Bolt Mods

[Intruder196]

What are you guys using to drill through the wedge in the bolt for the new firing pin? None of my drill bits will do more than scratch the metal surface.

[ak47dennis]

Your going to need a tungsten carbide drill.

[Abwehr]

Here is something else that MAY help drilling. If you can get the surface removed with a carbide Dremel tool, you will get past the hardened surface and drilling will be easier. Still, the carbide drill is recommended anyway, but removing the surface will make the drill bit last longer.

[Intruder196]

Your going to need a tungsten carbide drill.

I researched the MG42 FAQ and found a mention of using a carbide bit. Today I checked several tool places locally and nobody seems to carry them. They all ask if I am drilling concrete.
Any suggestions on where to get them? Also did you use any sort of cutting oil?

[TOM R]

when I need to drill hardened items i goto my local machinest because my mini drill press won't turn slow enough, the lower the rpm the better or so I am told, been thinking of installing a variable rheostat to slow down the motor so many projects so little time

[Sarin]

I have found a cheaper alternative for drilling through this part. Try a glass and tile bit. I used a Black and Decker brand. It was around $6.00 at the hardware store and it cut right through.

[Jason]

I'm not sure but I think that carbide bits need to spin fast to cut. I do know that you do not want to drill soft metals with the carbide as the bit really heats up fast and it can wipe them out.

[ak47dennis]

Some good points !! Abwehr the old dremel trick works well.

Try MSC or a local Grainger thats were I get my mills & drills, you can use a masonary bit those are carbide but you will trash it quick.

[Intruder196]

I tried using a glass and tile bit like was suggested above. It only drilled into the metal about 1/8" then ground itself down.
I went to a local Grainger today and they didnt have any carbide bits in stock. It will be here Monday.

What speed did you guys use to drill the hole? Should I use cutting oil?

[Plinker762]

I've had my kit for at least 6 months and this is the only mod I've gotten done.

I used a straight flute carbine bit from Mcmaster Carr (mcmaster.com) Looks like I used a 4.5mm. Part # would be 8842a48. Inch sizes start with 8944axx xx being the specific number for each drill size. I drilled the sleeve in my lathe since I felt it would be easier. Ran it at a medium speed, with no coolant or lube. Carbide bits can take a lot of heat compared to HSS. The straight flutes don't remove chips very well so I backed the drill out often. Didn't want to pack the bit. Carbide bits are very strong but don't like shock loads. This bit went right through without any trouble and left a very nice finish inside the hole.

I know from another project that these drill bits don't like case hardened material and tend to break when they hit the softer core. The sleeve was hard enough all the way through so this was not an issue.



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