A few lowers compared

[liliysdad]

So, if I were to hand you a Colt lower and a DPMS lower, and tell you either one was yours for the asking, you would pick the DPMS? Seriously?

While I do agree that a lower is a lower is a lower, as long as they are in spec, wasted machining removing flash marks means nothing.

 

[brennan]

And so does the name on the side.

 

[KurtM]

I build, shoot and play with ARs all the time, so I hope you will take this for exactly what it is....More than likely I would take the DPMS lower. In the last 4 years their lower is by far the best in general when I put them in my hole gage jig. The machining is very good. the finish uniform and hard. the trigger and hammer pin holes are RIGHT! the Mag catch is very uniform in placement ( not so with the prancing Pony...EVER!) and the mag well is always right ( even though try as you might you will never find a spec for it, cause they never thought to spec that protion of the lower...even in the orriginal AR Mil Spec.) and the cross pins are always located in the right place. Are ALL of them good, NO, but many more are good than most large manufacturers A,B,C.

Now I am not including the small custom shops in this cause Leitner Weise/Land Warfar, Noveski, J.P. etc. take the time to do it right Remember they start with the same darn blank, but they really put in the time, but for a big manufacturer I have had really good results with DPMS.

The very best of the Best Is Nordic Components who machines a good deal of the lowers used by the custom builders, but they don't sell lowers to the General Public KurtM

 

[CAR-AR-M16]

I think it was said best when someone pointed out that the "mil spec" of the AR is circa 1957, so you are worshiping 1957 metallurgy and technology.... basically. Great old timer but things do advance.

So, should we all throw our 1911 Pistols in the trash since they are 100 year old metallurgy and technology?





That was a joke in case some didn't get it.

 

[shepherm]

Just out of curiosity - how did you judge fitting other than visually? With a machining background, surely you have a set of calipers laying around. The measurements of the old M-16 lower receiver are on the net - I'd love to see the differences in even just the FP/Trigger hole sizes in the receivers you've got (and which are in/out of spec).

Possibly even some of the measurements on inside/outside dimensions - that would tell you which really are/aren't mil-spec.

To test fit I mounted them on a bench mount and checked for movement with 7 uppers. Sure I have calipers, but if you want I can use a vernier micrometer which measure .0001". Also I have depth micrometers and lots of other tools that measure to the .0001" or less if you need. If you post a link to the specs I will do my best to make a few measurements and let you know what I find out.

So, if I were to hand you a Colt lower and a DPMS lower, and tell you either one was yours for the asking, you would pick the DPMS? Seriously?

I would take the colt sell it and buy the DPMS and take the money and put in a Kreiger barrel blank. Don't get me wrong I like colt and own the two tested but your paying for the name on the lower.

While I do agree that a lower is a lower is a lower, as long as they are in spec, wasted machining removing flash marks means nothing.

Just that the company takes the time to care about the details. It still wont make it shoot better but if its cheaper and more machining done it hard to not pick it over the name.

So, should we all throw our 1911 Pistols in the trash since they are 100 year old metallurgy and technology?

That was a joke in case some didn't get it.

No you should just give that junk to me!

 

[HiredHand]

Well since only 3 companies make the blank lower receiver that everyone uses to mill out their "own" lower receiver, I fail to see how Colt is sooo much better than anyone else's cause they don't "sole source" their blank...it can come from any of the 3, same for upper blanks...except there are 6 companies that make the upper blank.

For Lower blanks..Martin Marietta, Cerro Forge, and Alcoa
For Uppers... Alcoa, Kaiser aluminum, Anchor Harvey, Mueller Brass, Marten Marietta, and Cerro forge, so can anyone tell me why Colt is so much better, when they mix and match all the above, just like all the other big builders? A Bushmaster upper with a key hole mark ( Cerro Forge ) is inferior to a Colt upper with a Key Hole on it how?? A Les Baer upper with the Key Hole is worse than a Colt Key Hole How?? They all came from the same forge, but I am to be told that when Colt buys it it magically becomes better??

I think it was said best when someone pointed out that the "mil spec" of the AR is circa 1957, so you are worshiping 1957 metallurgy and technology.... basically. Great old timer but things do advance.

I for one will take the one that has the best machining cause if they are doing that right, chances are that they took the time to make sure all the important holes are in the right place too!

What's with telling all the dirty little secrets? Aren't we supposed to believe that everyone does 100% of the machine work in house. I've seen numerous threads on fit and finish of AR receivers and I'm not convinced that even individual manufacturers are consistent. I can understand people's desire to have a nice fit/finish but function is at the top of importance.

Here's a list of who finishes forged blanks for who. Its older so things may have changed.

http://www.ar15armory.com/forums/AR15-Receiver-t15231.html

 

[HiredHand]

I build, shoot and play with ARs all the time, so I hope you will take this for exactly what it is....More than likely I would take the DPMS lower. In the last 4 years their lower is by far the best in general when I put them in my hole gage jig. The machining is very good. the finish uniform and hard. the trigger and hammer pin holes are RIGHT! the Mag catch is very uniform in placement ( not so with the prancing Pony...EVER!) and the mag well is always right ( even though try as you might you will never find a spec for it, cause they never thought to spec that protion of the lower...even in the orriginal AR Mil Spec.) and the cross pins are always located in the right place. Are ALL of them good, NO, but many more are good than most large manufacturers A,B,C.

Now I am not including the small custom shops in this cause Leitner Weise/Land Warfar, Noveski, J.P. etc. take the time to do it right Remember they start with the same darn blank, but they really put in the time, but for a big manufacturer I have had really good results with DPMS.

The very best of the Best Is Nordic Components who machines a good deal of the lowers used by the custom builders, but they don't sell lowers to the General Public KurtM

I have a friend who insists that his lower let the mag drop free.

 

[Fyrtwuck]

I've noticed lately that Colt uppers have a "keyhole" symbol on them with a "C" stamped nearby.

I see the keyhole uppers at the gunshows all the time with no other markings.

Is this a sign that they are all the same or that Colt is lowering it's quality?

 

[CAR-AR-M16]

I've noticed lately that Colt uppers have a "keyhole" symbol on them with a "C" stamped nearby.

I see the keyhole uppers at the gunshows all the time with no other markings.

Is this a sign that they are all the same or that Colt is lowering it's quality?

The "keyhole" symbol means that Cerro Forge produced the blank that the receiver was made out of. Many different manufacturers use Cerro Forge blanks (I have a Bushy with a "keyhole" forge mark). The "C" means that final machining was done for Colt. Most other manufacturers do not put any additional markings on their uppers.

 

[KurtM]

Yes You shoul throw away those old 1911s...haven't you heard about the STI 2011's? Same good features only they hold 16 rounds of .45, and metal that is to die for. Kurtm