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Drilling Bulgarian FSB for pins


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I am trying to put a Bulgarian ak74 front sight block on my saiga. I have my old fsb off and the new one is in place. The fsb already has holes through them and I have the correct pins that come with it (3mm I believe?). I have a 7/64 drill bit that I am using since its a tad smaller than 3mm. No drill press though, only have a hand drill. So here's a few questions:

 

Is 7/64 a good size for doing this?

 

It seems like if I just drill through I'll be taking a lot of barrel out, am I suppose to completely clear the holes of any barrel? I don't see how the pins would fit in otherwise...

 

Any other tips for doing this? I've read quite a few tutorials on this website and on the internet and they didn't' seem to answer the above questions 100%.

 

thanks guys

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That is the size bit that I used to do mine. But the stock pins wouldn't fit and I opted to not drill the holes any larger so I found pins that would fit and cut them to the proper length and tapped them in and it is all done. One thing I did that may be helpful though. After hearing from a couple of people that using a regular drill bit caused the bit to veer off the barrel and come out the other side at an angle I took one of my bits and ground off the angled tip and went very slow letting the sides of the cutting surfaces do the work and was able to drill straight through with a cordless drill. I have a drill press but found this method to work perfectly. I did chuck the rifle in a vise for this and I used oil to keep things cool.

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I have done a few gas blocks and sight blocks on both 7.62 and 5.45 AK rifles. I always reinstall with 1/8th inch pins because they are common. This is what was recommended to me a long time ago by multiple sources on another website when I asked about what size to use. I've never done it with a hand drill but have heard of people also having success with one. The size will be just fine. There is less material being taken out there than there is on a standard AK's handguard retainer.

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Ok so I drilled the hole and it went pretty smoothly, then as I broke through to the other side the drill bit snapped. I guess I'll just leave it in there instead of tapping it out and retapping one of the pins in. Still have to do the other hole but now I need a new drill bit. thanks for the help guys.

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I used a 7/64 cobalt drill bit on mines. I bought the pins off kvar but they wouldn't fit and I didn't want to make the hole larger so I ended up buying some nails and hammering those in then cut off the parts sticking out. So far so good. I've put a few hundred rounds through over the past few months and it works perfectly.

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