Well said Andy, very accurate...nothing to add there :thumb:The original setup is the so-called "GI" configuration. It's a short guide rod and a plug; the spring rides between them, and is captured by the slide when the gun's assembled. Arguable "con" is that the spring may kink. Browning is reported to have said, "I designed it to kink." Disassembly is done without tools. The gun can also be charged by pushing the lower portion of the slide against a hard surface. It is worth noting that the vast majority of guns built for "hard use" use the traditional and tested GI setup.
Full-length guide rods are common and popular, though I think many who have them haven't considered an alternative. Arguable benefits are that it helps keep the spring in line and consistent throughout its compression cycles. Weighted guide rods can be handy in competition to drive the gun faster. A downside is that the bushing has to be turned when the gun is in battery with this setup; some folks who have guns with properly-fitted bushings don't care for it, as it can possibly wear down the fit over time.
Full-length guide rods come in two flavors: one- and two-piece. Two-piece guide rods offer some flexibility in takedown, and arguably bridge the gap between the GI setup and the standard one-piece full-length guide rod. A downside to the two-piece system is that because it's meant to be taken apart, it's more likely to separate in recoil. Some pieces have interference fits for the last quarter-turn of the threads, and some are Loctited.
Some people switch the recoil system on a new gun before even shooting it. Regardless of your decision, make sure you know what you want, and more importantly, why you want it.
The wear on an alloy frame is a point that I had never considered, but it makes perfect sense. I prefer the 2 piece original GR, myself. Most come with the full length guide rod now and I don't usually change them to the 2 piece original.There are only two reasons for an FLGR other than those mentioned that I would ad. I have seen the dust tunnel on an alloy frame worn thin from spring contact from kinking and dragging. Was it rare? I don't know, probably very rare. To keep the frame from further wear an FLGR was a cheap fix. The other reason is convenience for changing top ends. With a FLGR the slide assembly slides off easily and stays together when changing to another caliber like a .22LR conversion kit. I find it interesting that most of the shooters that opt to change back to a GI rod and plug say it's because they want to eliminate the allen wrench but need one to remove their grip panels.
I don't need an ID, I know what it is. It's really very simple. The recoil spring is just cut off (raw end), on the front and smaller ID, on the rear, to have a force fit, to the rear half of the guide rod. The muzzle plug, end (front), has a small hole 90 degrees to the bore line, that holds the front of the recoil spring, when it's pushed in and rotated CW. The barrel bushing can be rotated, for removal without the front half of the recoil guide flying off. Rotate the recoil spring CCW and you can remove it. It's really a nice system and came from Colt that way. I can't figure why they aren't more common."captured" 2 piece guide rod. Please post a pic. Betcha someone can ID it.