I have Bushmasters m4 version with the mini-y comp. I dont like the feel of their handgaurds as they feel flimsy and they flex much. What is a better alternative to replace these handgaurds?

If the rifle came with the standard carbine handguards, then try moving to the "real" M4 handguards. Bushmaster should have them in stock, as well as lots of other places.

Bushmaster make a copy of the Colt M4 handguards.  I haven't seen them IRL yet so I can't comment on their stoutness.  "Real" M4 handguards have double heat shields and are bigger in diameter.  They definitely have a nicer feel to them than the stock Bushy carbine handguards.  Colt is the original manufacturer, but RRA and a few other companies carry them.  You can fid them on the EE quite often.

Cavarly Arms also makes a copy of the M4 handguards and they come in a variety of colors.  These of course are single heat shieled as are the Bushmaster, as Coly has the patent on the double heat shields.

Another alternative is the First Samco handguards with rails.  This is least expensive handguard with rails that I've seen.  They come in either 2 or 4 rail versions and are about as thick as M4 handguards when the rail covers are on.

Of course you can step up to the various rail system.  They are usually made from alluminum.  The prices vary as does the quality, but the go for about 200 beans and up (depending on the manufacturer).

Another alternative is to free float your barrel and use alluminum "tube" handguards.  Again they vary in cost and quality from company to company.

CavArms are the best choice (way better than Colt)
available from [url=ar15.com/forums/topic.html?b=7&f=22&t=165879]Adrenaline_Arms[/url] on the EE!