I ordered a lightweight carbine upper from Model 1 to replace my HBAR.  On the product page for this upper, Model 1 claims that the front sight base is forged.  My Rock River HBAR has what I believed to be a cast front sight base; it has a rough texture, not smooth like the upper/lower receivers, and there are large ridges that I took to be mold lines.

I got my lightweight today and the front sight base looks basically the same as my HBAR.  Am I wrong about the cast/forged thing, or did they screw up somewhere?  Anybody else buy from Model 1 and run into the same problem?

The only possible quirk is that I ordered a NM front sight with the upper ($8 upgrade).  I am going to put my XS front sight on it, but I figured I didn't have a NM blade and for eight bucks it would be worth having around.  I know kind of what a NM front sight should look like, and this ain't it.  It looks to me like an A1 front sight (five notches, thin round post).  I note that Model 1 sells a NM front sight assembly with set screws; this looks like it uses taper pins, so I'm guessing that they didn't just substitute the whole assembly.

It's no big deal, but I'd like to get the facts straight before I call them up.

jafager

jafager,

both are forged. The "ridges" you are reffering to are forging marks. same marks can be seen on forged lowers around the trigger guard loop.

halik

Here is a cast FSB on one of my uppers:



Notice that it doesn't have the seam that Troy talks about. It is also much more fragile than a forged FSB. There is now a large chunk taken out of the right side from a minor impact.

Lock at the "Up" near the front sight post.  

If it's indented (stamped in), then it's forged.  The casted ones have the Up rasied from the base.

As for the NM front post, there are both A-1 and A-2 posts (4 verses 5 indents for the tool).  Sounds like you just have a A-1 NM post and need the A-1 5 prong tool.

Quoted: Lock at the "Up" near the front sight post.   If it's indented (stamped in), then it's forged.  The casted ones have the Up rasied from the base. As for the NM front post, there are both A-1 and A-2 posts (4 verses 5 indents for the tool).  Sounds like you just have a A-1 NM post and need the A-1 5 prong tool.

Here is a different view to illustrate what Dano is talking about:

Quoted: Lock at the "Up" near the front sight post.   If it's indented (stamped in), then it's forged.  The casted ones have the Up rasied from the base.

Not always true, the cast FSB on my CMMG upper has an indented "UP" on it.







These cast FSB's seem pretty damn durable, I've banged it pretty hard on stuff with no damage other than a scuff mark.  I was going to to have ADCO replace it with a forged FSB when they were installing my FF-RAS MRE but after inspecting it Steve told me it was the best cast FSB he ever saw and that there was no reason to replace it.  Eitherway I'm not worried about mine breaking especially with all the extra protection from the FF-RAS MRE...

Usually the forging is rougher yhan cast and you can see where the grinder has gone over the steeland its somtimes beat up like tiny hammers have hit it and beat it up.

BravoCompanyUSA,

Yes DPMS makes these barrels specially for CMMG.  The FSB is cast but the rest of the barrel is up to spec with 4150 steel, NATO 5.56 chamber, M4 extended feed ramp, fully chrome lined and 1/7 twist.  

At the time I bought it CMMG was the only game in town for a 4150, 1/7 16" barrel other than Colt who, IMHO, charged too much.  These days it seems a lot of great manufacturers like LMT are making 16", 1/7 barrels.

Oh, and my FSB has survived stuff a lot harder than a rubber mallet...

So let me get this straight -- I ask a question which has to have been asked a million times before, and in the time it takes me to drive to the range, shoot a hundred rounds, and come back, I've got answers from seven different people, most of whom have a long history of being authoritative?  Man, I love you guys .

When I get a minute, I'll do a quick range report on the upper.  The difference was...enlightening.

jafager