Before going to hot loads, Have you tried different lubrication? Remember to lubricate the outside of the barrel as well. Sometimes this is all it takes to get the slide moving better. It is probably one of the easiest and cheapest things to try. Some very tight pistols will only work using a quality oil. Many semi-auto pistols work better with a light grease. I have at times put some grease in my range bag and then applied some to others pistols that had problems the they seemed to go away. My prefered grease is Brian Enos Slide Glide Lite. TW-25b also seems to work well.
Most people run Glock pistols pretty dry. When this is the case some good lube can do wonders.