HELP - Surefire pistol light switch question

Can some one tell me how to determine if a Surefire X300 weaponlight switch is a DG17 or DG18? I'm looking to buy one from a guy on another forum and he doesn't know which one he has. He said it isn't marked or else he doesn't know where to look for the markings. Can he measure the remote switch length and figure it out from that? I need the DG18 so it fits my 1911 with rail. I don't want buy it if it won't work. The DG18 is made to work on 1911s without rails when using the MR07 adapter.

Can anyone help me? I'd call Surefire, but I'd have to wait until Monday and I'd like to let this guy know ASAP so I don't hold him up from selling to someone else.

AR_Shorty said:

I need the DG18 so it fits my 1911 with rail. I don't want buy it if it won't work. The DG18 is made to work on 1911s without rails when using the MR07 adapter.

Click to expand...

Probably just a typo on your part, but, the DG17 is the one made to work on 1911s without rails when using the MR07 adapter.

Unless he had it personally mounted on the exact same gun and rail setup as you count on putting it on, it's going to be a gamble if it's right.

I agree.
Apart from trying it, I don't know of any definitive method for identifying a lone DG switch.

SureFire rarely uses dashes "-" in between the letters and numbers of a model number but the DG-xx 'DG Switch Grips' do.
As mentioned, the
DG-17 is for 1911s (and copies), without rails so requires an adapter (MR07)
whereas the
DG-18 is for railed 'versions' of the 1911 such as the SIG GRS 1911, Springfield TRP and Wilson Combat CQB

Yes, I need the DG-18. My bad. So if I get the DG-17 instead, how will it not fit? Will the arm of the switch just be too long or short? I assume that is the only difference?

I have a guess that the height of the arm will be too low, sitting too far from the trigger guard.