I recently purchased and installed a 21lb. recoil spring from the GlockStore.
Very soon after I ordered it, I had an “Oh Sh**” moment. I thought, “What if it is TOO heavy?”
So, I emailed the GlockStore support people. I told them that I have typically been using 180gr .40S&W, FNFMJ rounds by Winchester, and asked if the spring was “ok” for that ammo.
Well, I went shooting before I got their response, and the spring performed very well in my opinion. It made racking that first round a little more difficult, but not so much so that it was a problem. I went through about 120 rounds of the ammo I just specified, and had no “stove pipes” or any other feed type issues. And, indeed the recoil/muzzle jump had been reduced.
Not too long after I got home, I received an answer to my support question and they warned me that such a heavy spring was really intended for +P ammo, and that I may experience “stove pipes” with the ammo I specified. Luckily that was not the case, and fortunately, I carry some very heavy duty +P ammo by Hornady(?) – “Zombie Killers.” At least I think they’re by Hornady. I apologize if that is incorrect. I had bought a box of 20, loaded 2 magazines with it, and threw the box away, so at this point I’m actually only sure of the name “Zombie Killers.” Ah well. I know it is +P without doubt. It is a polymer tipped jacketed, segmented type hollow point, and I know I am more than confident that it is adequate for self-defense ammo.
If you are considering buying a heavier recoil spring for your Gen4 Glock 27, I would probably recommend a 19lb spring, but am here to tell ya that the 21lb spring was fine with the factory ammo I’ve been using. I tested at various distances and firing speeds, and not the first jam. Heck, the last 12 rounds I fired consisted of two 12 round magazines loaded with 6 rounds apiece, and I fired at a large target sheet that had 6, 6 inch targets on it, as fast as I could fire, rotating from one target to the next, left to right, top to bottom, reloading the second magazine, and repeating. Not the first problem, and except for what was apparently a “stance” issue on my part while firing at the target on the top right, my accuracy was definitely improved by using this spring.
So, if I do ever start getting “stove pipe” jams or the like, I’ll just buy another, lighter spring. But for now, heck, this 21 lb. version is doing just fine.
IF YOU WANT TO MAINTAIN YOUR RIGHT TO GO SHOOTING: