I have a G-20 slim. So far I have installed a heavier recoil spring and guide rod. I was going to buy a better barrel, but airplane parts to priority.
I carry mine in a chest holster while flying... For 30, well ok almost 40,,, years I was carrying a 44 mag,,, BUT... big bears have become a secondary problem compared to the two legged yahoos I run into out in the bush...
My carry loads are virgin brass, So I do not care about bulged brass.
200 grain Hornady XTP
13.8 grains AA #9
Starline brass
Fired from a stock Glock 20 SF
CCI-300 primer = 1,150 fps good group
Win WLP primer= 1,165 fps and a double group
CCI-350 mag primer = 1,190 fps and a group slightly larger than the 300s
Average velocity of 5 rounds Factory Loads from G-20SF
200 grain Hornady XTP= 1,050 fps (huge group)
175 grain WW Silvertip= 1,195 fps (Ok group)
180 gr Fed Hydra Shok= 955 fps wimpy FBI loads
200gr CorBon penetrat= 1,065 fps Not as advertised
200gr Norma FMJ (1980s) = 1,177 fps Very accurate, very clean, best accuracy of all factory ammo. Just need a time machine to buy more.
*200 gr XTP, 14.0gr AA#9, CCI-300,star-line, 1.255col, = 1,169fps good grp
200 gr XTP, 8.4gr 800X, CCI-300, star line, 1.259col, = 1,100fps large grp
200gr XTP, 13.8gr AA#9, CCI-350, Starline, 1.257col= 1,190 fps OK group
*200 gr XTP, 13.8gr AA#9, CCI-300, Starline, 1.257col= 1,136fps good grp
*Best groups of hand-loads today.
180gr Speer TMJ. 9.8gr 800X, CCI-300, Star-line, 1.257col=1,235fps huge grp
Note velocity spread from 1,190 to 1,280 fps during 15 rounds fired
180gr TMJ, 14.5 AA#9, Fed 155mag, Hornady brass, 1.250=1,168 blown primers, bad grp. no other pressure signs,,, wonder about those #155 primers BAD LOAD
G-20SF with stock barrel and spring.
200 grain Hornady XTP. All loaded to 1.250 col. Groups at 15 yards, temp 20F
All with 14.0 grains AA#9 Star-Line brass
CCI-300 = 1,162 fps (30fps ES) and a 2.0 inch group (within 7 fps from the other chronograph)
WW-WLR= 1,151 fps (7 fps ES) and a 1.5 inch group
CCI-350= 1,188 fps (18fps ES) and a 0.80 inch group
G-20 with 20 pound spring and new guide:
180grain Hornady XTP HP
14.7gr AA#9
CCI-350, 1.257 col taper crimp
1,322 fps OK group
200gr FMJ-FP Hornady
13.5gr AA#9
CCI-350
1,250 col taper crimp
1,220 fps good group
14.0 grains was 1,245 fps and over pressure. But good group
Taper Crimp Experiment:
Bullet: 200 grain Hornady FMJ-FP Case: Star-Line virgin Primer: CCI-350
Powder: AA#9 13.2 grains.
COL: 1.250 inch Fired from a Glock 20sf, 20 pound recoil spring and stainless guide rod. Stock 4.7 inch barrel Temp 20F. 20 knot wind, blowing snow.
0.25 turn crimp = 1,110 fps
0.50 turn crimp = 1,154 fps
0.75 turn crimp = 1,166 fps
1.00 turn crimp = 1,188 fps duplicates original Norma Load in Glock 20
1.25 turn crimp = 1,160 fps
1.50 turn crimp = 1,152 fps
155 grain Hornady XTP hollow points:
The brass, primer and COL are all the same.
Only 14.8 grain of AA#9.
0.75 turn crimp = 1,270 fps and a very nice group
1.00 turn crimp = 1,290 fps
1.25 turn crimp = 1,256 fps
1.50 turn crimp = 1,245 fps