Commercial buffer.

[ChrisO]

I have a spikes lower with a commercial buffer on it. Is the lower made for a commercial buffer or are the pitch on the threads the same and same diameter and the diameter just differs on the outer portion? I'm wondering if I can change to a milspec buffer or I need to get another lower. My concerns are the mil spec is made of stronger metal and I remember reading somewhere the threads go deeper into the receiver. I don't want to have to worry about this.

[DK9mm]

Either one will work fine.

[Josh3239]

Same lower, different sizes:

[ChrisO]

Cool, Wonder why anyone would go with commercial over mil spec then? Is it cheaper or something? I guess I'll have to pick up some milspec stuff. Well a whole milspec set up is going on the accessories page with a vltor emod just to let ya guys know .

[tomd1584]

Buffer? You mean receiver extension.

[ChrisO]

Buffer tube, Correct?

[tomd1584]

Technically called receiver extension. Most people just call it the buffer tube since it houses the buffer & spring.

[ChrisO]

Well in that case yes I meant the receiver extension haha. See learn something new everyday.

[Capt. Speirs]

Commercial Receiver Extensions are cheaper and weaker than Milspec. If you have a choice, go Milspec, you will then have a much larger selection of stocks, IMO.

[ChrisO]

But you guys are saying I can put a mil spec receiver extension on my lower, They are not milspec/commercial specific? I was confused since the OD's are different. Is it a taper?

[glockmeister]

I recently changed from commercial to milspec. I had no idea the two existed when I got it. Now that I know, milspec is what I wanted. Just an FYI, the castle nut will fit both a commercial and milspec. The buffer and spring will fit too. 28 bucks for a DD milspec tube.

[Josh3239]

But you guys are saying I can put a mil spec receiver extension on my lower, They are not milspec/commercial specific? I was confused since the OD's are different. Is it a taper?

It is approximately .015'' different. And it is threaded. You understand that at that small of a different it is just a matter how deep the threads bite? There is no commercial tube lower nor a mil-spec tube lower. All lower extention "towers" are drilled to the same diameter and the threads are cut with the same tap. There is a very teeny tiny difference that makes no functional difference as far as screwing in the extention goes.

You are getting hung up on the wrong details. If you have a commercial extention you need a commercial stock. If you have a mil-spec extention you need a mil-spec stock. Commercial extentions are weaker and have less stock options. The lower is not your concern.

[Nathan Krynn]

From the story I was told a long time ago a 4 letter word found it easier to export rifles with commercial buffer tubes and AR-15 carriers as it was not the same as USA military equipment. How true this is I don't know.

[tomd1584]

It is approximately .015'' different. And it is threaded. You understand that at that small of a different it is just a matter how deep the threads bite? There is no commercial tube lower nor a mil-spec tube lower. All lower extention "towers" are drilled to the same diameter and the threads are cut with the same tap. There is a very teeny tiny difference that makes no functional difference as far as screwing in the extention goes.

You are getting hung up on the wrong details. If you have a commercial extention you need a commercial stock. If you have a mil-spec extention you need a mil-spec stock. Commercial extentions are weaker and have less stock options. The lower is not your concern.

perfect explanation.

[ChrisO]

It is approximately .015'' different. And it is threaded. You understand that at that small of a different it is just a matter how deep the threads bite? There is no commercial tube lower nor a mil-spec tube lower. All lower extention "towers" are drilled to the same diameter and the threads are cut with the same tap. There is a very teeny tiny difference that makes no functional difference as far as screwing in the extention goes.

You are getting hung up on the wrong details. If you have a commercial extention you need a commercial stock. If you have a mil-spec extention you need a mil-spec stock. Commercial extentions are weaker and have less stock options. The lower is not your concern.

I know if I have a commercial spec tube I need commercial spec stock but what I was wondering if I could use either tube in any lower. Now I understand that I can. I have a commercial spec tube and commercial spec stock but I am wanting to go mil spec so I was just making sure I wouldn't waste my money. Thanks for all the help guys! I appreciate the replies.