Author Topic: NEED ADVICE!!! I may have created a tomato steak (Read 1356 times)

Yak Angler · « **on:** January 16, 2012, 09:30:36 AM »

My recently shortned 20 gauge handi needed in my opinion to be scoped for this years deer hunt to fully utliize slugs. I set my drill press to what I thought would allow .030" of chamber wall remaining and somewhere between hole # 1 which turned out prefect and hole # 2 something slipped on the press and before you know it I drilled into the chamber. To make matter's worse my 6/48-32 tap broke off trying to thread it.

Not a good start to this project either to say the least. I managed to remove the broken tap after about 1 hour of tinkering with it. The barrel is undamaged other than the recently drilled holes which i hope can still be salvaged for the scope mount. At the very least i could mount an H&R peep sight as I have an extra one lying around anyway.

Well I decided to take it out today and do a test fire to see what would happen to the shell with a hole about 1.5" from the breech face up the length of the shell. The hole diametre is .115" . What I hoped would happen is the plastic shell case would be strong enough to absorb the pressure spike and distribute the force without tearing. What happended was a little circle the same size as hole got blown out of the shell case where the hole was. Keep in mind my face was behind a 3foot diametre tree while testing. Either way this is bad new for me unless some of you can come up with another solution I haven't thought of yet I feel my options are as follows.

1. By another tap, rethread that hole and cut and polish a machine screw to fit flush with the bottom of the chamber when torqued. I doubt there would be enough pressure to blow out a propely installed screw.

2. Use the existing screws i already have which won't quite extend down to the chamber and use a bit of j-b weld on the underside to fill in the remaing gap after the screw is torqued and polish the chamber smooth.

3. Suck it up and buy another barrel

Well thoughts--has anyone here drilled into the chamber and ended up with a solid mount after tapping?

quickdtoo · « **Reply #1 on:** January 16, 2012, 09:46:50 AM »

Number one has been the method discussed previously, should work fine, shotguns don't develop enough pressure to be concerned with considering the small surface area of the hole as long as you can get a smooth finish on the end of the screw so it doesn't cause ejection problems due to the hull expanding into it, a little silver solder or epoxy may help if it is a problem.

Tim

Lon371 · « **Reply #2 on:** January 16, 2012, 09:51:36 AM »

Quote

1. By another tap, rethread that hole and cut and polish a machine screw to fit flush with the bottom of the chamber when torqued. I doubt there would be enough pressure to blow out a propely installed screw.

And blue thread locktight. Not saying you should try it. But that is what I would do.

Lonny

Yak Angler · « **Reply #3 on:** January 16, 2012, 10:34:35 AM »

Thanks guys i thought it might work due to the lower pressures on a shotgun, truly i was suprised that small of hole caused a blow out to begin with, once i get it supported from the sounds of it I will be ok which is good news. Now i guess i need to find another tap.

Any recommendations for a commong hardware store size. I don't want to have to source another 6/48-32 as they are hard to get up here.

Does anyone know of a standard size thats usually in stock in most hardware stores that is still small enough to find bolt heads that will fit into the recesses on the stock h&r rail?

quickdtoo · « **Reply #4 on:** January 16, 2012, 10:44:05 AM »

Brownells ships to Canada, that's where I usually get my gunsmithing stuff including the taps and screws. If you have a Bolt & Nut specialty shop, they can special order the taps for you, we have one here that has ordered 4-48 taps for me before, since they're small and break easily, I always order more than one from Brownells, shipping is the same as just one, but if I break it, I have to order another, then the shipping adds up, get the longer screw while you're at it.

Tim

MSP Ret · « **Reply #5 on:** January 16, 2012, 11:15:44 AM »

Adam_R, after reading and re-reading your posts it appears that if you go with option #2 you already have everything you need to complete the job. As Tim said, and I have expeirenced, a shotgun does not produce enough pressure to blow out a thraeded fastener from a properly threaded hole over the shell case, especially with a 6/48. I suggest you try that method, you should be GTG with it. If it does not work out, and I am pretty sure if done as you mentioned it will work out fine, you can always go on to another method, #1, which will just entail getting more parts. Number 3 is not in consideration since the barrel will be OK to use. The barrel will be similar to the sign that explains the day old vegatables at the market that are marked way down in price "not the best, but still good"...<><....

quickdtoo · « **Reply #6 on:** January 16, 2012, 11:29:15 AM »

I wouldn't recommend JB Weld to fill the hole between the chamber and short screw in option #2, it has marginal compressive strength, Superweld would be a better choice, it has over 3 times the compressive strength as JB at 36000 PSI.

Tim

casper_zip · « **Reply #7 on:** January 16, 2012, 11:32:35 AM »

Hey there:

Tim answered your questions, and the same thing happened to me with my 20 guage smooth bore. Tap the hole all the way thru to the chamber. If you have some, use a socket type threaded screw (gunsmith type), go all the way to the chamber, stop when you can feel it, or stop a lil short. That's what I done, stopped a lil short, then JB welded till all was as smooth as I could get it. After 24 hours, I used my powered tool with a brush on it, and used my polish and I polished the chamber smooth and slick. Don't use real abrasive stuff, you just need to polish and smooth it. When I mounted scope base, my screw went in just like all of them.

My gun ejects empties sailing over me sometimes. There are no marks on shells, and you can't see or feel the inside of the chamber because I took the time to polish it and not overdo it.

Hope this helps, and you should have no problems whatsoever. No way shotgun pressure will cause that plug screw to come out or loose.

Best,

casper_zip

Yak Angler · « **Reply #8 on:** January 16, 2012, 11:46:15 AM »

Thanks guys

I will see what i can locate tonight at my local hardware store, if they don't have what i need i will try brownells, I think i looked into them in the past and they had a high minimum order to ship to canada, not that i need an excuse to order more stuff but i was hoping to keep the budget as low as possible on this project.

Heck for under $ 200 i can buy a brand new ultra light slug hunter and it comes with the rail

I just hope after going through all this it groups half decent to 75-100 yards. If it does the work will be worth it

cwlongshot · « **Reply #9 on:** January 16, 2012, 11:52:52 AM »

I agree, I have done this (mistake same as you)and I KNOW its just fine...

Stay clear of the hardware store 6/32 threads, its a VERY weak screw! Go with the 6/40 or more thread count.
Drill the hole, tap it FL, mount the base figure the screw length to barely extend into the chamber. Apply good loctite. (I prefer the red) Then polish the screw to the radius of the chamber and enjoy your shotgun. Stop worrying , stop thinking about it and go shoot it!

You will see the slight indentation if you really look for it, but those threads are very very strong and the steel would fail if the threads did..

CW

quickdtoo · « **Reply #10 on:** January 16, 2012, 11:55:37 AM »

I don't see a min order requirement for non-firearm parts on Brownells' intl shipping page.

Tim

http://www.brownells.com/aspx/general/international.aspx

bilmac · « **Reply #11 on:** January 16, 2012, 12:05:38 PM »

I plugged the holes in a demilled 303 that were about a 1/4 inch dia. using about the method you describe as #2. I made sure to have plenty of epoxy on the threads too. I just put a tight fitting shell in the chamber with a lot of release agent on it to form the epoxy on the chamber end.

Yak Angler · « **Reply #12 on:** January 16, 2012, 04:21:04 PM »

You all have relieved my stress level significantly.

I ended up running out to the hardware store and got a 6-40 tap and bolts. I drilled out the first hole that went all the way through and re-threaded it. I also just drilled the final hole through into the chamber aswell. I figured i can't hurt it anyworse by doing that and atleast I will get a few more threads now too. I left the bolts hang just slightly into the chamber, red loctite on threads and polished them up really good in the chamber , this was after fitting the rail to the barrel and loctite on it aswell.

Got the scope rail mounted a few minutes ago and put a sacrificial lamb on it for testing this weekend. If all goes well and the rail holds up fine without any ejection problems i will likely mount a 1-4 power variable scope. This will likely be my go to gun if I can find a slug that it likes and can get 6" or better 100 yards groups with them. Everything from birds to deer with this 20 gauge is the goal.

here are a few pic's of the hopefully completed rail and thanks again everyone for your help.

bikerbeans · « **Reply #13 on:** January 17, 2012, 12:56:49 AM »

Adam,

Nice lookin' scattergun! When I d/t my 20 ga tracker II for a scope base on the last hole I was within about .015" ventilating my chamber. It doesn't take much too go all the way through as the steel, with a proper bit, is quite easy to drill. Nice recovery and let us know what slugs work the best.

BB

rbertalotto · « **Reply #14 on:** January 17, 2012, 01:18:23 AM »

I've seen this tried before. It didn't work. There is still quite a bit of pressure on those screws and not enough threads to hold them for long. At my range I saw a scope blow off a shotgun that was mounted exactly like you describe.

Hope it works out for you.

If it were my gun, I'd have the holes TIG welded shut and have a gunsmith D&T new holes. You need to use TIG welding to contain the heat in a very small area.

quickdtoo · « **Reply #15 on:** January 17, 2012, 05:19:10 AM »

Good work Adam!!

Quote from: rbertalotto on January 17, 2012, 01:18:23 AM

I've seen this tried before. It didn't work. There is still quite a bit of pressure on those screws and not enough threads to hold them for long. At my range I saw a scope blow off a shotgun that was mounted exactly like you describe.

Hope it works out for you.

If it were my gun, I'd have the holes TIG welded shut and have a gunsmith drill & tap new holes. You need to use TIG welding to contain the heat in a very small area.

Maybe on a 12ga, H&R won't drill and tap 12ga shotgun barrels, neither will most gunsmiths.

Tim

cwlongshot · « **Reply #16 on:** January 17, 2012, 06:50:13 AM »

Tapping a shotgun barrel presents some problems, MOST all are associated with thin steel. This is the reason the 12 GA is not tapped at the factory or most gunsmiths. This is a 20ga and should have sufficient material thickness. Other variables are weight of site. A conventional rear site weighs little and dosen't offer the ability of any leverage so it will hold up to being mounted on a thin barrel. But try to mount a heavy 4x16 variable scope and it's probable you will pull the threads right off/out of the barrel. (In the thin steel of LESS thickness than dia of the screw)

The basic mechanics of a tapped hole are as long as your amount of threads is greater then the diameter of the screw/bolt and the threads are cut properly it will be of sufficient strength. Couple that with good thread locker properly applied with suffisient drying time, (I like loctite red) you will not have any problems.

Fail to degrease the screws or the tapped hole OR not let the thread locker properly setup and YES it will fail...

CW

Yak Angler · « **Reply #17 on:** January 17, 2012, 01:14:44 PM »

Well i plan to test fire it about 20-30 times this weekend, hopefully the screws remain in place. I think if they are going to fail it will happen in the first few shots, if the screws are still in the gun after a couple a shots and the shell cases don't show any abnormal wear signs around the screw holes i will consider it salvaged and move on towards testing slugs for accuracy.

I am also waiting for a 9mm chamber adapter to come in so as long as the screw;s don't stick into the chamber to far to allow it to fit propely i will leave everything as is. The only protrude a hair so i think the chamber adapter will be ok

I probably have 10 threads and red loctite holding it all togeather , I would be amazed if it let go under shotgun pressure's. Time will tell and i will post an update soon

gcrank1 · « **Reply #18 on:** January 20, 2012, 07:11:05 AM »

A common mistake in drilling and tapping is using an oversize tap and an undersize screw, especially in the small screw sizes. Manufacturing tolerances can make a less than perfect fit. The standard recommended tap drill is for a 70something % thread; we like better than that for gun work. I use my NUMBER drill set and often the next size smaller drill than typically recommended. This also means that one MUST be very careful with the tap, use one new and sharp, and plenty of the proper tapping lube, but the threads are CLOSE. on any tap job of consequence I use a taper tap, if possible, and only run the tap in deep enough to get a close fit on the screw; if you go deeper it only widens the thread diameter. This means tap a bit, pull it, clean the hole and test fit frequently, but hey, you've got the time and its nice work.
Dollars to donuts that one that 'blew off' was a poorly done, hack job better suited to garage work than gunwork.

evidrine · « **Reply #19 on:** January 20, 2012, 11:34:45 AM »

Adam_R, that is a nice looking gun you have there. It looks like things turned out well. How short did you cut your barrel down? Did the shorter barrel affect slug accuracy any?

chefjeff · « **Reply #20 on:** January 20, 2012, 12:24:33 PM »

That would be a tomato STAKE.I looked at this post expecting to see a really exciting creation!

Yak Angler · « **Reply #21 on:** January 20, 2012, 01:20:29 PM »

Quote from: evidrine on January 20, 2012, 11:34:45 AM

Adam_R, that is a nice looking gun you have there. It looks like things turned out well. How short did you cut your barrel down? Did the shorter barrel affect slug accuracy any?

The barrel has been cut down to 19" it should now be cylinder choke, I have no idea how much cutting it down affected slug accuracy because I have only shot slugs out of it after I cut it down. Fired two shots into a tree at about 40 yards offhand and both shots created a large hole into the tree so I imagine they hit pretty close togeather. I was only using the front bead at that time. I hope to test fire a few more rounds tomorrow and hope the red dot helps a bit for accuracy, but truthfully tomorrow's testing is mainly for the integrity of the scope rail. If it doesn't blow off and no signs of significant hull damage to the shell I will call it a success and then mount a scope for some true accuracy testing with slugs.

Yak Angler · « **Reply #22 on:** January 20, 2012, 01:23:11 PM »

Quote from: chefjeff on January 20, 2012, 12:24:33 PM

That would be a tomato STAKE.I looked at this post expecting to see a really exciting creation!

With a name like chefjeff I'm not surprised that title caught your attention.

I must have been hungry when I typed this post originally

evidrine · « **Reply #23 on:** January 20, 2012, 04:40:39 PM »

Reason I ask is because I have a 12ga cut down to 18". Never thought of trying it with slugs. I will curious to see how it shoots when you get it all together. Please keep us posted.

gcrank1 · « **Reply #24 on:** January 21, 2012, 04:33:51 AM »

12ga. @ 18";....see if someone can get a pic of that going off at night

Yak Angler · « **Reply #25 on:** January 22, 2012, 08:42:03 AM »

Ok the good news first---the rail and attaching screws held up perfectly today. fired 50 rounds of trap loads through it in total busting clays to test it out. The slugs were fired next and the red dot sight dialed in after a few of them. Only shot it 50 yards as i was in hurry due to a family commitment. Accuracy was acceptable to me about 3-4" max group size for a 6 shot group ( all the slugs i had left after sighting in ). I am very happy with the slugs accuracy and other brands may perform even better. I only had challanger's with me today but so far everything looks good for deer hunting this year if i decide not to buy a muzzleloader for that purpose.

The bad news---Red dot sights suck for wingshooting due to the loss in field of view. I will be removing the red dot and scope rail and installing one of my spare ghost ring sights instead of a scope or red dot. My deer hunting grounds limit most shots to 100 yards and usually less than 40 yards so a scope isn't really required for me and the ghost ring will still allow for fast target aquisition when bird hunting as it won't hinder my field of view like a scope or red dot will, this 20 gauge needs to do everything all at the same time to fill my hunting needs as an all around game taker.

cwlongshot · « **Reply #26 on:** January 22, 2012, 01:09:14 PM »

Quote from: evidrine on January 20, 2012, 04:40:39 PM

Reason I ask is because I have a 12ga cut down to 18". Never thought of trying it with slugs. I will curious to see how it shoots when you get it all together. Please keep us posted.

I have one too, with its peeps it will shoot a soft ball ALL DAY LONG.. IF your shoulder holds up... At less then 5# its recoil is "smart".