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devilfish13

bullet guide FINALLY installed!

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One drill bit, three taps, what seems like a gallon of tapping fluid, three nights, and a lot of profanity later... I finally have my BG installed on my 7.62x39. I haven't test-fired it yet, but hand-cycling dummy rounds works great with both a Tapco and a milsurp... Others have warned about thicker metal and the job taking longer on a Vepr, I apparently didn't take it fully into consideration. I kept getting it tapped about 7/8 of the way and then it would stick... and I'd back it off, blow out the hole and clean the tap, more fluid, and... snap! First tap was the 2-flute from Dinzag, second one was a 3-flute from the local industrial supply shop... the one that finally made it all the way through? A cheap off-brand 3-flute TOOL STEEL (not HSS) from Menard's. It's all installed and looks quite pretty now, actually. I'm impressed.

 

I suppose I didn't need to post about this, but after the frustration I guess I just wanted to vent. Anyone else have interesting experiences like this BG'ing a Vepr?

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One drill bit, three taps, what seems like a gallon of tapping fluid, three nights, and a lot of profanity later... I finally have my BG installed on my 7.62x39. I haven't test-fired it yet, but hand-cycling dummy rounds works great with both a Tapco and a milsurp... Others have warned about thicker metal and the job taking longer on a Vepr, I apparently didn't take it fully into consideration. I kept getting it tapped about 7/8 of the way and then it would stick... and I'd back it off, blow out the hole and clean the tap, more fluid, and... snap! First tap was the 2-flute from Dinzag, second one was a 3-flute from the local industrial supply shop... the one that finally made it all the way through? A cheap off-brand 3-flute TOOL STEEL (not HSS) from Menard's. It's all installed and looks quite pretty now, actually. I'm impressed.

 

I suppose I didn't need to post about this, but after the frustration I guess I just wanted to vent. Anyone else have interesting experiences like this BG'ing a Vepr?

 

i had issues with it also,done many saiga's and never had any problems. was more than 1/2 way thru on 7.62 vepr when the tap broke, went slow backed it out several times cleaned then snap! tried to shatter it out with a punch and a hard smack with a big hammer.....no luck. drilled the guide hole out a little bigger grabbed the mig and welded that bitch in. put two tacks in one on the front and one on the back of the guide.....2000+ rds later solid as a rock.

did my homework with several builder's opinions on the trunion before putting heat on it and many said the metal was much more heat tolerate than the saiga being thicker and all....so it got welded. it's not going anywhere. 032.gif

Edited by adjc

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Hmm.

I have tapped a couple of Saigas with out any issues. I have a New Vepr .223 and this has me concerned.

I guess I need to look for a 3 fluted tap.

I have the Dinzag taps and drill bits. Which size tap broke on you ?

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Hmm.

I have tapped a couple of Saigas with out any issues. I have a New Vepr .223 and this has me concerned.

I guess I need to look for a 3 fluted tap.

I have the Dinzag taps and drill bits. Which size tap broke on you ?

 

it was a 6/32 craftman's tap, was from an older set my dad had from many years ago. virgin tap never been used.

Edited by adjc

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Hmm.

I have tapped a couple of Saigas with out any issues. I have a New Vepr .223 and this has me concerned.

I guess I need to look for a 3 fluted tap.

I have the Dinzag taps and drill bits. Which size tap broke on you ?

 

Mine were both 6-32, the 2-flute HSS from Dinzag and a 3-flute HSS from the local industrial supply shop. I was hesitant to use the 3-flute since I don't have access to a tap extractor with 3 fingers, only a 2-finger model at work. If I couldn't get it threaded with the cheapos I'd bought (I got 2 sets just in case), I was going to upsize it and use an 8-32, but didn't end up needing to.

 

Btw, the guide works flawlessly and hasn't jammed on me yet over ~120 rounds split between fmj and sp from milsurp mags.

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Yeah these trunnions are a bit thicker. I went really slow and am suprised I didnt break mine on my 5.45. I had it squeaking but it never did break. I though it was going to though a few times. It took me almost 2 hours to get mine tapped. I dont use a tap wrench though. My method is rather hillbilly, as I use a pair of vise grips and bit down the tap a bit and lock it in the grips. seems to work great though, as Ive done several BG's now this way and havent had any break yet doing it this way. lol.

 

Glad you got it in there though Squidkitten!

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I broke 2 taps in my 7.62x39 vepr. Like the others I have done a couple saiga's and they were a brezze but the vepr was another story. Glad Im not the only one that had problems. Took about 2 hours to complete. Welding sounds like the way to go!

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I have been waiting on my BG to come in from Dinzag,and hearing that they were the same as the Saigas, I removed my Saiga BG and tapped my vepr for the BG and it was not too bad. It was not as easy as a Saiga, but it was not eo difficult.

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Yeah, they're the same. Sounds like you were either lucky or a lot more experienced with taps... I hadn't tapped anything in about five years, back when I was taking prereq's for CNC classwork. It ought to drop right in when you get it.

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I have tapped a few holes in my day, but I have had them break off before and they are a ***** to get out .

I would say that I got lucky.

I am going to help a friend drill and tap his next.He ordered his a couple days after I did.

Are most of the taps breaking in the 7.62X39 models ?

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Has anybody ever riveted their bullet guide in with a rivet similar to the rivets used to rivet the receiver together? I think this way is mil spec and is probably the best way to do it.

post-44407-0-41875000-1398782624.png

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Ive seen a few people use pop rivets. They seem to have held up so far, but Ive never done one like the factory.

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You should be able to drill it out and tap larger. Our take a punch and chip it out. They are brittle.

Edited by Ak Monty

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You should be able to drill it out and tap larger. Our take a punch and chip it out. They are brittle.

 

Could I possibly drill it out with a smaller or same size bit? Then,pick up where I left off (so to speak) with a fresh 6/32 tap, so I don't have to go buy a bigger tap and screw?

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You should be able to drill it out and tap larger. Our take a punch and chip it out. They are brittle.

 

Could I possibly drill it out with a smaller or same size bit? Then,pick up where I left off (so to speak) with a fresh 6/32 tap, so I don't have to go buy a bigger tap and screw?

 

You really cant drill taps, they are harder than most drills,. I have fractured them with tiny punches, but if its in very deep its a bear.

you could try a tap extractor, but they have a habit of breaking as well, so go easy.

In extreme cases taps have to be removed by plunge EDM

 

PS you can also kill the temper of the tap with a torch, then it can be drilled

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I've done a bunch that went easy and then one that was PAIN. Broke two taps in it. First one, I was finally able to break out and the second one I was able to break out as well but it wasn't easy. I could only get about 1/2 a turn before they would bind. I think the drill bit was not the right size. Opened it up a bit larger and re-taped it and it worked fine.

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I've done a bunch that went easy and then one that was PAIN. Broke two taps in it. First one, I was finally able to break out and the second one I was able to break out as well but it wasn't easy. I could only get about 1/2 a turn before they would bind. I think the drill bit was not the right size. Opened it up a bit larger and re-taped it and it worked fine.

 

What size did you eventually drill/tap it that worked?

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I've done a bunch that went easy and then one that was PAIN. Broke two taps in it. First one, I was finally able to break out and the second one I was able to break out as well but it wasn't easy. I could only get about 1/2 a turn before they would bind. I think the drill bit was not the right size. Opened it up a bit larger and re-taped it and it worked fine.

 

What size did you eventually drill/tap it that worked?

 

I think I went to 10/24 with a #25 bit IIRC. Mainly because that is what they had at the store. It was either that or 8/32

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Threads will develop most of their strength even in over sized holes.

 

Its not uncommon to drill slightly over size holes to tap very hard materials.

 

An 8-32 calls for a #29 drill (.136)     A #28 is (.140)

That would give you .002 per side, and make Tapping hard material a bit easier .

If you happen to break a tap, It will extract easier as well.

jim

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