First things first…This is my first AR15.com post, my first AR 15, and most importantly, my first modification on this rifle. So if I make assumptions or mistakes, please feel free to throw me under the bus…

Samson Manufacturing Evolution Series http://www.samson-mfg.com/ar-15_html/category/Samson_Evolution.html
After many hours of research, I finally found a lead on a free-floating hand-guard / fore-guard on my Bushmaster Carbon 15. I called the Samson rep to see if it would work on a C15, and he was not 100% sure, so I called bushmaster for some detailed specs regarding the barrel nut. Turns out that the threads/diameter are different on the Carbon 15 superlite upper (I think most already knew that). The good news is that the teeth are the same, including their diameter and sprocket teeth spacing. If you own a carbon 15, and want a free-floating handguard, Samson Manufacturing has your solution, and they are very helpful. I have already seen all the wonderful posts going on about how spectacular this rifle is...

https://lh6.googleusercontent.com/-3UudEx6FqLU/TpzjyPnZb_I/AAAAAAAAAv0/vxFXAo2M374/s800/patpend.jpg

You shouldn’t run into any major issues, but there are a couple of hurdles you will have to leap.
First, make sure you have the right tools, and the right accessories before you start. Since my shop is 200 miles away, I didn’t have what I needed to make this work at my apartment. I had to use a local gunsmith, and pickup some hobby files from the local hardware store. You might also look into a new low profile gas block.

Tools
Make sure you have the right pin extractor/punch, the punch must have a dome in it so it won't slip off the pin when you hit it with the following.
A big hammer, or a local gunsmith with a bigger hammer.
A barrel-nut wrench, compensator wrench, etc. I borrowed one from a fellow AR15.com co-worker.
You will need a small file. (Explanation to follow)
Allen wrenches, The Evolution rail comes with the two for the rail and accessories.

https://lh6.googleusercontent.com/-luROUnRSI_w/TptIAI7SJbI/AAAAAAAAAvs/6qggTdVX5dc/s800/tools.jpg

Additional Parts –  GasBlock
A low profile gas block might be necessary. I bought the 7EX with the expectation I could use the same gas block. If I was willing to do a bit of grinding I wouldn’t need to purchase a new one, but the whole goal at this point is having a featherweight AR.  The sling attachment, and bayonet attachment make this gas block unworthy, at least for me. Feel free to grind the original to fit, but I can't help ya with that one.
I have not purchased this low profile gas block yet, LaRue Tactical will probably be my choice, but it is made of steel. I did however come across this company http://www.egwguns.com/gas-blocks/ar-gas-block/ who makes a low profile, .625, Aluminum gas block. Thoughts? Remember this Bushmaster model comes with a pencil/featherlite barrel that is .625 in diameter.

https://lh5.googleusercontent.com/-4q89ijGFqVA/TptB4rqXXbI/AAAAAAAAAvg/kIOWNrJYX9o/s800/gasblock.jpg


The evolution rail is manufactured with quality in mind. I am around machined aluminum quite a bit, and these guys did it right. I will end up purchasing the 15in model since the 7ex isn’t going to do what I had hoped. I personally like the look of the 15in on and M4 anyways, it all works out in the end.

https://lh3.googleusercontent.com/-TN-tJoIdgV0/TptB1AFz5yI/AAAAAAAAAvg/4xNhm2dPnY8/s800/start.jpg

The installation process is on Samson Manufacturing's You Tube page. http://www.youtube.com/user/SamsonManufacturing/
Take the time to watch these videos a couple of times, if you are a newb like me. Follow along during install for some details that could easily be missed.

Evolution Rail meets Carbon 15 upper
There are two tabs that help square up the Samson picatinny rail  to the upper. I have not messed much with other uppers but the c15 upper is missing the slots for this to line up correctly.
https://lh4.googleusercontent.com/-PeipU2U0S2k/TptB2Zq_IUI/AAAAAAAAAvg/eT1JFwqxqhw/s800/EVOtabcloseup.jpg

https://lh6.googleusercontent.com/-AyGINMrcZ8o/TptB25mH4eI/AAAAAAAAAvg/yuG8tQL7X98/s800/railline.jpg

This means you need something to remove these guides in the tabs. This isn’t difficult with a square hobby file, a couple of minutes of patience and you will have a clean cut. You don’t want to grind off the entire tab, so make sure you take some time to visually meet these two up, between filing, so you don’t over do it. Below is the tab ground off, notice the bright shinny aluminum.

https://lh5.googleusercontent.com/-aMHkCIONED4/TptB3IsFm0I/AAAAAAAAAvg/n3j8UqMSn8A/s800/EvoFile.jpg

I am enjoying the looks of my new handguard, and look forward to getting the Gas Block so I can actually shoot this C15 again. Any other constructive thoughts are welcome. I am new to ARs and any knowledge, is good knowledge. Well almost...
Here are some more photos.
https://lh3.googleusercontent.com/-dX2INzPIaH0/TptB1lPhO0I/AAAAAAAAAvg/EEvP868hMr8/s800/c15.jpg
https://lh3.googleusercontent.com/-79OG5SamCT8/TptB3gkVdkI/AAAAAAAAAvg/lLQcilNcBu8/s800/completeupper.jpg
https://lh5.googleusercontent.com/-E2lBbpsQzeg/TptB36RSX5I/AAAAAAAAAvg/dn_FbWmTddU/s800/freefloat.jpg
https://lh5.googleusercontent.com/-fNNAKtQo3C4/TptB5NAJj4I/AAAAAAAAAvg/eLp1mhkzkMM/s800/completeC15.jpg

tough crowd

I like it, have you weighed it?

ETA: I guess you need a gas block first...

There's not much love for bushmaster and particularly the carbon15 around here... next time make a thread about is brand X better than brand Y. Joking... (kindof)

Nice post OP. The rail looks good on your carbon15.  Welcome to Arfcom.

Looks cool.   I have a carbon 15 (older) that the bullets were hitting below the feed ramps.   After reading this, I'm thinking about pulling it apart and replacing some parts/solving my probs.



Bob

Thanks for the positive feedback guys.
When I bought this rifle, I was looking for an inexpensive AR for hunting Hogs. Had no idea what I bought, and I don't think the Academy Rep knew either... After finding out all of the problems I would face, I was bound and determined to find a fix for the handguard issue. I have also found out the stock is Mil-spec, and most everything else is the same, can even swap straight up... But those threads on that barrel nut have caused a lot of newbies some serious issues... I always thought an AR was an AR..
I know this is not a mag dump gun, and in return I treat it as such. I am however looking forward to finishing a light AR to keep around for years to come, Then building an AR10 for those damn Hogs... Now I have to start researching the different weights of grips, stocks, and flashlights... maybe an aluminum compensator?

About posting in the wrong forum. My bad! I noticed that after I posted

Also like the mod, I might have to check into it.  I just got the chance to fire mine this morning.  Bought it for some of the same reasons you did.  Light weight, good entry level platform to start with.  I plan on hunting more paper with it though.  So far no problems didn't miss a beat.  But just 50 rounds so not even broken n yet.

Looks good. Are you planning a front sight?

I have not put it on the scales yet, although I will. Just got my Aluminum Gas block in today. Will update the thread with pics soon.

I had not planned on adding sights. It came with a cheesy red dot which will go back on it for now. Soon I will invest in something with some better quality. Probably another red dot.

Like to know the weight when you find out?

Welcome to AR15.com