G45, Welcome to CPF!
What are you applications and ranges at which you need more light?
Are you use the MN60 or MN61 lamp?
And are you viewing the targets through a scope?
To my eyes the difference between the throw of the UltraStinger (thin body), TigerLight 8" (very fat body) and a SureFire such as the M4 is not that significant although the both do have smaller, tighter beams compared to the M4.
I have no idea whether it would fit on your rifle, but assuming that the recoil isn't heavy, I would consider putting a classic 9NT (discontinued) rechargeable model with a 3" diameter TurboHead reflector. The 9NT doesn't have a 1" diameter body though - it's thicker similar to the UltraStinger I guess.
Perhaps a "12PM" with either the SRTH 2.5" diameter reflector or a 3" diameter reflector is a possibility. With the N62 lamp (500Lu/12mins) the beam is about as bright and tight as SureFire have ever made. The 9NT can still be found (or 9N and T3 TurboHead) if you search online for retailers or ask here on CPF.
I personally don't think there is a flashlight of the same size and power of the M4 that throws much further and is more suitable for weapon-mounting
Al