barrel and bolt combination...

[sharmanajusmc]

so I have read all over that mg34s are finicky on barrel bolt combinations, my question is when you do have a pair that is mismatched what does it do? light strike? not unlock correctly?

[JBaum]

Depends on whether it's too tight or too loose. Too tight, and the firing pin may release before a complete lock up. Too loose doesn't seem to be as much of a problem, but just right is best.

Just right is determined with headspace gauges.

Frequently, people just try a few combinations until one works properly, then they mark the pair and shoot them together. Not exactly the wisest choice I think, but I've seen it done dozens of times.

[biochembri]

My experience is that bolt barrel combinations do need to be tested for compatability. I did not consider it important, but when I was having problems with my mg34 semi I tried all different changes, but it only started to work when I changed the barrel! The problem I was having was failure to eject, seemed as though the locking was to tight.

Brian