Which rails would you recommend? Any problem with installing drop in rails vs free float rails? I heard rumors that they can torque the barrel or damage the gas system if putting a "tacticool" grip on it?

There would be no problems when a quality rail is installed correctly. I do not like quad rails. I highly recommend Noveske NSR's or other lightweight keymod rail systems. No need for all that extra M1913 real estate.

I like Troy or Midwest low-profile rails. I would not waste money on a drop in rail. I'd just buy a Magpul MOE and be done with it. You can fasten a light to those, and that is all you need.

I would ask what are you going to attach to the rails?

Full rails are not quite antiquated but in my opinion, there are better options.

Looking for a light and laser?

I used to use LaRue rails and Daniel Defense, both are great rails but I didn't like the feel of the rail as much as a round tube. When Troy came out with their Alpha rail, it was perfect for me.

The top has a solid rail and it comes with short sections of rail to attach anywhere else you want them to mount whatever you need.

I mount a light on the top rail with a VTAC mount and a front sight in front of the light on a 13" rail. I also have a sling attachment on the top rail just in front of the receiver. I have a sling stud on the bottom up front for a bipod or regular carry strap.

Take a look at them but if you want a full rail, LaRue or DD would be my choice.

I have a Larue on one AR that has been great. I'm also very happy with my Samson Evo.

The EVO series has standard screw holes every 90 and "s" shaped cuts at the 45 degrees positions all with internal slots that allow modular rail sections and accessories to be attached. They attach using 2 heat shields that lock onto the barrel nut and interface with the rail which secures with 2 Allen screws. They also utilizes 2 small tabs on the rail to ensure proper alignment with receiver and eliminate wobble/movement.

I agree with TWR that a solid rail up top with smaller modulars that can be added is best. Mine is set up similar to TWR's as I have an angled QD Mount on top just forward of the receiver, single solid swivel on bottom for the bipod. My light is mounted to the front right side of the rail at 45 degrees on one of the 2" modular rail sections.

Some pics from Samson's site showing the rail and mounting options:

I am a fan of the Daniel Defense Modular Float rail and the Midwest Industries Gen-2 SS rail. I do not like the feel or have a need for quad rails.

KeyMod

I was a fan of the MI SS rails, that is, until I bought a Diamondhead VSR-T:



Absolutely the most comfortable free float I have ever had.

I want to position the light on the side and laser on top if it doesn't interfere with my front sight? The laser will get moved to the left side of the rail? I will have to figure out the best configuration for manipulation? Don't need a bottom grip but the light/laser is a definite.

So far I've been happy with putting a tube on, and then adding a short rail here or there only as needed.

I have never seen the use for all kinds of rails all over the place.

Granted I'm not a tacticool kind of guy, I just want what I need to make things work. And no more.

This is the Troy Alpha rail with built in sight, I have the VTAC mounted light on top and a VTAC sling mount next to the receiver.

Depending on the optic and laser, I think you could mount one there too. LaRue makes their LT135 scope mount that sits a little higher so a PEQ laser will ride up top too. http://www.laruetactical.com/larue-tactical-sprm4-193-mount-qd-lt-135

Thanks TWR, that may work actually.

It appears that the Troy is a "free float" rail? I have a "standard" gas tube so I would need to mount a low profile gas block which shouldn't be to difficult and remove the front sight.

Rost, I agree don't need rails everywhere either. Just enough to put my light/laser.

I did see crimson trace made a laser/grip combo as well? Another option without having to get a quad rail put on.

Depends - what barrel make and what type of pins?

The gas tube "size" makes no difference, it's the height/shape of the gas block that matters.

Also, not all "low profile" gas blocks will fit under a free float tube. The Troys rails are pretty generous, but the Noveske NSRs require the lowest profile gas block.

Do you have a delta ring installed? If so, you'll need to pull the barrel to get it off, or cut it away.

The Troy rail will mount to the existing barrel nut, which is nice.

With a recip saw, dremel and a bench grinder a standard front sight post can be "low profile" in about 30min. Buff it up after your sure that it fits, and be advised that barrel whips a lot more than you'd think when it fires and you don't want it hitting the rail, so, take away every thing that doesn't HAVE to be there and then heat it up and put a couple coats of Brownell's Oxpho Blue.

I'm a fan of the Troy Alpha rail (the cheese grater version), but mostly because I've already got QD attachments and stuff for them and standardization makes things simpler. If I'd've started out with another version I could've been just as happy with something else, I'm sure.

I've shaved down a few front sight posts to fit under Troy rails. I took one off and did it on a bench grinder and did the other in place with a dremel. The bench grinder was a much easier, cleaner job.

This was the dremel job. It's rough looking, but is also covered with a rail so it's good enough for me.
Before


After

And fully functional...did you pull the barrel, or just cut the delta ring assembly?

I cut it off both times.

Good info, I didn't realize the free float rails differed enough to make a distinction for which low profile gas block I would need? Looking at a Larue low profile block. Yes I believe my AR has a Delta Ring so cutting would be easier way to take it off. A dremel and channel locks should take care of it.

Yup, just passing on experience from the school of "bought the parts, then bought the parts that would fit together"...

The LaRue "should" fit under the Troy rail, hopefully somebody reading has one mounted and covered with a Troy.

http://www.laruetactical.com/larue-tactical-low-profile-gas-block-lt-202

But, I'd bet it will hit a Noveske NSR, or other low clearance rail.

Not as sexy, but about guaranteed to clear anything you mount over it:

http://www.amazon.com/Troy-Profile-Rifle-Block-0-75-Inch/dp/B003RCBQSI

This is another popular one that covers the two front sight tower base contact points on the barrel, that are sometimes left unfinished. It will go under an NSR, but strikes the inside of the rail:

http://www.amazon.com/gp/product/B0...IKX0DER&pf_rd_r=01NJFBRSVVE6KQK6AZS9

It is labeled and sold as "low profile", but may not work with the newer thin tubes. There is another version that has a full lug along the top, it's thick and hits the gas tube channel.

Clamp-on: "usually" have a thicker base, also can hit in the Noveske, had one that didn't fit in a Troy Alpha, but did clear under a different Troy rail.

http://www.amazon.com/Yankee-Hill-M...33&sr=1-1&keywords=yhm+gas+block

What is the barrel brand, and do you know if the front sight base (FSB) has friction pins, or peened taper pins?

I'd seriously look at the Troy or VTAC Alpha rails. They use the GI barrel nut so you'd be able to do the install yourself with very little effort.
This new Troy looks very promising as well:
https://troyind.com/products/sdmr-rail-10-blk

You've gotten some pretty good advice here from AH64guy.

Let us know what you end up going with.

I like that design as well, just build an upper for a hunting with a similiar rail, same design with the round body and short rails up front.

And I'm a "cheese grater" fan as well, the Troy lock-up on the barrel nut has been solid for everything I want to do with the rifle.

Nice. I like the looks of that but the Alpha had the front sight included? So approximately another 100.00 for the front sight if I go with the newer rail? Not a deal breaker though?

Some of the Troy rails have a built in sight, some don't.

I use a Daniel Defense fixed front sight that's $60 and a MBUS flip up is only $40.

Good to know I'm a fan of DD as well!

Bluedreaux, why not just remove and replace the gas block? To save money? I have heard how hard the removal is and truthfully after removing 6 or 7 I just don't see it.

I really like the Samson Evo. It serves my needs perfectly.

Because I've got more time than money.

I've got a Colt left that I shaved down, done a few of them. Why shave one down? It's already pinned to the barrel and I like a pinned gas block. My others are low profiles but pinned as well by Noveske.

You can buy the Alpha rail with or without the sight, I have both and prefer with.

Do you have a preference for a low profile block? I'm looking for something "solid" that won't come loose or have any other issues. Great info in this thread guys. Thanks again.

The Troy or Yankee Hill in the second link will meet 99% of your needs.

Great, much appreciate it! Thanks.