Anybody use a heat sink like JP Rifles is selling?  Do they work well? Worth the money?  I was thinking about using one under YHM lightweight handguards if they seemed worth it, and if it will fit.

These handgueards only fit the JP medium contour barrel.  My guess that is really an HBAR.  You will void all weight savings by puttin one of these on is my guess.  Even though its aluminum, it looks heavey and they designed it for bench rest rifles.  It would cool a little to a lot more, but tell me just what kind of rifle you are putting it on and what the rifle is built/used for.

BTW... probably wont fit under YH free floating handguard.  You would need a large diameter free float tube

Well I'm putting together a predator gun.  I was thinking the contrast under the handgaurd would provide a unique contrast if it were useful.  I can't justify the added price/weight if it won't help too much.

It would look great, but yes I dont think its worth it.  It sure doesnt give the look of a battle rifle

Heat sinks work great. the only draw back is the additional weight for some users.
We tested in full-auto, using barrels with heat sinks. we did our reading using a infared gun.
During our testing the barrels were about 200 deg's lower heat were the heat sink area of the
barrel was compared to the area on the barrel without the heat sink. Our result: Heat Sinks work.

Frank
POF-USA  

Just how hot were the barrels getting might I ask. and What temperatures at what parts of the barrel (chamber, middle, FSB, muzzle)