Blitkrieg buffer failure

[MoRivera]

That's interesting, I wouldn't have thought there'd be enough space left.  I tried putting one of these spacers at the bottom of the buffer spring......

 

...with the same setup I described and the bolt couldn't get back to lockup.  So essentially I guess it 'short-stroked' the cycle.  I actually expected that and got the spacer above  just in case I want to go back to the normal carbine-sized 5000 Kynshot.  

[echotango]

You can also get nylon spacers at Home Depot for $0.65.  I am running 3 of them with a 5015hd and Orange spring in a 14.5" brl. 

[HoMiE]

On 12/28/2018 at 11:47 PM, Hallz said:

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.

In my initial quick test trying both 5007 and 5015hd it was hard to tell any difference with the same load between buffers. 

[RaylanGivens]

2 hours ago, Startingover said:

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

 

The A5 receiver extension is about 7/8" longer than a standard carbine extension.

 

Your wave springs compress to about 1/16" and a quarter is about 1/16"...  The sum total of your quarter, wave springs, and half inch spacer is 11/16" total...  That's a bit less than the amount you gained by going to the A5 receiver extension...  Your bolt still locks because your bolt travels further back than a standard carbine tube and buffer setup.

 

[Startingover]

11 minutes ago, RaylanGivens said:

 

The A5 receiver extension is about 7/8" longer than a standard carbine extension.

 

Your wave springs compress to about 1/16" and a quarter is about 1/16"...  The sum total of your quarter, wave springs, and half inch spacer is 11/16" total...  That's a bit less than the amount you gained by going to the A5 receiver extension...  Your bolt still locks because your bolt travels further back than a standard carbine tube and buffer setup.

 

I am not sure on the exact length of the spacer, but yes, if it still has enough momentum to compress all of it completely.

[MoRivera]

So after a range session today wit the A5 tube and 5007 (9mm model) Kynshot.........frankly, I didn't like it as much.  It basically felt the same way as always with any heavy/9mm buffer that I've tried, you just feel the overall 'movement' of everything more and it cycles more slowly.  Just clunkier overall.

 

So I think I'm just going to go back to what I had settled on before......carbine tube, model 5000 (regular 5.56 carbine) Kynshot/Blitzkreig buffer, .308 carbine spring and a wave spring.  I can really see now why some PCC shooters prefer to short-stroke and remove the weight from the BCG....quicker is better, and the 'extra jolt' or recoil doesn't seem to bother me as much as all that slower mechanical stuff going on with a heavier/slower buffer.  If I want less recoil I need to shoot less powerful loads than factory, period.  I've tried a few subsonic 147's through my gun and it felt like .22's.  But overall, I get my dot back on target quicker with the lighter 5000 setup....no doubt about it.  Again, just hope it holds up.  Now I gotta change buffer tubes again. 

[RaylanGivens]

48 minutes ago, MoRivera said:

So after a range session today wit the A5 tube and 5007 (9mm model) Kynshot.........frankly, I didn't like it as much.  It basically felt the same way as always with any heavy/9mm buffer that I've tried, you just feel the overall 'movement' of everything more and it cycles more slowly.  Just clunkier overall.

 

So I think I'm just going to go back to what I had settled on before......carbine tube, model 5000 (regular 5.56 carbine) Kynshot/Blitzkreig buffer, .308 carbine spring and a wave spring.  I can really see now why some PCC shooters prefer to short-stroke and remove the weight from the BCG....quicker is better, and the 'extra jolt' or recoil doesn't seem to bother me as much as all that slower mechanical stuff going on with a heavier/slower buffer.  If I want less recoil I need to shoot less powerful loads than factory, period.  I've tried a few subsonic 147's through my gun and it felt like .22's.  But overall, I get my dot back on target quicker with the lighter 5000 setup....no doubt about it.  Again, just hope it holds up.  Now I gotta change buffer tubes again. 

 

What spacers were you using with the A5 tube?

 

If you make a delrin spacer that is the difference in length between the carbine tube and the A5 tube, you won't have to switch tubes to go back and forth...  You can just  pop in the spacer and use your carbine setup.  I used to do that when I used a JP SCS buffer for a specific Steel Challenge load.

 

[MoRivera]

1 hour ago, RaylanGivens said:

 

What spacers were you using with the A5 tube?

 

If you make a delrin spacer that is the difference in length between the carbine tube and the A5 tube, you won't have to switch tubes to go back and forth...  You can just  pop in the spacer and use your carbine setup.  I used to do that when I used a JP SCS buffer for a specific Steel Challenge load.

 

The wave spring and quarter pretty much exactly took up the extra length compared to the carbine tube.  I also have one of these spacers....

 

 

...which I can use in addition when going back to the 5000 buffer in the A5 tube, and this spacer pretty much approximates the length difference again.  So I might just do that.

 

But when I had the 5000, the .308 carbine spring, and the carbine spring in the carbine tube the buffer spring had some pre-load because of the space that the wave spring took up behind it.  So I think I'll try the above spacer first in the A5, but if I still don't like it I'll go back to what I had before with the carbine tube. 

 

 

Edit: actually yeah if I put that New Frontier spacer at the very back of the A5 tube, wider end facing forward it should be pretty much the same as a carbine tube.  So I'll try that first.  But part of me wonders how well that 'lip' will hold up, if (like pictures I posted earlier) it bends quarters.  I think I will just go back to the carbine tube, that way I'll be sure....so far it's the most 'tried and true' combination for me, if you will.

 

Edited January 4, 2019 by MoRivera

[RaylanGivens]

2 hours ago, MoRivera said:

The wave spring and quarter pretty much exactly took up the extra length compared to the carbine tube.  I also have one of these spacers....

 

...which I can use in addition when going back to the 5000 buffer in the A5 tube, and this spacer pretty much approximates the length difference again.  So I might just do that.

 

But when I had the 5000, the .308 carbine spring, and the carbine spring in the carbine tube the buffer spring had some pre-load because of the space that the wave spring took up behind it.  So I think I'll try the above spacer first in the A5, but if I still don't like it I'll go back to what I had before with the carbine tube. 

 

Edit: actually yeah if I put that New Frontier spacer at the very back of the A5 tube, wider end facing forward it should be pretty much the same as a carbine tube.  So I'll try that first.  But part of me wonders how well that 'lip' will hold up, if (like pictures I posted earlier) it bends quarters.  I think I will just go back to the carbine tube, that way I'll be sure....so far it's the most 'tried and true' combination for me, if you will.

 

 

If you use the same spring/spacer setup in the A5 tube that you used in the carbine tube, you would actually be lengthening the stroke...  not shortening it.

 

My charging handle won't pull back far enough to lock the bolt open...  The easiest way I have found to determine how much I am short stroking the bolt is to measure how far past the trigger reset point the bolt will pull back...  You can hear and feel the click...  If the bolt pulls back further after the trigger reset with the A5 tube than the carbine tube, you need to add spacers or something to the A5 setup to get back to the same amount of stroke you had with the carbine tube.

 

[MoRivera]

34 minutes ago, RaylanGivens said:

 

If you use the same spring/spacer setup in the A5 tube that you used in the carbine tube, you would actually be lengthening the stroke...  not shortening it.

 

My charging handle won't pull back far enough to lock the bolt open...  The easiest way I have found to determine how much I am short stroking the bolt is to measure how far past the trigger reset point the bolt will pull back...  You can hear and feel the click...  If the bolt pulls back further after the trigger reset with the A5 tube than the carbine tube, you need to add spacers or something to the A5 setup to get back to the same amount of stroke you had with the carbine tube.

 

I might not have been clear.....I didn't use a spacer in the carbine tube (with the 5000) or the A5 (with the 5007), I have it as an extra item for something I didn't end up using it for.  I specifically went with an A5 tube to lengthen stroke to fit both the longer 5007 buffer and the wave spring, both of which in a carbine tube didn't pull back far enough to lock bolt on empty mag which is something I want to maintain.

 

The difference comes in where I would put that spacer if I wanted to go back to the carbine-length setup.  If at the very rear of the tube...before the wave spring/quarter/buffer spring/buffer, then I would be effectively simulating what I had in the carbine tube, BUT with the pictured spacer and the wider part facing forward (as it would need to be to support the wave spring), it would probably break the lip off.  I could also use the spacer as intended plugged (smaller end facing forward) into the end of the main buffer tube, assuming that it would match the stroke length of the buffer in a shorter tube....after the wave spring and quarter.  But then that would be lengthening the spring as opposed to the bit of pre-load as it was in the carbine tube, which I also think contributed to the feel I had gotten used to.  Obviously a solid delrin or maybe even a thick-walled PVC pipe spacer in the rear would do the trick, but I don't want to bother getting more stuff now.

 

It was a pretty quick switch back to the carbine length buffer tube.  I also use a ratcheting castle nut/end plate which makes it a little easier.  I'll just keep the A5 around and maybe try it in a 5.56 somewhere down the road.

 

 

Edited January 5, 2019 by MoRivera

[MoRivera]

Here's essentially what I was dealing with, please excuse the rawness of the illustration.  The top one being what I started with before (and went back to), the next the A5/model-5007 setup, and then the two variations on 'simulating' the top setup in the A5 tube.......

 

 

 

 

Obviously, the very bottom is pretty much the same as the top one, but again I don't trust that spacer outer lip to hold up (made of some had plastic or the like).  A solid/cylindrical spacer would do the job, but don't want to bother right now.

Edited January 5, 2019 by MoRivera

[RaylanGivens]

On 12/21/2018 at 9:18 PM, HoMiE said:

Yes, I made my own 1/2” 2oz weight 

 

Are you running a weight in the bolt and also a second SS weight in front of the buffer?

 

[HoMiE]

1 hour ago, RaylanGivens said:

 

Are you running a weight in the bolt and also a second SS weight in front of the buffer?

 

Yes, and I run the qc10 bolt which has a heavier bolt weight since it has “wings” that go along where the hammer travels. 

[RaylanGivens]

1 hour ago, HoMiE said:

Yes, and I run the qc10 bolt which has a heavier bolt weight since it has “wings” that go along where the hammer travels. 

 

Interesting...  I've been running a Taccom Extreme 9mm bolt without the weight for quite a while...  It shot well and I never really thought about adding any weight to the buffer system until lately...

 

Recently bought an RB5015HD for a second/backup PCC rifle I'm building...  it will also be a spare in case the RB5007 in my original PCC rifle breaks...  Also bought one of their SS weights to try.

 

Brian at Blitzkrieg suggested running both a bolt weight and the SS weight for 9mm PCC rifles...  Since I wasn't running any weight at all, and since I have a spare bolt with a 2.6oz weight, I decided to test them at the range...  First shot about 15 rounds with my current setup (no bolt or buffer weight)...  Swapped in an identical bolt, but with the 2.6oz bolt weight...  shot a couple of mags full and didn't notice a huge difference...  swapped out my RB5007 and installed the RB5015HD...  keeping the bolt with the weight...  and shot another few mags full...  It was difficult to tell the difference...  It seems to shoot a little smoother this way, so...  I left it set up with the bolt weight and the RB5015HD...  I've shot a few matches with it that way.

 

I was afraid that the extra bolt weight would make it shoot slower, but that is not the case...  Another thing I noticed is that the brass seems to come out cleaner now...  less soot on the cases...  The bolt seems to be easier to clean, too...  although it is a new bolt...  My plan is to continue shooting with the RB5015HD and the weight in the bolt.

 

[HoMiE]

3 minutes ago, RaylanGivens said:

 

Interesting...  I've been running a Taccom Extreme 9mm bolt without the weight for quite a while...  It shot well and I never really thought about adding any weight to the buffer system until lately...

 

Recently bought an RB5015HD for a second/backup PCC rifle I'm building...  it will also be a spare in case the RB5007 in my original PCC rifle breaks...  Also bought one of their SS weights to try.

 

Brian at Blitzkrieg suggested running both a bolt weight and the SS weight for 9mm PCC rifles...  Since I wasn't running any weight at all, and since I have a spare bolt with a 2.6oz weight, I decided to test them at the range...  First shot about 15 rounds with my current setup (no bolt or buffer weight)...  Swapped in an identical bolt, but with the 2.6oz bolt weight...  shot a couple of mags full and didn't notice a huge difference...  swapped out my RB5007 and installed the RB5015HD...  keeping the bolt with the weight...  and shot another few mags full...  It was difficult to tell the difference...  It seems to shoot a little smoother this way, so...  I left it set up with the bolt weight and the RB5015HD...  I've shot a few matches with it that way.

 

I was afraid that the extra bolt weight would make it shoot slower, but that is not the case...  Another thing I noticed is that the brass seems to come out cleaner now...  less soot on the cases...  The bolt seems to be easier to clean, too...  although it is a new bolt...  My plan is to continue shooting with the RB5015HD and the weight in the bolt.

 

Similar results, the pcc always felt harsher to me when I removed weight. And heavier setup does seem to help with less soot on cases and in chamber area. 

[Startingover]

Is there somewhere good besides directly from Blitzkrieg to buy these buffers?

I bought my first one from directly, and often prefer to do that, especially if there may be a warranty issue down the road.

However I am not afraid to save a few bucks also!

[Flatland Shooter]

https://www.brownells.com/search/index.htm?k=hydraulic+buffer&ksubmit=y

 

They often offer a 10% discount + free shipping.  Code MFV expires at midnight but in a week or so they may offer it again.

[Startingover]

9 hours ago, Flatland Shooter said:

https://www.brownells.com/search/index.htm?k=hydraulic+buffer&ksubmit=y

 

They often offer a 10% discount + free shipping.  Code MFV expires at midnight but in a week or so they may offer it again.

I looked at Brownells, but I just looked up Blitzkrieg, they were out of stock.

I dont think I realized Kyntec was selling the 9mm directly.

[MoRivera]

On 12/7/2018 at 8:52 AM, MemphisMechanic said:

 

It’s the flattest-shooting combination I have tried in my rifle. 

 

I run a Guard so the action isn’t direct blowback and the bolt is much lighter. I run a wave spring, then a single quarter, then a 5oz hydraulic buffer for a .308, then a Sprinco red spring.

 

I just installed this myself......Kynshot model RB5005, for a .308 carbine. 5oz. but same length as the RB5000 .223 carbine model (which I had in there before).  .308 Carbine spring, quarter, wave spring.  Will test out this week and see how she feels.  Regular blowback PCC with weight in bolt. 

Edited February 11, 2019 by MoRivera

[MoRivera]

bump fire post......

Edited February 11, 2019 by MoRivera

[Startingover]

24 minutes ago, MoRivera said:

I just installed this myself......Kynshot model RB5005, for a .308 carbine. 5oz. but came length as the RB5000 .223 carbine model (which I had in there before).  .308 Carbine spring, quarter, wave spring.  Will test out this week and see how she feels.  Regular blowback PCC with weight in bolt. 

I will be interested to hear your results 

[MoRivera]

Shot the PCC at a plate shoot tonight with the RB5005 in.  Like the regular RB5007 9mm model, the hydraulic piston has less resistance than the standard carbine RB5000, but not as loose/spongy.  In the gun, it cycled and functioned fine, felt a bit milder in recoil than the lighter RB5000.  But I mistakenly brought a bunch of 124gr Freedom 9mm, and that felt much different than the 115gr Blazer Brass that I normally shoot.  The 124 was moderately softer, but seemed to cycle much slower and there was more muzzle movement/sway.  Almost felt like it was under water in comparison.  The 115 again had a sharper 'jolt', but it was very quick and the dot stayed on target better.  My plate runs were markedly quicker with the 115gr, it was a stupid oversight packing my jar of 124.  Definitely sticking solely with the 115.

 

So the RB5005 works fine, and I guess I'll keep the RB5000 around as a spare.

[Flatland Shooter]

Has anyone with trigger reset problems and a Blitzkrieg buffer solved the problem with hotter ammo? 

 

In practice, not a single problem with trigger resets.  But in a recent match, I had lots of problems. Turned my AR9 into a lever action gun.

 

My thoughts are that in practice I'm holding the gun tight into my shoulder but in the heat of a match stage, I trying to get by with a looser grip.

 

I'm running the RB5007 with a JP .308 carbine spring and 134 PF ammo.  I've loaded up some ~138 PF rounds to play with.  Maybe that will solve the problem.

[Startingover]

5 hours ago, Flatland Shooter said:

Has anyone with trigger reset problems and a Blitzkrieg buffer solved the problem with hotter ammo? 

 

In practice, not a single problem with trigger resets.  But in a recent match, I had lots of problems. Turned my AR9 into a lever action gun.

 

My thoughts are that in practice I'm holding the gun tight into my shoulder but in the heat of a match stage, I trying to get by with a looser grip.

 

I'm running the RB5007 with a JP .308 carbine spring and 134 PF ammo.  I've loaded up some ~138 PF rounds to play with.  Maybe that will solve the problem.

Does it need just a tiny bit more travel?

[Flatland Shooter]

10 hours ago, Startingover said:

Does it need just a tiny bit more travel?

 

Not sure.  With the same ammo used Thursday night I tried to replicate it at the range this afternoon.  The trigger reset every time.  I even tried shooting it one handed like a pistol to give it every opportunity to fail.

 

I also bumped up the powder by 2/10's and increased the PF from 134 to 136.  No noticed increase in dot movement so I think I'll stay with that for a while.