How much "Egg" is to much ?

[OK92]

i'd stretch the top cover

[PullThru 1948]

Originally Posted by OK92

i'd stretch the top cover

Sadly, this was the cause of the issue. To much of a stretch though. That bad.

Lesson learned : Don't assume a factory produced blank is good to go. Treat it the same as one you bent yourself--Measure everything.

[tanvil]

I'd go with the 'if the rivet head covers it' approach.

[akblue]

You can shim the top cover at the rear or add a shim to the rear trunnion vertical stop ledge to tighten the top cover fitment. Just another option.
A spot welder and a strip of receiver stub at the rear downturn on the cover.

A recent pic of a sort of similar thing but done for a different reason. It extends to the cover bottom area. Yours need not be this large of course.

Spot welded to the cover.

[PullThru 1948]

Already have the Rivets partially seated, bit messy but not finished yet.

Have to prioritize getting a new Vice this Morning from Sears ?.

Two loud "clicks" last night : Bolt down slots cracked apart when Tightened.
It's a "Craftsman"().
Been a "Good" week so far !!

[PullThru 1948]

Update: Not comfortable with the Egging or the the way the Rivets needed to be formed to attempt covering the hole.

Suppose it would have been strong enough ?, many seem to "egg".

However , considering the physical properties of the Rivet steel is not going to change, to suit my screw up. It's going to react to squeezing/compression in a predictable way : ie, won't just "hang a right" when it sees the extra space !!.

That's my story anyway. Demilled and starting a "new" build.

Someone very experienced in AK Manufacturing suggested I check the position of the Rear Sight Base, in relation to the trunion. The Gap at the rear dust cover, that started this whole mess is close to the space seen, where the RSB doesn't fully contact the trunion.

Before I start the project thinking I should move the RSB back a few clicks.

How does one MOVE that RSB Pin though ??

Thanks again for all the comments/suggestions.

Oh, almost forgot, Sears essentially told me to shove it on the Vice.

So NO more Sears Purchases from me. "Normal Wear and Tear".

No mention of Catastrophic Metallurgical failure . Screw 'em.

[akblue]

You can move the RSB to the rear but then your forward stacking of components is "off". The gas block and/or gas tube will be improperly stacked.
Pre-fitting parts before final drilling or build is always a good idea to uncover the oops factor.

I think the egged rivets would have been fine.
But since that nor the detailed receiver cover small shim from above suit you....,

You can go oversize rivets. A 3/16 rivet has a larger shank which will open up the trunnion a bit to .1875". Over drillimng the rear trunnion long rivets was common in early build days when metric rivets or 5/32" rivets in longer lengths were scarce or unobtainable.
You would turn down the head on the 3/16 rivet (spin & file n a drill press) to standard or slightly oversized toi get good coverage of any remaining egging.

[PullThru 1948]

Thanks akblue, good points.

Thinking, for today at least, I'll just look at and measure, as I must be missing something.

Had it built on a Curtis Flat and not loose on the dust cover. It functioned perfectly. If anything, OAL of the Polish is arguably 1/16" longer than the Flat (when bent).

There are slight differences on FCG locations (based on the "X and "Y" location)

I'll have to go buy a 12" digital Vernier. Need one.

[PullThru 1948]

Interesting observation : the dust cover for the troublesome project is in fact, the longest one I have.
Going to check all receiver lengths, as all I can find so far, of any significance is the Polish Rec. Blank is longer than the AK Builder Flats I've bent historically.

[akblue]

Speaking of receiver covers. If you can find a Yugo M76 receiver cover it is longer than a standard AKM cover. It is smooth vs ribbed but can be shortened to a custom fit on any over length rear block to RSB fitment. Just an FYI. But probaby just as easy to spot weld the rear cover spacer though.
I may have an extra M76 cover but not certain. I have used one before for this very issue but was related to a barrel replacement difference in stacking vs a new build.