mharris Posted October 17, 2012 Report Share Posted October 17, 2012 I am a complete newbie to AR's but i am building a dpms 308 lr for my 14 yr old son. I have purchased so far the upper, lower, trigger kit, new grip, and a magpul stock. I ordered from Brownells the long buffer, buffer tube and spring. Currently nothing holds the buffer and spring in the tube. Will the bolt assembly permanently hold the buffer in the stock to provide the force to move the bolt or am I missing a part? I know this might be a retarded question but I come from pistols and none of my group shoot AR's so I have no guidance. Thx Quote Link to comment Share on other sites More sharing options...
planeflyer21 Posted October 17, 2012 Report Share Posted October 17, 2012 Welcome from AZ mharris!Someone will be along shortly to answer your question.Jon Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted October 17, 2012 Report Share Posted October 17, 2012 Mharris, welcome!From the looks of it, you're missing a buffer detent and spring. Had you bought a complete "Lower Parts Kit" these parts would have been part of that package. http://classic.brownells.com/.aspx/pid=24084/Product/BUFFER-DETENThttp://classic.brownells.com/.aspx/pid=24085/Product/BUFFER-DETENT-SPRINGThese two parts drop in the hole at te end of the threads where the buffer tube screws in. While holding the detent in with your finger, screw the buffer tube in till the lip of the buffer tube just passes the edge of the detent. The nipple at the top of the detent should still be exposed. That nipple is what holds in the buffer and spring. Now my question is, exactly which model Magpul stock did you buy? The long tube (also referred to as a rifle length or A1 tube) only fits fixed length stocks. I know magpul makes a fixed version, but I want to make sure you're not trying to put a collapsible stock on a fixed tube. Quote Link to comment Share on other sites More sharing options...
edgecrusher Posted October 17, 2012 Report Share Posted October 17, 2012 Currently nothing holds the buffer and spring in the tube. Will the bolt assembly permanently hold the buffer in the stock to provide the force to move the bolt or am I missing a part? I know this might be a retarded question but I come from pistols and none of my group shoot AR's so I have no guidance. Thxwhen you buy a lower parts kit for your lower receiver, you will get a buffer retainer and buffer retainer spring that will fit into the lower receiver. they will hold you buffer and spring in place. let us know when you get them and we'll help you in assemblyalso in regards to robocop's comment, depending on the stock you have, you may or may not have the right buffer tube, hopefully when you ordered them the sales person was knowledgable to get the right items for you. Quote Link to comment Share on other sites More sharing options...
unforgiven Posted October 17, 2012 Report Share Posted October 17, 2012 Welcome from Indiana brother mharris. Quote Link to comment Share on other sites More sharing options...
mharris Posted October 18, 2012 Author Report Share Posted October 18, 2012 Thx for the welcome everyone. We have the rifle length magpul prs type stock that has the adjustable cheek and back plate. I called brown ells and they gave me the parts numbers for the tube buffer and spring. We got the dpms lower with the parts kits installed but no detent and spring. That is what I needed I think. Quote Link to comment Share on other sites More sharing options...
mharris Posted October 18, 2012 Author Report Share Posted October 18, 2012 Are the detent and spring 308 specific or does it matter?.223Mharris, welcome!From the looks of it, you're missing a buffer detent and spring. Had you bought a complete "Lower Parts Kit" these parts would have been part of that package. http://classic.brownells.com/.aspx/pid=24084/Product/BUFFER-DETENThttp://classic.brownells.com/.aspx/pid=24085/Product/BUFFER-DETENT-SPRINGThese two parts drop in the hole at te end of the threads where the buffer tube screws in. While holding the detent in with your finger, screw the buffer tube in till the lip of the buffer tube just passes the edge of the detent. The nipple at the top of the detent should still be exposed. That nipple is what holds in the buffer and spring. Now my question is, exactly which model Magpul stock did you buy? The long tube (also referred to as a rifle length or A1 tube) only fits fixed length stocks. I know magpul makes a fixed version, but I want to make sure you're not trying to put a collapsible stock on a fixed tube. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 18, 2012 Report Share Posted October 18, 2012 Are the detent and spring 308 specific or does it matter?.223They're AR-15 parts, directly. No difference in those parts between the two platforms. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 18, 2012 Report Share Posted October 18, 2012 The only small parts you need to worry about the the .308AR are:Bolt catchBuffer springBufferTake down pinPivot pinAll the other parts are AR-15 parts. You can use the AR-15 safety, the takedown/pivot detents and springs, safety detent and spring, grip, grip screw, trigger assembly, mag release assembly (and it's spring). Receiver extensions (carbine or rifle) are the same, most of the time. Exceptions to that include the VLTOR A5 setup for AR-15s - don't use that on a .308 AR. Rock River Arms stuff is different, also, for their .308 AR (LAR-8).Large parts need to be specifically .308 AR - receivers, BCG complete, barrel, barrel nut, rails, etc.If you start thinking about mixing Armalite patterned parts and DPMS patterned together - get ahold of us before you purchase. Some things work, many don't. Quote Link to comment Share on other sites More sharing options...
mharris Posted October 18, 2012 Author Report Share Posted October 18, 2012 Wow thanks for that info that helps a lot. I think for congruency sake I'll stay dpms parts as much as possible. It is expensive enough as it is. I am very glad I found this forum it is a great resourse. I searched throug the pics in another thread and found a pic of the detent and spring behind the buffer. good forum Quote Link to comment Share on other sites More sharing options...
mharris Posted October 22, 2012 Author Report Share Posted October 22, 2012 Mharris, welcome!From the looks of it, you're missing a buffer detent and spring. Had you bought a complete "Lower Parts Kit" these parts would have been part of that package. http://classic.brownells.com/.aspx/pid=24084/Product/BUFFER-DETENThttp://classic.brownells.com/.aspx/pid=24085/Product/BUFFER-DETENT-SPRINGThese two parts drop in the hole at te end of the threads where the buffer tube screws in. While holding the detent in with your finger, screw the buffer tube in till the lip of the buffer tube just passes the edge of the detent. The nipple at the top of the detent should still be exposed. That nipple is what holds in the buffer and spring. Now my question is, exactly which model Magpul stock did you buy? The long tube (also referred to as a rifle length or A1 tube) only fits fixed length stocks. I know magpul makes a fixed version, but I want to make sure you're not trying to put a collapsible stock on a fixed tube.You were right i installed the spring and detent and we are good to go. Thanks for the help Quote Link to comment Share on other sites More sharing options...
Robocop1051 Posted October 22, 2012 Report Share Posted October 22, 2012 Great to hear! Dont forget to post pictures when you're done. Quote Link to comment Share on other sites More sharing options...
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