I need a 5.5 - 6" handguard for my 6.25" 300blk barrel
Other than SLR and Odin works it looks like no one else makes one 

So how bad of an idea is it to shorten a handguard and do you have and recommendations on which one to cut apart

If I were going to try to cut down a handguard, I'd try with the Matrix Arms 7 inch handguard. It's not a bad handguard, and the price wouldn't worry me to much if it got buggered. Looks like you might be able to shave an inch off the front. Joebob carries these, as well as a couple other places.

I have a 6.5 inch Oly Arms barrel in my SBR and I cut down a Midwest Industries Gen 3 keymod rail just behind the third slot from the front, leaving 4 key holes.  This made it short enough to use a FH wrench and install a birdcage without removing the hand guard.  I couldn't get the holes and the slots to line up perfectly, so there is a slight crenelation at the front, which is not enough to snag on anything and kind of looks cool too!  Here is a pic with a thread protector installed on the barrel, but you can tell where the shoulder of the barrel is...  the only really hard part was the top, the rest was just cutting the small areas between holes.  i wrapped gorilla tape around it and made sure it was perfectly straight, then worked with hacksaw and then finished it with a hand file and a thin coat of rustoleum flat black.



Did the same once before with a Larue 7 inch rail, but this one is much slimmer and less $$ :)  ymmv

Parker

I'm committed I Just ordered a Aero Precision Quantum KeyMod (Its an Aero M4E1 Enhanced Upper) to cut down it was cheap enough to try at $63

I don't think it's a bad idea. I just had  work done on the Troy 12 inch alpha rail to clear the suppressor mount on my 12.5 inch 308 build
I'll probably end up cerakoting it at this point.

If you'd like I'll post a picture to give you an idea of how it turned out in my case.

Id like to see what they did

And ill post a pic or two when the new handguard gets here (currently weather delayed) 

Milled down three sides of a quad, but still not slim enough. Would cover part of the suppressor, so my use it in pistol build.

I would go with the SLR hand guard.  I have one of the Solo Lites 10" and it is a really nice hand guard.

Its done I cut .75" off the end, milled a new recoil lug slot for the front sight base and drilled and tapped the mounting holrs for it Attached File

And it on the gun

17.75" collapsed 
Attached File

Man that looks great. Nice work!

Love those really compact pdw AR's

I just picked up an inexpensive 4" free float quad rail for less than $20 bucks on Ebay, works great on my 7" pistol

Nothing wrong with cutting down a hand guard. I had a buddy with a mill cut down my Mega Machine megalithic upper. MM only makes rifle length in the quad rail variant and I needed the threads exposed on a 11.5" bbl.

This is what I was thinking. On ebay and Amazon there are some rails for around $20. If I was going to cut one, I would probably go with one of those first.

c'mon, anyone can/will cut up a $20 rail!

dupe, sorry!