AK-Builder Barrels - Wow.

BradMacc82 · Oct 10, 2016

Curtis makes a fine barrel, I'll give him that.

Nice sharp rifling, even chrome lining, concentric threads (for suppressor fun), and already had the extractor and hand-guard cap cuts done.

Price is reasonable too.

Maybe it's my luck finally running out, but I'll be damned if I can even make a dent in this bastard when it comes time to drill the gas port.

I'm somewhere between 11 and 13 bits used today, and no progress to speak of. Either snap the bit before it bites into the barrel, or it just doesn't cut into the barrel. All the bits that broke, managed to get them out, so I'm pretty sure I'm not trying to drill thru a broken bit remain.

High Speed Steel, Black Oxide, Titanium, 8% Cobalt High Speed Steel - nothing. Just more broken or dulled bits. 135 degree split point, just like what Curtis sells for drilling the port out.

I'm at a loss for words.

iH8DemLibz · Oct 10, 2016

I'm guessing you work hardened the material while you were wearing out the bits.

Not criticism. Just information.

You may need to anneal that port area and try again with a carbide bit. Or try the carbide first without annealing.

Good luck with it.

BradMacc82 · Oct 10, 2016

Eh, worst case scenario, I'll have a single shot AK pattern - maybe then it'll be MD-compliant...

mopar92 · Oct 10, 2016

Try using wheel bearing grease just dip the bit in at low speed first. It cools the bit and doesn't get soung everywhere if you don't use too much.

BradMacc82 · Oct 10, 2016

I'm calling it for the night, bit #14 just bit the dust.

Time to walk away from it, before I get tempted to fire up the plasma cutter.

Fox123 · Oct 10, 2016

iH8DemLibz said:
I'm guessing you work hardened the material while you were wearing out the bits.

Not criticism. Just information.

You may need to anneal that port area and try again with a carbide bit. Or try the carbide first without annealing.

Good luck with it.

This but I would try carbide bit. What speed are you turning it at?

BradMacc82 · Oct 10, 2016

Fox123 said:
This but I would try carbide bit. What speed are you turning it at?

Moderate speed with cutting oil, I don't have a nice drill press or end mill to chuck this fvcker into, so I get to improvise, adapt and overcome by going at it with a handheld drill.

Ideal, no. What I got right now, yes.

Fox123 · Oct 10, 2016

http://www.kennametal.com/en/products/20478624/556249/3924453/100047208.html

BradMacc82 · Oct 10, 2016

I'll figure something out, or just say F It and let this thing go to the wayside.

Figures though, what should be an easy and straightforward task - I manage to turn into a clusterfoxtrot.

DutchV · Oct 10, 2016

If it's just the surface that's hardened, you can grind through the top layer with a cone-shaped Dremel grinding bit, then try to drill again.

Matlack · Oct 10, 2016

Your using a hand drill? No wonder your breaking bits. You cannot hold a concentric hole with a hand drill. Nor can you control your velocity. All this while trying to drill on a curved and hardened steel surface using incorrect bits. I can't see why you aren't succeeding with this task.

Striknine · Oct 11, 2016

Bring it by and we'll throw it up on the drill press. Just bought two new bits that will work for this application. If that doesn't work we can pull the gas block and start the hole with the dremel.

BradMacc82 · Oct 11, 2016

Matlack said:
Your using a hand drill? No wonder your breaking bits. You cannot hold a concentric hole with a hand drill. Nor can you control your velocity. All this while trying to drill on a curved and hardened steel surface using incorrect bits. I can't see why you aren't succeeding with this task.

Nice Armed Ferret impersonation, but I deal with him plenty, so that level of condescension doesn't really have much of an effect anymore.

But I suppose when you're trying to drill a 45 degree hole into a stainless barrel, there may be better options than a hand drill.

DutchV · Oct 11, 2016

BradMacc82 said:
Nice Armed Ferret impersonation, but I deal with him plenty, so that level of condescension doesn't really have much of an effect anymore.

But I suppose when you're trying to drill a 45 degree hole into a stainless barrel, there may be better options than a hand drill.

You may want to chat with Striknine about his offer. A drill press, maybe some v-blocks and a clamp would increase your chances quite a bit.

BradMacc82 · Oct 11, 2016

Striknine has been a huge help already, it's how I've gotten this far without monkeyfvcking this entire build from day one. We'll figure something out, and there's a few others that chimed in offering assistance. Which is appreciated.

BradMacc82 · Oct 19, 2016

Gas port got drilled, turned out to be a frag of drill bit still in there. Would feel like a dumbass for that, but I have to restart this project.

Ruined the receiver doing the heat treat, worried Mapp gas wouldn't be enough to hit the appropriate heat range - used oxy/acetlyane. Cracked it at the hammer axis pin hole, and can see where the metal started to flow on all areas hit with the torch. Lesson learned.

Still not my most expensive lesson.

BradMacc82 · May 3, 2017

2nd time around, didn't ruin the receiver trying to heat treat. But the carrier will hang up at full rearward travel when racking it manually. Shoots great, for a 12.5" barrel. No other real faults to speak of. But, the carrier hanging up like it does has been a thorn in my mind for long enough.

3rd time is the charm? New heat-treated blank is on order from Childer's. It's time for a rebuild.

hungryjoseph · May 3, 2017

I had this problem also, with the carrier hanging up in the rear. I think the push button for the recoil spring acts as a guide to keep the carrier aligned with the rails. If the rear trunnion holes are drilled slightly too high, then the carrier can become misaligned and pop out.

BradMacc82 · May 14, 2017

Turns out the ejector was also peening over - badly. Guess my heat-treating attempt didn't work out.

So, add that in with the sticking carrier (with and w/out FCG in) - it's rebuild time. Already have it 98% demilled. Just need to drill the blank and pop the barrel out so I can pop out those other rivets - and get it back together again, again, and again.

Maybe (hopefully) the 3rd time really is the charm.

BradMacc82 · May 30, 2017

Attempt #3, almost complete. Need to weld in the rails and set the center support, and then it's mechanically complete.

Maybe the 3rd time really is the charm? Some of my best/cleanest rivets to date, carrier doesn't pop out/hang up at full draw (with recoil spring and fcg in), and the receiver/rails are already professionally heat-treated - so it's going to be really hard for me to F those up. I'm cautiously optimistic.

5:08pm yesterday -

12:09am last night -

**Yes, I have the BFA on in the pics. I know.

AK-Builder Barrels - Wow.

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