Bullet Guide SNAFU

[Palouse 0]

While I generally do not like to bring my failures to the attention of others--particularly when they are caused by my own impatience--I need some help. I snapped the tap in the hole I drilled in my trunion despite having read cautions about flexing the tap. It's flush with the trunion, but it snapped at a slant, and attempting to drill the remaining tap out with a drill bit makes the bit dance like a whirling dervish. So much so that I worried about the drill bit snapping. So far, I've given thought to:

 

Having a local machine shop spot weld the guide to the trunion, Dremel grinding off any slag/excess and Oxpho-Bluing anything in the white

Buying an end mill to chuck in my drill press to drill a bigger hole and buy a bigger tap and screw

Figuring out how to access the other side of the trunion and riveting the guide on (not talking pop rivets here)

 

My first question is, have any of you had this problem, and if so, what did you do about it (I'm not looking for any JB Weld solutions)? If not, and you're more "machinist-inclined" than I am, I'm all ears.

 

ETA: I did find this: http://www.crawfordproducts.com/structural-blind-rivets.htm about structural blind rivets--carbide rivets for high vibration applications.

Edited April 12, 2010 by Palouse

[vbrtrmn 167]

Someone did this before, there's a thread on it, though I'm too lazy to search for it. If I recall correctly, people recommended that the guy hammer the shit out of the tap to shatter it. Search for broken tap or something like that and you should find the thread.

 

I think the main problem for snapped tap is not enough lube or tapping to quickly. Tapping is like fucking, you get better results, when you slow down and use lots of lube.

[Palouse 0]

Someone did this before, there's a thread on it, though I'm too lazy to search for it. If I recall correctly, people recommended that the guy hammer the shit out of the tap to shatter it. Search for broken tap or something like that and you should find the thread.

 

I think the main problem for snapped tap is not enough lube or tapping to quickly. Tapping is like fucking, you get better results, when you slow down and use lots of lube.

 

Thanks. I'll take that approach.

 

I did a search but must've been using the wrong search criteria.

[vbrtrmn 167]

Feeling slightly less lazy now, try one of these, found them all by searching for "broken tap" (yes in quotes)

http://forum.saiga-12.com/index.php?showtopic=9252&st=0&p=75321&hl="broken tap"&fromsearch=1&

http://forum.saiga-12.com/index.php?showtopic=11944&st=0&p=97375&hl="broken tap"&fromsearch=1&

http://forum.saiga-12.com/index.php?showtopic=3484&st=0&p=30145&hl="broken tap"&fromsearch=1&

http://forum.saiga-12.com/index.php?showtopic=21437&st=0&p=185715&hl="broken tap"&fromsearch=1&

http://forum.saiga-12.com/index.php?showtopic=46428&st=0&p=429225&hl="broken tap"&fromsearch=1&

[SaigaNoobie 66]

Fix it with some JB weld.

[jjvgnslngr 3]

"Tapping is like fucking, you get better results, when you slow down and use lots of lube."

 

Can I use that when I explain the process to the guys at my shop? They can't seem to figure out why the machinist (me) gets pissed when I have to try and remove the taps they snap off.

[storm1 2]

i did the same thing this past weekend, wd40 with tweezers and long nose pliers came right out broken in little pieces...

[Palouse 0]

Many thanks to all.

 

A good whack with a punch and it broke to pieces. Dental tools fished out the small stuff. Now that I'm back in business, I'll heed the slow-with-lots-of-lube advice.

 

However, this whole process has forced me to take a good look at the lower trunion area, and I'm curious to know what prevents me from just bolting the bullet guide on with a good dose of Loctite on the nut? The backside looks easy enough to get to. Anyone gone that route?

Edited April 14, 2010 by Palouse

[oliverb 4]

I had the same thought when installing my guide. Don't see why not.

[Spikester 93]

I think the trunion is tapered and the nut would not be tightening against a flat surface.

[Palouse 0]

I think the trunion is tapered and the nut would not be tightening against a flat surface.

 

Ah. That would be why not more are doing it. Nuts...I was looking for an easy out. I may measure it, though, just to see how much taper there is.

[icefire 10]

I did the same thing. My drill bit slipped a bit and the first hole I drilled was too close to the chamber. Instead of modifying the BG as I should have done, I drilled another hole in the right place. but they broke thru together, leaving me with a figure 8 shaped hole. Pics of this are in my gallery.

 

Tried to tap the right one, and the tap snagged and snapped. I got the pieces out, and did this.

 

I found another screw that would fit in the hole. I tapped the hole just one or 2 threads that it would let me. Then I filed down the threads on the screw I was going to use so it would thread down in, although not tighten up all the way. So, at this point, I has a screw in a hole that was holding down the BG, but loose. So, I roughed up the trunnion surface that the BG was going to fit onto, and roughed up the bottom of ther BG, then, I used JB weld as "super locktite" to hold in the screw, and also put some on the bottom of the BG to hold it in. So, what I ended up with was a BG that still has a screw down in the hole to prevent movement, is JB welded into the hole tightly, AND the BG itself is JB welded down onto the trunnion.Then I dremeled the head of the screw down flush and filed it smoother. This is working fine, after filing the front of the BG a bit to fix a feed problem that a lot of BG's have. I wouldnt just use JB weld without a screw of some sort, but the way I did it is working....

[Wade Pruetz 103]

I did the same thing on a buddys gun...thank god it wasn't mine! I am pretty sure those taps included in the kits are crap, I have taped lots of holes...all female of course...well once when I was in jail...anyway I have never broken a tap so easily as that POS that came with the bullet guide kit.

[L5K 162]

I just got through installing my bullet guide. I got an actual 5.45 guide from K-Var, used the grinder to make it fit and clear the lug on the left side of the Saiga. This guide also came with the actual rivet to install it. So, what I did was I measured the rivet which was about .197" and I looked at a drill chart and saw that a #10 drill bit is .1935" so I used that for the hole in the trunnion. Then I used a file to add a slight taper to the rivet, so it would just start into that hole, and then I easily hammered it into place. The sizes of the hole and the rivet result in a press fit which is similar to how the pins in the front sight block and gas block are installed and they do not come out. This should be just a difficult to remove as they are. For good measure however, I took off the lower handguard, and saw that about half of the rivet is now sticking down into the area under the trunnion, so I used a punch to mash on it so that IF somehow vibrations ever make it want to come up, it can't because the bottom edge is bent and mashed to the side.

[Vermiform 26]

Just broke one off flush in the trunion. Whacked it twice with hammer and punch and it shattered. Fell right out. Chased the threads with new tap and it works fine! Someone write a good sticky on this. I was on ebay looking for tap extractors when I decided to come back here and do a quick search.

[Vermiform 26]

and just broke the second tap in another rifle. Punch - Hammer - Whack - Shatter method works good, definitely getting the technique down.

 

Dunno what's wrong with me, haven't broken a tap in years. Guess I need a break; gonna go download some porn me thinks.....

[gunguy98 5]

On all my conversions I've only ever just drilled the hole and used a small bolt and nut secured from the underside with red locktite. They are perfectly solid and after many thousands of rounds haven't moved or became loose at all. This method is so much easier.

[Palouse 0]

On all my conversions I've only ever just drilled the hole and used a small bolt and nut secured from the underside with red locktite. They are perfectly solid and after many thousands of rounds haven't moved or became loose at all. This method is so much easier.

 

This, next time.

[Avtomat 3]

I just had the same issue, my tap was all the way through and snapped as I was backing it out. Used the hammer and a sharp hard punch and knocked the broken piece right out. I did run a new well oiled tap through the threads and cleaned them up. The bullet guide fits great now and is tight. There is enough thread sticking through the trunion to add a nut. I will add this and red loctite at final assembly. Thanks to this forum I did not panic and was able to correct things in a couple of minutes.

[Runithard 0]

Maybe I'm crazy, but I'm thinking of just using a high grade epoxy to hold the bullet guide. If it can hold 2000lbs, it should be fine to set this.

[Jpnorris87 3]

Ok....a common misconception about tapping a hole is that you throw some oil on it and just screw it in the hole. THIS DOES NOT WORK WITH STEEL! Yes you can get by with this on aluminum and softer metals but it will not work on hardened steel.

 

 

Drill the right sized hole...and drill it straight. Lube up the tap and the hole. Start the tap in the hole. Pay careful attention to starting it straight. If you start the tap at an angle, you will snap it every time. Once the tap is started the key is HALF A TURN IN, FULL TURN OUT. Every full rotation or so, pull the tap completely out and clean the hole. When tapping hard metals you have to clean the tap out frequently. The metal shavings build up and can lock up the tap.

 

 

Go slow and do it right the first time.

[CPE1704TKS 24]

Ok....a common misconception about tapping a hole is that you throw some oil on it and just screw it in the hole. THIS DOES NOT WORK WITH STEEL! Yes you can get by with this on aluminum and softer metals but it will not work on hardened steel.

 

 

Drill the right sized hole...and drill it straight. Lube up the tap and the hole. Start the tap in the hole. Pay careful attention to starting it straight. If you start the tap at an angle, you will snap it every time. Once the tap is started the key is HALF A TURN IN, FULL TURN OUT. Every full rotation or so, pull the tap completely out and clean the hole. When tapping hard metals you have to clean the tap out frequently. The metal shavings build up and can lock up the tap.

 

 

Go slow and do it right the first time.

 

And a piloted tap in the drill press used to drill the hole helps a lot. Loosley place in the chuck, it keeps the tap aligned with the hole. And remember, cutting oil, half in, full out. Take your time, this is not the time when speed counts.

[Gopher 7]

Maybe I'm crazy, but I'm thinking of just using a high grade epoxy to hold the bullet guide. If it can hold 2000lbs, it should be fine to set this.

 

would this actually work? how much is this epoxy, or is it to outrageous of a price to meddle with?