Anyone know how to increase range without increasing fps?

Best to start with the hop up components (bucking/nub) and then possibly the barrel.

FPS != range; just determines how quickly the BB lands on target (or perhaps misses the target as the case may be ... ). As HH has intimated, hop set-up and barrel are where you want to focus your attentions, followed possibly by the weight of BB albeit in a very limited set of circumstances as it depends _greatly_ on the length of the barrel and means of ejecting a BB from said barrel.

Airsoft_David wrote: »

Would the barrel increase fps?

It can. Among other things. The tighter the tolerance between the BB size and circumference of the barrel, the more efficient the force behind the BB as it travels the length of the barrel as there will be less air to escape around the BB. You also run the risk of BB jams if using BBs that do not have consistent quality-control regards their diameter tolerances & surface quality. On top of that balancing act, wider bore barrels can allow more air around the BB, helping to stabilise trajectory so it's all a question of compromise rather than "What am best FPS"; what is your objective? What is your style of play with that particular RIF? etc.

Chasing FPS for the sake of chasing FPS is a fools errand if you can't land a BB on-target. Range & accuracy will prove to be more productive pursuits over chasing the FPS limit. True story (although I did not witness it I was at the event in question): bunch of Irish lads went to Sennybridge for a milsim event; held a building like it was fort knox such to the effect that several UK players who would have been running guns at a higher FPS due to higher legal limits locally start to complain and make accusations about "hot" guns. A marshal went into the building with a chrono and checked every one of them and said it would be their pleasure to go back to the accusers and let them know every assault rifle & support gun was not only legal but under the legal limit by 10% (328fps Irish vs. 350fps local). The Irish lads were out-ranging the locals with better accuracy; fps be damned.

Airsoft_David wrote: »

So hopup buckings and all that is good but i know nothing about actually installing them.

YouTube is your friend, plenty of instructional videos for pretty much every job on 99% of weapon platforms.

Velocity doesn't nessearily increase range per se, but there is a huge misconception here. Typically when we talk about higher FPS we're actually talking about energy (joules), like 300 vs 400 FPS with a .2g BB (so higher energy), rather than shooting a .12g bb to gain FPS (300 fps with .2g vs 400fps with .12g or whatever it would be).

Higher energy = better range, with diminishing returns. So you want the maximum joules legally possible with a heavy BB, as heavier BBs retain energy better over distance.

But as other's have said, the most important upgrade is the hop up, barrel isn't so important as long as it is high quality (smooth, no defects), I find 6.05-6.08mm gives the best results, but that's with a high air volume (that's a whole different topic).