Carbine -vs- rifle buffer length for precision large frame AR?

[ToddM]

Is there any downside to running a carbine length buffer tube on a precision large frame AR? I'm already running a JP SCS buffer, which just uses a solid spacer for the rifle buffer, so it seems like there wouldn't be any negative impact to cycling.

Seems like it's almost impossible to get a shorter LOP out of the rifle length buffer, unless you go with like the PRS gen 2 with a rubber strip for a recoil pad. There are some other options that seem fairly adjustable but they use a carbine length buffer tube Tacmod/LMT/MDT. A couple guys have also modified the PRS Gen 3 with a carbine buffer to gain 1/2" to 3/4" of LOP by modifying the carbine spacer.

Thanks

 

[TonyTheTiger]

You can get some pretty heavy carbine buffers, at least 9oz that I'm aware of. Couple that with whatever spring rate is ideal for your application and it's no different than the same weight in a longer tube.

 

[_Windrider_]

Is there any downside to running a carbine length buffer tube on a precision large frame AR? I'm already running a JP SCS buffer, which just uses a solid spacer for the rifle buffer, so it seems like there wouldn't be any negative impact to cycling.

Seems like it's almost impossible to get a shorter LOP out of the rifle length buffer, unless you go with like the PRS gen 2 with a rubber strip for a recoil pad. There are some other options that seem fairly adjustable but they use a carbine length buffer tube Tacmod/LMT/MDT. A couple guys have also modified the PRS Gen 3 with a carbine buffer to gain 1/2" to 3/4" of LOP by modifying the carbine spacer.

Thanks

I generally use the PRS Gen 3 with a rifle length buffer. The LOP is an issue and Magpul needs to address it. For most shooters it’s too long. Happens to work for my long hanging arms. Unless u modify the carbine adapter for the prs, the LOP is identical. If it were me and I needed a shorter LOP, I’d use a carbine buffer and a collapsible stock with a LAW folding adapter for additionalconcelament capability.

 

[TonyTheTiger]

Oh and the Tacmod and XLR stocks are great. An RPR takeoff stock works fine for cheap, it just sucks to adjust and its a bit ugly.

 

[_Windrider_]

Oh and the Tacmod and XLR stocks are great. An RPR takeoff stock works fine for cheap, it just sucks to adjust and its a bit ugly.

The RPR stock belongs in the trash.

 

[TonyTheTiger]

The RPR stock belongs in the trash.

If you have one in the trash I'll pay shipping to my house. Its worth at least that much.

 

[KTAK]

Magpul UBR has an A5 buffer tube so you can use regular buffers (3.25 in, just leave out the spacer, it's in the install directions). Pretty amazing amount of adjustment and rock solid in each notch. I am running an H3 with a clipped DPMS rifle spring (it is now just a hair shorter than a carbine spring) Works great, hasn't failed to feed yet and always locks back. Having a little bit extra spring over the carbine spring is nice... even clipped its stiffer than the carbine spring, and if math is your thing the clipped spring has 34 coils and the DPMS carbine spring only has 28

 

[TACC]

Interested in knowledge and information here.

 

[Docsherm]

I have two large frame ARs that have an A5 buffer tube with a rifle spring and an AR15 H buffer. Very smooth and i have had no issues at all. One is a carbine gas system and the other is a rifle gas system.

 

[C_R_Slacker]

I have two large frame ARs that have an A5 buffer tube with a rifle spring and an AR15 H buffer. Very smooth and i have had no issues at all. One is a carbine gas system and the other is a rifle gas system.

Yep. A5 extension with standard size carbine buffers and an armalite spring. You have a lot of flexibility with this setup because you can experiment with different buffer weights to tune the rifle.

 

[hlee]

The RPR stock belongs in the trash.

If you have one in the trash I'll pay shipping to my house. Its worth at least that much.

I don’t throw gun stuff away, generally. I did replace the rpr stock on my rpr with a magpul prs. The rpr stock went into the prs box, and into a drawer. Recently, I started building up a new lower and that rpr stock is doing temp duty there until I decide to change it out. Once adjusted it is ok, though it is sharp in all the wrong places, and not a real joy to shoot. It does the job and was free, so there’s that. Given the choices of not having a stock, using the rpr stock, or shelling out for another magpul prs, I’m glad I didn’t shitcan the rpr stock.

 

[Paradox]

Is there any downside to running a carbine length buffer tube on a precision large frame AR? I'm already running a JP SCS buffer, which just uses a solid spacer for the rifle buffer, so it seems like there wouldn't be any negative impact to cycling.

Seems like it's almost impossible to get a shorter LOP out of the rifle length buffer, unless you go with like the PRS gen 2 with a rubber strip for a recoil pad. There are some other options that seem fairly adjustable but they use a carbine length buffer tube Tacmod/LMT/MDT. A couple guys have also modified the PRS Gen 3 with a carbine buffer to gain 1/2" to 3/4" of LOP by modifying the carbine spacer.

Thanks

If its a PRS either works, comes with two adapters, i can't imagine needing any more LOP, i maybe used half of it, and simple move of the scope will cure that

 

[Paradox]

You can get some pretty heavy carbine buffers, at least 9oz that I'm aware of. Couple that with whatever spring rate is ideal for your application and it's no different than the same weight in a longer tube.

I'm trying to imagine what would possibly need that much weight?

 

[TonyTheTiger]

I'm trying to imagine what would possibly need that much weight?

Never used one myself, but I've heard of both large frame guys and PCC guys using really heavy buffers quite a bit, and at least one small frame 5.56 guy on here that uses them.

 

[Evintos]

I'm trying to imagine what would possibly need that much weight?

Never used one myself, but I've heard of both large frame guys and PCC guys using really heavy buffers quite a bit, and at least one small frame 5.56 guy on here that uses them.

Suppressed straight blowback AR9s could use more than 9oz. 9oz buffers usually get the total mass (bolt+buffer) to around 20-25oz range which works 90% of the time. However, depending on the ammo, with suppressors and higher ROF (binary, etc), sometimes you'd want to bump that up to a 10oz or 11oz buffer to primarily prevent OOBs.

 

[Paradox]

Never used one myself, but I've heard of both large frame guys and PCC guys using really heavy buffers quite a bit, and at least one small frame 5.56 guy on here that uses them.

I never even realized there were so many combos and so many people messing with them, honestly I've never used anything but the stock stuff and never had an issue, plus being used to shotguns and bolt actions, the 556 feels like a pellet gun, and even my 308 AR barely kicks, so i wonder what's up, as it seems there's been a ton of feed and buffer type issues, myself included, but in my case it was just educating myself on what's meant when the say a DPMS like to be run wet.

I also notice a lot of folks, a few of my friends included that for some reason when building an AR they have the need to buy parts from 20 different vendors, and the the most important feature they all must have or their build be ruined is to buy the most expensive adjustable gas block they can find, because they all think it will somehow make the gun immune from any stoppages. So of the dozen or so I own i'm super lucky or they are full of shit. either way its frustrating, but i wonder at the end of the day what the real cause was? too dry?, block off center, shitty ammo? kinked gas tube, etc. i'm wiling to bet that for any brand new build or factory purchase, its gonna be oil related like mine was, along with my bcg machining being a little rough, so emory cloth and a drowning in oil and problem solved

 

[Paradox]

Suppressed straight blowback AR9s could use more than 9oz. 9oz buffers usually get the total mass (bolt+buffer) to around 20-25oz range which works 90% of the time. However, depending on the ammo, with suppressors and higher ROF (binary, etc), sometimes you'd want to bump that up to a 10oz or 11oz buffer to primarily prevent OOBs.

Yeah I know they use them in those, just haven't seen anyone use one that heavy for the large format guns. my DPMS 308 is 5.4