Drill + tap failure. Backwoods Outdoors Corbeil Ontario.

J

Jimbobob08

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Few weeks ago I had a 44mag rifle drilled + tap from a local establishment who’s a business member here. I installed a pursuit red dot on the rail. I sighted the rifle in with factory hsm hard cast loads for a moose hunt and plinked a little, total 20rounds fired. Rifle was cleaned yesterday. Today I attempted to sight in my standard factory hornady 240xtp ammo for deer and on the second shot the rail/red dot came flying off. There’s a lot of red loctite. The threads are almost non existent in receiver. I did not clean up the loctite residue so it’s hard to see threads on bolts. There’s some sort of damage on the underside of rail and where it mates to barrel, like blobs of loctite acted like a spacer?

The establishment requested the rifle was returned. I’m not a gunsmith or machinist by trade, but ran a drill in a machine shop for nearly two years and know this shouldn’t of happened and the driller knows for a fact when a drill + tap goes wrong. The excessive loctite appears to be coverup? Is my train of thought correct to this point?

I can send pictures to anyone’s email or cell if you care to post pictures pm me.

Thanks folks.

Edit to add. As of Nov 9 2023 the establishment, backwoods outdoors in Corbeil Ontario, has made no effort to correct the situation. The owner Darren Cropper botched the job. It’s searchable now so hopefully it saves future gunnutz some troubles.
 
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If the threads are barely there, perhaps the wrong size tap drill size was used .
An oversized hole and a starter tap will give faint threads, the job should have been finished with a bottom tap.

They now need to redrill to a larger size like a #8, hopefully they initially used a 6-48.

You can also get "oversize" 6-48 screws from Brownells, I used them on a sloppy hole once.

It definitely needs retreading though
 
Tools breaking happens all the time, its entirely possible that something such as the tap breaking and needing to be extracted, damaging the threads in the process. It is very easy to do when tapping the tiny fine threads in what is often hardened steel receiver to mount a rail. They could have thought that the red Loctite and what remains of the threads would be enough to hold. Another possibility is it was actually the excess Loctite that caused the bolt to not hold and the threads underneath are fine. Loctite is not like glue, more is not better. Yet another could be that the bolt was over tightened or the excess Loctite caused a hydro lock if the hole is a blind hole and caused the bolt to have to be overtightened to sit right.
Regardless of the reason or cause, if the shop has requested that you return it to them then I would assume they intend to investigate it and make it right. Be that by re-tapping, correct application amount of Loctite or if required they could even likely use a Helicoil to completely replace the threads.

Feel free to DM if you'd like an opinion on your pictures or more info.
Cheers.
 
If it was a blind hole tapping it is easy to strip the threads while trying to thread to the bottom... a touchy job... but you know if you screwed it up... and the excess of red Loctite adds to that... Loctite can't fix non existing threads...

Hopefully they can do a quality fix second time around...
 
Looked closer and holes appear to be oblong. Likely struggled to drill it and oversized the holes with minimal threads. Still can’t make heads or tails of the rail/barrel damage.
 
Pics would probably go a long ways here.

This website makes posting pics super easy. Upload them there, then just take the direct link they give and and stick it in the URL box here when you click insert picture.
 
Uuuuhhh yup, I'd say they botched that job pretty bad. Doesn't look like you stripped the receiver threads out with the screws either. Looks like either the holes were drilled oversize, as there's not much (Or any?) thread visible in them, or like FCD said they didn't have a bottoming/plug tap and the hole wasn't deep enough for their taper tap. Either go up a size, or install a real short thread repair insert like a heli-coil or something. Ugly...

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There are some problems on the picture website right now... I can not even access my photo albums that are there right now...

Having now seen the pictures... I would suggest the shop replace your rifle or have a competent smith redo the holes to 8x40 and alter the base to accommodate the larger screws. I would not trust the original 'smith' to fix this.
 
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That hurts my feelings to see that you paid for that. I'm no machinist, but a lifetime of tools and a dozen years with access to a very nice machine shop has taught a few things and I wouldn't call that a finished job unless I did it hammered.
 
It looks like the guy measured the screws and drilled to that size..forgot to use the tap drill size for the screws he was using. you should be able to go the next size up. You may need to open the hole in the red dot though.
 
It would be interesting to try a #31 and then a #28 drill in the holes and see what their diameter is. The #31 should bottom. #28, the clearance drill for 6-48 shouldn't enter the holes.
From the photos, it appears that threads barely started. I'd be interested in seeing if a 6-48 bottoming tap would engage those partial threads and cut further into the holes.

It almost looks as if the mounting screws were pegs and the base was glued on.
From the look of the adhesive lumps, it appears that the bottom of the base was not a good fit on the barrel. There shouldn't be enough room for gobs.

Drilling and tapping blind holes is one of the jobs that gives one white hair. Measure diameter, and knowing the diameter of the bore, calculate wall thickness. Then calculate the depth that can be safely drilled. Plug then bottoming taps, to get as many good threads as possible. I hate mounting front sight ramps on sporter barrels.
 
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