Ignoring the obvious difference of length, what are the differences between the short entry buttstock and the regular sized buttstock.  Is there a difference in spring tension or length?  Are the pistons the same?

I just saw one of those in an NRA rag..rock river made it I think..
I'm going to assume it uses the same shortened parts as a collapsable stock does...buffer and buffer spring...the end of the tube would be threaded to accepy the stock like a standard stock...but i'm only guessing..I'm planning on buying one tho...my arms are short and an A2 stock is tooo damn long

bybon,

The RRA Entry stock uses the carbine (or CAR, or collapsible stock) buffer, tube and spring.
Also, the entry stock does not have the storage compartment for a cleaning kit.

I wish they had made it about 1" longer.
I didn't want to spend another $20-$50 for a stock extender, so I went back to my A1 stock.

Thanks guys that is all I needed to know.  20 -50 bucks for a stock extender!  What a rip!

It is VERY short. A tad too short for an average sized adult to shoot comfortably IMO. I got it, not as a 'Tactical Entry' stock, but so my nephew could shoot my AR-15, so that's not a major deal for me, it's a pretty quick job to swap out the stocks.

As others mentioned, it uses a carbine length buffer tube, assembly, and screw, which is it supposed to come with - mine didn't, but it was an error, and my buffer is on the way.

An A-2 Trapdoor buttplate WILL fit though, just in case you hadn't thought of it. The compartment is of course much shorter, but a good bit roomier than the A-2 storage compartment.