Which Buffer Tube and Spring for DPMS LR-308 and Collapsible Stock?

[Buck Wilde]

I have a DPMS LR-308B from around 2009. This is the one with the varmint handguard and fat barrel. The fixed butt stock is heinous, and I would like to put a collapsible stock on it. Today I managed to get the old stock off, and then I learned the buffer tube, like the stock, is evil and abnormal. It has to be replaced.

This turned out to be an immense can of worms. My understanding is that DPMS stock buffer springs are too light for .308, so I should change it, and I can't just use any old AR-15 buffer tube.

Rather than dig myself further into confusion, I thought I'd come here and just ask: what should I get? I don't need advice on the stock, but the buffer tube is a mystery.

 

[Ravenworks]

You need to stop and do some research.
You're taking a rifle and putting a carbine stock on it.

 

[Buck Wilde]

Actually, this is my research. I took the old stock off to find out how it worked. I'm not replacing anything until I get some help.

The original A2 stock is not for me, so I want something adjustable with padding.

 

[bfoosh006]

There are 2 dominant "patterns"... please note the buffer tubes and buffer lengths do not interchange.. trying to do so will create issues.

DPMS Pattern.... AR15 carbine tube, 2.5" buffer length I use Tubbs Flatwire 308 Recoil Springs ( yes it will fit. )

Armalite Pattern.... Vltor / Armalite carbine buffer tube ( 3/4" longer ) , normal 3.25" AR15 carbine length buffers... and again for me, a 308 Tubbs Flatwire 308 Recoil Spring

Not everyone likes the flatwire aspect... it is slightly more effort to install, since the the flatwire doesn't readily slide past the buffer retaining spring, but the 308 Tubbs certainly works well. The spring rate on the Tubbs is well thought out.

KAK sells a 5.3oz 2.5" buffer. I use those in my DPMS pattern carbine setups.

 

[bfoosh006]

As for padding.... ( recoil pad ) Limbsaver makes some real recoil pads for Magpul collapsible stocks... 3 versions, they are well worth the money.

https://www.nokick.com/category_s/211.htm

 

[Buck Wilde]

Thanks for the help. The old buffer is 5.25" and 5.4 oz. I don't know if that's useful information at all, but it made me feel like I was doing something.

When you mention the different patterns, are you saying I can pick whichever one I want?

Anything that makes recoil mushier and more pleasant would be nice. On a forum member's recommendation, I picked up a couple of Adaptive Tactical padded butt stocks, and they work great on AR-15's.

 

[rpoL98]

you'll need the 2.5" shorty AR-308 carbine buffer, 5.3oz, 5.4oz or more weight. AR-15 7" inside depth carbine buffer tube. 7" inside depth is the normal USGI mil-spec depth. Slash HeavyBuffer AR-308 carbine buffer spring.

that's one combo that will work. It would help if you had an adjustable gas block, like the SLR Sentry.

 

[Buck Wilde]

I have never worked on a gas block. Do bull barrels take regular gas blocks?

 

[bfoosh006]

Thanks for the help. The old buffer is 5.25" and 5.4 oz. I don't know if that's useful information at all, but it made me feel like I was doing something.

When you mention the different patterns, are you saying I can pick whichever one I want?

Anything that makes recoil mushier and more pleasant would be nice. On a forum member's recommendation, I picked up a couple of Adaptive Tactical padded butt stocks, and they work great on AR-15's.

Yes, you can pick either one... again, you must use the specific parts because of the lengths of the various parts.

And, yes, that is also useful info... that shows your rifle will function with a 5.4oz buffer weight

You will have to measure your barrel at the gas block area to know what size Adj. GB you would want. The typical ( 99% ) sizes are .625", .750", .875", and .936"
So you should be able to figure it out without removing the current gas block, by checking with a 3/4" open end wrench ( .750" ).. or 7/8" .875"

Adj. GB's have made all my Large Frame AR's far more comfortable to shoot.

Easier on you, easier on the parts, faster follow up shots, and far less "vigorous" cycling and more positive function.

 

[hlee]

The receiver extension on your rifle is not “abnormal.” It is a completely normal “rifle length extension.” What you want is a carbine length extension. Your buffer is also rifle length. You will need a dpms 308 carbine buffer, not an ar15 carbine buffer. Depending upon which stock you choose, you will need to source either a mil-spec or a commercial carbine extension. They are different. The stock will designate either mil-spec or commercial. The bull barrel is most likely 0.936” at the gas journal. You will need that diameter gas block.

 

[mtrmn]

Everything in this kit will work together well. You can put another type of stock on the tube if you want. This will be the .75" longer "Armalite-length" collapsible stock. The buffer and spring will be the correct weight and length for the tube.

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[Buck Wilde]

You guys are extremely helpful. I'm so pumped about putting a comfortable stock on this gun, I might even consider getting another upper. I bought the upper with the bull barrel a long time ago when I was getting dubious advice, probably at The High Road. This gun is just for the range, but if it ever had to be used for self-defense, a lighter barrel and an M-Lok handguard would be nice.

 

[rpoL98]

B5 Systems Bravo buttstock is comfortable (to me), comfortable buttpad also, softer than the Magpul CTR.

 

[Ravenworks]

As for padding.... ( recoil pad ) Limbsaver makes some real recoil pads for Magpul collapsible stocks... 3 versions, they are well worth the money.

https://www.nokick.com/category_s/211.htm

For what those cost he could be well on his way for a setup from Heavybuffers.com
Remember he's trying to lose length not add it

All my big frame guns shoot softer than my small ones.
I know you said you were doing research in your reply to me.
But listen, the MORE you read up on this platform the less money you will waste.
You want a nice gun start ready every day from RELIABLE resources.


Tom- (95) from https://forum.308ar.com ,can be a total dick but he knows what he's talking about when it comes to large frames.

I'm not being a dick, I'm trying to show you answers to stuff.
You may think you were doing research but in all actuality you tore something apart BEFORE you asked anything.

 

[bfoosh006]

For what those cost he could be well on his way for a setup from Heavybuffers.com
Remember he's trying to lose length not add it

All my big frame guns shoot softer than my small ones.
I know you said you were doing research in your reply to me.
But listen, the MORE you read up on this platform the less money you will waste.
You want a nice gun start ready every day from RELIABLE resources.


Tom- (95) from https://forum.308ar.com ,can be a total dick but he knows what he's talking about when it comes to large frames.

I'm not being a dick, I'm trying to show you answers to stuff.
You may think you were doing research but in all actuality you tore something apart BEFORE you asked anything.

I don't think 35 bucks is to much for a real recoil pad. And there really are night and day differences between the OEM Magpul "pad" and the Limbsaver.....especially when it comes to the reduction in felt recoil as the OP asked about.... and the thickness of a recoil pad is no where near the difference between a adjustable collapsible stock and a rifle stock, .... IE just extend the stock one less notch.
So not sure why that matters.

For the OP, and others...seriously.. The suggested recoil pad is well worth the money. Far softer feeling at the shoulder.

And without being flippant, Ravenworks , have you tried one ?

A heavy buffer and a quality recoil spring is also part of the formula for a good running Large Frame AR... combine it with a Adj. GB , and anyone can get a very soft shooting Large Frame in no time flat.
Heck if I can do it,... darned near anyone can.

The starting price for Slash's setup is $115 for the carbine setup, the 2.5" 5.5oz buffer and his carbine recoil spring ( DPMS Pattern )

KAK sells a 2.5" 5.3oz 308 Carbine buffer for $55 ( pretty sure MidwayUSA sells the same thing for $40 ) , add a Tubbs 308 recoil spring for $20 bucks... and you just paid for the recoil pad.

Even a moderately priced .750 Click adjustable Adj. GB is available from Aero Precision... around $65, heck of a deal.

I completely agree about getting a Large Frame AR to shoot softer then a small frame... all mine are extremely soft shooters.
308 and 6.5CM, various barrel lengths, various conventional gas system lengths.

All of them use Tubbs Flatwire 308 recoil springs.. all run Adj. GB's .....both carbine patterns use 5.3oz'ish buffers and rifle patterns use 9.3oz buffers.
So I am making suggestions based on my experiments and conclusions, Not just throwing money at the firearm.

The OP can make up his own mind as to how much money he is looking to spend.. we all are here are just offering suggestions.

Ultimately, he might do one portion at a time, and then decide to try some more suggestions.

And As for wasting money trying to get his AR to shoot the way he would like .... Lol, ....AR's are bottomless money pits, heck even a box of FGMM ammo costs more online, then the recoil pad I mentioned.

If someone had the perfect formula.... they would be very rich.

Until then, a little tuning can reap huge benefits.

 

[r.tenorio671]

...to swap out your current rifle length buffer system, this is all you would need and is "DPMS pattern compatible" : https://www.aeroprecisionusa.com/m5-308-carbine-buffer-kit-1 NOTE: The buffer tube is exactly the same as the AR-15 buffer tube, only the buffer and spring differ, heavier weight and spring rate specific to AR-10 operating pressures.

...for a "padded" collapsible stock, this will fit that Aero buffer tube very well: https://www.joeboboutfitters.com/Ad...rformance-Adjustable-MILSPE-p/at-02012-nr.htm

Based on your statement regarding limited experience in working on AR's, I make these suggestions to facilitate your ease in making the swap, simple unscrewing of castle nut, unscrewing buffer tube then screwing on the replacement carbine buffer tube, castle nut and endplate, inserting carbine buffer and spring. Depending on your existing barrels gas port size, you may OR may not experience "over gassing" once you switch over to the carbine system. If you experience any "over gassing", you can opt for a heavier buffer or adjustable gas block of your choice.

Good luck!

 

[rpoL98]

Aero 308 carbine buffer is "only" 3.8 oz. IMHO needs to be in the 5 oz range.

 

[bfoosh006]

Aero 308 carbine buffer is "only" 3.8 oz. IMHO needs to be in the 5 oz range.

This... there is a reason so many of the heavier buffer weights are sold. They truly help

For that matter... the same can be said for the Adj. GB's.

 

[Ravenworks]

I don't think 35 bucks is to much for a real recoil pad. And there really are night and day differences between the OEM Magpul "pad" and the Limbsaver.....especially when it comes to the reduction in felt recoil as the OP asked about.... and the thickness of a recoil pad is no where near the difference between a adjustable collapsible stock and a rifle stock, .... IE just extend the stock one less notch.
So not sure why that matters.

For the OP, and others...seriously.. The suggested recoil pad is well worth the money. Far softer feeling at the shoulder.

And without being flippant, Ravenworks , have you tried one ?

A heavy buffer and a quality recoil spring is also part of the formula for a good running Large Frame AR... combine it with a Adj. GB , and anyone can get a very soft shooting Large Frame in no time flat.
Heck if I can do it,... darned near anyone can.

The starting price for Slash's setup is $115 for the carbine setup, the 2.5" 5.5oz buffer and his carbine recoil spring ( DPMS Pattern )

KAK sells a 2.5" 5.3oz 308 Carbine buffer for $55 ( pretty sure MidwayUSA sells the same thing for $40 ) , add a Tubbs 308 recoil spring for $20 bucks... and you just paid for the recoil pad.

Even a moderately priced .750 Click adjustable Adj. GB is available from Aero Precision... around $65, heck of a deal.

I completely agree about getting a Large Frame AR to shoot softer then a small frame... all mine are extremely soft shooters.
308 and 6.5CM, various barrel lengths, various conventional gas system lengths.

All of them use Tubbs Flatwire 308 recoil springs.. all run Adj. GB's .....both carbine patterns use 5.3oz'ish buffers and rifle patterns use 9.3oz buffers.
So I am making suggestions based on my experiments and conclusions, Not just throwing money at the firearm.

The OP can make up his own mind as to how much money he is looking to spend.. we all are here are just offering suggestions.

Ultimately, he might do one portion at a time, and then decide to try some more suggestions.

And As for wasting money trying to get his AR to shoot the way he would like .... Lol, ....AR's are bottomless money pits, heck even a box of FGMM ammo costs more online, then the recoil pad I mentioned.

If someone had the perfect formula.... they would be very rich.

Until then, a little tuning can reap huge benefits.

The point I'm trying to make is for the guy to do some reading on his own before he tears something apart starts a thread then has 20 things thrown at him.
As for that pad,he's trying to lose length, but let me guess you probably have one so he needs one.

Slashs 10oz buffer in a Carbine tube along with his spring is second to none.

 

[Buck Wilde]

The gun isn't torn apart. I took the stock off to see how it worked, and I put it back on before I put it away.

 

[bfoosh006]

I actually tried the 10oz buffer weight, for me it caused muzzle dip when it slammed home. YMMV.

The OP asked about a pad... I offered a suggestion. It is completely his decision if he would like to try one or not.
Just trying to offer suggestions... that is one of the points to these forums ? ... isn't it ?

Not everyone knows about these various parts being available.

And yes I do use them... they are very effective. If a simple pad can reduce felt recoil , and make firing more comfortable why wouldn't I suggest it ?
Especially if the OP asked about something that could do that.

Again... have you tried one ? And vice versa... you don't use one so he doesn't "need" one ?

I don't understand your train of thought. Clearly Limbsaver sells a bunch of them. So the pad does what it is designed to do. Lrifle.essen felt recoil... just like a pad on a shotgun or a large caliber

 

[bfoosh006]

The gun isn't torn apart. I took the stock off to see how it worked, and I put it back on before I put it away.

Lol... it is your gun. I learned about mine basically the same way. They aren't that complicated... and as far as I am concerned, you are asking the right questions to achieve your stated goal.

Please, I hope I wasn't sounding like a dictator as to what you "needed" to do.

I truly am just offering advice.

 

[Buck Wilde]

Nearly all advice is helpful. It could be worse. I could be listening to a bunch of trolls, telling me why no one should buy DPMS.