The C8 is a great size and can throw pretty well all things considered, while remaining fairly pocket sized.
Two big things that affect throw are:
-reflector diameter
-size of reflector in relation to the size of the LED
In simple terms, the larger the reflector the better the throw for a given LED/output.
But also a smaller LED in the same size reflector will throw better, e.g. An XP-G2 instead of an XM-L2 in a C8 will throw further. The trade off is, smaller LED’s produce a smaller hot spot and don’t pump the lumens out, so the spill beam is dimmer.
That said, to get this benefit you need to drive the light hard enough.
I have a Convoy C8 with an XP-G2 in and a 3amp Qlite driver. It’s really very nice.
If you want Int’l Outdoor sell one:
http://intl-outdoor.com/xintd-c8-v5-xpg2-s2-multioption-18650-flashlight-p-789.html
Or it’s very easy to build one by just buying the LED and driver. Or an even more potent driver.
Next up you might want to consider de-doming. It’s actually quite easy. If you de-dome an XM-L2 you’ll get way more throw from it, but still retain quite a high lumen output, although the spill beam will dim slightly. You’ll also get a warmer tint, so you need to de-dome the right tint LED to end up with something that looks nice.
Again either build from parts, or modify yourself.
If you are in the USA you could easily modifiy one of your current C8’s, although the Convoy ones are nice quality if you want to start fresh.
Get an LED on a DTP copper star (makes a huge difference to just mounted on aluminium).
And a 3amp Qlite driver as a starting place or visit Mtn Electronics and get a driver capable of 4- 5 amps or direct drive and it’ll really perform, while still being compact.
TIP:
You must use good batteries, even now, crappy batteries are crappy and will offer lousy performance and runtime.
Good 18650’s have 2500-3400mAh depending on type. Cheap **fire branded ones might only have 300-500mAh and suffer massive voltage sag (yes even the ones listed as 4000-5000mAh, it’s all lies!).
Panasonic 3400mAh are a good general use battery and will offer long runtime when not pushed really hard.
If you want max output on a high amp setup you’ll need some high performance IMR or INR batteries. Purple Efests are good, as are Samsung 25R’s. But you might have to drop to 2500mAh. The difference is, these batteries can offer more current and sustain their voltage better than things like the 3400mAh ICR’s. So runtime will be less on lower modes, but on high/max outputs these cells will offer the highest PEAK outputs and the best sustained stable outputs.
If you want to buy de-domed ready to go, then the only one available is the Olight M2X Javelot. But it’s obviously more money than building a C8.
If you just want throw on a budget, the Jacob A60 is still very good. But it produces a narrow pencil beam and very little spill. Basically it shines a real long way, but only lights up a very small area.