DPMS upper block good enough for everything?

AR/M4 AR Technical Discussion
1

I notice in the recommended tools post both a DPMS upper block ( http://www.brownells.com/aspx/ns/store/ProductDetail.aspx?p=17094&title=AR-15+UPPER+RECEIVER+BLOCK ) and a normal clam shell upper block are listed for serious AR builders to have. Is there a reason for this / is the DPMS upper block not good enough for doing all functions? Does it provide enough protection for taking off and putting on barrels (is that the reason to own both types)?

I currently own a DPMS upper block and I wanted to figure out before I start building a few more rifles (I’ve already used it to build a few rifles, but I mainly use it to do flash hiders and accessories).

2

I went cheap and bought a DPMS Flipper which works for both the upper and lower.

3

Having broke a Colt C AF upper at the bottom right corner of the ejection port by using similar device (actualy had a bar that went through the upper and a flat plate that bolted to the bar allowing the bottom of the upper to be supported, I’d say no way!

I’ve used hard wood blocks in a vice on AR-10’s and would reccomend them before relying on the DPMS holder. The Brownells clam shell is what I use now.

4

Doesn’t the Brownells Clam Shell leave some big marks on the upper rec?

5

I’ve never seen a mark left on one. It’s made of some kind of plastic and works well for me.

6

Were you putting on a barrel or taking one off? This is exactly what I was worried about happening.

7

I was taking one off, it’s always a risk you run but probably almost never happens. The tool I was using had done quite a few before mine without any problems. After the fact, we saw the design flaws in the tool and I ordered a clam shell type from Delton. I also found out a little heat from a propane torch does no harm and goes a long way towards loosening a barrel nut that is too tight.

Yes it made me mad at the time but it made me dig into the why’s and how to’s of the AR. Before that I just shot them.

8

Roger, I’ve been thinking about the why’s and how to’s a great deal lately.

The wood block you used on AR-10 uppers…did you use the upper block for internal support and put wood on the sides of the upper to hold it in place? I’m only thinking I don’t want to mar the finish with a clam shell holder (actually the finish isn’t all that important…besides I’ve seen the marks, it’s just a rubbed area…I have to remember it’s a tool not a show piece).

9

I used hard wood blocks, one on the top of the upper(a flat top upper of course), the other on the bottom and locked them in a vice. This was as good as was available for the AR-10’s. The guys at ADCO told me how to do it and it worked fine.

Again, I’ve changed uppers for myself and others and never had a complaint about a mark the clam shell put on the upper. I know we’re all supposed to be tuff guys and these are tools but if I scratched or marked somebody’s upper, they’d tell me about it.

Mine has a Military part number of ABK 16-1 with Brownells marked right on it.