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cryogenic419 · November 6, 2014, 06:44 AM

Its a fun round to play with, very versatile. You can go from mild .40 power loads up to the nuclear type loads. I've a Gen 3 G20 and a Gen 3 29 SF both of which offer really decent case support.

Heres what I have noticed when it comes to these guns. Accuracy is such a finicky thing, some guns/ammo combos are inherently more accurate than others. I shot these with Hornady and Winchester SD rounds and accuracy was acceptable but in my mind could have been a bit better. I also chronoed these loads and they were up there velocity wise, it was kind of all over the place. The 29 seemed to exhibit this less than the 20. Once I started loading up my own rounds for it I noticed the same pattern, accuracy was decent but velocity was all over the place. Also seemed like the hotter the load the bigger the groups got. Again the 20 did not seem to show this as much as the 29. Everything I have seen says they have the same weight recoil spring. Not sure if the dual spring setup while being the same overall weight reacts differently in the early stages of firing.

Started researching as much as I could about 10mm and came to the conclusion that for the hotter loads I needed a heavier recoil spring. I elected to toy with only the 20, picked up some heavier recoil springs. Sure enough the heavier the spring the more consistent velocities became and groups tightened up, to a certain point. Finally settled on a spring weight that worked well with my hotter reloads, plinking reloads, and factory SD ammo allowing everything to cycle without a hiccup. The factory spring weight that the Glocks are currently shipping with seems to work just fine for factory plinking loads and most SD loads. If you move up to Doubletap, Buffalo Bore, or really hot handloads you may want to consider moving to a heavier spring. The lighter ones allow the slide to start moving really early in the firing process and may be robbing you of some accuracy and velocity.

Above all else keep in mind this cartridge and the guns chambered for it have their limits.

November 6, 2014, 06:44 AM	#21
cryogenic419 Senior Member Join Date: March 29, 2009 Location: NW Ohio Posts: 569	Its a fun round to play with, very versatile. You can go from mild .40 power loads up to the nuclear type loads. I've a Gen 3 G20 and a Gen 3 29 SF both of which offer really decent case support. Heres what I have noticed when it comes to these guns. Accuracy is such a finicky thing, some guns/ammo combos are inherently more accurate than others. I shot these with Hornady and Winchester SD rounds and accuracy was acceptable but in my mind could have been a bit better. I also chronoed these loads and they were up there velocity wise, it was kind of all over the place. The 29 seemed to exhibit this less than the 20. Once I started loading up my own rounds for it I noticed the same pattern, accuracy was decent but velocity was all over the place. Also seemed like the hotter the load the bigger the groups got. Again the 20 did not seem to show this as much as the 29. Everything I have seen says they have the same weight recoil spring. Not sure if the dual spring setup while being the same overall weight reacts differently in the early stages of firing. Started researching as much as I could about 10mm and came to the conclusion that for the hotter loads I needed a heavier recoil spring. I elected to toy with only the 20, picked up some heavier recoil springs. Sure enough the heavier the spring the more consistent velocities became and groups tightened up, to a certain point. Finally settled on a spring weight that worked well with my hotter reloads, plinking reloads, and factory SD ammo allowing everything to cycle without a hiccup. The factory spring weight that the Glocks are currently shipping with seems to work just fine for factory plinking loads and most SD loads. If you move up to Doubletap, Buffalo Bore, or really hot handloads you may want to consider moving to a heavier spring. The lighter ones allow the slide to start moving really early in the firing process and may be robbing you of some accuracy and velocity. Above all else keep in mind this cartridge and the guns chambered for it have their limits.