JP Silent Capture Buffer/Spring

[molonlabetn]

I've been eyeing one for my SBR for awhile, its just been hard to justify spending ~$150 to replace my current setup (which has never given a hint of a problem). Anyone have experience with this device? What do you think?

[MacGyver]

It is a lot quieter!  I guess it depends on how you view the cheese grater over metal sound.  Personally, I've always equated that with the sound of freedom :)

[molonlabetn]

Heh. Honestly, since I've been running the Wolff extra power spring with a light coating of grease, I can't hear my buffer at all... Even suppressed. So, replacing with a JP would simply be for reliability and recoil control, IF it helps with that at all.

[MacGyver]

Dolomite_Supafly built one that allows for using 1911 springs.  I kind of like that setup since you can easily tune the rig with known weight springs.

[mikegideon]

Heh. Honestly, since I've been running the Wolff extra power spring with a light coating of grease, I can't hear my buffer at all... Even suppressed. So, replacing with a JP would simply be for reliability and recoil control, IF it helps with that at all.

 

I haven't used that spring, but am a big JP fan. If you really want recoil control, you can go with their low mass stuff and an adjustable gas block.

[sigrug17]

Running one for awhile thru my 16" AR gas build.  It to me, makes it feels like a piston gun.  It is quiet, I like it for a 'regular 16" gas AR.    I don't know how'd it run at all in an SBR.

[Mark A]

Well, I bought one of their kits along with the adjustable spring kit and one of their low mass BCG's for the CMT 308 I am building. I also got one of the Micro MOA adjustable gas blocks. I have 2 goals:

 

1) Create as soft shooting but reliable gun as possible

2) Have a suppressor setting that is also reliable.

 

I am curious about the dynamic between the adjustable springs and the adjustable gas block. I'm hoping they will work together but it may be that I can mostly tune through one or the other.

 

The really interesting part is I don't really know much about tuning a gas system. So far my plan is to start where is doesn't cycle and increase gas until it does. I'm sure there is a better method that has like actual science involved.

 

I'm hoping that the system will also be fairly quiet.

 

Now if my rail would just get in but it isn't scheduled for production until late June...

 

Mark

[MacGyver]

What rail did you go with, Mark?  The KAC?

[molonlabetn]

Well, I bought one of their kits along with the adjustable spring kit and one of their low mass BCG's for the CMT 308 I am building. I also got one of the Micro MOA adjustable gas blocks. I have 2 goals:

1) Create as soft shooting but reliable gun as possible
2) Have a suppressor setting that is also reliable.

I am curious about the dynamic between the adjustable springs and the adjustable gas block. I'm hoping they will work together but it may be that I can mostly tune through one or the other.

The really interesting part is I don't really know much about tuning a gas system. So far my plan is to start where is doesn't cycle and increase gas until it does. I'm sure there is a better method that has like actual science involved.

I'm hoping that the system will also be fairly quiet.

Now if my rail would just get in but it isn't scheduled for production until late June...

Mark

Sounds like a nice setup. I only have a two position gas block (piston gun), so what I did was increase buffer weight and spring weight combinations until the gun would short stroke with the gas in the suppressed setting without the suppressor mounted, using XM193. That ended up perfect for both settings when selected appropriately. I ended up with a +15% Wolff buffer spring and an H2 buffer, but I'm considering dropping buffer weight to the slightly lighter Spikes T2, if I dont go the JP route, just to give the bolt a little shorter lock time. As it is, recoil is as mild as I've ever felt in any short piston AR.

[Mark A]

What rail did you go with, Mark?  The KAC?

No... in spite of your excellent advice I went with a Troy rail. What can I say, I guess I am a bit of a Troy fan boy. The KAC just looked a little clunky to me. Troy just did away with the TRX line in favor of the Alpha line and it is taking time to get the various models out of the factory.

 

They are making a 308 VTAC now which I would have really liked to get but they are only offering it in the low profile DPMS and the CMT is a high profile. I don't know if there is an advantage one way or the other. I do know that my M&P 10 is the low profile version.

 

I'm hopeful now that more folks are starting to make 308 AR's that one standard will win out and simplify things as it can be tricky buying pieces and parts...

 

I'm still anxious to see yours...

 

Mark

[Mark A]

Sounds like a nice setup. I only have a two position gas block (piston gun), so what I did was increase buffer weight and spring weight combinations until the gun would short stroke with the gas in the suppressed setting without the suppressor mounted, using XM193. That ended up perfect for both settings when selected appropriately. I ended up with a +15% Wolff buffer spring and an H2 buffer, but I'm considering dropping buffer weight to the slightly lighter Spikes T2, if I dont go the JP route, just to give the bolt a little shorter lock time. As it is, recoil is as mild as I've ever felt in any short piston AR.

Thanks, that is good info.

 

I'm going to show my ignorance now: You mentioned reducing the lock time. Won't that possibly lead to a reduction in accuracy? What is the reasoning in your wanting to reduce the timing?

 

Thanks, Mark

[molonlabetn]

Thanks, that is good info.

I'm going to show my ignorance now: You mentioned reducing the lock time. Won't that possibly lead to a reduction in accuracy? What is the reasoning in your wanting to reduce the timing?

Thanks, Mark

Because of the extra power spring, my cycle rate is already significantly slower than even a rifle length system, plus with a very heavy buffer. Going from a 4.6oz H2 to a 4.3oz T2 will actually reduce recoil for me slightly... a lighter reciprocating unit will begin moving sooner and have less momentum at the rear of its travel, which is why race guns use light buffers and lightened carriers. Heavy buffers improve reliability when matched to the power of the ammunition, and springs mostly regulate bolt speed... One reason why full-size semi-auto pistols are more reliable than compact ones when properly sprung, because they have more reciprocating mass opposing the recoil impulse. With gas systems, you can either reduce mass and turn down the gas for fast lock times and low recoil, or increase mass and overgas for reliability. Edited May 1, 2014 by molonlabetn

[Johnny Rotten]

Wouldn't your HD spring and going lighter on the buffer = bolt bounce

[molonlabetn]

Wouldn't your HD spring and going lighter on the buffer = bolt bounce

If I was going all the way down to a standard 3oz carbine buffer, maybe, and even then it would only be an issue on full auto.

[graycrait]

even if you don't keep the JP in this rig permanently it is fun to monkey around with.  I had an older HBAR that I installed this in with an adjustable gas block, seemed to be a good set-up for that sort of rig.  I would think it would be a good way to go for a coyote gun.