Need ideas for picatinny rail or other mount for smooth hand guard

[Scuba591]

My AR build is coming along. I have received this...
**BLEM** 20" RXA15 BULL SS UPPER

I bought the non blemished version. I underestimated the weight of this upper. I will mostly be bench shooting with this AR. I would like to also use the rifle unsupported. My issue is the round hand guard. Are there any accessories avail to mount a rail, for a bipod or hand guard, to this? I was told there also might be gas blocks that come with a rail mounted underneath. I could use some recommendations. I thought about mounting a stud and going from there; however, I am not sold on that idea.
I am impressed with the redxarms upper. The upper, left handed BCG and charging handle cost me $460.00 shipped. I thought it was a decent price.
Am I correct in thinking that a regular picatinny rail would have to modified, rounded, to fit tightly onto the round hand guard?
The gas block fits a .936 bull barrel.

 

[M67]

Find a machinist/gunsmith to drill and tap for a Magpul MOE rail section and epoxy it in place for strength (they could also concave the rail a touch). Or you can find a 2 piece Weaver rail section (just need 1 section of course) that has a slight curve, something that fits a Savage with a round receiver or the front of a Remington 700. Something close. Just remember, 5 minute Epoxy works wonders for strength.

Or, if you're feeling frisky and have a drill, bit, correct tap (I believe 10-32), and a machine thread sling swivel, you can give it a try yourself. You just need a stud on the rail to run a bipod adapter on it.

Guess it depends too what bipod you have at the moment.

I wouldn't go for a gas block mount, keeping the barrel free float and such

 

[halfmileharry]

Change out the handguard to one with a rail on it and get one with ventilation. Solid handguards tend to get a bit warm if you run them out at all. That's the reason I went to the ventilated ones.
Free float is a plus and I try to stick with them.
It's probably going to be as cheap to change to a light weight FF guard as it would be to take it to a machinist.
You're really limited as to what you have right now.

 

[rob63]

Not sure if I have followed exactly what it is that you are asking for, but is this sort-of what you are talking about?
3" Rail for the Customizable Forearm System (3/8" Tall)

 

[halfmileharry]

You can get the basic handguard for rail mounting. Costs will start around $50 up to hundreds depending on what you want.