Just got my hy-tech mag block. I had to hammer it into place and not unlike prom night I thought about using some sort of lube. In the end I just pushed hard and it went in, but back to the block problem. . .

My question is this. Will the tight fit hinder or bind when I start shooting? I've yet to order my upper. Thank for reading. And I appoligize to anyone that had flashback to highschool.

Tip the upper open,,,, hold mag release (on the lower) and insert the block.  Watch for the 223 bolt hold finger, some like to snag the back of the block, especially if the hammer is standing straight up
Now close the lower.....

If you notice the top sides of the block, they are a bit higher than the surface on the lower,, see........

That higher surface contacts the bevel in the upper, thus pushing the block down a smidge, and binding the AR mag release, so you cannot drop the block readily, unless you have a super finger.

No that wasn't it. . .

It took me an hour of file use to remove enough stock so that it slide in without binding. Block fits fine now.

Now I have to buy an upper.

Are you using a Bushmaster lower? Mine was tight. I had to use a mallot to hammer it in. With over 1000 rounds through it the block has loosened up enough that I can  pull it out. It won't drop free when the mag release is pressed.

NO. It's a Grizzly lower.