Which Recoil System? JP SCS Gen 2 vs MBX PCC Buffer System

[gnhowell1]

Ahh, thanks Max.  Read the following and just tossed it underneath the whole assembly...

If any of you guys have the 9mm JP SCS, you'll want the CS100-M11 to do pretty much the same thing. It did improve the SCS for me a lot. You put it under the plastic bumper at the bottom of the SCS. 

 

[Aircooled6racer]

5 hours ago, Maxamundo said:

Yall silly gooses


 

 

Hello: The JP buffer that Max is showing is the one for a regular 223 with only three weights. The regular 9mm JP one has 4 weights to shorten the stroke for the 9mm bolt. If you use that wave spring under the 9mm JP buffer with 4 weights you will get a really short stroke and may have some problems. Thanks, Eric

[Maxamundo]

2 hours ago, Aircooled6racer said:

Hello: The JP buffer that Max is showing is the one for a regular 223 with only three weights. The regular 9mm JP one has 4 weights to shorten the stroke for the 9mm bolt. If you use that wave spring under the 9mm JP buffer with 4 weights you will get a really short stroke and may have some problems. Thanks, Eric

 

No! The video is meant to show how to install it on a 9mm SCS. I just don't have one on hand! It only shortens the stroke by about a half inch which should stop the bolt catch from functioning but it is still WELL beyond the amount of cycle length you need to get the trigger to reset, so you should have no problems. This video is meant ONLY to explain installation on the 9mm SCS, you should never run a spring like this on the rifle SCS because a longer cycle is actually important for proper extraction and feeding with the longer .223 rounds. I took the spring out again immediately after recording the video.

 

If you must preserve bolt catch function, you can instead get a shorter spring like the M5-M7 (I'm not sure which one it is) and do the exact same thing. It will be slightly less effective at reducing recoil but will still allow you to lock back manually.

[Maxamundo]

4 hours ago, gnhowell1 said:

Ahh, thanks Max.  Read the following and just tossed it underneath the whole assembly...

If any of you guys have the 9mm JP SCS, you'll want the CS100-M11 to do pretty much the same thing. It did improve the SCS for me a lot. You put it under the plastic bumper at the bottom of the SCS. 

 

 

 

My bad, I thought it was more obvious that there was spacer under the bumper on the inside. I'm surprised people are trying to get their upper and lower back together with that rod sticking out ? that will permanently lock them together unless you unscrew the buffer tube with the gun fully assembled

[littlefish]

On ‎7‎/‎14‎/‎2017 at 1:21 AM, Maxamundo said:

If any of you guys have the 9mm JP SCS, you'll want the CS100-M11 to do pretty much the same thing. It did improve the SCS for me a lot. You put it under the plastic bumper at the bottom of the SCS. 

How many steel and tungsten weights for this setup? 2 and 2?

Edited July 20, 2017 by littlefish

[Aircooled6racer]

56 minutes ago, littlefish said:

How many steel and tungsten weights? 2 and 2?

Hello: I am running 3 steel weights and one tungsten weight for reloads. I am also using the green JP spring on one of my setups. The other setup has a black JP spring, one aluminum weight(I made it), one steel spacer and two tungsten weights. For me the weight range is 4.6ozs-5.1ozs depending on the spring used. I do coat the JP rod with a dry film lube and that helps also. My standard type setup I am using a 223 spring, Frontier plug and a Rock River buffer. You can also try the 4.6oz buffers as well. Whatever setup you end up using always test with one round at a time to make sure you don't get a unwanted bump fire or full auto situation. Lots of good info here for the tinkerers in all of us. Thanks, Eric

[Maxamundo]

1 hour ago, littlefish said:

How many steel and tungsten weights? 2 and 2?

I liked 4 tungsten and a lighter spring like white or black.

[BigBamBoo]

Just a update.

 

Got out to the range this morning and shot the new Taccom ULW upper (very cool by the way) and tried the Taccom tune-able buffer and the Blitzkrieg buffer. Along with different JP springs. 

 For this rig, the Blitkreig with the JP .308 carbine buffer spring worked out the best. It have me the softest and flattest shooting combo. And was the quietest setup of the two.

 

Again, this is for my setup...YMMV. 

[TRUBL]

41 minutes ago, BigBamBoo said:

Just a update.

 

Got out to the range this morning and shot the new Taccom ULW upper (very cool by the way) and tried the Taccom tune-able buffer and the Blitzkrieg buffer. Along with different JP springs. 

 For this rig, the Blitkreig with the JP .308 carbine buffer spring worked out the best. It have me the softest and flattest shooting combo. And was the quietest setup of the two.

 

Again, this is for my setup...YMMV. 

115's?

[BigBamBoo]

Yes, just WWB 115 grain ammo. 

[TRUBL]

On 7/20/2017 at 2:33 PM, BigBamBoo said:

Yes, just WWB 115 grain ammo. 

interesting.......we've tried that set up, the set up seemed 'clunky'.....did change split times, but seemed like it was driving more forward......can't quite explain it. Went back tot he rifle spring and it felt smoother......now that it all with the taccom 2 stage system that can use the rifle spring. The blitzkrieg could not use a rifle with out a spacer in the back that allowed for more compressed spring

 

[BigBamBoo]

What stock are you running? I have a Fortis on this rig and it is a bit heavier then a mil-spec or similar collapsible stocks. So my carbine feels a little @ss heavy and that might mitigate the "forward driving" you are feeling?

 

 Don't get me wrong Tim...your system works well. I have it in my JP GMR-13 upper based carbine and it works very well. Here is a video from yesterday with me shooting that rig...I am the in the blue shirt.

 Compare the movement of my friends rig that is set up just about the same as mine except he has a Heavy Buffers Q-buffer in his. You can see mine shoots a little flatter.

 

 

[TRUBL]

they seemed very similar for sure.......I did notice a couple instances where yours actually seemed to dip some, very little, but it dipped.

 

Tim

[BigBamBoo]

19 minutes ago, TRUBL said:

they seemed very similar for sure.......I did notice a couple instances where yours actually seemed to dip some, very little, but it dipped.

 

Tim

 So how to mitigate the dip?

[TRUBL]

Just now, BigBamBoo said:

 So how to mitigate the dip?

lighter recoil spring.

Everyone is sooooooo caught up with how much the muzzles rises, thats a bunch of crap......as long as the gun comes back to POA before you can double tap is key. And when I mean double tap, I mean sight once and double tap. I know for a fact that we are doing double taps on steel at 25 yards (6" square plates) with our barrels, recoil systems and 124's 

 

May not hit the second shot everytime.......but we are doing 80% and at distance......makes us very confident to double tap anything at 10yards for sure.

 

[BigBamBoo]

Well my trigger finger is not that fast. My double taps are pretty slow.

 

The dot does seem to come back pretty fast with the setup I have now on both rigs. Don't think I am going to mess with them right now.

 

I am thinking about selling my GMR-13 setup and get another one of your uppers.

[KzBoost]

Just saw a video by JP stating that the SCS buffer should stick out from the buffer tube about 1/8" to obtain some pre-load, they recommended using a quarter as a shim at the end of the buffer tube. Is anyone else doing this? This whole time I was throwing my SCS (including the one on my AR15) without a quarter/shim and having it sit flush with the buffer tube. Am I doing it wrong? 

I'm worried about over-travel caused from shimming the SCS and shearing the gas key..

Edited July 25, 2017 by KzBoost

[BigBamBoo]

Your over tra

5 hours ago, KzBoost said:

Just saw a video by JP stating that the SCS buffer should stick out from the buffer tube about 1/8" to obtain some pre-load, they recommended using a quarter as a shim at the end of the buffer tube. Is anyone else doing this? This whole time I was throwing my SCS (including the one on my AR15) without a quarter/shim and having it sit flush with the buffer tube. Am I doing it wrong? 

I'm worried about over-travel caused from shimming the SCS and shearing the gas key..

The over travel would be less with "shims". I do not use shims but have removed material from the buffer tube so I can screw it further into the lower receiver which yields the same results as shims.

 I did that to lesson the over travel so the bolt would only travel rewards about an 1/8" past the bolt stop to help lesson bolt stop breakage.

[nickbfishn]

I got my free samples in from Smalley today. I ordered a CS100-M11 & M10.  I ordered both simply because I was afraid the M11 might be a little to long and since they were free I figured why not. Anyway, I'm going to play around with both sometime this week on my JPSCS and I'll report back with my findings.

 

Max, did you try different springs as well, or just go straight to the M11? 

[10cup]

1 hour ago, BigBamBoo said:

Your over tra

The over travel would be less with "shims". I do not use shims but have removed material from the buffer tube so I can screw it further into the lower receiver which yields the same results as shims.

 I did that to lesson the over travel so the bolt would only travel rewards about an 1/8" past the bolt stop to help lesson bolt stop breakage.

I have a JP-15 223 as well as the GMR-15 rifle both with the SCS buffers.  Neither one has a quarter spacer in it but they do stick out  about an 1/8" or so from  the buffer.  I was told by JP that as long as there is some preload on the buffer and it is not loose (shake the rifle and feel the movement) you are ok.  Hope this helps.

[BigBamBoo]

Yes, that is what I achieved by "shortening" the buffer tube to remove the over travel.

 

Seems JP changed their stance on pre-loading the SCS spring. 

 

The attached picture is from the paperwork that came with my SCS. This was one of the original 9mm SCS.  

[nickbfishn]

8 minutes ago, BigBamBoo said:

Yes, that is what I achieved by "shortening" the buffer tube to remove the over travel.

 

Seems JP changed their stance on pre-loading the SCS spring. 

 

The attached picture is from the paperwork that came with my SCS. This was one of the original 9mm SCS.  

This makes sense to me because I would think they don't want a gap between the bolt and buffer for several reasons, including having the metal parts slam together (no good) and to smooth out the operation altogether (very good).  This brings me to another question.  Are you supposed to remove the buffer detent when using the SCS?  I'm not sure of the exact name, but its the little pin that keeps the buffer from springing out of the tube when taken down.

[10cup]

Just now, nickbfishn said:

This makes sense to me because I would think they don't want a gap between the bolt and buffer for several reasons, including having the metal parts slam together (no good) and to smooth out the operation altogether (very good).  This brings me to another question.  Are you supposed to remove the buffer detent when using the SCS?  I'm not sure of the exact name, but its the little pin that keeps the buffer from springing out of the tube when taken down.

Yes, both of my JP guns came with no buffer detent pin.  

[nickbfishn]

Just now, 10cup said:

Yes, both of my JP guns came with no buffer detent pin.  

 

Makes sense.  I'm going to tinker this evening and see what happens. I'm pretty sure I have a slight gap because of the detent pin.

[BigBamBoo]

I don't run the buffer detent even with standard buffer/spring set up. Makes for easier cleaning, swapping springs, etc. Just have to be aware when opening the upper receiver.