I understand that there are military and commercial spec.. and that there is a size difference.. but I am going to put together an AR15 at some point.. and I have an extra buffer tube, spring, buffer from my DPMS 308.. I assume I can not use the buffer.. but can I use the tube? I honestly do not know how to idetify one from the other?

 

thank you in advance for the help..

Here's a graphic I got from a site awhile back when I was curious about the same question. Disregard the Magpul CTR stock, but it explains the dimensions and design on the left.

 

ETA: As for buffers, you could possibly reuse the buffer you currently have. People who consistently shoot higher powered ammunition (62g+) have been recommending H/H2 buffers (heavier buffers). And for springs, that's one line of products I'm not really familiar with at all-- sorry.

* So is it safe to say if it is slant in the back it is commercial?

* if the buffer is "too heavy" or whatever.. would that cause any malfunction? or damage?

 

thanks for all the info! the diagram is really useful

I've never heard of a heavy buffer causing damage. However, if you're shooting lower powered ammo, it can cause short stroking*.

And yea, I think it would be safe to say that you have a commercial buffer tube.

 

*Short stroking can be caused by, seemingly, a million different things. My answer was in direct reference to what you asked (if a heavier buffer can cause malfunctions). Its just something I wanted to note is all for future reference (though, I hope not!)

With buffers, run a buffer (and action spring) that matches your gas system. Carbines are notoriously overgassed so they typically benefit from a heavier buffer. Too heavy of a buffer will result in short stroking. I suggest starting with a H buffer and moving to heavier only if necessary.

 

As for reusing the buffer, spring and extension from your .308, it may or may not work. Some manufacturers use interchangable parts, case in point, LMT.

With buffers, run a buffer (and action spring) that matches your gas system. Carbines are notoriously overgassed so they typically benefit from a heavier buffer. Too heavy of a buffer will result in short stroking. I suggest starting with a H buffer and moving to heavier only if necessary.

 

As for reusing the buffer, spring and extension from your .308, it may or may not work. Some manufacturers use interchangable parts, case in point, LMT.

 

 

still figuring all out what I need.. I do have a box of AR parts from various ARs that I have owned.. if I don't have to buy a tube, stock, spring, buffer etc.. it is a few less parts that I need to buy all at once..