View Full Version : Low Profile Pinned Gas Block?
Does anyone know where I can get a low profile pinned gas block that will replace a standard Front Sight Base. It needs to fit under a rail (Daniel Defense, Larue, etc.). The only ones I have seen are all set screw or clamp on type. I don't trust anything other than a true pinned gas block, because I have seen several set screw gas blocks come loose. Thank you for your help.
Robb Jensen
12-15-08, 10:44
None would work. They'd have to offer several variations of the same thing. When barrels are made the FSB and barrel are drilled for the pins. So the exact locations of the pins varies from manufacturer to manufactures and varies even from the same manufacturer.
Deskjockey
12-15-08, 10:49
I apologize in advance for the hijack.
Rob, on my 10.3" that you have seen, I am interested in the DD Omega 9.0 and removing the FSB and going to flip-ups.
Can you simply replace the FSB with a Lo-Pro Gas-Block, or would you have to grind down the FSB as it is already pinned for that Colt barrel and can't be replaced?
Also, would DD Omega work in this configuration?
Thanks,
Tyler
Robb Jensen
12-15-08, 11:05
I apologize in advance for the hijack.
Rob, on my 10.3" that you have seen, I am interested in the DD Omega 9.0 and removing the FSB and going to flip-ups.
Can you simply replace the FSB with a Lo-Pro Gas-Block, or would you have to grind down the FSB as it is already pinned for that Colt barrel and can't be replaced?
Also, would DD Omega work in this configuration?
Thanks,
Tyler
I do the 'shave' of the FSB to make them fit under rails. All three of my SBRs have 'shaved' FSB and are held on by the factory/OEM 2 pins. A lo-pro gas block can be used instead and then drilled and pinned but it costs more. An Omega rail has very little room under it. I have done one like that for a fellow M4C member but it's not going to be easy to ever remove the 'shaved' FSB because I had to grind the pins down so everything is flush.
I had to 'shave' it while it was still attached to the barrel because it's a CMMG 14.7" barrel with a perm. attached A2 flash hider. It's also a .625" barrel and I'm not even sure if I could get a .750" barrels FSB small enough to fit under there. There's only a very small amount of free space between the one I did on the .625" barrels gas block.
I'd suggest a 9" Lite Rail. That's what I have on my 10" SBR.
http://img.photobucket.com/albums/v408/gotm4/shavedFSB/shavedFSB4.jpg
http://img.photobucket.com/albums/v408/gotm4/virginiaarmspics/omega12147three.jpg
Deskjockey
12-15-08, 12:38
Everywhere is out of the 9.0 Lite. Rob, would the DD Mk II RIS for the Mk18 Work? Found one of those.
Robb Jensen
12-15-08, 13:00
Everywhere is out of the 9.0 Lite. Rob, would the DD Mk II RIS for the Mk18 Work? Found one of those.
Should be fine, that's what the Mk18 RIS II was designed for (a 10" upper), the MK18 RIS II are 9.5" rails, that's the rail that's on my 12.5" SBR.
G&R built up some nice ones.
https://www.m4carbine.net/showthread.php?t=8207&highlight=Mk18
Robb Jensen
12-15-08, 13:07
Does anyone know where I can get a low profile pinned gas block that will replace a standard Front Sight Base. It needs to fit under a rail (Daniel Defense, Larue, etc.). The only ones I have seen are all set screw or clamp on type. I don't trust anything other than a true pinned gas block, because I have seen several set screw gas blocks come loose. Thank you for your help.
Here's some other pics of some that I've 'shaved'.
This LMT has a 12" Troy over it with an ARES piston conversion.
http://img.photobucket.com/albums/v408/gotm4/virginiaarmspics/adfe3166.jpg
http://img.photobucket.com/albums/v408/gotm4/virginiaarmspics/dd656eec.jpg
http://img.photobucket.com/albums/v408/gotm4/virginiaarmspics/881e696c.jpg
This Bushy barrel has a 12" Troy rail mounted over it.
http://img.photobucket.com/albums/v408/gotm4/virginiaarmspics/3gunrifles014.jpg
My now 12.5" Bushy barrel under a Mk18 RIS II rail.
http://img.photobucket.com/albums/v408/gotm4/gunpics/IMG_6025.jpg
http://img.photobucket.com/albums/v408/gotm4/gunpics/IMG_6028.jpg
http://img.photobucket.com/albums/v408/gotm4/gunpics/IMG_6023.jpg
http://img.photobucket.com/albums/v408/gotm4/gunpics/sbrs24.jpg
I guess the only viable option would be to shave the fsb. What do you use to cut and grind, a dremel? On a side note- if you can't get a shaved fsb under a Daniel Defense Omega rail, what rail would you recommend? I really want one that has quick detach swivel cups with rotation limiters. I currently have a 7" DD Omega rail and I like the swivel cups.
Robb Jensen
12-15-08, 19:24
I guess the only viable option would be to shave the fsb. What do you use to cut and grind, a dremel? On a side note- if you can't get a shaved fsb under a Daniel Defense Omega rail, what rail would you recommend? I really want one that has quick detach swivel cups with rotation limiters. I currently have a 7" DD Omega rail and I like the swivel cups.
I use a plasma cutter, die grinder and a grinder, then sandblast and refinish with Norrels along with the barrel.
I recommend the DD Lite Rail or RIS II rails or a LaRue. The newer LaRue rails have them built in. You can bolt on a DD QD sling mount onto any rail.
Deskjockey
12-15-08, 19:37
Dude, looks great.
Rob, what would be the turnaround if I order and get the RIS this week?
Thanks.
Just a big recommendation for Rob's work. He shaved down the FSB on my LMT 10.5" SBR and installed a 9" LaRue rail. Looks and works great.
I've shaved several gas blocks as well and agree that this is the best route when looking for a lo-pro gas block. I used a hack saw to make the big cuts, and a dremel and hand file to round it off. I just paint them with hi-temp grill paint when I'm done.
In the white
http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/IMG_0896Small.jpg
Inside a DD M4 rail
http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/IMG_0898Small.jpg
Finished gun
http://i134.photobucket.com/albums/q111/rob_s/gun%20stuff/6933-01.jpg
Verbal Kint
12-16-08, 04:23
I've seen your handy work, in previous posts regarding your low pro gas blocks, but never commented before. I must admit the finished product looks very nice and, more importantly, the fit and function is top notch.
Awesome job, Rob.
Thanks for the ideas. I have the metal working skills (used to be an iron worker), I was just wondering if there were any other options. I have been looking at Troy MRF rails- mainly the 10" version. Does anyone have an opinion on that rail with a shaved fsb? The main reason for the Troy is the fact that I don't want to mess with disassembling the barrel (I don't have a barrel wrench or armorer's block). My other favorite would be a DD Lite Rail.
Verbal Kint
12-16-08, 18:55
Thanks for the ideas. I have the metal working skills (used to be an iron worker), I was just wondering if there were any other options. I have been looking at Troy MRF rails- mainly the 10" version. Does anyone have an opinion on that rail with a shaved fsb? The main reason for the Troy is the fact that I don't want to mess with disassembling the barrel (I don't have a barrel wrench or armorer's block). My other favorite would be a DD Lite Rail.
This isn't a slight towards you, at all, so please don't take it that way... but whenever I hear people basing their components off of not having the tools to install them, I cringe.
If it was a KAC URX rail, requiring the $400+ tools (or however much the two tools cost now) that would be one thing. But you're talking about a barrel wrench and block... and possibly a strap wrench and torque wrench if you don't have those / can't borrow or rent them.
You obviously have the skills, from what you said above, and the competence to do the work. With the small cost of needed tools, compared to the expense of the rails you're looking at, I'd go with whatever you really want... and pick up any needed tools.
Plus, you're a guy... you can't have too many tools. ;)
Robb Jensen
12-16-08, 20:44
Dude, looks great.
Rob, what would be the turnaround if I order and get the RIS this week?
Thanks.
A week or less. :D
I've shaved several gas blocks as well and agree that this is the best route when looking for a lo-pro gas block. I used a hack saw to make the big cuts, and a dremel and hand file to round it off. I just paint them with hi-temp grill paint when I'm done.
I did exactly the same thing.
A word of note, the Larue rails are a really tight fight. It took cycles of grind, fit, grind, fit, grind, ad naseum.
If you want to keep the FSB available for a configuration change you can use a low pro gas block and pin it. Only thing is you will have a pin groove exposed when you put the FSB back on. YHM makes a nice low pro block for $20 and its a lot less work to drill a pin then hack a FSB all up.
I use this jig (http://www.rainierarms.com/?page=shop/detail&product_id=1089,my design) to dimple the barrel to align the block. Then its a matter of setting it up ind a mill or drill press. I drill in the center of the block with the bit 50% in the barrel and 50% in the block. Drill with a #31 bit, I use a cobalt jobber bit and ream with a 2/0 taper reamer to fit the pin. For the gasblocks a 3/4" long 2/0 will work and can be trimmed (length) up to fit as needed.
Deskjockey
12-21-08, 16:43
Well,
I dropped off my 10.3" Colt upper to Robb on Wednesday, he had the FSB "shaved" on Thursday and the the rail mounted on Friday.
I went with the 9.5" DD Mk II Ris from Rainier. I added a set of Troy FDE Flip-ups, from LaRue. They turned out to be 15.00 cheaper than any were else. All vendors were excellent and extremely timely.
For anyone that has never met, spoken, or had Robb do some work for you, he is excellent people. I highly recommend him for anything that you need done, and I highly recommend Virginia Arms for your needs in NoVA.
I am in the process of moving, so I will post picks once I get settled, but thanks Robb. Appreciate it.
Robb Jensen
12-21-08, 18:33
Thanks for the nice words. It truly does look friggin' bad ass!
Thanks for the nice words. It truly does look friggin' bad ass!
How about a photo then? :cool:
Robb Jensen
12-22-08, 04:52
How about a photo then? :cool:
I didn't have a chance to get some pics, it's been stupid busy at the shop and I don't bring my camera with me to work everyday. Sales are up about 60% in the shop I work in.
Deskjockey
12-29-08, 16:14
Here are some photos. Just note that A) the gun is used alot and B) I suck when it comes to photos.
http://i89.photobucket.com/albums/k232/truffleshuffle_1980/SBR1.jpg
http://i89.photobucket.com/albums/k232/truffleshuffle_1980/SBR3.jpg
http://i89.photobucket.com/albums/k232/truffleshuffle_1980/SBR2.jpg
http://i89.photobucket.com/albums/k232/truffleshuffle_1980/SBR4.jpg
http://i89.photobucket.com/albums/k232/truffleshuffle_1980/SBR5.jpg
Awesome. The well used look is fantastic.
Does anyone know where I can get a low profile pinned gas block that will replace a standard Front Sight Base. It needs to fit under a rail (Daniel Defense, Larue, etc.). The only ones I have seen are all set screw or clamp on type. I don't trust anything other than a true pinned gas block, because I have seen several set screw gas blocks come loose. Thank you for your help.
i suggest chopping the FSB down and reshapping it in to a low profile. nothing a Dremel and some time can't take care of just go slow and be careful.
My take.
How to taper pin a gas block (http://www.jobrelatedstuff.com/forums/topic.html?b=3&f=4&t=416100)
Less work and cleaner look then chopping a FSB. You can also reuse the FSB on that barrel if you wanted to in the future but you would have an extra taper pin groove. ;)
I've never installed a LP gas block before, what is the best way to make sure the gas holes are perfectly aligned? I'm thinking about going to flip sights on the front, I was reading this thread about the shaved fsb, and now trying to figure out should I shave mine or just buy one, and who makes a good gasblock that seems secure better then others?
Thanks
I've never installed a LP gas block before, what is the best way to make sure the gas holes are perfectly aligned? I'm thinking about going to flip sights on the front, I was reading this thread about the shaved fsb, and now trying to figure out should I shave mine or just buy one, and who makes a good gasblock that seems secure better then others?
Thanks
Read the link in my post above yours.
Read the link in my post above yours.
Are all aftermarket gas blocks have the same set screw spacing as the jig in the link, or is the jig for only a certain brand gas block?
Robb Jensen
01-29-09, 21:31
Are all aftermarket gas blocks have the same set screw spacing as the jig in the link, or is the jig for only a certain brand gas block?
On most the rear set screw is in the same position or close enough to work most of the time. On some it is not and causes problems. However your FSB 'shaved' will always have the same taper pin holes as it did as a FSB when you remove it 'shave' it and reinstall it.
Just sayin'............;)
On most the rear set screw is in the same position or close enough to work most of the time. On some it is not and causes problems. However your FSB 'shaved' will always have the same taper pin holes as it did as a FSB when you remove it 'shave' it and reinstall it.
Just sayin'............;)
I'd venture a guess and say all of the rears are in the same location since the gas port in the gas block is drilled through this hole. The jig uses the pointed set screw into the barrel gas port to align. The front hole varies (Vltor and Larue are the same, PRi is very close but not quite)
The shaved FSB is a strong way to go if you don't grind too much away. I don't like it since I like the option to go back to a fixed FSB in the future, tough to do it if you grind it up. For me it's less work to pin on Vltor block then hack and refinish a FSB but I have the tools to do it too. It's all good. :D
Are all aftermarket gas blocks have the same set screw spacing as the jig in the link, or is the jig for only a certain brand gas block?
The jig was designed around the Vltor and LaRue which have the same spacing. The PRi I tried was close but not quite the same.
Since the gas port is drilled through the rear hole all of the gas blocks I've seen have the rear set screw hole in the same location, right below the gas port. The jig uses a pointed set screw tightened into the barrels gas port to align itself.
Just wondering which would be better other then a shaved front sight, a low profile with set screws or a low profile with clamps? to me seems like the clamp style would be a little stronger and easily adjustable if ever needed especially if the set screw style was not dimpled right from the get go. I'm just trying to figure out which one would be more feasible for me, I plan on putting ona troy free float, so I trying to figure out which one would fit with no probles and very little chance of moving on me.
Robb Jensen
02-02-09, 06:05
Just wondering which would be better other then a shaved front sight, a low profile with set screws or a low profile with clamps? to me seems like the clamp style would be a little stronger and easily adjustable if ever needed especially if the set screw style was not dimpled right from the get go. I'm just trying to figure out which one would be more feasible for me, I plan on putting ona troy free float, so I trying to figure out which one would fit with no probles and very little chance of moving on me.
A low profile with a set screw AND a pin is the best way if not using a shaved FSB, this is why Noveske gas blocks are set up this way.
Set screws would hold a gas block for most people especially if its covered by the FF tube/rail, but if you to be damn sure it can't/won't move then pin it. As long as you know or the person doing the work knows what they're doing you'll be good. It's stupid simple to remove a FSB and shave it and reinstall it. You can't misalign it and you don't need a gig.
I noticed that www.specializedarmament.com is offering 'shaved' FSBs as an option. Ken Elmore must believe as I do that the FSB from the factory is the most reliable......I'm just sayin' ;)
I agree with GotM4 that the shaved FSB is the best option.
Mike,
Thank you for your interest in Daniel Defense and our products. While our gas block will fit, it doesn't fit well. With the limited amount of space under the Omega Rail, I recommend that you consider the CMMG Micro low profile gas block. If you have any more questions, please feel free to contact me.
Best Regards,
Joe Marler
Sales Representative
This is in reguards to the Question ,
What gas block will fit under an omega rail
comp1911
I am impressed with the ease of your dimpling jig. I just ordered one from Rainer Arms. My weapons are more of a hobby for me and I like the options of varying the configurations from time to time and feeling like I have a brand new rifle. I was not able to find your pinning jig for sale and was wondering if you could point me in the right direction. Ialso look forward to seeing your fsb jig soon.
comp1911
I am impressed with the ease of your dimpling jig. I just ordered one from Rainer Arms. My weapons are more of a hobby for me and I like the options of varying the configurations from time to time and feeling like I have a brand new rifle. I was not able to find your pinning jig for sale and was wondering if you could point me in the right direction. Ialso look forward to seeing your fsb jig soon.
The pinning jig is still under development I guess. I got the water jet sample last week and with a little file work looks like it is viable. Problem is the waterjet vendor has not given me a price yet. I also need to hone my machining skills if I'm going to do the machine work myself. Most likely I'll try to sub it out though. Once everything falls together, it looks like Rainier may be the dealer for these as well.
As far as the FSB jig, the job shop I use is getting busy and the proto type gets bumped down the production line. I did make a change to the design to simplify things so hopefully that will get bumped through.
Thanks for your comments. Stay tuned. :)
well after reading this thread I decided to go ahead and shave my fsb, one thing I was wondering and this is for either gotm4 or rob_s on the bottom where the taper pins go do you think the corners on it should be shaved as well or will they be ok to fit into a troy 10", I havn't received the troy rail yet waiting for the delivery man, so I went ahead and shaved the fsb to get it ready, but in some photos here I see the corners shaved all the way around and on rob_s it looks like he left the corners intact, I copied the pics and circled where I am talking about.
http://i2.photobucket.com/albums/y17/jedimac/shavedFSB4.jpg
http://i2.photobucket.com/albums/y17/jedimac/IMG_0896Small.jpg
Has anyone shaved their fsb and installed a troy rail over it? if so did it have good clearance?
Robb Jensen
02-13-09, 05:07
Just round the edges well and the shaved FSB will fit under the Troy rail well. The tightest spot inside the Troy rails is the wide of the gas block at the top of it. Just make the front and back edges the same width as the middle spot and it'll fit. Be sure to remove enough metal where the supports were as well.
The reason the one I shaved for a DD Omega looks like it doesn't have taper pins is because that one has a perm. mounted A2 flash hider and is 14.7" long making it 16". The Omega has very small inside dimensions.
Just round the edges well and the shaved FSB will fit under the Troy rail well. The tightest spot inside the Troy rails is the wide of the gas block at the top of it. Just make the front and back edges the same width as the middle spot and it'll fit. Be sure to remove enough metal where the supports were as well.
The reason the one I shaved for a DD Omega looks like it doesn't have taper pins is because that one has a perm. mounted A2 flash hider and is 14.7" long making it 16". The Omega has very small inside dimensions.
Thanks gotm4, appreciate the info. I'll post some pics of my build when I get it finished.
Well with the help of you guys on here and grant at G&R, my first fsb shave went smoothly and heres the results of the build I was working on. I would like to thank everyone who helped me out with your knowledge and grant for awesome products.
http://i2.photobucket.com/albums/y17/jedimac/IMG00015.jpg
Robb,
How much would it cost to have my FSB shaved, rail installed, and a new FH installed ??
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