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Trigger guards must be made of diamonds


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I made some progress on a couple Saiga conversions (.223 and .308), and got to the point where I need to drill a hole in the solid mounting tabs on the trigger guards.

 

I got a 5/32 cobalt drill bit from Ace Hardware, and it worked incredibly good for the rivets that I drilled out, but the trigger guards are not responding at all, as if they are just too hard to drill through. I'm using a 24v Makita cordless hand drill.

 

I was all set to reuse them, and already have my .308 trigger guard reshaped after much painstaking effort, but now that I'm unable to get the holes drilled in them, I'm considering buying some aftermarket conversion trigger guards and be done with it.

 

I was thinking they are hardened, spring-like material, and maybe one option is to anneal them with a map gas torch. For that matter, if I'm going to be working with a torch, I wonder how feasible it is to soften the metal enough to bend the front tab back so I can reuse the existing hole instead of drilling through the mag catch tower, which is what I'd planned to do when I still thought drilling the hole was possible.

 

I suppose there's no hard in ruining the old trigger guards by trying to anneal them if I'll default to aftermarket ones anyway. So, to anneal them, I get them pretty hot with a torch and them dunk them in oil? Or let them cool naturally? I understand cooling them rapidly in water would harden them. Somehow I have the impression that cooling in oil does the opposite.

 

By the way, the .308 doesn't have a pistol grip hole, so that's another argument for going aftermarket, although I was probably going to run a Hungarian SA85M thumbhole which looks like I can secure through the sporter trigger slot that is there. Even if I did run the thumbhole, having a grip nut hole would be nice if I wanted to put different furniture on it in the future. I'd prefer to get all the hacking and painting out of the way now.

 

Actually, I think I just realized a hiccup to the aftermarket trigger guard with built-in grip nut. The Hungarian SA85M thumbhole stock doesn't use a grip nut, and instead gets a screw from the inside into the wood through the grip nut hole. If I run an aftermarket trigger guard with built-in grip nut, the grip nut will interfere with the stock which is solid under the grip nut hole except for the small screw hole. I don't want to hack up the SA85M thumbhole stock.

 

The .223 has a grip nut hole, thankfully. But for that I have a VLTOR CAR-style receiver extension for a Magpul CTR, so it's getting a pistol grip, probably a Hogue.

 

Any suggestions on drilling through the trigger guard tabs?

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Annealing is mentioned in this video, and repeated at the beginning of the next in this series, but the method described is to use a belt sander. I don't have one of those, and I've already dressed the trigger guard so I wouldn't want to sand any more of it.

 

http://www.youtube.com/watch?v=3iIsZJ89ZNA

 

It sounds like a torch is gonna be the way to go for me.

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Let me clarify, the trigger guard is already off and all I need to do is put a hole in the front mounting tab so I can bolt it down through the mag catch tower. In that case, I think annealing the tip is the only logical way to move forward.

 

In my attempt I also tried drilling as slow as I could, and it just doesn't grab the metal it seems. I didn't use "cutting" oil, but I put a drop of air tool oil that I had handy.

 

When drilling the rivets with the cobalt bit, I was amazed at how well it worked at very slow rpms. Not so with the trigger guard tab.

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I would try putting the trigger guard on some soft wood (so that the wood would dent along with the TG), then taking a heavy metal punch to it, and hitting it HRAD. That oughta make a nice little indent in there, which would not only center the drill bit, but also make its center rest lower, making the bit catch easier.

 

That is, if I read your post correctly, and you are having trouble drilling through the trigger guard and not something else.

 

In fact, I'm gonna go try that right now with this spare TG that I have laying around.

 

 

EDIT: okay so i dont know which saiga version you are having an issue with, or what thickness that TG is, but here are the results of my super science experiment:

 

 

I put a trigger guard (from a 762 saiga. measured thickness 1.55mm) on a piece of wood, and put a 11/64 cobalt bit through it. it caught fine. it was more difficult to punch a nice crater (i didnt drill through the crater in this "experiment") in it than it was to drill it. Was using a 5-8 year old corded drill. Although I might mention, that the bit slipped off the TG half way though and hit the concrete. Then once it was all the way through the TG, it caught and started spinning. I had to reverse the drill to get the bit out. Then I tried to drill another hole, and it started slower than the first. Perhaps I dulled the bit when it slid off and hit the concrete? Maybe it dulled after it got stuck in the TG and made it spin? Either way it has a nice slight bend in it now.

 

 

Anyway, if your TG is the same thickness (1.55mm) then I would try using a different drill, or different drill bit. Maybe your bit dulled out? It does happen. Perhpas try bravely applying more pressure.

 

 

 

Hopefully I read your post right and my lengthy scientific research trials were relevant.

 

EDIT 2: I really wish that it was made out of diamonds... I could use some right now.

Edited by Agent Lemon
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I use a screwdriver and a hammer to break the weld. Its not a rivet, but a weld that is as hard as a rock.

If you drill, start with a small bit then step it up in size.

The TG weld stumped a few metal manglers (sheetmetal mechanics) until a welder spotted the problem.

Hard Russian weld.

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I wonder how feasible it is to soften the metal enough to bend the front tab back so I can reuse the existing hole instead of drilling through the mag catch tower, which is what I'd planned to do when I still thought drilling the hole was possible.

 

I just did this for my latest S12. A good torch, bench vise, and a pair of channel locks, and you're good to go. :up:

One note though- make sure you bend it back in line with the other side. On my first attempt it looked ok until I mounted it and it was riding against my extended mag release. So it was a good 1/16" off.. homer.gif Doh!

 

I understand cooling them rapidly in water would harden them. Somehow I have the impression that cooling in oil does the opposite.

 

Eh.. Yes and no. Quenching it in water will realign the structure of the steel, making it harder, but more brittle. In oil, it theoretically "normalizes" the steel by cooling it at a much slower rate. Just be prepared for a shit-ton of smoke...

 

Even if I did run the thumbhole, having a grip nut hole would be nice if I wanted to put different furniture on it in the future. I'd prefer to get all the hacking and painting out of the way now.

 

Good call on getting it out of the way. I found a great source for that hole location:

http://forum.saiga-12.com/index.php?/topic/27641-a-couple-decent-templates-for-cutting-pistol-grip-hole/

If you choose to go that route. I found it to be a PITA, but if you take your time, it shouldn't be too bad.

 

Any suggestions on drilling through the trigger guard tabs?

 

Heh.. Patience and a lot of bit sharpening. I burned up about a half dozen bits trying to drill through mine. I laughed when I saw the title of this thread. All I could think was, "Right??"

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I've got two trigger guards to drill holes through, .308 and .223. Both are already off the receivers and off the sporter plates. The one I'm trying to drill now is the .308 one, which has already been reshaped and prepared for installation with the exception of the front mounting tab hole and the matching hole in the receiver under the mag catch tower. The next trigger guard I have to do after that one is the .223 one, which I haven't tried drilling yet and still have reshape and cut off the extra section at the rear for the lower buttstock screw.

 

I have a small but well defined dimple made in the front .308 trigger guard tab, which was mostly the result of a spring punch which is now pretty dull (it was new when I started on this, and had a sharp tip). I was using regular "black" drill bits before, and after the little dimple they were no longer making any progress.

 

The cobalt bit I have now was brand new earlier today, and I only used it to drill two Saiga trigger/hammer pins and three sporter plate rivets after I had already ground them down totally flush with a carbide Dremel tip, from the outside. So, the cobalt bit is practically new and should still be somewhat sharp I think (it looks sharp, unlike my black bits). The rivets I drilled with it cut very easily at a low rpm. I suppose it's possible that the cobalt bit is dulled now, but if it is I think it would have been the trigger guard that did it, because the other rivets were so incredibly easy to drill. The cobalt bit really impressed me, until I got to the trigger guard that was the original reason I bought it.

 

I don't know if it would be helpful, but the carbide Dremel bit I have can probably remove some of the trigger guard tab where I'm trying to drill. Maybe if I can make a big enough dimple with it, I can get the cobalt bit to catch.

 

I'm not the most comfortable (well, experienced) working with an open flame torch, but I'm willing to learn and buy/use tools. All I have is the handheld Bernz-O-Matic type, with an old yellow canister of map gas that I'm not sure how much is left. My next course of action is to use that torch to heat up the tab and try to anneal it. It sounds like the right way to anneal it is to let it cool as slowly as possible, even burying it in sand to slow it down more than air cooling. I can harden it again after drilling the hole if I wanted, by heating and then cooling faster, maybe in oil if that's the best method.

 

Like Jetmech mentioned, I might have better luck drilling a smaller hole first. So far, I only have the one cobalt bit. The rest of my bits are whatever the normal black ones are made of, so I'd be looking at buying a smaller cobalt bit to try that. It's only $4 more, but it would be nice to get these done with the tools I already have. After these to I'll be doing an S12 and I should be done for a while. It is fun and challenging and I'd like to do more, but unless another Saiga falls in my lap I don't plan on getting any more.

 

JohnnyDingDongs, I don't have any experience with sharpening bits yet. I should look into that so my bits don't end up being disposable. As far as heating up the tab to flip it backwards, does it have to be glowing orange or how hot?

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Are you trying to drill through just trigger guard material, or are you trying to drill out the welding that is inside of the existing holes on the trigger guard?

 

I'm not sure on how you did yours, but I just ground off the rivets/bumps/whatever from the outside of the gun using a file, and then it just came off. The result was a trigger guard with 2 open holes on one side, and then a closed hole with a bit of weld sticking out of it on the other side. If I recall correctly, I just ground any weld material flush with the rest of the TG, and then just used a punch to knock out the remaining weld.

 

I dont know anything about torches btw so I cant comment on that.

 

Also +1 to carbide bits. I used one to drill through a sink to install a filter once.

 

As for making use of your current gear, I would just reccomend applying lots of pressure. The rivets came off easy because they are shaped like a crater, making the bit naturally get in there, allowing the bits sharp edges to work at the crater from inside out. With a flat piece of metal, youll either want to punch it first, or just apply LOTS of pressure to it, to make it start forming a crater. But if you do, make sure that you dont hurt yourself/ anything else incase your bit slides off of the TG in either direction.

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Are you trying to drill through just trigger guard material, or are you trying to drill out the welding that is inside of the existing holes on the trigger guard?

 

I was under the impression that the front mounting tab of the stock trigger guard had no hole. Keep in mind this is the .308 I'm working on. It's been a little bit since I got that trigger guard removed and to it's current stage, so I don't remember exactly whether the front tab was riveted or spot welded, but from what I'm dealing with now, I think it's a solid piece of metal that was spot welded to the sporter plate. The .223 trigger guard that I removed tonight (last night now) was spot welded at the front. I broke that weld by using the twist method. I think the .308 trigger guard was the same. So, I don't think there is a welding in a hole per se, but there is a spot weld there, which I'm trying to drill through.

 

Maybe I should say that the location where I'm trying to drill is in the middle of the front tab, where it was welded before. There's a spot weld depression on the bottom/outside surface of the tab, and that's where I want to put the hole. I am drilling from the opposite side, on the bottom (when the rifle is rightside up).

 

I'm not sure on how you did yours, but I just ground off the rivets/bumps/whatever from the outside of the gun using a file, and then it just came off. The result was a trigger guard with 2 open holes on one side, and then a closed hole with a bit of weld sticking out of it on the other side. If I recall correctly, I just ground any weld material flush with the rest of the TG, and then just used a punch to knock out the remaining weld.

 

Not that I expect you to read every detail, but I mentioned above that I Dremeled off the three sporter plate/trigger guard rivets with a carbide bit from the outside (bottom). I then drilled and drove out the three rivets and then sheared off the remaining spot weld at the front of the trigger guard to separate it from the sporter plate. This resulted in a circle of sporter plate material at the spot weld remaining on the trigger guard, which I then ground down flat with the front tab. I think you are describing this as weld material, but I would call it sheet metal from the sporter plate. It is weld material too, as it is metal that was welded, but I don't think what currently remains is anything that can be punched out as it's just the trigger guard strap itself remaining.

 

However when you write that you used a punch to knock out the remaining weld then I have to question my understanding of what I'm trying to drill through. I don't see why there would be any hole there to have weld material inside it if it is spot welded there. To me that would mean it's just the strap of the trigger guard itself, solid so that it could be spot welded to the sporter plate with no filler material unlike mig/tig/braze/etc.

 

Now, at the rear where it was riveted rather than spot welded, I did the equivalent of what you describe in that I knocked out the remnant of the rivet there. In my example, this knocking out was of the receiver instead of the trigger guard, since I went from the outside/bottom (sporter plate/trigger guard side) instead of the top/inside (receiver side) with the Dremel. I just did this a few hours ago on the .223 so my memory is still pretty good as far as what was involved. I'm almost positive the .308 was the same process and configuration.

 

I dont know anything about torches btw so I cant comment on that.

 

Also +1 to carbide bits. I used one to drill through a sink to install a filter once.

 

As for making use of your current gear, I would just reccomend applying lots of pressure. The rivets came off easy because they are shaped like a crater, making the bit naturally get in there, allowing the bits sharp edges to work at the crater from inside out. With a flat piece of metal, youll either want to punch it first, or just apply LOTS of pressure to it, to make it start forming a crater. But if you do, make sure that you dont hurt yourself/ anything else incase your bit slides off of the TG in either direction.

 

I appreciate your helping and responding to this thread. In my example when I drilled with the cobalt bit I was drilling into the flat surfaces of the rivets which I had Dremeled basically flush with the sporter plate/trigger guard and then spring punched. As for the hole I'm trying to make now in the front tab of the trigger guard, I have a decent enough depression in it that there's not really any problem with the bit walking. I have put a decent amount of pressure on it so far, to the point that it does end up deflecting off in different directions (wish I had a drill press), but I feel like I'm forcing it and not letting the tool do the work. I'm thinking the high drilling pressure method works when it works because in those instances the metal is soft enough to displace from the pressure and give the cutting edge of the bit something to bite into. With this darn trigger guard, it seems so hard that it's not working, yet.

 

I'm going to give the torch annealing process a shot next. I'm optimistic that it'll be the missing technique to allow me to move forward.

 

By the way, my Makita has a hammer drill function in case it has any application here. I'm thinking not though.

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I have a small but well defined dimple made in the front .308 trigger guard tab, which was mostly the result of a spring punch which is now pretty dull (it was new when I started on this, and had a sharp tip).

 

I don't know if it would be helpful, but the carbide Dremel bit I have can probably remove some of the trigger guard tab where I'm trying to drill. Maybe if I can make a big enough dimple with it, I can get the cobalt bit to catch.

 

You're on the right track here. A number of things happen when a bit burns up while drilling. The heat and pressure of the drilling process end up working against you if things get fouled-up. Your bits fry, for one thing, but then it gets real nasty. The intense heat and cutting fluid work to basically temper the steel where you were trying to drill. On top of that, as your bit heats up and is being pressed down and spun, it begins to degrade, tracking bits of its own material through the workpiece and embedding them there (picture a piece of chalk being dragged along and leaving a trail of itself as it goes.) So now you've got a tempered, strengthened, abrasion-resistant spot right where you want to drill. It gets better.. On top of that, the spot you need the bit to grab onto is now polished from having the dull bit dragged across its surface.

Wow, I've never really spoken or written that out before.. Sounds dismal at best. It's not! There are ways around this and you've already pointed one out. What kinds of bits do you have for the dremel? If you have something small enough and cylindrical (diamond-tipped would be great), you might be able to rough that spot back up and take out some of the 'galded' material before drilling again. This is exactly what I had to do.

post-32852-0-33590400-1327251734_thumb.jpg

That bit in the foreground was a pretty decent one when I started. Notice how the abrasive material is gone. It got me through two trigger guards and still has a bit of life left though.

 

I suppose it's possible that the cobalt bit is dulled now, but if it is I think it would have been the trigger guard that did it, because the other rivets were so incredibly easy to drill. The cobalt bit really impressed me, until I got to the trigger guard that was the original reason I bought it.

 

post-32852-0-07354400-1327251367_thumb.jpg

If it looks like the one on the right, it's trashed. Notice how straight and clean the cutting face is on the left? Once that straight face gets rounded or chipped, it's time to sharpen. Once it goes blue like that other one, it probably wont ever hold a good edge again. Not with these tiny bits, anyway.

 

I'm not the most comfortable (well, experienced) working with an open flame torch, but I'm willing to learn and buy/use tools. All I have is the handheld Bernz-O-Matic type, with an old yellow canister of map gas that I'm not sure how much is left.

 

JohnnyDingDongs, I don't have any experience with sharpening bits yet. I should look into that so my bits don't end up being disposable. As far as heating up the tab to flip it backwards, does it have to be glowing orange or how hot?

 

Sharpening bits is easy. It's a breeze if you have a sharpener, but they're pricey. I use a bench grinder and it works great.

 

I'm sure that MAPP gas torch will be sufficient. I used:

post-32852-0-12010300-1327252011_thumb.jpg

Propane and was shocked that it worked so easily.

As far as color of the steel, it depends where you are. I know it sounds goofy, but indoors vs. outside makes a difference. Indoors, it will become malleable once it has reached a dull 'cherry red.' You do want to shoot for a shade of orange. Try to get it as hot as possible, as it will cool rapidly as soon as you remove the heat source. If it hits yellow, pull the flame back. I don't think you'll have any trouble. Outside in direct sun, it will barely look 'cherry red' but in fact be quite malleable.

Sounds like you have a pretty good idea of what you are doing and I'm betting your TG comes out better than my first attempt.

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Torch will do it. Don't really have to get it cherry red. Just get it to glow a bit and let it cool on its own. A carbide bit at a slow speed will do it too. Cutting fluid will help. Being nicely punched will help. Do NOT use a hammer drill. That's for soft materials.... well, softer than hardened steel. You'll shatter your bit and probably worse bouncing all over the place. I have a hand punch press that would have done a good job if I could find it. It has carbide bits and has gone through harder and thicker stuff in the past.

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Thanks! Looking forward to getting this behind me.

 

On another note, how do you like the Hogue forend? From what I've seen, I'm interested in them.

 

I think I'm going to do my .223 in Desert Tan / Flat Darth Earth furniture, to match the Hogue grip I bought when I thought Arsenal / K-Var was still making the desert tan NATO length AK74 style buttstock. They discontinued them.

 

Now I have a VLTOR receiver extension and am going to put an FDE CTR stock on it and was thinking to either paint the original forend to match or kicking around the idea to get a Midwest Industries rail in FDE. I like the optic-specific mount they offer, but it seems like it's an AK-style only thing, as they don't have a Saiga (longer toward the sight block) version, probably because they are looking for a bolt-on thing without having to remove the heat shield from the gas tube. I could get the AK one and put a regular gas tube on to fill in the gaps, but then would feel like I'd need a Saiga-AK.com bolt on lower retainer so the upper retainer didn't look off balance.

 

I had forgotten for a moment about the Hogue forends. I don't see too many pics of them, but I'd like to see more. I'm not a huge fan of overdone and heavy quad rails, but when I saw the FDE one from MI it caught my eye, especially since a website that I am slowly filling a shopping cart for has them as well and their prices are pretty good.

 

I'm glad you posted that pic, because it reminded me about the Hogue forends, and if I'm trying to match the Hogue grip then it would seem to be an obvious option if you like the style which I do.

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I like my hogue forend. If feels right to me. But I have hogue stuff on a lot of my guns so it's a feel that I'm used to.

If you can find a FDE one, it makes sense to match your grip. The newer ones are supposed to have a matching top/gas tube cover. Older ones are just black. Make sure you get what you want...

I don't plan on hanging anything off them. So the rails and top cover with the rail are relegated to the junk drawer.

I have a retainer spring in the top handguard and it is nice and tight. The hogue top guard has the cut out for it. Don't think if it would be tight enough for an optic. But I'm not going there anyway...

I was able to get the lower handguard nice and tight with a bolt on retainer that I made from a standard bulgy retainer. I've since swapped FSB and GB and now have a real lower retainer on. It isn't as tight as I could get with the bolt on but it it does fine.

The heat shield in the hogue seems like it would want to rattle, touches the barrel and interfered with my retainer lever, the gas block lever and cleaning rod. After trimming it, shimming it with tinfoil and finally breaking one of the tiny retaining tabs, I ditched it. I don't think it will be a problem and if it is I'll do something else. If hogue made a traditional grip with the overmold, I'd have one. I like the way the hogue grip feels. But I love the look of the standard AK grip.

good luck with the drilling

rich

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I had the same problem when doing my .223. The spot weld on the trigger guard ruined several regular hardened bits and a carbide bit; they barely made a divot in it. I can't explain it, other than that the spot weld must have been hot as hell when it was done. I ended up bending the trigger guard up and taking out the weld with a chisel from the rear of the rifle. I couldn't reuse it, but it came off.

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I suppose there's no hard in ruining the old trigger guards by trying to anneal them if I'll default to aftermarket ones anyway. So, to anneal them, I get them pretty hot with a torch and them dunk them in oil? Or let them cool naturally? I understand cooling them rapidly in water would harden them. Somehow I have the impression that cooling in oil does the opposite.

 

No, you want them to cool in still air. Oil quench still hardens, just not as much as water. It's the rate of cooling that makes the hardening process work.

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I suppose there's no hard in ruining the old trigger guards by trying to anneal them if I'll default to aftermarket ones anyway. So, to anneal them, I get them pretty hot with a torch and them dunk them in oil? Or let them cool naturally? I understand cooling them rapidly in water would harden them. Somehow I have the impression that cooling in oil does the opposite.

 

No, you want them to cool in still air. Oil quench still hardens, just not as much as water. It's the rate of cooling that makes the hardening process work.

 

Yes, thank you. Further down in the thread I mentioned cooling slowly. When I do it, I'll either cool them in still air or bury them in sand or something similar.

 

I'm looking into buying a drill bit sharpener (Drill Doctor). They were on sale through Amazon's Gold Box deals the other day, but when I shopped prices I found that Tooltopia or someplace was cheaper if I wanted to also get the adapter to do reverse bits.

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  • 2 weeks later...

I didn't know these things were so hard to drill. I'm going to have to give mine a shot even though I bought a replacement trigger guard.

 

There is one saying that goes when it comes to drilling steel. "Lots of ass and a little gas." Your worst enemy when drilling steel is to get too much heat into the material. When that happens it called work hardening. If you get to that point it's near impossible to drill a hole through you material with a hand drill unless you anneal the material.

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  • 1 month later...

Spot welds DO produce diamonds! It also hardens the metal. I use a cold chisel to 'shatter' the spot weld when removing the TG.

 

Annealing with a torch removes the hard temper,and evaporates the microscopic diamonds. Re-tempering a trigger guard is not really necessary, but heating it to a dull 'straw' color and dropping it used motor oil will re-temper the steel and give it a nice black color.

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