Broken Thompson drum, or is it?

[Maine-iac]

So, we were rattling off some rounds the other day, and my buddy was loading mags, and he asked me to help him with the drum mag, which... Wasn't taking tension. 

Now, this was a $169 GunBroker special, so I feared the worst, that the spring had snapped. 

So tonight, I cracked it open, ready to rivet the spring back together when this greets me on opening the drum up. 

I guess this one was made on a Friday? At least the spring isn't broken! 

[68coupe]

I've never dissected a drum before. What keeps the spring in place, when assembled correctly? Rivet, pin, staking, spring tension? The hole in the spring looks much larger than the stud it's not hooked up to. Inquiring minds want to know.

Karl, 68coupe

[Maine-iac]

17 minutes ago, 68coupe said:

I've never dissected a drum before. What keeps the spring in place, when assembled correctly? Rivet, pin, staking, spring tension? The hole in the spring looks much larger than the stud it's not hooked up to. Inquiring minds want to know.

Karl, 68coupe

As far as I can tell, nothing at all. Now, if the pin had a flange on the spring end, the spring coils would hold it captive. Without it, well, you can see the problem above. 

 

So I peened the pin over lightly, to prevent it from passing through, and welded the body back together. 

 

[bug]

How is the other end of the spring attached to the rotor pack body? Welded?

[Maine-iac]

3 hours ago, bug said:

How is the other end of the spring attached to the rotor pack body? Welded?

Held on by a rivet that's welded to the outer wall of the spring cannister.