AR15 buffers - mil spec vs. commercial

[ZBill]

I need a carbine buffer (the short one I believe) for a Bushmaster AR15 with a 16 in barrel. The buffer I located will not fit in the Bushmaster buffer tube. After checking around I believe the Bushmaster requires a buffer with a smaller diameter head - not sure what that part is called.

If I am correct where would I get this buffer? - I looked at several web sites including Bushmaster and could not locate a commercial-size buffer.

Thanks for any assistance. Bill

 

[SpentCasing]

Should fit. (Just to establish you are doing things correctly)Are you pressing the spring loaded plunger down all the way and its still not going in?

 

[ZBill]

will not fit even with the plunger removed.

Just measured two tubes with a caliper - the inside of the Bushmaster tube is .98 and the other - I think a Stag Arms - is 1.12.

Thanks for the reply, Bill

 

[cyclopsshooter]

the larger one is commercial, the small is milspec

 

[helotaxi]

The internal dimensions are not different between the commercial and mil-spec, only the external dimensions. The mil-spec tube has the threads rolled in which raises them to a larger diameter than the rest of the tube. The commercial tube has cut threads in a larger diameter tube. The internal dimensions and the buffer and spring are the same size.

 

[ZBill]

thanks for the explanation folks

I must have misused or misread my caliper - I will go to the shop and get a new buffer today.

Thanks again, Bill