Tapping Scope base Screws... what am I doing wrong?

[Trickymissfit]

Use a metric Crescent wrench for metric threads! Really now, 8-40 threads should be no problem provided you're drilling the hole the right size, using a good high speed tap and a tap wrench, and using a good quality tapping/cutting fluid. I've been buying 6-48s and 8-40s from JGS Tool. Good high speed tools. Brownells is trying to become the "WalMart" for gunsmiths and some of the tools they offer, especially cutting tools with their name on them, are WalMart quality. MSC has special thread taps & dies, too. I do all my threading with the barrel removed Why deal with a 'blind hole' unless you have to. Sounds to me like you should have had a professional do it! 416R is no more difficult to drill and tap than 4140HT is.

A few years back a buddy of mine named Tony decided to do a rebarrel on his 700 Remington chambered in 7STW. Don't remember the blank name, but it was a good name brand. He went ahead an trued the action prior to threading the barrel. Good thing as there must have been .015" taper in the threads (so bad that he actually pulled a couple threads removing the barrel). He wanted to do it with a 16 thread, and I had a couple taps, and they literally wobbled in the hole! I told he need to start all over there. He ended up with a 1.09-18 thread that was dead strait. Told him to cut a couple blanks to fit the thread very tightly. Gave him a couple six inch pieces of A2 that I had stashed in a cigar box. He cut the blanks, and of course they came out nice. Told him to put one away as the master gauge for that barrel thread. The other one I hardened, and literally made a crude looking tap out of it with some grinder work. I knew Tony had somekind of a big rail mount he was going to install, as I ground the bottom side to fit the action for him. He comes down to see and asks if I had any extra 8-40 taps and a couple drills. I bought them by the box so of course I did. He gets the rail mount installed, but has a burr in the female thread that makes installing the barrel a pain without tearing up some threads. I hand him the crude looking tap! (I saw this coming two weeks prior). Told him I knew this was gonna come to place. The plug was razor sharp, and I actually cut a finger on it. I knew that he ruin those threads otherwise.

Take the advice from other folks here. When you buy tooling, you usually get what you pay for. You want good drills but only need a half dozen. Then do a group buy with buddies. Samething with taps and reamers. While on the subject, everyone needs a small Albrict (SP) keyless chuck. Buy that one and forget the rest.

gary

 

[Hired Gun]

For gun work it really pays to buy really good American made taps from MSC. They are not cheap but thy cut super nice. I believe your tap is soft or dull.

I budget a brand new tap for each receiver. No drill bits for me on that job. I use an end mill and correct them as they are cut. Lots of times they are slightly out of line. A proper job will have that new scope with in a click or two of the scopes center when you get it sighted in. That's part of why gunsmiths charge $100+ to cut these 4 holes.

 

[DocB]

A left-handed Crescent wrench is perfect for those pesky left-handed threads too!

Dammit!! I knew I should have bought that left-handed crescent wrench. Harbor Freight had a standard and metric set. Darn!

PS.. Back in the days when I was serving as a Second Mate on a heavy lift ship, the Chief Engineer taught me a trick when tapping... before you start run the tap into a lemon. When it gets difficult, back it out and run it into the lemon again. Works like a charm!

DocB

 

[Clark]

I cannot feel the difference with the small screw holes, but in bigger ones I can feel that MolyD takes less torque that Tap Magic.

When the going gets tough, I go to the next larger size drill.

 

[joshua99ta]

I didn't use a fixture to drill and tap. I use a magnetic level with a v cut in it to help get it straight. I know its not ideal but it has worked for years. I'm looking at some fixtures to help keep it straight. I'll never attempt it on stainless again but carbon steel I'm not scared of.

I was not using a 2 flute tap. I'm going to look more into some better taps. These were from brownells.

I'm no machinist at all. Never messed with a lathe or mill. However I am looking into purchasing both. I've just got to get a shop built that's large enough to handle the extra room needed for both machines. Between my dad and I we have already filled a 50x70. I've got friends willing to teach me the ropes. I might eventually be able to get my hands on a late member of LRH's old mill and lathe.


I used a #28 drill bit.

I don't believe the metal got hot. I kept it lubed and it drilled soo easily.

 

[Clark]

joshua99ta,
We were given a microwave in 1982 and have used one every day ever since.
I got a table saw in 1984 and used it at least once a week ever since.
I got a mill and a lathe 12 years ago and have used one once a week ever since.

Don't wait until you are old like me to tool up.

 

[joshua99ta]

I'll definitely be acquiring some once I get a place to put em. I'm finishing my little investment house I bought in town and just purchased another 8 acres next to the piece of land where I'm planning to build within the next couple of years. I'll have 17 acres of the original 80acres of my great grandfathers old farm, I hope to eventually buy the other 63 back.

I'm planning on either a 60x80 or 65x165 building. I already have the 65x165 I'll just need to relocate it b/c that property where it is will probably be sold before long.