Galaxy meaning Milky Way and all



That is probably true then, from a practical standpoint. Of course anything can be made full auto with enough modification even if all that's left over is the barrel of the original parts. Some manufacturers have been jumping through hoops to make weapons it can't be done to, or is very hard to, and I'll use that as anecdotal evidence of why its not that hard in their eyes with most guns.

I'm going to have to skip around a bit, so apoligies if I skip anytihng major here.



The big conceptual difference - more than mechanical because there are multiple mechanical means to achieve effectively parallel goals - is that a semi will do everything after a shot to get the next bullet ready but won't fire it until you pull the trigger again, and an auto will fire it if you have the trigger pulled. In some weapons (I won't say most, not sure) this amounts to adding in an extra bit, certainly with anything open bolt the procedure is more complex for semi than auto, but fundamentally -barring some bizarre rifle designs - determination of auto and semi is entirely in the trigger mechanism.



The M16 was full auto and a king of jamming, so it got the forward assist built in on to the M16A1 which was full auto, the A2 had single and burst, ditto the A4 (my personal fav weapon) and the A3 was full auto. There aren't as many of these kicking around as AKs and its harder to usefully modify because its a serious precision weapon in terms of the parts, hard to knock up replacements. Every last one of them is easily modded to full auto, A2 and A4, and I mean easily. Here a piece, often called a disconnector, is actually responsible for turning the 'full auto' off after a certain number of shots (not listed on the parts but its in the schematic, not for sale obviously) and thus making it burst. In some cases - and here's where the file comes in, you'll have something that looks like a quarter sized disk with, say, 3 grooves in it, and on 3 round burst it catches in each groove and fires again, stick in a fourth groove and its 4-round burst, stick in 5, etc, do it symetrically around the whole length (depending on the bit) and now it's full auto. In others, you could simply remove the thing entirely and render it full auto or replace it with one with no grooves, just a flat disc. It's all about the specific mechanics. Theoretically any semi can be rendered full auto simply by arranging a mechanism that pulls the trigger as soon as it reset, like some home-made spring driven widget you place over a trigger, it would be slower but not really appreciably so compared to human reaction speed. So it can essentially always be done. With the AR-15 though its unavoidable because it is a M16 and the M16 is essentially a full auto weapon retrofitted to semiautomatic.



I'm kinda curious why you'd even be filing the firing pin in the first place.