Blitkrieg buffer failure

[HoMiE]

13 minutes ago, Neomet said:

 

Were you running the weight/SS spacer with the 5015hd?  

 

Yes, I made my own 1/2” 2oz weight 

[Neomet]

Cool.  Thxs!

 

[RaylanGivens]

On 12/21/2018 at 8:44 PM, HoMiE said:

Shoot a couple hundred rounds comparing my 5007 to 5015hd buffer. Initial impression is the 5015 does feel slightly firmer but it was very hard to tell them apart. I think it will take some more testing to see how long the hydraulic resistance holds up. My 5007 buffers seem to loose the hydraulic dampening after only a few thousand rounds. 

 

What powerfactor ammo are you shooting?  I want to buy a spare buffer...  Running 137 pf...  Wondering if that is powerful enough to benefit from the RB5015 buffer?

 

I noticed that my RB5007 seems to have lost its hydraulic dampening, too...  When I press down on the plunger, it feels like a spring only...  I remember one of the early KynSHOT videos where you could hear the suction when the plunger was pressed up and down.  My RB5007 still works well though.

 

[HoMiE]

1 minute ago, RaylanGivens said:

 

What powerfactor ammo are you shooting?  I want to buy a spare buffer...  Running 137 pf...  Wondering if that is powerful enough to benefit from the RB5015 buffer?

 

I noticed that my RB5007 seems to have lost its hydraulic dampening, too...  When I press down on the plunger, it feels like a spring only...  I remember one of the early KynSHOT videos where you could hear the suction when the plunger was pressed up and down.  My RB5007 still works well though.

 

I run around 135-138pf ammo. 

[MoRivera]

15 hours ago, RaylanGivens said:

 

What powerfactor ammo are you shooting?  I want to buy a spare buffer...  Running 137 pf...  Wondering if that is powerful enough to benefit from the RB5015 buffer?

 

I noticed that my RB5007 seems to have lost its hydraulic dampening, too...  When I press down on the plunger, it feels like a spring only...  I remember one of the early KynSHOT videos where you could hear the suction when the plunger was pressed up and down.  My RB5007 still works well though.

 

When I asked someone at Kynshot about the 5007 not having as much plunger ''resistance" as in the 5000, I was told that because of the higher speed of reciprocation with a blowback, the fluid pressure needed to be less so as not to burst the hydraulic chamber.  Supposedly at speed, the resistance stiffens up in reaction.  But I dunno, I've pressed the plunger on the 5007 pretty fast, and it still fells a lot less than the 5000 when pressed slowly.  I use the 5000 with my PCC along with an extra wave in spring the back of the main buffer spring.  A few thousand shots by now, and luckily its hydraulic chamber seems to be holding up.  Still may want to either try the 5005 which is the same size as the 5000 but 5.0 oz. compared to the 5000's 4.2 oz, or an A5 buffer tube with the 5007 and the wave springs, as I like how it cushions the rearward travel of the buffer.

Edited December 24, 2018 by MoRivera

[RaylanGivens]

8 hours ago, MoRivera said:

When I asked someone at Kynshot about the 5007 not having as much plunger ''resistance" as in the 5000, I was told that because of the higher speed of reciprocation with a blowback, the fluid pressure needed to be less so as not to burst the hydraulic chamber.  Supposedly at speed, the resistance stiffens up in reaction.  But I dunno, I've pressed the plunger on the 5007 pretty fast, and it still fells a lot less than the 5000 when pressed slowly.  I use the 5000 with my PCC along with an extra wave in spring the back of the main buffer spring.  A few thousand shots by now, and luckily it's hydraulic chamber seems to be holding up.  Still may want to either try the 5005 which is the same size as the 5000 but 5.0 oz. compared to the 5000's 4.2 oz, or an A5abuffer tube with the 5007 and the wave springs, as I like how it cushions the rearward travel of the buffer.

 

Interesting...  I never tried pressing down on the plunger when I first got my RB5007...  After the release of the RB5015, I tried it and it seemed like just a spring...  no hydraulic pressure that I could feel.

 

I've got 7 or 8 thousand rounds through my RB5007 and it still shoots well...  I don't have any weights in the bolt or in the buffer tube, so I suspect the buffer takes a beating...  I have a new, spare bolt with a 2.7oz weight that I am thinking of trying next time I go to the range...  I want to compare it to the same bolt without the weight back to back.

 

[MoRivera]

Another interesting thing I've noticed on the 5007 is that just by hand, if you orient the buffer with the plunger end facing up and depress, you only feel 'spring' resistance, but if you flip it 180˚ with the plunger end facing down, you feel more of the hydraulic fluid.  Not a whole lot, but definitely a difference from when it's upright.  So I guess the rearward action of the cycle pushes that fluid into the chamber more, which seems to go along with what Kynshot was saying.

Edited December 24, 2018 by MoRivera

[longbeard]

Used to race offroad RC cars, and we would tune shocks with pistons and fluid.  It was much easier to see what we called "pack" by holding the 10 lb. car and dropping it.   The more the pack, the less that initial drop made the shocks move.  You could work the shocks by hand, but never see it in action until you dropped it.

 

Theoretically, the harder and faster the blow to the plunger, the more the initial dampening effect.   Not a linear equation really, but that's the idea.  Initial jolt absorbs the brunt and the rest of the travel smooths it out.  IMO.  That's what a hydraulic has over a spring which in my mind is more linear (and predictable).  Not sure how you would visibly see this without special equipment on these buffers.

 

 

[MoRivera]

Sorta' like reactive fluid or such.

[HoMiE]

1 hour ago, MoRivera said:

Sorta' like reactive fluid or such.

It all has to do with how the shock valve stack are, you have high and low speed base and piston and control how the fluid moves throughout. At low speed you can have minimal compression but at high speed more compression resistance. Same thing with rebound. 

[BurdDawg69]

B

 

 

 

 

Edited December 26, 2018 by BurdDawg69
Mistake, please delete, posted in wrong thread.

[reballz]

Crazy. I have over 10k on my blitzkrieg. No issues at all. Are you guys that are breaking them running wave springs also?


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[Neomet]

18 hours ago, reballz said:

Crazy. I have over 10k on my blitzkrieg. No issues at all. Are you guys that are breaking them running wave springs also?


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Most often, but not always the issues surface when short stroking.  

[HoMiE]

Mine broke with short stroke and too light of a recoil spring. 

[MoRivera]

I have an A5 tube incoming, so I'm going to try it out with the 5007 and wave spring.

[cvincent]

Has anyone ever taken the snap ring out of the buffer to see what’s inside?


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[HoMiE]

3 hours ago, cvincent said:

Has anyone ever taken the snap ring out of the buffer to see what’s inside?


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Fluid will probably come out and probably void warranty. 

 

It just stopped working?

[cvincent]

Fluid will probably come out and probably void warranty. 
 
It just stopped working? [emoji1744]‍[emoji3603]

I just bought one, the new HD version. Doesn’t feel very hydraulically dampening to me. Just feels like a spring. I was jusT curious if anyone has seen the insides.



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[Hallz]

I have both, the HD is a bit stiffer and the dampening is a bit more.  To be honest I could not tell the difference with 125-135pm loads(115 or 124's) and extra power 223 spring,.... with 145pf 115's I can tell. With a 308 rifle spring I could not tell any difference.

 

Typical load, fast powder and 115's, 140+pf.

[Bill_Van]

Off topic but relative to a point...... so, I purchased a Blitzkrieg and a JP .308 rifle spring and have a little concern with the spring going solid possibly causing the buffer or spring to fail per-maturely or who knows what else!

 

Can the rifle spring run properly in a carbine extension tube? Will be on a 7.5" and 10.5" 9mm upper(s)  and a M16A1 lower.

 

My original plan was to protect the lower from the blowback battering. Also using KNS pins as additional protection. BTW, it runs like a top with a RRA 9mm buffer Spikes spacer and Wolff XP 223/9mm spring. Just want a little peace of mind for an expensive lower!

 

 

Edited December 30, 2018 by Bill_Van

[HoMiE]

2 hours ago, Bill_Van said:

Off topic but relative to a point...... so, I purchased a Blitzkrieg and a JP .308 rifle spring and have a little concern with the spring going solid possibly causing the buffer or spring to fail per-maturely or who knows what else!

 

Can the rifle spring run properly in a carbine extension tube? Will be on a 7.5" and 10.5" 9mm upper(s)  and a M16A1 lower.

 

My original plan was to protect the lower from the blowback battering. Also using KNS pins as additional protection. BTW, it runs like a top with a RRA 9mm buffer Spikes spacer and Wolff XP 223/9mm spring. Just want a little peace of mind for an expensive lower!

 

 

Spring doesn’t go solid or at least it doesn’t with JP 308 rifle. You can test by running the spring over buffer, it should get to about 90-95% with the buffer fully compressed. 

[longbeard]

As Homie said. It's not going flat.

If you look on the blitzkrieg website you'll see they recommend 308 rifle for full length barrels and carbine for shorter. You'll be fine with either. I use a carbine 308 with my setup.

If there was a concern, it would be using the carbine in a rifle length tube which would be too short.

Also,
.223 is technically a weaker spring than 308 so you're actually moving up in weight from what you currently use.

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[MoRivera]

Got the A5 buffer tube in today.  So essentially, I have the same setup as before with a hydraulic buffer (this time the 5007 9mm-sized), a .308 carbine spring, and a wave spring with a quarter as separator.  Cycling the BCG by hand, it seems the same as my prior setup with a 5000 (carbine-size) buffer, in that it pulls back and 'stops' just past the bolt catch and then there's a little extra firmer cushion behind it...like 2/5 to 1/2 inch.  That's again ideal for me as I do run 10-rd mags sometimes and can use the lock back, but it doesn't go back way past the bolt catch.  Will test it out tomorrow to see how it feels.

 

Interestingly, here is the quarter that I had in there before.  Looks like it was getting hit hard enough to dome/cup it a bit.....

 

Edited December 30, 2018 by MoRivera

[Bill_Van]

Thanks to both of you for the clarification. As soon as the weather clears up I'll give a try! Got a JP 308 Carbine on the way so I should be covered with several choices for the best configuration.

 

 

[Startingover]

On 12/29/2018 at 8:27 PM, MoRivera said:

Got the A5 buffer tube in today.  So essentially, I have the same setup as before with a hydraulic buffer (this time the 5007 9mm-sized), a .308 carbine spring, and a wave spring with a quarter as separator.  Cycling the BCG by hand, it seems the same as my prior setup with a 5000 (carbine-size) buffer, in that it pulls back and 'stops' just past the bolt catch and then there's a little extra firmer cushion behind it...like 2/5 to 1/2 inch.  That's again ideal for me as I do run 10-rd mags sometimes and can use the lock back, but it doesn't go back way past the bolt catch.  Will test it out tomorrow to see how it feels.

 

Interestingly, here is the quarter that I had in there before.  Looks like it was getting hit hard enough to dome/cup it a bit.....

 

I am running an A5 tube.

I have the orig 9mm blitz, jp 308 rifle, then a quarter, a wave, a steel spacer (idk how long, 1/2"-ish?) and then another wave spring in the bottom.

My bolt lock still works