Good rear bag for AR stock?

[HAMBURGERATTACK]

I'm looking for a rear bag for my AR. Using a magpul SL stock and shooting off a Eberlestock Pack-Mountable Shooting Rest (mounted on a LBT 3 day assault pack).

Trying to figure out what size I need and looking for recommendations.

Want something that I can attach to my pack. Really like the Armageddon gear stuff so currently looking at their brick/x-wing/squishy rear bags.

 

[padom]

@Precision Underground Love my bags from them use them damn near every day

 

[HAMBURGERATTACK]

@Precision Underground Love my bags from them use them damn near every day

Those look nice - what size should I get?

 

[sjmpcc022]

Do you own a tape measure?

Can you read it?

If you can shoot distance you can figure this out.