[MrChefur]

Finally made it to the range.
Packing the barrel made no difference on the excessive rate of fire. It added quite a bit of friction but did not change anything else, same malfunctions.
We took the booster cap off and immediately got a ~50 round burst off before a malfunction. Still a bit fast.
Turned the spring down a good bit. Rate of fire came down, got another 50-60 round burst off before a malfunction.

This burst ended with a misfeed. The same bent bullet thing, but it corrected itself and chambered. Just not quite all the way, because the case mouth was warped.

Right after this video we turned the spring down even more and finished off the belt.
The stuttering fire I think is the headspace. This gun came to me with 6x 0.004" headspace shims installed on the lock tail, and wouldn't even chamber live ammo. If I recall correctly, it now has 4 shims and closes on a GO gauge with slight drag. I'll take another shim off and see what happens.

I've never improved a firearm before by removing a part

 

[IMBLITZVT]

This is looking familiar!

 

[MrChefur]

Haha, yup that's the one. Notice the booster cap I took off, haha.

 

[IMBLITZVT]

Haha, yup that's the one. Notice the booster cap I took off, haha.

Great video, glad to see it running! A few minor things... Its not a Finnish built gun. Its a Russian built, Finnish captured gun. Those marks on the top cover are Finnish arsenal reworking marks. So it is on the correct Sokolov mount. It would not have had a tripod mount like Finnish guns. Finally there is no water circulation. The steam tube pulls off steam that condenses in a can and then you can pour that recondensed water back in the tractor cap by hand. Not that the Russian ever really did this judging by historical pictures.

Also, I noted when Brandon was cycling the gun. The lock (bolt) face is not dropping down as it normally would. You might have a problem in that lock. Do you have another? Something is off here. Its hard to tell what. That lock face should drop down when you pull the cocking handle. If you don't understand I can video it for you.

 

[IMBLITZVT]

Also, I noted when Brandon was cycling the gun. The lock (bolt) face is not dropping down as it normally would. You might have a problem in that lock. Do you have another? Something is off here. Its hard to tell what. That lock face should drop down when you pull the cocking handle. If you don't understand I can video it for you.

Now I will grant that the springs on the top cover should force this down but frankly, it does not look like it come far enough back to do that? Makes me wonder on your cams. Are they positioned correctly and are they the right size...? Could that force you to run it at a higher cycle rate to get enough recoil to to pass the cams and allow the lock face to drop?.... Maybe?

 

[MrChefur]

It was very dirty, the lock drops fine when it's clean. It started doing it that day, it previously worked as expected.

 

[IMBLITZVT]

It was very dirty, the lock drops fine when it's clean. It started doing it that day, it previously worked as expected.

Ok, I do see the back of the lock rising up a bit when he cocks it which might give a look of not going to clear the rear of the cam. Of course things always have issues as soon as you film or show someone...

 

[MrChefur]

I should note that this is a parts bin gun by the previous builder, there was dykem and grinding everywhere in the lock assembly.
So I don't think clearances are what they should be. Also one of the axis pins on the lock walked out and was jamming the arm, it just did it again while I was hand cycling it. Gotta figure out why those are coming out.

 

[GrimesSU]

I should note that this is a parts bin gun by the previous builder, there was dykem and grinding everywhere in the lock assembly.
So I don't think clearances are what they should be. Also one of the axis pins on the lock walked out and was jamming the arm, it just did it again while I was hand cycling it. Gotta figure out why those are coming out.

The axis pins should be blocked by the lever arms when assembled and shouldn't be able to walk out.

It's possible that someone messed with the lock more than necessary as you mentioned earlier.


I would just get a replacement lock and headspace it to the gun.