Mil-Spec Parts

[mcdaniel52761]

I know about the commercial and mil spec buffer tubes, but when it comes to other parts of an AR.....are they different? I have a commercial spec DPMS and would like to upgrade some of the parts. Carrier, spring, buffer, etc... Most of what I come across says "mil spec" and was wondering if all of the parts were different or just the stock on the buffer tube.

 

[HOOfan_1]

mil-spec on most other parts might not necessarily mean they are not interchangeable.

Stuff like Mil-spec bolts, just means the material they are made of and the testing they go through, but are interchangeable as far as fit and function.

"full auto" bolt carriers have more material on them, but again in a semi-auto gun, they are interchangeable as far as fit.

There are different barrel diameters as far as gas blocks go.

More than likely, the only thing that isn't interchangeable on your DPMS are the stock and receiver extension

 

[mcdaniel52761]

Ok, thanks. I was hoping it was mainly pertaining to the butt end and the barrel of the rifle.

 

[taliv]

the "commercial" versions of most of the rest of the parts are dimensionally identical and interchangeable but are usually made from cheaper materials and finishes or have not followed the rigorous testing procedures that are part of "mil-spec".

if you have a question about a specific part, please let us know.

 

[adelbridge]

GI barrels will interchange with your DMPS as long as the gas system is the same. As far as swapping BCG and springs, if you gun runs well leave well enough alone. DPMS tested the gun to run as assembled and you wont improve it much unless it has one of those older carriers with an unshrouded firing pin. The only springs I would consider replacing is the trigger and hammer springs for something around 4lbs.

 

[mcdaniel52761]

the "commercial" versions of most of the rest of the parts are dimensionally identical and interchangeable but are usually made from cheaper materials and finishes or have not followed the rigorous testing procedures that are part of "mil-spec".

if you have a question about a specific part, please let us know.

Was considering a FailZero EXO carrier group, David Tubbs buffer spring as well as extractor and ejector springs and either a Spikes t1 or t2 buffer. Thought I would weigh my original buffer and see which one of the two is closest. This is my first AR and while I don't know a lot, I've been reading some good things about the parts that I listed above. By the above post, maybe I should also consider changing out the trigger and hammer springs as well. Slowly learning

 

[taliv]

ok so some commercial parts are made from BETTER parts than mil-spec and have better finishes

how much you spend is not a reliable indicator of quality, but it's a good guess most of the time. obviously, people charge a lot for new crazy coatings like failzero and salt bath nitriding and boron nitriding and NiB. like moly coating, the fad will likely pass soon for most of them. hopefully one or two are demonstrably superior and become the new standard. at this point though, most of us are in the "well that sounds like it might be an improvement, so maybe i'll try it" camp.

just remember there was a period of a year or two where everybody and their dog was blathering incessantly about how great moly coating was. now almost nobody uses it. so yeah, we're in the peak of the hype cycle for a lot of these products right now.

as far as changing springs and buffer weights, keep the originals around in case you find out the new ones don't work.

 

[gotigers]

gun show unmarked parts < some commerical parts < milspec parts < good commercial parts.

Example: Geissele isn't milspec, but is better than milspec.

 

[mcdaniel52761]

Gotcha. Guess I was mainly concerned about the fitment but sounds like most of it is all compatible

 

[gotigers]

Most AR parts and accessories are interchangeable between ARs. There can be a big difference in quality. I will buy any of it depending on needs. Except, i don't buy unmarked parts at gun shows. Even then you have to be careful because there are chinese knock offs, especially on Ebay. Magpul, LaRue and others have been copied. Buy from known sellers.