gravismaximus Posted October 4, 2018 Author Report Share Posted October 4, 2018 Was just about to ask, (98 just replied) so I will about this. That's exactly what I was thinking coil count has to matter. I went and found my ar15 spring that came with my buffer tube just to see how long it is... Don't you know, it's 11 1/4 long that's really close to that 11.5 so I was going to ask if I would be safe (no gun damage) to try and see what happens with it for poops and giggles. I noticed immediately the coil count difference. For under 2 inchs longer it has 13 more coils,. There a lot closer together on this spring and I would suspect that would make it a weaker spring although it just about has the length I need. So am I correct in assuming that the spring (ar15) would allow enough room for the 308 BCG to travel back without bottoming out because it's 11.5 and less? I will get a 308 spring, just wondering. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 4, 2018 Report Share Posted October 4, 2018 Don't run an AR15 spring in a 308, brother. It's not strong enough to handle that weight and force. You'll have some recoil at your shoulder that isn't good for your shoulder, and not good for the rifle. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted October 4, 2018 Report Share Posted October 4, 2018 (edited) From Mrraley, Some specs that ArmaLite puts out... RECEIVER EXTENSION TUBES •.223 / .308 rifle length 9-11/16” (inside depth) •.223 carbine length 6-15/16” (inside depth) •.308 carbine length 7-5/8” (inside depth) BUFFER SPRINGS •.308 buffer spring rifle and carbine length 14-1/8” •.223 buffer spring rifle length 13-1/2” max – 11-3/4” min •.223 buffer spring carbine length 11-1/4” max – 10-1/16” min BUFFERS •.223 rifle length 5-7/8” – weight 5.2 oz •.308 rifle length 5-3/16” – weight 5.4 oz •.223 carbine length 3-1/8” – weight 3.0 oz •.308 carbine length 3-1/4” – weight 5.4 oz And DPMS The following specs are DPMS parts that will allow an aftermarket AR-15 carbine buttstock with a commercial receiver extension/buffer tube, internal dimensions - 7" x 1", to be used on a DPMS LR-308: DPMS LR-308 Carbine Buffer Spring - Midway #: 813595 DPMS #: 308-CS-10A Relaxed Length - 11 3/8" Compressed Length - 3 1/4" 28 coils (inclusive of both ends) spring rate - ≈10lbs/in (tested over 2" travel from rest on buffer retainer pin) DPMS LR-308 Carbine Buffer - Midway #: 232006 DPMS #: 308-CS-10B Length - 2.938" ( ? ) Should be 2.5" Flange Diameter - 0.969" Barrel Diameter - 0.686" weight - 3.808 oz. DocLarsen Edited October 6, 2018 by survivalshop Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 5, 2018 Report Share Posted October 5, 2018 (edited) ^^^ The DPMS LR-308 Carbine buffer isn't almost 3" long, no way. It wouldn't run in that 7" internal depth receiver extension - the BCG wouldn't come back far enough to lock back, at all. It's 2.500" long, within a few weird thou... 2.938" on it is unpossible. Edited October 5, 2018 by 98Z5V Quote Link to comment Share on other sites More sharing options...
gravismaximus Posted October 5, 2018 Author Report Share Posted October 5, 2018 Ok so I ordered the orange sprinco spring and was getting ready to buy some tungsten weights to swap out to make a 5.1 oz buffer, vs the 3.8 I have now, when I recall that guntec buffer I bought was powder filled. Sure enough I took the end off buffer and there's a plug in there holding the powder in. I looked online on multiple sites looking for my buffer and found no mention of it being tungsten filled powder. Questions are, do companys make buffers with powder that's not tungsten? Is tungsten powder lighter than tungsten weights? How? It's tungsten still. More dense in a soild form? Is it better to have the inertia of moving weights in a buffer vs the filled non moving powder? The little pads that go in between the weights- are they there just to keep the weights from hitting each other (breaking), if so why isn't there one between the metal buffer case and the first weight that goes in? Don't want to buy the weights if I'm still going to end up at 3.8. thanks for the help guys. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 5, 2018 Report Share Posted October 5, 2018 (edited) For your buffer, do one of the things I stated in the thread I linked in this thread. Have you weighed your buffer that you have? Do you know it's 3.8oz? I can tell you what makes a 3.8oz buffer that's 2.5" long, and I did in the thread I linked earlier. You can make a maximum of a 5.15oz buffer that's 2.5" long. You can make it yourself. If you want to make that minimum buffer operating weight that a .308 Win AR needs (5.4oz), then you need to look at aftermarket manufacturers. HeavyBuffers.com is the only one. kakindustry.com coms even closer to the 5.4oz minimum, with a 5.3oz, 2.5oz buffer. Your choices are very limited, and it loks like you committed to the Sprinco Orange spring, so you need to either make, or buy a buffer that's pretty close to 5.4oz. And 2.5" long. In that thread, I made a 5.7oz buffer with a combination of parts, and it came up 0.069" short of 2.500". One quarter down the receiver extension solved that problem... Edited October 5, 2018 by 98Z5V Quote Link to comment Share on other sites More sharing options...
survivalshop Posted October 5, 2018 Report Share Posted October 5, 2018 (edited) 8 hours ago, 98Z5V said: ^^^ The DPMS LR-308 Carbine buffer isn't almost 3" long, no way. It wouldn't run in that 7" internal depth receiver extension - the BCG wouldn't come back far enough to lock back, at all. It's 2.500" long, within a few weird thou... 2.938" on it is unpossible. Ya I didn't look at that as close as I should have , I just copied & pasted from another thread here , also notice the length of the spring ( I have a used one that is 11 1/4" long & still worked fine when replaced with a Tubb's Flat wire spring ) & coil count , but some can measure the Coils differently & spec's by retailers can be misprinted , like Midway ! I edited it with a " ? " The DPMS Buffer system is designed to use a 2.5" long Buffer , 11.5" Spring ( or close to that ) with 29 coils & a AR 15 Receiver Extension . The system works when these components are correct , As has been posted . Edited October 5, 2018 by survivalshop Quote Link to comment Share on other sites More sharing options...
gravismaximus Posted October 5, 2018 Author Report Share Posted October 5, 2018 I did read it, must have missed how you got it to 5.7 thou. You used a steel body with two tungsten weights right, that's what I'm planning to do ,so at least I'll be close. My short buffer is magnetic so it's not aluminum, must be steel. I'm going to buy a scale today to be sure on weight. If it don't work still I'll buy the kak. But how are they getting the extra .3 oz tungsten body? Anyone know about the powder question? Are the weights more dense (weigh more) I appreciate all the help 98z5v and survivalshop. I started looking into switching to a ar10 setup but it'll cost more in the end (have to buy everything recoil system again) although I'd have more options. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted October 5, 2018 Report Share Posted October 5, 2018 You also have to remember that adding weight to a system designed for a specific weight system/Spring , may also cause issues , no matter what you read on the internet, keep that in mind . All you need is the correct spring to get your Buffer system to the original DPMS spec's . Nothing wrong with changing to the AR 10 system , but why , when all you need is a Spring .If you want this used known to function Spring I have , PM me with your address & I will send it to you to try , if it works out your issue , keep it or send it back when you get the correct one . I'll even send the Buffer with it .They are stock DPMS Buffer system from a DPMS Carbine LR 308 Lower . Also note that you may have multiple issues that cause failure to feed , but you do have an Spec Buffer Spring which we have seen here to cause all kinds of issues , so you need to straighten it out one way or the other first . I also noticed you were sanding the Gas Rings on the Bolt , I would not do that , they will wear & break in all by a higher round count , as will the Bolt Carrier Group . Was the Aero Upper assembled or did you assemble it ? On a New Build , built with an Adj. Gas Block , you should always have it wide open ( like a non-add one ) for break in of the action , then adj. to your liking after the Action smooths out . I don't use them at all , the only one I have is on my Piston system AR 15 & the Piston system came that way . Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 6, 2018 Report Share Posted October 6, 2018 14 hours ago, gravismaximus said: I did read it, must have missed how you got it to 5.7 thou. You used a steel body with two tungsten weights right, that's what I'm planning to do ,so at least I'll be close. My short buffer is magnetic so it's not aluminum, must be steel. A decent magnet is gonns get stuck to those weights inside of an aluminum buffer body, through the aluminum. Don't count on your buffer body being steel, until you take it apart and try to stick a magnet to it, stripped of all it's internals. The easiest way to gain weight in a buffer is a stainless steelbody, over the aluminum. That alone took my Aero buffer from 3.7oz to 5.15oz. I loaded the aero buffer guts into the DSG stainless buffer body. The aero already comes with two tungsten weights in it. The combination of the tungsten and stainless body is what made it 5.15oz. The 5.7 buffer I did was a Slash Heavy Buffer RRA LAR-8 Carbine buffer. The RRA carbine buffer is 2.25" long, with a modified bumper on the end. I change it to a regular bumper, and it only came up 0.069" shorter than 2.500" long. I made up the needed length difference with a quarter down the extension. The big difference in the Slash buffer is that the body (stainless) doesn't step down, like regular buffers do - it's thicker; more stainless means more weight. Quote Link to comment Share on other sites More sharing options...
gravismaximus Posted October 7, 2018 Author Report Share Posted October 7, 2018 I should receive my spring and tungsten weights this week and hopefully will be able to test it next weekend. I'll take you up on that offer survival if the heavy buffer and spring don't fix it. I measured my buffer after I calibrated my scale with the 2- 5.5 weights needed. it weighs 3.65oz . And I called gun tec. They told me my buffer was not tungsten powder filled but rather had steel weights in it. When I pulled the cap off it I see a plug inside, and nothing moves when I shake it. So do companys make buffers with weights inside that don't move? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 7, 2018 Report Share Posted October 7, 2018 4 hours ago, gravismaximus said: So do companys make buffers with weights inside that don't move? They do whatever they want, to make a buck. I'm not kidding. There's no set of prints to follow, no specs, and they do whatever they want... That's one of the very reasons that the DPMS-based recoil system is so jacked up... Quote Link to comment Share on other sites More sharing options...
survivalshop Posted October 7, 2018 Report Share Posted October 7, 2018 (edited) Geissele makes a replacement weight for Buffers .https://www.brownells.com/rifle-parts/receiver-parts/recoil-parts/recoil-buffers/super-42-tungsten-buffer-weight-prod87957.aspx Edited October 7, 2018 by survivalshop Quote Link to comment Share on other sites More sharing options...
gravismaximus Posted October 8, 2018 Author Report Share Posted October 8, 2018 (edited) Just tried to remove guts from my gun tec buffer to find out there are no weights. It's just a solid peice of steel. I drilled into it about 3/16 inch, differently not a cap. Bummer now I have to find a steel buffer with steel weights that I can replace with the tungsten weights I ordered. Or just buy the kak buffer. Edited October 8, 2018 by gravismaximus Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 8, 2018 Report Share Posted October 8, 2018 (edited) 2 hours ago, gravismaximus said: Bummer now I have to find a steel buffer with steel weights that I can replace with the tungsten weights I ordered. DSG Arms. It's $22. https://dsgarms.com/dsg-4201-0021 Sign up for the notification, and they'll email you when it's back in stock. It won't be OOS for long... With 2 tungsten weights in it, you'll be at 5.15oz buffer weight. Edited October 8, 2018 by 98Z5V Quote Link to comment Share on other sites More sharing options...
survivalshop Posted October 9, 2018 Report Share Posted October 9, 2018 Midway has them in stock https://www.midwayusa.com/product/1003326948/dpms-buffer-lr-308-carbine & so does Brownells . Quote Link to comment Share on other sites More sharing options...
gravismaximus Posted October 12, 2018 Author Report Share Posted October 12, 2018 I went ahead and bought a kaw heavy buffer, 22 dsg arms + 20 for the weights. I spent 1$ more and went with the kaw on sale with free shipping at aimsurplus. I just got it tonight it weighs 5.7oz on the scale installed it and the springco. So this weekend I will find out if it was the fix. Can you get a buffer that's too heavy to the point it messes with the rifle timing? Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 12, 2018 Report Share Posted October 12, 2018 2 minutes ago, gravismaximus said: I went ahead and bought a kaw heavy buffer, 22 dsg arms + 20 for the weights. I spent 1$ more and went with the kaw on sale with free shipping at aimsurplus. I just got it tonight it weighs 5.7oz on the scale installed it and the springco. So this weekend I will find out if it was the fix. Can you get a buffer that's too heavy to the point it messes with the rifle timing? Not when the system is designed for 5.4oz, and you're running 5.7oz - that 0.3oz isn't the "make or break" right there. I'm running a 5.7oz shorty buffer in the .260 Rem. Behaves fine. Quote Link to comment Share on other sites More sharing options...
gravismaximus Posted October 17, 2018 Author Report Share Posted October 17, 2018 Well I was able to test it over the weekend and..... I'm pumped it works like a champ. Was able to ammo dump a mag with no problem, haven't done that since I was in the Army 18 years ago, felt so good. Thank you for the help everyone. Now it's time to get it sighted in better, I'm only using battle sights and my groups are around 4". Ewww. Maybe it's the cheap fedral ammo I'm using?? I'll start a new post for that after I read some of the previous threads on it if I need to. Quote Link to comment Share on other sites More sharing options...
98Z5V Posted October 17, 2018 Report Share Posted October 17, 2018 I love hearing this kinda stuff, man. I really do. I'm glad it's running like it should. Quote Link to comment Share on other sites More sharing options...
survivalshop Posted October 18, 2018 Report Share Posted October 18, 2018 Thats great . Quote Link to comment Share on other sites More sharing options...
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