[shadow29483]

Just a few more quarks and I'll be finished with the receiver build portion.

With the front trunion installed tight,the back of the mag will not seat flush on the receiver. I've filled down the bottom of the bolt guide rails but it still has almost 1/4" gap on the back. (between receiver and mag)
What's going on here?
When the trigger guard is fasten down tight, the mag catch wants to stick like hell and won't lock. And I have to bump it against the table to release.
What's it hitting?
I can't tell? I loosend the screws on the trigger guard, that gave it about an 1/8" than it snaped right into place. The trigger guard and selector stop are flush with the front rear of the well. What the hell? :angry: :dunno: :angry:
Thanks.....Shadow

 

[Trotsky]

Please stop filing your bolt guide rails.... I hope your receiver is not toast.

Generally, the FIRST part installed is the trigger guard/selector plate. You can even do this temporarily with 8x32 screws.

THEN - the front trunion is brought in - your mag acts as a guide: bring the trunion back so the mag snaps in tightly, yet two or three different mags ALSO fit well. This test allows you to set the trunion in to the proper depth. Mark, and proceed to rivet.

If you do the job this way? What you are describing simply can't happen. So I'm guessing the trunion went in FIRST, follwed by the TG. You can recover from this.

Mark potential stick points on the mag with a Sharpie... get it dark. Insert as far as you can, not forcing it, but being assertive. Now look at the mag - see where the ink got rubbed off (latch area, sides, back top next to the crossbar). This will tell you where the problem is. Crossbars can be gently dremmeled - stop plates can be gently milled to thin them... etc. But first, you must determine exactly where the mag is seeing interference.

 

[shadow29483]

-mag-

Trot,
Thank god I'm not riviting....I WOULD be in trouble!
It worked!
I'm doing a screw build, And what I did was installed the TG than the front trunion.
When I tapped for the trunion I ass-umed the holes for my (vulcan) premilled receiver were in there correct spot.
Nope!...Wrong!
I installed the TG, put the mag in, than butted the trunion up to it, I used 2 smaller drill bits to hold the trunion in place temperary so the trunion had room to give. I tested two different mags and they snapped in and popped out. Smooth!
I than took the 2nd bit out, And set my screws(tight)in the front.
Marked the holes that were almost an 1/8" off center, then filied to fit.
Set the screws....And worked like a dream!
Thanks sooo much! Some dude told me that the bottems of the rails were hitting the mag......so I drimmiled.
I new something was'nt right, So I stopped!
The area where I dremmiled was the very bottom (sides)of the rails.
Where it attached to the receiver.
I'm going to "quinch and temper" them And I think they'll be ok.
I hope!
Thanks again.
Shadow :thumbup1: :thankyou:

 

[7.62x39]

Trotsky,
Good call.

Shadow,
Glad you got it straightened out.

 

[sks_hunter]

VERY good call, and great description... The guys on this board kick ass!!!

 

[Trotsky]

Best part of this? YOU get a working gun

Yup - I've never used a Vulcan(hesse) receiver... but I have heard from others that the predrilled holes are often just in the wrong place. You did a good job

 

[yosuthnmasa]

So I have heard from many people that the trigger gaurd is the place to start. Does this mainly apply to pre fabbed receivers that might have their front trunnion holes off a bit. I actually followed Max's guide and did the front trunnion first and I didn't have any problems. But, I did drill my own holes. I noticed on my ACE blank that the front didn't need any trimming. In fact, it was almost a little to loose with the lower handguard. If I cut at all it would've made it even looser (with the tabs on the lower handguard). So, if I install the TG first, and the move the trunnion to the correct place (lets say away from the front of the receiver), I would end up cutting more off of the end of it and making the lower HG more loose.

Is it more wise to start at the front trunnion with an ACE, and the TG with a pre fabbed receiver? I don't have any experience except with the ACE blanks, but I would love some more advice on where to start with other receivers. I take it since the holes are predrilled on a Tapco flat, that it might be more smart to start with the TG.

 

[7.62x39]

If you are starting with a receiver that already has the TG holes drilled and the trunnion holes undrilled, like most prefab receivers, then yes, you should start with the TG, since it's location is predetermined, while the trunnions is not.

Starting with a blank you can go either way.
On a blank I start with the trunnion to ensure a good fit to the foregrip, then let the mag determine the location of the TG

 

[shadow29483]

-Mag seating-

I finnaly finished the seating of the mag and altered the holes to fit.
Everything sets fine as for the front trunion and the trigger guard.
But I had to file the trunion holes a pretty good bit. I'm kind of worried that the holes may be to big though. The screws set fine and the heads are in place, but the hole is much bigger.
Exactly how much pressure or tension is on the front trunion?

The screws are smaller than the normal button heads, they look more like a small rivet. I got em' from "gtbehary". They're bad to da' bone!
Although the heads are smaller and I had to adjust the holes out alittle, they do sit nice in the trunion. I guess my question here is.....with a little lock-tite and a good bit of torque, do you think it'll hold and be ok?
Thanks guys,
Shadow

 

[yosuthnmasa]

Thanks Max!

Shadow, it depends on how much of the head of the screw is over the receiver. Did you have to do this on all of the front trunnion holes? I would assume if the head of the screw covers most of the hole and you loctite them babies down, you should be ok. You could always weld them back up and redrill, if you can get ahold of the Tig. How bout some pictures of your nearly finished AK??!

 

[shadow29483]

-Pics-

I've got a bunch of pics in about 4 disposables, a while back my camra was stolen. And I don't have a scanner so I have to use the one at work.
I'm waiting till' I get them all done then I'm scanning them all at once.
And I can't aford digital right know but I WILL post the pics soon.
Thanks....Shadow