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I noticed some people saying they're worried about being temporarily blinded (ie- loosing their "NV Goggles") after firing one shot. I've fired my Glock 17 w/ tritium sights outside at night to test different kinds of ammunition I was carrying. I've found a number of types of ammunition that have very little effect on night vision. With the good ones I could shoot the target over and over, and go through a full magazine in such a manner, without loosing much, if any ability to see the target.
Federal's Tactical LE Hydrashock +P+ 124gr is not one of the best rounds for low light, as it makes an extremely bright (Almost white) flash. The Winchester LE Ranger +P+ 115gr is not bad at all though, with very, very little flash and surprisingly soft recoil considering it's traveling at 1335 fps out of a 4" (or 4.5", I can't remember what it said they used) barrel. It's probably my favorite round of any I've fired so far. Also, WWB 147gr JHPs are surprisingly good for not making much flash at night and are surprisingly accurate out of my G17. They seem significantly more accurate than the WWB 115gr FMJ, which does also have very little muzzle flash. I must say now that I think about it, I have yet to encounter a Winchester round that puts out a lot of muzzle flash in 9mm.
The type of gun that might actually ruin your night vision in one shot would be something like a 12ga with an 18" barrel firing a 3" Magnum round. The flame coming out of one of those can be massive, enough to entirely obscure the target and everything directly surrounding it during the flash. I can't be sure and I'm not going to try to measure it, but it seems like the fireballs I get can be about 1-2 feet in diameter, and are super bright (Once again almost white), especially when viewed in low light.
This image is of the G17 shooting a WWB JHP. As you can see, it's extremely small to begin with and what you can see is orange/red. Red is the lowest in intensity on the light spectrum and will cause the least disruption of NV, hence the reason many aircraft cockpits use red lighting.