[whenmonkeysfly]

Originally Posted by robert91922

- Glock 20
- IGB custom barrel 4.6" w. full supported chamber
- primers: CCI 300 Large Pistol
- recoil spring: DPM MS 3-spring system for Glock 20/21 (yellow main spring)
- firing pin spring changed from standard to "Red - 28 Newton"
http://www.glock.com/english/options...gpinspring.htm
- powder: Vihtavuori N350
- bullets: Speer GDHP 155gr
- brass: Starline (new)
- OAL: 1.262
- temperature: 25 oF (-4 oC)
- 1 string: 3 shots only
- distance from 1st Chrony screen: 3m (approx. 10 feet)
- I cleaned barrel quickly with brass-brush and hard-plastic brush after fourth string (after 12 shots)

load (grains)~~~~~average (fps)

11.0.................1417
11.2.................1434
11.4.................1455
11.6.................1465
11.8.................1493 primers flattened
12.0.................1512 primers very flattened, 1 primer fell out

IMO 11.2 load would be max if I'm gonna make SD loads with these components for winter carry. For hot summer days should drop down to 10.4 (or lower) or use slower powder e.g. 3N38.

Thanks for the data Robert! I've got a boatload of Vihtavuori N350 and a few thousand Rainer 165 grain TC bullets that I could push to ~1200-1250fps. I use both blue and red flavors of Newton Springs in a number of my Glocks. Really good for those hard CCI-350's.