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What is the difference between the (2) JP Rifle 9mm Silient Buffers?


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On the JP Site, I see there are (2) silent buffers for the 9mm.  One has what looks like (3) Tungsten, and (1) weight, while the other has (3) steels and (2) Tungstens.  In the description it says that the "enhanced" buffer i.e. the one with more weights, is best suited for the heavier non JP bolts, as it allows for the bolt to stay closed longer.  If you use it with the JP bolt, will it stay closed too long?  Which one would be best for a JP bolt with a short barrel.  I understand that barrel does not really matter as there is no gas on the bolt, but with the shorter barrel the pressure in the barrel will release (when the bullet exits) faster correct?  

 

Just don't want to but the wrong one first.

 

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I am going to call and talk to Adam about this tomorrow. However, the way I think this works is like this:

 

The new buffer has the exact same amount of buffered mass. 3 tungsten + 1 steel = 3 steel + 2 tungsten. The new version allows you to have up to 5 tungsten weights if you need it (vs a highest mass of 4 tungsten weights on the old). This is most likely an answer to other bolts having to lose their bolt mass inserts to run the SCS. The new system basically answers the call for people running higher PF ammo or people running non-JP bolts that need to add more mass into the system for it to work properly. So, in theory, both will run exactly the same in a stock set up w/ a JP bolt, but the new one has the ability to add more mass to the buffering weight (25% more). People running hand loads in JP's are going to lighter weights and lighter springs, so I would guess that the regular SCS will be the better option if running a JP bolt. 

 

(I will clarify with Adam tomorrow and update this thread) 

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Hello: I don't know what the carrier weight is on the new buffer but I do know the weight of the weights. Tungsten weights are 1.4815ozs, steel weights are 0.6949ozs so you can figure out what the total of all the weights are for the two buffers. If you are running reloads get the 4 weight buffer and make it lighter. If you are running factory ammo in a 14.5-16" barrel I may think of getting the other buffer but still think the 4 weight one will work fine. I am running 16" barrels with lightened buffer setup with 147 grain bullet in the 134PF range. Thanks, Eric

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I've shot both and for competition I prefer the 4 weight SCS. The 5 weight actually has more buffering potential beyond just the weights as the slide is made out of steel vs the aluminum of the 4 weight slide. The 5 weight actually felt softer to me but the dot moved way more and my double taps were usually alpha charlie instead of two alpha with the 4 weight at the same distance. If I was shooting recreationally, had a higher caliber gun like 40 or 45, or had a bolt that needed the weight removed to be compatible with a SCS I would run the 5 weight. 

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11 hours ago, nickbfishn said:

Eric, I went ahead and ordered te 5 spring kit and 3 steel weights based on your input the other day. I see you say you're shooting 147's at about a 134pf, care to share your load data?

nick

Hello: Sure, I am using 2.8 grains of Tite Group, Winchester small pistol primers, various brass, Acme 147grain bullet loaded to 1.145" OAL. These powders also work 2.8 Universal clays and 2.9 WST. This is in a 16" Wilson Arms stainless barrel.  I have also shot 124's but like the recoil impulse of the 147's more. Splits are the same for both on the timer. Thanks, Eric

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Update. 

Loaded 147 bayou bullets

3.0 n320

1.125 OAL

 

my setup is using the 9mm JPSCS II as is with no midofication.

 

the loads worked, but my dot movement was more with my reloads that they were with factory blazer 115 ammo. 

 

I shout about 50 of each and would even put 5 & 5 in the same mag to see if I was  hallucinating, but the factory moved less. 

 

To get even stranger, the factory had more felt shoulder recoil, but the 147's made the gun bounce more. 

 

Thoughts?

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115s are cycling the bolt faster. You are noticing more up and down with the 147s because the bolt velocity is lower.

 

If you lighten up the weights and or springs in your SCS the 147s can have the same dot movement with lower shoulder felt recoil. 

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On 6/17/2017 at 3:45 PM, MHitchcock said:

115s are cycling the bolt faster. You are noticing more up and down with the 147s because the bolt velocity is lower.

 

If you lighten up the weights and or springs in your SCS the 147s can have the same dot movement with lower shoulder felt recoil. 

I got my SS weights and springs in so now it's time to test and tune.

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On 6/14/2017 at 7:30 AM, Aircooled6racer said:

Hello: I don't know what the carrier weight is on the new buffer but I do know the weight of the weights. Tungsten weights are 1.4815ozs, steel weights are 0.6949ozs so you can figure out what the total of all the weights are for the two buffers. If you are running reloads get the 4 weight buffer and make it lighter. If you are running factory ammo in a 14.5-16" barrel I may think of getting the other buffer but still think the 4 weight one will work fine. I am running 16" barrels with lightened buffer setup with 147 grain bullet in the 134PF range. Thanks, Eric

Eric, this may be splitting hairs, but do you have a preference on where the 1 tungsten weight falls amongst the 3 SS weights? I'm sure it doesn't make a shits difference, but curious if you have an opinion on that?

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1 hour ago, nickbfishn said:

Eric, this may be splitting hairs, but do you have a preference on where the 1 tungsten weight falls amongst the 3 SS weights? I'm sure it doesn't make a shits difference, but curious if you have an opinion on that?

Hello: Curious that you should ask that. I did play around with moving the tungsten weight in different spots. I found that putting it in the first position towards the bolt worked the best for me. I think it has to do with the "O" rings taking up some of the shock as the buffer moves back. If you have time and like to tinker, try it in different positions to see what you like best. Thanks, Eric

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