Need a adjustable .936 gas block

fleaman308

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Sep 25, 2007
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I need an adjustable .936 gas block. One that is easy to adjust, maybe a three position or more. Size is not a problem the gas block is out side of the forearm. Anyone with some ideas?
 
For factory production options...you've got a couple different models from JP Enterprises (a low-profile and one with a picatinny rail top section...since yours is outside the rail), as well as the one from PRI.

You may also be able to source a custom unit like the positional block you mentioned from Paladin Machine:

Paladin Machine Service
3832 Gates Ford Rd.
Kershaw, SC 29067

(803) 475-7542

No website...sorry. I may be able to find their e-mail...if I do, I'll post it for you, but they are GTG!
 
I recently had a JP .936 adjustable used in my 6mm Fat Rat build that you can see in a post I'm documenting elsewhere here on the Hide. It's typical JP quality so no issues with that but its mounted on a 2" extended gas system on a 26" barrel and even with it turned all the way down the action is cycling about as hard as I would want it to now without a suppressor so I'm thinking its going to be over gasses with a suppressor. I'm guessing the gas port is a little oversized in the barrel but I'm surprised I can't shut the gas down more with the gas block.
 
I recently had a JP .936 adjustable used in my 6mm Fat Rat build that you can see in a post I'm documenting elsewhere here on the Hide. It's typical JP quality so no issues with that but its mounted on a 2" extended gas system on a 26" barrel and even with it turned all the way down the action is cycling about as hard as I would want it to now without a suppressor so I'm thinking its going to be over gasses with a suppressor. I'm guessing the gas port is a little oversized in the barrel but I'm surprised I can't shut the gas down more with the gas block.

I believe they are 8-32 threads. Just run a bottoming tap in and youncan close it all the way.
 
I have 4 of the pri adjustable blocks and they work great. Everyone bitches about the screw backing out but the vibra tite that comes with it fixes all the problems. After 1000 rounds through my ar10 the screw has not moved at all.
 
Is that safe to do on the barrel or do I need to remove it? Just want to make sure the shavings aren't gonna clog anything...

I've done it on the barrel before, simply because it would have been a pain to remove with the way the upper was set up. The chips are nothing an air compressor can't handle.

For the record, I like the PRI better.
 
I recently had a JP .936 adjustable used in my 6mm Fat Rat build that you can see in a post I'm documenting elsewhere here on the Hide. It's typical JP quality so no issues with that but its mounted on a 2" extended gas system on a 26" barrel and even with it turned all the way down the action is cycling about as hard as I would want it to now without a suppressor so I'm thinking its going to be over gasses with a suppressor. I'm guessing the gas port is a little oversized in the barrel but I'm surprised I can't shut the gas down more with the gas block.


With the JP gas block you should be able to turn the gas all the way off to the point where you could run it like a straight pull bolt gun. If you cant do that then it is not installed correctly. You need to remove the gas screw and run a tap in through the gas block where the gas adjustment screw goes in. what you are doing is tapping the gas tube so the set screw can engage and then block the gas tube. Currently you adjustable gas block really isn't doing anything. Once you go though these steps you will find a huge difference in function.

link to JP instruction sheet:
http://www.jprifles.com/document_pdfs/JPGS8_522.pdf

This is the line that matters for you:
4. Make sure that the gas port in the gas tube is aligned with the gas port in the block. Then, run a 6-32 tap into the gas
screw hole to blend
the gas tube into the tapped hole and allow the screw to fully engage.
 
With the JP gas block you should be able to turn the gas all the way off to the point where you could run it like a straight pull bolt gun. If you cant do that then it is not installed correctly. You need to remove the gas screw and run a tap in through the gas block where the gas adjustment screw goes in. what you are doing is tapping the gas tube so the set screw can engage and then block the gas tube. Currently you adjustable gas block really isn't doing anything. Once you go though these steps you will find a huge difference in function.

link to JP instruction sheet:
http://www.jprifles.com/document_pdfs/JPGS8_522.pdf

This is the line that matters for you:
4. Make sure that the gas port in the gas tube is aligned with the gas port in the block. Then, run a 6-32 tap into the gas
screw hole to blend
the gas tube into the tapped hole and allow the screw to fully engage.


Thanks for the hot tip... Figured I should have actually read the instruction.
 
For factory production options...you've got a couple different models from JP Enterprises (a low-profile and one with a picatinny rail top section...since yours is outside the rail), as well as the one from PRI.

You may also be able to source a custom unit like the positional block you mentioned from Paladin Machine:

Paladin Machine Service
3832 Gates Ford Rd.
Kershaw, SC 29067

(803) 475-7542

No website...sorry. I may be able to find their e-mail...if I do, I'll post it for you, but they are GTG!

Here ya go. Call them directly.
 
I was looking at Paladin for a switchable gas block for a 0.875" barrel. Is the Paladin block heavy? Does it weigh any more than a JP or other low profile gas block?

They are not a lot heavier, but they are somewhat based on the fact that they are steel and not alloy and because they are somewhat larger in size than other blocks. I think my last 0.750" 3-position block from Paladin weighed around 4.5oz or so, but just remember when making comparisons that you look at the design, construction, features and materials used because not all blocks are created equal. ;)
 
They are not a lot heavier, but they are somewhat based on the fact that they are steel and not alloy and because they are somewhat larger in size than other blocks. I think my last 0.750" 3-position block from Paladin weighed around 4.5oz or so, but just remember when making comparisons that you look at the design, construction, features and materials used because not all blocks are created equal. ;)

Thanks. That is what I was curious about as they looked alittle heavier being steel and they look slightly more beefy. However, I do realize that you get some benefits from that slight extra weight as well.
 
Not the best photo but here's the Paladin 3 position on my Maten build.

ETA: it won't fit under a DD 7.62 Lite rail.

e74ae72331cec899cada90a1a18951b1_zps3d8559e7.jpg
 
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Not the best photo but here's the Paladin 3 position on my Maten build.

ETA: it won't fit under a DD 7.62 Lite rail.

e74ae72331cec899cada90a1a18951b1_zps3d8559e7.jpg

Where is the adjustment screw on the paladin block? I want a low pro .936 block with front adjustment screw and it looks like wilson combat is about the only (reasonable cost) choice. (To fit under a tube. Looking at JP/vtac style or Sampson Evolution 15" tubes for my LR-308 build with 24" Lilja).
 
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