The light bulb brighter than T6 has U2, but the improvement is not great. To be brighter, SST50 and SST90 driven by high current are needed. SST90 can reach more than 2200 lumens, but the flashlight is relatively large. The brighter CSM360 has too much astigmatism to be used for hunting.

If you want more than two or three thousand lumens, you can consider the HID flashlight, which is not small. But there are many options.