JP silent captured spring

[Dolomite_Supafly]

You could try removing the pin and then removing the bolt weight. Most blowback carriers have the weight added after the fact and held in place with a pin.

The other alternative is to chuck the entire bolt carrier in a lathe and drill through the weight. I suspect when you hit the pin it will get difficult. I guess you could remove the weight and drill it separately then install two halves of the pin in so the rod can pass through it.

[Suputin221]

You could try removing the pin and then removing the bolt weight. Most blowback carriers have the weight added after the fact and held in place with a pin.

The other alternative is to chuck the entire bolt carrier in a lathe and drill through the weight. I suspect when you hit the pin it will get difficult. I guess you could remove the weight and drill it separately then install two halves of the pin in so the rod can pass through it.

I have considered doing this for my 9mm but the extra weight in the carrier is there for a very good reason. Removing it is a fairly bad idea. The extra weight is probably marginal for a 9mm and the 40 has even more recoil impulse so making the carrier lighter in that case is a really bad idea. The thing will just beat up the gun and have a ton of perceived recoil.

On top of that the JP silent spring system is made of aluminum which means it is nowhere near as heavy as a 9mm buffer. So that would reduce even more weight. If you got the JP system to work in a blowback 9mm the gun would beat itself to death and have a very heavy perceived recoil impulse.

In my case I built a silent spring "buffer" out of steel and it weighs just a wee bit less than a 9mm buffer so in that case it may be possible to drill out the carrier weight to get the thing to run. However I am not at the point where I am desperate to try this quite yet. I would probably make a second carrier weight so that if the experiment doesn't work out as planned I can reinstall the original weight.

[Hooz]

I've been kicking around the idea of making an SCS setup for my 9mm SBR. I'm going to see if using brass weights with a steel system will get the weight close to what I've got now with the buffer + carrier weight.

I'm also planning on making the sliding assembly longer to match the dedicated 9mm buffers (or carbine length buffers + spacers) out there to prevent bolt overrun.

Having a retired tool-and-die maker with a garage machine shop for a Dad has its advantages sometimes.

[ThreeHundredTraveler]

I ran the standard spring that came with the Captured Spring and it works fine with subs and supers. Running a AR-Stoner 16" carbine gas lightweight profile barrel, upper is a DPMS Slickside, Lancer mags and no muzzle device. It ran all factory ammo, subs and supers.

I then drilled the gas port to .125" and installed a Syrac adjustable gas block. I can now fine tune the rifle to a specific load with the springs and gas. The feel is similar to a typical space rifle. Now remember when fine tuning the rifle to a specific load, it does negatively impact the ability to quickly change the type of ammo you are running. I put the stock spring back in and tuned the gas block to run everything after deer hunting season, but I am sure I will take the time this spring to tune for both subs(UMC220gr) and supers(Barnes blacktips) again.

Let's say you settle on two types of ammo and you are not concerned about a couple hundred dollars. Since you remove that nasty little pointy thing in the buffer tube thread area anyway, couldn't you have two JPs ready to go for either load and a MicroMoa slide gas for one or the other. A few seconds and you are converted for the alternate load. And with the MicroMoa a no cycle at all setting too.

[talonxracer]

I ran the standard spring that came with the Captured Spring and it works fine with subs and supers. Running a AR-Stoner 16" carbine gas lightweight profile barrel, upper is a DPMS Slickside, Lancer mags and no muzzle device. It ran all factory ammo, subs and supers.

I then drilled the gas port to .125" and installed a Syrac adjustable gas block. I can now fine tune the rifle to a specific load with the springs and gas. The feel is similar to a typical space rifle. Now remember when fine tuning the rifle to a specific load, it does negatively impact the ability to quickly change the type of ammo you are running. I put the stock spring back in and tuned the gas block to run everything after deer hunting season, but I am sure I will take the time this spring to tune for both subs(UMC220gr) and supers(Barnes blacktips) again.

Let's say you settle on two types of ammo and you are not concerned about a couple hundred dollars. Since you remove that nasty little pointy thing in the buffer tube thread area anyway, couldn't you have two JPs ready to go for either load and a MicroMoa slide gas for one or the other. A few seconds and you are converted for the alternate load. And with the MicroMoa a no cycle at all setting too.

Yup, I know the preset positions on my gas block for either supers or subs, I put the buffer retainer back in so that I can use the JP for supers and a conventional buffer/spring for subs. A second JP CS buffer without the buffer retainer pin installed in the lower would be even easier as you mentioned.

[Suputin221]

I ran the standard spring that came with the Captured Spring and it works fine with subs and supers. Running a AR-Stoner 16" carbine gas lightweight profile barrel, upper is a DPMS Slickside, Lancer mags and no muzzle device. It ran all factory ammo, subs and supers.

I then drilled the gas port to .125" and installed a Syrac adjustable gas block. I can now fine tune the rifle to a specific load with the springs and gas. The feel is similar to a typical space rifle. Now remember when fine tuning the rifle to a specific load, it does negatively impact the ability to quickly change the type of ammo you are running. I put the stock spring back in and tuned the gas block to run everything after deer hunting season, but I am sure I will take the time this spring to tune for both subs(UMC220gr) and supers(Barnes blacktips) again.

Let's say you settle on two types of ammo and you are not concerned about a couple hundred dollars. Since you remove that nasty little pointy thing in the buffer tube thread area anyway, couldn't you have two JPs ready to go for either load and a MicroMoa slide gas for one or the other. A few seconds and you are converted for the alternate load. And with the MicroMoa a no cycle at all setting too.

I'm not familiar with how the spring is retained on the JP unit but I can change out springs on my unit in only a few seconds. So I have a couple of extra springs and can just change to suit whichever setup I am running.

[Suputin221]

Just for shits & giggles I added a Law Tactical folding stock knuckle to my 10" Blackout with the captive spring recoil system.

It seems to work fine. I left out the retaining pin so the captive spring system does drop out of the buffer tube a bit too easily. I may install the retaining pin but it is pretty nice to be able to pull it out so easily when I want to change the spring.







I def like the look of the gun with the stock folded although it is pretty wide.

[IslandTimes]

Just for shits & giggles I added a Law Tactical folding stock knuckle to my 10" Blackout with the captive spring recoil system.

It seems to work fine. I left out the retaining pin so the captive spring system does drop out of the buffer tube a bit too easily. I may install the retaining pin but it is pretty nice to be able to pull it out so easily when I want to change the spring.







I def like the look of the gun with the stock folded although it is pretty wide.

Wait, how does the bolt cycle with that setup? I thought there was a rod in the JP captured spring that goes into the bolt carrier when it cycles, which would be a problem since the law tactical adapter plugs up the back of the bolt carrier?

[Suputin221]

Wait, how does the bolt cycle with that setup? I thought there was a rod in the JP captured spring that goes into the bolt carrier when it cycles, which would be a problem since the law tactical adapter plugs up the back of the bolt carrier?

Benefits of having a lathe. I drilled a clearance hole through the middle of the plug for the guide rod.

[aleaddict]

Nice thread . . .

Can you tell me why there are two relief cuts in the body? I know one holds the retaining clip but what is the purpose of the 2nd cut? Thanks!