CC Italian wrote:That’s what I figured but I find it funny it only does it with 135 grain load and both magazines must be loaded fully. I tried around 10 different loads from various manufacturers and only could replicate it with this Double Tap load. If I have 14 in the 15 round mag it won't replicate the problem. I tried many times and I couldn't get it to reoccur no matter if I had 1 or 14 rounds in the mag. Same with the 10 round clip. If I load 9 in the mag and chambered a round I could not get it to occur. Like I said letting the slide slam shut will solve the problem but It also must have something to do with the magazine spring when fully compressed with a full mag.
The situation you're experiencing is not the fault of the loads in the cartridges, although there could be a slight difference in the cartridges' inertia when chambering.
Your gun is designed so that when the slide is fully retracted and released, the breech face delivers a known and sufficient level of energy to the back of a cartridge in the magazine to release it from the magazine feed lips, drive it into the chamber and lock the slide shut. If you interfere with the design function by "riding" the slide forward with your hand, the result is a variable and lesser level of energy imparted to the cartridge. Depending on how much you interfere with the slide's return, you could cause a failure to go into battery with any round in the magazine, but obviously the issue would show up most readily with the first round from a full magazine, because of the high level of friction between the cartridge case and the feed lips under the maximum pressure of the fully compressed magazine spring. For this reason you won't find this technique to be recommended or endorsed in the operating manual of any handgun.
This is all a really long way of saying that if you retract the slide all the way and let it go like the manual that accompanied the gun tells you to do, a well designed gun like a Glock will always chamber the round and lock the slide into battery. If you don't use the gun in the manner it was designed and "ride the slide" forward you'll continue to experience failures of the slide to go into battery without an extra rap on the rear of the slide. There's no advantage to this practice, and, as you have discovered, lots of downside.
The slide hold open lever is a small sheet metal part that is hard to find and release under stress. It is designed primarily to lock the slide open after the last shot. Glocks load best when the slide, whether held open by the slide stop or not, is released by pulling the slide to the stop at the rear and then released. Some call it a "slingshot" technique. It works with virtually any semiauto handgun (a training advantage) and eliminates fumbles with slide stop levers of varying size.
