Newbie hybrid AR-15 clone question

[Hawk]

The brown truck just brought a real purty Bushmaster dissipater upper. (I just had to make an online purchase and do my part for the legal fund )

Anyhoo, I go to put the new guy on my Rock River varmint lower and it doesn't want to close - 5 minutes with a 6" swiss file on the takedown pin "block" and she goes together tight - kinda needs "snapped" closed. Should I file a touch more or can I leave it? I rather like the idea of a tight fit. Don't want to be hurting the thing, though.

The Rock River only has a couple rounds through it (bought it more or less on impulse 'cause I couldn't believe how nice the trigger was) and it's my first AR kinda thing - like I said "newbie".

Thanks in advance. I'm really looking forward to that light Bushie upper with the RR NM trigger.

 

[Duke of Lawnchair]

First of all, congrats on your new "toy."

Second, it's great that you've decided to support Bushmaster. My items from BM arrived yesterday and will be placing another order for a lower receiver parts kit.

Last but not least, the lower to upper fit can be as tight as you would like it to be, as long as you don't need an arbor press to drive the rear take-down pin out. If anything, polish it off a bit and you're most likely good to go!

 

[Hawk]

...guess I'm set.

Thanks.

The rear pin moves nicely with a nylon drift and mild whack with the brass hammer. Guess I'll leave it tight. I sure like the feel of the thing and can't wait to take it to the range - I see fiscal trouble on the horizon. If nothing else, 720 rounds of Eric's Swiss ammo is going bye-bye in a hurry.

Agreed on Bushmaster - I don't have the kind of disposable income needed to jump on an upper just 'cuz of the Brady Bunch - they did, however, knock me off the fence with respect to timing and manufacturer. I never thought I'd see the day when I'd be glad to pay MSRP on a web site.

Hijacking one's own thread:

My C&R FFL showed up today!
Thanks to all.

 

[Redlg155]

I wouldn't worry about it. Rock River lowers are a bit tight, but that's a good thing. My last RR that I put together with a JT kit was very tight. I took some force the first few times getting the upper and lower together, but after that zero problems.

I've got two bushy lowers in my safe right now that have more play than the Rock Rivers.

Good Shooting
RED