CRASH! What went wrong?

[blue109]

HA!

[survivalshop]

  One night I had a little too much Vodka at the Marina where I docked my Boat &  I sorta fell asleep in my cabin ( well mostly ) with my feet hanging out , so a couple of the ladies in the get together , thought they needed sprucing up & painted them Red . I woke up the next morning early & took the boat out to the swimming area & anchored it & went for a swim .

  There was another boat there with a guy & his wife , it was only wast deep water so I walked over to chat , well I jumped up & sat on their swim platform & that when the guys wife asked if I always paint my toe nails & I took a look & said , them MF & LOL . She had those removal pads on the boat & even took the crap off for me , what a woman .

 So , no , its coming off . <laughs>

[ironmonster]

So I got my heavy buffer parts today so I got the rifles out and did some tinkering. First off the PWS buffer cannot be screwed in another rotation. It is as far as it can physically go (it bottoms before you can make another revolution)

As you can see there is a huge difference in the Tubbs spring vs the heavy buffer spring. The Tubbs spring will not even go on the heavy buffer as the diameter is larger. So with the buffer tube out of the rifle with the Tubbs spring and standard DPMS buffer the carrier can and does go into the tube fare enough for the sectional change to make contact.

With the heavy buffer and spring it bottoms with about 5/16 from the top of the buffer tube to the sectional change on the carrier. So the problem I was experiencing is physically impossible with this new combination.

Now this is a little confusing to me as the buffer itself is only about a 1/8 longer, not long enough to account for the 3/8 difference (5/16 + the 1/16 it crashes)

The rim seems to be shorter on the heavy buffer but in my mind that works against, not for increased clearance.

Also with the heavy buffer and spring it will collapse far enough that the bumper on the buffer will hit before the spring collapses to solid, it won't with the DPMS and Tubbs spring.

It's going to be a bit before I can go shoot these but I am 99.99% sure I am golden at this point.

[ironmonster]

Yeah, really. All the information was presented to you, and you kept looking for another source of the problem. I got your attention, at the very, very end, though. You wouldn't listen before that.

You have to understand something - arseholes that know everything show up here all the time. Literally, all the time. It doesn't matter to me if you own a machine shop, or anything else. what really matters to me is how many 308AR problems you've fixed.

It's strange that you only got pissed off because of how i closed my post.

By the way, everybody else - your buffer slams into the back of your receiver extension every time you shoot your rifle. That's the design. Your spring doesn't stop it, either from spring weight, or coil bind. If the spring stopped it from spring weight, you'd never be able to lock the BCG back by hand. if it stopped it from coil bind, you'd be replacing buffer springs every time you went out shooting.

That's not hypothetical...

ironmonster, I'm not pissed at you, in any way. I just find it odd that you were given the reason for your current issues, and you kept looking for more reason that didn't even pertain to the situation. I also find it odd that if I hadn't posted my very last sentence, then you probably wouldn't have said a word. if you were offended by that, then too fucking bad.

See the thing is though, at least 85% suggestions where wrong, just looking at what was in front of me I could see that. I don't know much, but I can stand in front of my gun, read what someone wrote, look at my problem and say "Nope, Not it". Doesn't mean I'm not listening.

I don't know why exactly, but the combination of the standard DPMS buffer and the Tubbs spring is the problem.

As you said in another post the coil does not bind (run out of travel) before the buffer hits,, well it was and did. That was a combination thought to work with a standard carbine RE and at least with a Aero upper and BCG it doesn't.

And yeah, I did take offense. I took offense because I was listening and working on solving the issue. I had looked at everything everyone had said and took to heart what seemed to be relevant. Those things you yelled at me for not listening to? They didn't solve my problem.

I don't have any problem with they way you handled it, I thought it was abrasive and unnecessary but hell about half of life is abrasive and unnecessary. If I knew you better maybe I wouldn't have taken it that way, but I don't.

Alls well that ends well, on with life ;-)

[blue109]

if anyone asks, just tell them staking castle nuts is for sissies. staking the entire extension to the lower is how real men do it.

[ironmonster]

? Whaaaatt?? You don't stake the inside of the tube to the receiver? Your obviously not up on the latest tactical trends. All the "Real" operators have been doing it for years...

;-)

[washguy]

Iron  im running 2 tubbs springs with a Dpms buffer and mil tube on them....no problems...on 2 of my 308's I run a plain ol spring and Dpms buffer

on a mil tube...and on 2 of my 308's I run a sprinco orange spring with a plain ol buffer and mil tube...go figure?   lol  :) Wash

[ironmonster]

Iron  im running 2 tubbs springs with a Dpms buffer and mil tube on them....no problems...on 2 of my 308's I run a plain ol spring and Dpms buffer

on a mil tube...and on 2 of my 308's I run a sprinco orange spring with a plain ol buffer and mil tube...go figure?   lol  :) Wash

 

What carrier are you using with the Tubbs and the DPMS buffer?    What lower?  Out of curiosity measure the distance from the back of the carrier to where it gets bigger?   See if that is any different than the Aero?

 

Also would you take your carrier and just push it in the receiver extension and see where it bottoms?  What is the distance from the top of the buffer tube to the sectional change in the carrier when it is fully collapsed?

 

 

I have the two .308's,  One had the PWS tube, the other has a UBR with the included tube.   Both had DPMS buffers and Tubbs springs, both of them the carrier hit the buffer tube boss  (the one with the UBR was slight, but it still hit)     It may be a combination of the Aero components with the Tubbs/DPMS stuff.     There is no doubt though with what I have the Tubbs spring collapsed is bigger than the length of the standard DPMS buffer.    There is no way for the bumper to touch the end of the receiver extension as the spring locks up first.

 

I actually took the PWS tube out (I was surprised that the damage did not lock it in there, but it didn't) and installed a standard mil spec tube on my receiver and it changed nothing.   I even went though all of the ones I had to find the shortest inside measurement and the carrier still bottoms with the Tubb's/DPMS set up.

 

I have probably $500 worth of Tubbs springs in my other AR's.   I use the buffer springs, ejector and extractor springs in a lot of guns.   In my 5.56 guns they have run perfect.     I am a fan,   I was real hesitant to give up the Tubbs spring in the .308 but the combination of it and the standard DPMS buffer simply is not functional.

 

98Z5V wanted me to stack quarters up in the buffer tube, while that would have kept the carrier from crashing it is a cover up fix ignoring the real issue which is a spring and buffer that was incompatible  with the Aero carrier and receiver.    The spring would have just come to the fully compressed state that much sooner, still a crash with the buffer bumper never making it too the quarters.     Its kind of like everyone on the internet telling you to drill out your gas port when you gun wont run.    Yeah, you can overgass it and force it to function, but there is a reason why it wont run with the proper amount of gas, why not fix the actual problem?    An AR with an 1/8" gas port will run with a plethora of problems, right up until it destroys itself.

[ironmonster]

I guess I should also ask, I am assuming you are running the .308 Tubbs spring right?    Because the 5.56 spring would allow the DPMS .308 buffer bumper to touch the end of the receiver extension before it "bottomed out" but I cant imagine its got enough push to keep the system happy.

[washguy]

Yep 308 tubbs  :) Wash

[FaRKle!]

I just measured some carriers of mine:

MWS:

-Front of carrier to end of shoulder: 3-9/32"

-Overall carrier length: 7-7/8"

PWS:

-PWS' shoulder is ~1/8" longer, but their .308 EBT is about 3/4" shorter internally (still fits an AR-10 pattern buffer system though).

-Overall carrier length: 7-7/8"

[98Z5V]

As you said in another post the coil does not bind (run out of travel) before the buffer hits,, well it was and did. That was a combination thought to work with a standard carbine RE and at least with a Aero upper and BCG it doesn't.

 

 

They don't coil bind.  If it did, that's a clear indication that something is wrong with your parts combination.  Also, you don't have a standard carbine RE...

 

98Z5V wanted me to stack quarters up in the buffer tube, while that would have kept the carrier from crashing it is a cover up fix ignoring the real issue which is a spring and buffer that was incompatible  with the Aero carrier and receiver.  

 

Suggested that for one simple reason - fastest, most effecient way to deermine how far you're off on the length.  1 quarter?  2? Or 3?  The thickness of a quarter is 0.066".  You were also talking about machining a spacer, if I recall correctly.  Stack quarters, count quarters, multiple, machine.  Done.  That's the easy way, and you probably have all the "precision measurement slugs" right in your pocket.

 

Tell you this much - pistol-caliber ARs that run on blowback operation, those BCGs have more travel because they're shorter - there's no bolt.  They also, like 308ARs, break bolt stops when they overtravel.  I didn't buy a special, longer 9mm buffer for my 9mm AR.  They exist, though.  I run the H3 buffer in it, with $1.75 in the end of the extension.  Same amount of money in the back of my 45AR.  It's a simple decision.  <thumbsup>

 

You were given an easy way to measure the excess distance, and instead, you try to turn it around as some half-assed backyard fix.  when it's not, and you didn't understand the reasoning for the suggestion in the first place...  Your call...

[ironmonster]

They don't coil bind.  If it did, that's a clear indication that something is wrong with your parts combination.  Also, you don't have a standard carbine RE...

 

 

Suggested that for one simple reason - fastest, most effecient way to deermine how far you're off on the length.  1 quarter?  2? Or 3?  The thickness of a quarter is 0.066".  You were also talking about machining a spacer, if I recall correctly.  Stack quarters, count quarters, multiple, machine.  Done.  That's the easy way, and you probably have all the "precision measurement slugs" right in your pocket.

 

Tell you this much - pistol-caliber ARs that run on blowback operation, those BCGs have more travel because they're shorter - there's no bolt.  They also, like 308ARs, break bolt stops when they overtravel.  I didn't buy a special, longer 9mm buffer for my 9mm AR.  They exist, though.  I run the H3 buffer in it, with $1.75 in the end of the extension.  Same amount of money in the back of my 45AR.  It's a simple decision.  <thumbsup>

 

You were given an easy way to measure the excess distance, and instead, you try to turn it around as some half-assed backyard fix.  when it's not, and you didn't understand the reasoning for the suggestion in the first place...  Your call...

 

But I did swap out the PWS receiver extension for a standard mill spec one at one point.    With the receiver extension out of the rifle (either of them, the PWS or a Mil-spec one)  if you put the tubbs spring and DPMS buffer in there and then compress it with the carrier where the carrier changes diameter it comes in contact with the tube.         With any 7" receiver extension, the tubbs spring, DPMS buffer and Aero carrier it will crash.

 

And I get what your saying,   But you got to admit by stacking up quarters in there your not figuring out why those parts dont work in this case.    I dont need any quarters with Slash's heavy buffer and spring,  I would have needed to stack 2 bucks in there with the DPMS buffer and Tubbs spring  to get the same clearance and the spring still would have been collapsing to solid.   Why?   There is not that much difference in the length of the buffers.   There is something else in play that I am missing.  

 

I think I figured out a simple way to show & measure the collapsed height of the springs.    Tomorrow when I get to the shop I'll take some pictures.

[98Z5V]

 I would have needed to stack 2 bucks in there with the DPMS buffer and Tubbs spring  to get the same clearance and the spring still would have been collapsing to solid.  

 

No way - you saying you were more than 1/2" off?  0.528"?  Blowbacks don't even need that much...

 

Also, on which tube are you saying that for - the PWS, or the standard carbine?

[ironmonster]

Both the standard carbine and the PWS are the same inside length (depending on which you measure,  As I reported I found them to vary .156 between the 6 I had on hand but even with the shortest one the Tubbs/DPMS combo crashes with the Aero carrier)   And I am not saying it needs 8 quarters in there to work, it only needs 2-3 to not crash and probably 4 to give in a bit of clearance and still not over travel. what I am saying is it needs 7-8 quarters in there to give as much clearance between the top of the buffer tube and the sectional change on the carrier as you get with no quarters in the tube and Slash's buffer and spring.

 

Thats the other thing.    I did do all this.    If you read back a few posts I talked about measuring the quarters, measuring the buffer tubes trying to figure out how much I needed.    You say I missed the point, but I did all the work.

 

I'll take some pictures.

 

One thing I am wrong about.    I keep saying the Tubbs spring is collapsing to nothing,    I am saying that because out of the gun if you collapse the spring the overall length is greater than that of the DPMS buffer. (best I could determine, I'll verify today)       Thinking about it more though in my rifle it is probably not collapsing all the way because the carrier is hitting first.   If you put quarters in there though then you reduce the inside measurement enough that the spring collapses.  Either way the buffer bumper cant come in contact with the rear of the receiver extension because the collapsed length of the spring is greater than that of the DPMS buffer

 

I will build a simple rig to measure the various springs collapsed and report overall lengths of the buffers and report back later today to verify im not talking out my ass here.

 

I just want to understand,   I want it to work yes but I also want to understand why it is or isnt working.

 

In any case its this combination of parts, I am sure of that.   The Tubbs spring and DPMS buffer sounds like it works find with other carriers/receivers fine.   It might be because the shoulder is in a different spot on other carriers but I still think if that is the case the spring is bottoming before the buffer bumper touches   (not that its suppose to, but that it is)

 

I'll know for sure here in a bit after I do some experimenting

Edited April 18, 2015 by ironmonster

[ironmonster]

And 8 quarters is probably an exaggeration, but not much of one. The difference is three eights to 7/16 of an inch so it's probably more like 6 to 7 than seven-eight

[ironmonster]

Ok first off try and keep the "I fucking told you so" to a minimum. I got one coming and I know it.

I thought the spring was bottoming because best I could force it down over the buffer it seemed to run out of buffer before running out of spring. Using something else to manually compress the spring it's clear it's not.

Both the Tubbs and Slash's spring measure 2.073" compressed. From the top of the rim of the buffer to the end of the bumper it measures 2.242". So there is about 5/32" difference or the size of a trigger pin. So it comes close to fully collapsed, but doesn't

The one pic is to show the mark where the carrier hit the receiver on the rifle with the UBR

The pics with the carrier pushed in the receiver extension show that "$2" I am talking about (that really probably more like $1.50. In any case one the Tubbs/DPMS crashes, the Slash's buffer and spring has like 7/16" clearance fully compressed.

So I am interested to see how other carriers compare, it's obviously a combination of the Aero carrier, standard RE, Tubbs/DPMS that is a fail. I am assuming if others check carriers it will show either a different overall lenght, different length to the shoulder or both.

[washguy]

Iron  in pic #5 you have the tube on the receiver right? I count 4 threads showing at the retainer pin. so I went and pulled out a few of my 308's...I got zero thread count at the retainer pin.  whats up with yours?  :) Wash

 

all in good fun I cant let this slide   :)

 

       "  I own a fab/blacksmith shop and have a basic machine shop.  I know how to run a fucking tape measure.    The PWS tube is dead nuts 7" inside, the other tube is 6 7/8". "

 

so being a blacksmith im sure you fab horseshoes ....and you know what they say   " close only counts in horseshoes and hand grenades"   <lmao>     Wash

[ironmonster]

I assume it's just the way Aero's are made? That is the UBR tube and you will notice at the top the tube is pretty close to flush.

As far as close and blacksmithing goes...

Well you could say I am a far cry from a machinest. If I don't like the way something fits I get a bigger hammer. If I still don't like the way it looks I hit it with the hammer until I do. My theory is if you can't fix it with a hammer you got an electrical problem.

Edited April 18, 2015 by ironmonster

[ironmonster]

The clean side and dirty side of my shop, the big forging hammer out in the middle is a 102 year old Nazel 4B, a 350 lb hammer that strikes 150 blows a minute. I have 5 power hammers and 4 hydraulic presses.

In the back of the crowded pic you can kind of make out my Bridgeport, lathe and shaper. Like I said I am no Machinest, but I can get by enough to make my own tooling for the hammers and build simple parts.

I also manufacture a line of blacksmith tools under the Quick and Dirty name

www.quickanddirtytools.com

www.monstermetal.org

[ironmonster]

Close up pic of the Nazel, you can see my 210 ton Williams White forging press behind it. Just those two machines weigh close to 18 tons.

[washguy]

I assume it's just the way Aero's are made? That is the UBR tube and you will notice at the top the tube is pretty close to flush.

As far as close and blacksmithing goes...

Well you could say I am a far cry from a machinest. If I don't like the way something fits I get a bigger hammer. If I don't like the way it looks I hit it with a hammer until I do

Good man!  you have been keeping me up at nite thinkin bout what in the hell is going on?   so,you did get the slash stuff in?

sorry for asking...but 4 hours of getting my face cut on has left me no choice but to hit the pain meds pretty hard...and if you did

whats the result?  Hate to bring this up after you spent all that hard earned cash on slash..but I run sprinco orange buffer spring in one new build....and that bad boy really works  in recoil and in the timing too... Brownells lowered the price of the DPMS lower to 109 bucks yesterday.....just a thought    :)  Wash

[ironmonster]

Mmmm. That pic is right side up on my phone... Sorry.

[survivalshop]

  Isn't that kinda short for a DPMS 308 Carbine Buffer , 2.24" ?   Mine are all around 2.5" . Unless thats the measurement to the Buffer spring seat to the bottom of the Buffer .You may have some tolerance Stacking issues , If you found something that works ,  go with it .

Edited April 19, 2015 by survivalshop

[ironmonster]

That is from the top of the shoulder to the top of the buffer, as I was measuring if there was enough room for the spring to compress without compressing to solid so the lip wouldn't count.

Overall it's almost exactly 2.5" (2.507")

Yeah, it might be a bit before I can see how they run but with the Slash's buffer and spring it no longer is possible for the carrier to come in contact with the receiver or extension.

As long as they run good I'll be golden.

I am still curious about other carriers, what is it about the Aero that is different?

Edited April 19, 2015 by ironmonster