This is a purely academic question.  I have recently become fascinated with the venerable Ma Deuce.  I've been reading about it's history, function, and maintenance.  In my internet searches, I have found that there are quite a few companies that offer semi-auto conversions for this beast.  While reading manuals and literature, I've studied the procedures for headspace and timing adjustments that need to be performed when a barrel is installed.  I understand what headspace and timing are, and the importance of each.  My question is this:  Is it still necessary to adjust timing in a semi-auto conversion?  I know that headpsace is very important, but since the gun cannot fire in full-auto, is timing still important?

Again, this is just academic - more of a thought experiment.

Thanks for enabling my curiosity :)

-Parker

It's not hard to do. And it will save you from having a separated case being stuck in your chamber. While your at it be sure to get a broken case extractor for your toolkit.

I understand how timing is done, and why timing is done (at least on a full auto), but i'm just curious if it's necessary on a semi auto...  I know headspace is still absolutely necessary, but timing seems to me a moot point on a semi-auto only gun.

Barring any kind of super-human finger speed and control, I don't ever see an instance when someone would be able to pull off a second paddle actuation before the bolt made it back into battery (assuming all else is the same - cyclic rate of 450-600 rpm implies that on it's slowest, there are 7.5 rounds being fired per second, or one round every .133 seconds in full auto).  Jerry Miculek might get it done, but a roughly 1/8 second between paddle presses seems extreme.

Again, this is purely academic - I don't own an M2 and probably won't anytime in the foreseeable future.  I'm just thinking about its operation and wondering...

-Parker

There is no such thing as timing on a semi auto M2hb or 1919.

Are you saying it's simply not necessary (for the reason I previously mentioned), or that it's not an option?  I suspect that in the semi-auto conversion, the mechanism for timing is removed... is this correct?

-Parker

In a semi it is just not needed.

You are correct. In auto with the butterfly mashed the timing is important as if it fires too early all hell breaks loose inside her and the locking block/barrel extension are destroyed. On a semi there is no way you can mash-release-then-mash again before the bolt locks up. I haven't seen a semi M2 in a long time but I doubt the timing mechanism is even in the receiver as it doesn't matter unless it's a full auto gun.

Semi Auto M2s don't even have a timing nut.

agreed, mine has no timing nut. Just set headspace and fire.