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Old March 7, 2010, 08:45 PM   #1
Dr. Strangelove
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Broken scope base screw removal?

I'm replacing the scope bases on a Remington 700, which was purchased used. They are older Redfield bases, and apparently permanent Loc-tite was used, or some similar product.

The screw heads were stripped, I resorted to a trip to Sears for a set of Drill Out Micro Power Extractors, which worked well on all but one of the screws, which broke in two, and is broken off almost flush with the receiver.

The bases are off, and my set of extractors seems to have given it's all. I could swap them for another set, it being Sears and all, but I'm wary of attempting to drill this one out, because I don't have a drill press and am doing this by hand with a power drill. I don't want to strip out the hole and have to have it re-tapped.

Give up and have a machine shop finish the job? Any suggestions?


Last edited by Dr. Strangelove; March 7, 2010 at 08:51 PM.
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Old March 7, 2010, 09:12 PM   #2
James K
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That receiver looks odd, I hope it wasn't in a fire or something like that.

Anyway, the answer is to give the job to a gunsmith or, if you know of a good one, a machine shop. It requires a sold drill press or milling machine set up to keep the drill from wandering, plus a stiff starter drill. Once the old screw is drilled out, the hole can be cleaned up with a 6x48 tap. That is a non-standard size used in the gun industry, so a machine shop may not have the tap, though a gunsmith certainly will.

You can get new screws from the gunsmith or from Brownells.

Jim
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Old March 7, 2010, 09:32 PM   #3
Dr. Strangelove
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Nope, no fire, someone epoxied the bases to the receiver. It's an 8mm Remington Magnum, but that's a bit over overkill in my opinion.

Yep, I believe I will leave this one to the pros. I have the new bases and screws already, I just need to have this screw drilled out.
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Old March 8, 2010, 08:14 AM   #4
Johnsusername
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Hi,
Find a machine shop that can burn it out.
They make machines for burning out broken taps.

John


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Old March 8, 2010, 10:10 AM   #5
kraigwy
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I agree with taking it to a machine shop.

There are two options that I use.

1: Drilling it out on a milling machine with a carbide drill bit.

and

2: Coating the action ( around the screw) with Heat Stop (sold by brownells) and welding a small bolt (same size as the screw) to the head of the screw, which will allow you to get a hold of the screw to twist it out.

The heat applied by the welding loosens the loctite.
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Old March 8, 2010, 11:36 AM   #6
Clark
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I have always hear that one should drill and tap with 6-48, and if they ever strip out, to drill and tap with 8-40 in the same hole.

100 rifles I have drilled and tapped later, I have never had 6-48 fail.

But I have seen broken off screws and bolt in automotive situations, and trying to drill and and then tap the original thread never seems to work well.

I would drill for easy out, put in some Kroil and put on a little heat and see if it will unscrew out of the hole.

If not, I would drill out that screw and make it an 8-40 hole.
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Old March 8, 2010, 02:05 PM   #7
thekyrifleman
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In the midst of an exciting football game this past fall, I broke the the rear base screw on my Rem 700 Ti. Thought I had just wrenched on it too hard and took it to a gunsmith. Result...he fixed it but also told me that the hole had not been tapped completely, i.e., I had run out of threads... so he retapped all...still the 6x48's...just some info for you to mention to the smith or machinist...might save problems in the future.
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Old March 8, 2010, 02:57 PM   #8
thallub
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I heat the screw with a micro torch. This releases the Lock Tite. Then a reverse twist drill bit is used to take out the screw. After a few revolutions of the drill the broken screw usually starts to turn.

http://www.irwin.com/irwin/consumer/...rwinProd100128
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Old March 8, 2010, 03:33 PM   #9
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All good suggestions, but NOT for a person using a hand held power drill. As for redrilling and tapping to 8x40, that is the resort if the original hole is drilled oversize in getting the old screw out. If the owner decides to go that route, then all four holes should be drilled and tapped to 8x40; having just one in an odd size is (IMHO) sloppy and the sign of a poor job.

Jim
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Old March 8, 2010, 04:18 PM   #10
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If you're worried about applying heat, a trip to the coldest deep freeze you can find for a couple of days will often break the Loctite loose, as well.

Or, you can use dry ice.
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Old March 9, 2010, 06:18 PM   #11
waterfowler
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Get yourself a center punh, smack the punch in the center to create a large dimple in the center of the broken bolt. Then get a EZ-out and match a drill bit to the ez out. Drill almost to the bottom, then gently with a hammer put the ez out in. You have really only one shot otherwise the ez out will break. Then twist and it should come out. That is how I do it on engines, and I have been shown that. Otherwise if it dont work, drill hte bolt out and tap it to the correct pitch.
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Old March 9, 2010, 08:38 PM   #12
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The EZ-Out works on auto screws/bolts but they generally are a lot bigger than the tiny 6x48 base screws. There are EZ-Outs made that small, but they do break easily. (Voice of experience here.) In my experience, if tricks like heating or freezing don't work, drilling with a minor diameter drill is the best route. Then you pick out the threads or use a 6x48 tap to clean up.

Jim
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Old March 9, 2010, 08:58 PM   #13
Dr. Strangelove
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Wow, thanks for all the replies. There is lots of good info here, but I'm going to let the pros handle this one.

The Sears Micro Extractors worked on seven of the eight bolts, but this last one is just broken off too close to the receiver top for comfort. I don't have a drill press, and a few calls around town have yielded prices of $15.00 - $20.00 for the removal job, so... I'm just going to pay to have it done.

I've learned a some good lessons here:

1.] Get the right tool for the job. The reason that the last bolt broke off is because I originally tried to drill them out, and went too far with this one. (I knew this rule already, but chose to ignore it...)

2.] This was a Gunbroker deal, and it's not even my rifle, but I won't buy another used rifle without requesting that the scope bases be removed prior to purchase.

3.] Never use permanent Loc-titeā„¢ on screws that you, or someone else, may want to remove one day.
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Old March 10, 2010, 03:11 PM   #14
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"seven of the eight bolts"??? There should be only four scope base screw holes in that receiver. Are you counting the screws in the scope rings or did someone drill four more holes in the receiver? BTW, the scope ring screws and the base screws are not the same. Ring screws usually are 6x40 where base screws are 6x48.

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Old March 11, 2010, 12:44 AM   #15
Dr. Strangelove
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Quote:
"seven of the eight bolts"??? There should be only four scope base screw holes in that receiver. Are you counting the screws in the scope rings or did someone drill four more holes in the receiver? BTW, the scope ring screws and the base screws are not the same. Ring screws usually are 6x40 where base screws are 6x48.

Jim


Well, I was using Natural Light as the cutting lube....

Four base screws is the correct number.
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