Ridiculous question: Need to know length of 20" AR with retractable stock

Hey sorry to post a thread with a rediculously simple question, but I can’t find this info for certain anywhere. I need to know the overall length of an AR with a 20" barrel and retractable stock, PREFERABLY but not limited to a Magpul UBR. I need to know if it will fit in a 37" rifle case.
Thanks.

The overall length of my 16" Colt 6520 (M4 stock, collapsed) is 32 inches.

So… adding 4 inches of barrel length brings the OAL to a theoretical 36 inches.

Sounds like you’re good to go.

Ok, thanks! I just hope it fits in a 37" one of this:
http://www.blackhawk.com/product/Rifle-Case,140,134.htm
or this:
http://www.blackstonetactical.com/catalog/product_info.php?cPath=51&products_id=406

My 20" BCM measures 36" . It will fit in a 37" case, but I use a 40".

My M15A4T 20" with A2 FH on a LMT Defender lower and SOPMOD stock is approx 36 3/4" collapsed.
I’d go with a 40" or 42",especially if you ever plan to use a longer FH like a Vortex etc…Regardless added space gives room to let the zippers breathe.

Big help, thanks guys!

Just slapped my A4 upper, with A2 flash suppressor, on my carbine lower with UBR stock. With the 1/4" rubber pad that came with the UBR, fully collapsed the overall length is exactly 37".