed. And like I said, you have the benefit of having a great machine all ready dialed in on the hole should a problem ocur.

But that's just my opinion.