Short stroking my PCC

[Thomx]

Hello guys,

 

I've been following the forum for years, first time I signed up and posted

 

 

I'm going to get a 9"5 PCC Pistol from ADC (Europe).

 

I just did the homework on trying to choose the right buffer system and how to short stroke the best my PCC.

 

I just need help to know if the following options make sense (especially option 2)

 

1) Option 1

- Get the Blitzkrieg 5020SS buffer system (which is 5,3" compressed in length) (Blitzkrieg says the 5020SS shorten the stroke of the bolt  by 1.3" when installed in a standard AR15 buffer tube ; by 0,5" in AR10/A5 carbine buffer tube)

- Get a A5 tube which is 0,75" longer it seems (not so easy to get in Europe)

- Get a JP .308 carbine recoil spring

- Add spacer(s) in the back (and tinker with it to find the perfect ajustment)

 

2) Option 2 (this is where I don't know if it adds up)

- Get the Blitzkrieg 5015HD buffer system (which is 3,90" compressed in length)

- Get the Blitzkrieg buffer weight (adding 0,75" in length)

- Stay with my factory tube (seems 0,75" shorter than A5 tube)

(Will the 5015HD and the buffer weight be to long for my factory tube ? The system seems to be longer than 5020SS + A5 tube)

- Get a JP .308 carbine recoil spring

 

Thanks.

 

Edited November 21, 2021 by Thomx

[Adamj]

Sounds like you really have done your homework. 

 

I did everything you listed in Option 1 and the results have been impressive. I allow the bolt to travel just enough to reliably eject a case. This setup cycles the bolt quickly and has little dot movement. 

[Walli]

What kind of ammunition do you intend to use?

If you are going to use factory ammunition option 2 might be the better choice. If you reload 115 gr ammo with PF 130-135 option 1 should be better.

[Thomx]

I'm going to use 124 grains reloaded ammo ; factory probably in match

 

In a standard tube, the 5015HD with buffer weight and will make the PCC function ? (I don't want to tamper/change with the tube if I can avoid that)

[zzt]

If you intend to stay with the carbine tube, the standard or HD Blitzkrieg buffer and their short stroke slug with a JP 308 carbine spring is your best bet.  Leave the weight in the bolt.  Using reloaded ammo for practice and factory for a match is not a good idea.  You can tune for one, but not both unless they are the same PF.

 

On the advice in this forum I tried an A5 tube.  Using the exact same setup as in the carbine tube except adding a 3/4" short stroke adapter behind the spring resulted in a softer shooting gun.  It doesn't make sense, but it is true.

 

1 hour ago, Thomx said:

In a standard tube, the 5015HD with buffer weight and will make the PCC function ?

 The answer is yes.  It will even function with sub-minor loads.  I use the standard strength buffer, because I mostly shoot sub 100PF loads in mine for steel challenge.  It functions flawlessly at 132PF, only the recoil is greater.

[Thomx]

Thanks ZZT !

Yes I will train and compete with the same PF ammo (mb only reloaded).

 

To be clear : an A5 tube = a rifle tube ? ; whereas the stock tube on all PCC is a carbine tube ?

(I'm a little confused between A2 and A5 tubes)

[Ner]

tried almost all exist top buffers and springs on my ADC 

As for now shooting with your Option 1 and 133-135PF 115. BW in

 

[WxGuy]

Here's my go to setup;

 

A5 buffer tube (rifle tube)

Blitz 5006 buffer

.308 JP rifle spring

Hiperfire trigger (Eclipse and PDI)

1-2 quarters in the bottom of the tube.  Short stroked all the way!

130-135pf ammo 

 

This setup has been 100% since I put it together over 10,000+ rounds ago.

Edited November 21, 2021 by WxGuy

[Thomx]

What does it change if you don't get an A5 buffer tube but instead put a spacer the size of the length difference of the factory buffer tube / A5 buffer tube ?

Edited November 21, 2021 by Thomx

[WxGuy]

The advantage to the A5 tube/5006 long buffer is buffer weight and recoil reduction in the short stroke.  I guess you could use the A5 tube and add a spacer and run a shorter carbine buffer and carbine spring setup.  This will result in a lot of experimentation where as the info I posted is proven (check out the Brekke Custom Guns website).  All of my PCC friends have gone to this setup from carbine setups in their AR9 style lowers.  Like everything, YMMV and experimenting to find "your" setup is a fun journey.  The main goal is to mitigate the dot bounce in your setup.

 

Edited November 21, 2021 by WxGuy

[zzt]

3 hours ago, Thomx said:

To be clear : an A5 tube = a rifle tube ? ; whereas the stock tube on all PCC is a carbine tube ?

 

An A2 rifle tube and an A5 tube are different, even though they are approximately the same length.  An A5 tube is essentially a carbine tube that is 3/4" longer.  If you want to short stroke the A5 you have to add another 3/4" behind the spring.  I use the shorter MBX adapter that fits inside the spring.  You could use conventional spacers, but that will increase preload if you care.

 

Here is my carbine setup in order of insertion into the tube:  JP 308 polished carbine recoil spring, Blitzkrieg KYN-RB5007 standard buffer and Blitzkrieg KYN-R15015098 buffer weight/short stroke adapter.  I have removed the buffer retaining spring and pin.  My bolt weighs 12.5 oz. with the 3 oz. weight inserted.

 

My A5 tube setup is the same except an MBX 3/4" short stroke adapter is inserted first.  I like the A5 tube because it feels better and balances the gun better.  I also think it a tad softer.  If you don't use the extra short stroke adapter the bolt will lock back on empty, and the action will feels smoother, softer and slower.  The downside is double tap splits.  The extra spacer definitely speeds things up.  At 25 yards I can put all rounds well within the A zone as fast as I can pull the trigger.

Edited November 21, 2021 by zzt

[Kwontanamo]

I’ve recently starting my build idea for a PCC and this is something I didn’t consider. Thanks for the input everyone!