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Buffer Tube, Buffer and Buffer Spring


Robocop1051

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What is the difference between the 5.56 and the 7.62? I'm asking because I'm in the middle of my 7.62 build and I have a lot of 5.56 parts laying around.

I'm pretty sure the Buffer Tube is the same, and I can assume the Buffer Spring in the 5.56 is weaker than the 7.62 (but I'm not sure)... and I have no idea about the difference in the actual Buffers.

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  • 1 month later...

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

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Just remember the Armilite Carbine receiver extension uses "there" buffer spring , where as DPMS compatible rifles use the std. AR carbine receiver extension's.

In other words , you can use any AR carbine receiver extension in a DPMS type AR 308 ,but will need 308 buffer spring & buffer.

If you use a Armilite buffer spring in a std AR carbine receiver extension you may need to alter it for proper function.(longer spring , as shown above )

Some mix them & you can , but I don't . Its just me . Why mess with some thing that works , these company's spend a lot on R&D to make sure the combo of components work.

And then you have the custom made springs & buffers , as show above also.

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I picked up a Bushmaster ORC last night, this is my first post here. 

If I'm reading the above posts correctly: I should be able to take the LMT mil spec buffer tube from my 5.56 gun and install it on the 7.62 gun using the buffer and spring that came with the 7.62 gun.  Since I'm replacing the 5.56 gun in question with the 7.62 gun I'd like to use as many of the aftermarket parts as possible.

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Correct.  <thumbsup>

Since the ORC already comes with a carbine length receiver extension, the LMT piece should be a direct swap.  I don't know if the ORC uses a mil-spec size or commercial size receiver extension, but it should be easy to measure and determine.  If the O.D. of the tube is 1.14", it's mil-spec.  If it's 1.17", it's commercial.  The LMT stock is mil-spec sized.

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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"

Flange Diameter - 0.969"

Barrel Diameter - 0.686"

weight - 3.808 oz.

DocLarsen

edited to include tube dimensions

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  • 9 months later...
  • 4 weeks later...

Anyone tried removing the snubber on a buffer to change the weights inside???? I did couple years ago but gave up cuz I didn't have one to replace it if I destroyed original ....wondered if there was a trick to it,  after driving out roll pin. It's come up again while contemplating different buffer weights and spring for new rifle.

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Anyone tried removing the snubber on a buffer to change the weights inside???? I did couple years ago but gave up cuz I didn't have one to replace it if I destroyed original ....wondered if there was a trick to it,  after driving out roll pin. It's come up again while contemplating different buffer weights and spring for new rifle.

Lots of guys experiment with that on the AR-15 side of the house, to come up with the perfect combination for their rifle and ammo - basically, they buy a standard buffer (3 x steel weights) and the H3 buffer (3 x tungsten weights), and you can make any combination you might need, with those parts. 

No reason that shouldn't work on a .308 AR buffer.  <thumbsup>  Maybe go ahead and pick up something of H1 weight and the H3 weight, so you've got more total weight to play with - the .308 can use the extra weight.

Another option completely outside of messing with taking apart buffers (which isn't a bad option, in the least), is to just get a Tubb CWS.  More weight is the ultimate goal, and you can far surpass "total weight added" by using the CWS.

Read this, for an idea of what I'm talking about - I added enough to a 5.56 gun to make it fully functional for my ammo, in that combination...    I had a few 5.56 guys telling me beforehand that it wouldn't even run like that - Bah!  ;D  Runs like a champ in my config.

http://308ar.com/forum/general-discussion/how-much-cyclic-weight-is-too-much/

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  • 3 months later...

I have been using heavy tungsten powder in my buffers in AR and LR platforms.  Heavy tungsten powder is heavier than normal tungsten powder by about one ounce per a given rifle length buffer and the only place I know of to get it is from HDTP.  It is terribly expensive though but if you can get enough people together to order 10 pounds or more, the price is cut in half.  I have had great luck with it and you have infinite adjustability over the weight.  I find it gives a dead blow affect to the buffer** and according to Spikes, it reduces bolt bounce although that is not an issue really in semi autos.

**drop a normal buffer on the floor from about 3 feet and watch it bounce back up into the air.  Do the same with a buffer of the same weight but with tungsten powder. It hits the ground and sticks, no bounce back at all.

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  • 11 months later...

Negative!  That's not going to work at all. Your buffer/tube combo is incorrect. With the AR15 tube you need a CAR-10 buffer and spring. Or if you want to keep the current buffer and spring you need to get a VLTOR/ArmaLite extended length buffer tube.

Contact me thru www.heavybuffers.com if you have any questions.

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Yes... Armalite AR-10 H3 buffer and spring.

The "AR-10" and "LR-308" extension tubes were sold out everywhere and I figured out they are the same as AR-15 tubes.

So Armalite "AR-15" tube and AR-10 buffer/spring.

Better read what mrraley posted above ^^^, with the Armalite specs.  Check your stuff closely, before you try to shoot anything... 

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Negative!  That's not going to work at all. Your buffer/tube combo is incorrect. With the AR15 tube you need a CAR-10 buffer and spring. Or if you want to keep the current buffer and spring you need to get a VLTOR/ArmaLite extended length buffer tube.

Contact me thru www.heavybuffers.com if you have any questions.

That's it right there. Clint is the man, and I suggest you contact him. I have his products on all my rifles, and won't go elsewhere. Top notch!

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It has nothing to do with the stock, but the tube/ spring buffer combo. The tube you chose is 6 15/16" inside length, but should be the  7 5/8" tube with the choices made in the spring and buffer you bought. The choices you have are change the tube, or buffer and spring.

I love Clint's product as seen here,

http://308ar.com/forum/heavy-buffers/don't-think-there's-a-difference/

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Negative!  That's not going to work at all. Your buffer/tube combo is incorrect. With the AR15 tube you need a CAR-10 buffer and spring. Or if you want to keep the current buffer and spring you need to get a VLTOR/ArmaLite extended length buffer tube.

Contact me thru www.heavybuffers.com if you have any questions.

I got it figured out... geesh. Long tube, long carrier, short buffer. I got this:

https://www.primaryarms.com/308_CAR_receiver_extension_8_collapsible_p/pa308car-tube.htm

And yes Slash, I thought about just getting your buffer. But, it does not work out as good for me right now. You obviously have a great reputation and I know that is not just given. Thank you for your help.

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  • 2 months later...

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