Ak rails

[TATER313]

Last week when I built my ak74 trying to drill the holes in the rEceiver thru the rails was almost impossible. We dulled up many bits small and large. We had the same problem over the weekend all new colbalt bits. We believed the rails were over harden. We eventually had to heat them up a little to relax the metal a little to be able to drill thru them. We even dulled a small step drill. Was wondering if anyone else was having this problem.

[Alex$]

Had this problem with an amd65 rail set about 3 weeks ago, guy was pushing on drill bit hard enough to pop a weld when I walked up to him. Re-welded rails, annealed aNd re-drilled with a new bit.

[jrock]

I experienced said issue on first build.
bp helper at next build provided a cut down bit, reducing deflection, w\a little oil, it went thru much easier.
also made sure spots welds were not too close to area.
sidenote: demilling xyz parts ahead of bp saves ton of time, if u have parts prior.

[TATER313]

At my build party we had several kits with this issue, we used smaller drill bits with cutting oil, dremel with diamond bits, the only thing that worked was reheating area to soften metal then it went thru with ease.

[bruceflinch]

Drilling at slow RPM?

[TATER313]

slowly

Drilling at slow RPM?

We used high quality drill bits and used cutting oil and still no luck.

[tujungatoes]

Next time only harden just the ejector tip before welding in your rails, and drill and ream all other holes before heat treating the axis pin holes. Your spot welder, drill bits, and reamers will thank you.

[Alex$]

No hardening done in my case. I thought the guy drilling might have work hardened it, I flipped it over and drilled. The receiver drilled as expected, the rail itself was a b*tch until I annealed it.

There was a definate issue with the rails.

[69Mach1]

We experienced this at our last few build parties. The rails could not be drilled through easily. There were 3 cases of this happening at each BP.

[TATER313]

I do not harden the ejector until after we weld the rails and rivet everything. only about a 3rd of the builds had this issue and all were welded in the same spots. the rest were easy to drill with ease.

[TATER313]

Nicoroshi said he had the same problem this weekend.

[Anti-Hero]

I've drilled out broken drill bits easier than one of my rails yesterday. It took heating the rail before it would drill.

[tujungatoes]

weird

[Varg Vikernes]

One side's rails seemed to be harder than the other. I wanna say it was the scope rail mount side that had the super hard rail.

[nicoroshi]

Nicoroshi said he had the same problem this weekend.

Yep, definitely heat hardened BEFORE package was opened.