[Eliott]

When assembling my Mossberg 535 barrel, should the pump be forward (closer to the barrel) or rearward (closer to the stock) when I initially put the barrel in? The instructions were sort of vague, and it doesn't seem to want to go in when the pump is rearward but it seems to fit good when done that way. This is my first gun, however, so I wanted to make sure I'm doing it right.

[rcmodel]

Page 5 of your owners manual says:

"Move the forearm rearward until the front of the bolt is mid-way in the ejection port."

That seems pretty straight-foreword to me.

You do have an owners manual, don't you?
You did read it, didn't you?

If not, here it is:
http://www.mossberg.com/manuals/500_835_590_535_en_o.pdf

rcmodel

[Eliott]

I did read the manual, but this is my first gun and I know next to nothing of the real names for parts, so it took me reading that and the manual as a whole over and over to understand it.

Just to make sure I'm understanding it:

Move the pump rearward around half way until the bolt can be seen halfway, assemble the barrel, and then pull the pump rearward all of the way.