Geisselles new SPR barrel with special gas system

[BurtG]

The hatefest between Bill Geissele and Mark Larue continues to be one of the silliest and most entertaining bits of AR mfg lore. I hope they never get over it.

Was not aware of that.

Only of Frank and mark

 

[B4forever]

Ripcord Gas Block; .750 | Ripcord Industries

LEAD TIME: Ships within 2-3 Business Days Our Gass Hole is now available for Criterion barrels with .750 gas block journals! There are a ton of gas block options on the market today. While some companies make better components than others & are better at consistently holding very specific...

www.ripcordindustries.com

This might be a decent option for a tight fitting gas block.

 

[Jsp556]

This a re-barrel or a whole new project Burt?

 

[Bigjake83]

Gas holes are. Special. View attachment 8630758View attachment 8630759View attachment 8630760


Contour seems perfect. AI barrel for comparison

View attachment 8630762

Good to see that the Gasport groove don't go all the way around so a clamp or set screw AGB should work perfectly, honestly I haven't had a recent Geissele barrel that was over-gassed.

The new Gas Port diameter on the standard Barrels are gauging at .075-.076

 

[TheOE800]

Is that a keyway for a tabbed gas block?

Edit: Must be for their shitty cast gas block which now has a dowel pin protruding from the rear https://geissele.com/super-gas-block-black.html

 

[Leicafan1990]

Gas holes are. Special. View attachment 8630758View attachment 8630759View attachment 8630760


Contour seems perfect. AI barrel for comparison

View attachment 8630762

Would you be able to measure the distance between the centers of the two gas block dimples? I’m curious what the size is. I’m sure they spaced them for their gas block but I’m not a fan of their block since it’s cast instead of machined. Hopefully there is another block that lines up.

 

[BurtG]

I see they have a heavy barrel & standard here:

https://geissele.com/upper-receiver-groups/5-56.html

But I can’t find the Geissele contour for the life of me.

Unless it’s this?

View attachment 8630169

Not a barfcom member BTW.

What year did you win the uppers?

Your uppers have the chrome lined barrels?

Yes CL. Won last year I think

 

[BurtG]

I would ask Geissele since they have the most experience with what makes those guns run.

They’re going to say to use their gas block, since they can’t control anyone else’s dims.

For me, I would want something press-fit, so I would spec the block to be sized to the journal.

Most of the after-market gas blocks have to be sized to slip-fit, otherwise they’ll be dealing with a high return rate on a low-cost part, which will make that particular SKU not generate revenue to justify it.

Measure the journal when you get it to see if it’s actually .750”, vs .7492” or something under-sized.

With 3 ports and the volume of the trench, any leakage will likely short-stroke the BCG.

You’ll want an efficient BCG too, not a sloppy nitrided cheap parts BCG that are all so common today.

as far as BCG I’m a fan of JP LMOS

 

[BurtG]

My tracking information has the barrels arriving on the 6th, I'll post pics with full details when they arrive.

I have everything needed to assemble them into complete Uppers.

I went with the following parts.

Vltor Mur FDE upper receiver for increased rigidity over the standard Geissele upper receivers.

Geissele FDE 15" MK16 Handguards.

Standard low profile Plain Jane Gas blocks, I would normally go with SA Set screw AGB but I'm sure as their standard Barrels are gassesd perfectly it won't be needed.

I'll try the Geissele Gas Blocks but the pre drilled pinning hole gives me pause for potential gas leaks, I won't know my options until I have the barrels but I'll demonstrate on here what will be best suited for this application in full detail.

( When I do a finally assembly I always seal my Gas Systems with Loctite 620, the gas tube is sealed in the Gas block and the Gas block is fully sealed around the gas block journal.)

Geissele Ambi FDE Charging Handle.

For BCGs I pick up to different types.
(1) BCM in FDE
(2) Superlative Arms FDE Carrier and JP bolt kit with Springco Gas rings.

Let me know if you have any specific questions or concerns and I'll do my best to address them.

Also one of these complete Uppers will go to the PX.

Jake

Why not an enhanced upper

 

[Leicafan1990]

Ripcord Gas Block; .750 | Ripcord Industries

LEAD TIME: Ships within 2-3 Business Days Our Gass Hole is now available for Criterion barrels with .750 gas block journals! There are a ton of gas block options on the market today. While some companies make better components than others & are better at consistently holding very specific...

www.ripcordindustries.com

This might be a decent option for a tight fitting gas block.

Finding a tight fitting gas block can be a crap shoot in my experience. I don’t even worry about it anymore. If you do have a loose fit where the block slides around with little resistance, you can easily fix it by sealing it with Loctite 620.

Here is the method that I use that works well for me. I haven’t seen any carbon leaking from my gas blocks after applying the Loctite this way.

First, apply a thin bead of Loctite 620 around the barrel, directly in front of the gas block shoulder but behind the gas port. When you slide on the gas block, the rear of the gas block will be sealed. Don’t pull the gas block forward because you don’t want to smear the Loctite over the gas port.

Next, use the gas block set screw hole that doesn’t line up with the gas port hole. You are basically using this set screw hole as an access port to apply Loctite around the circumference of the barrel. Spin the gas block around the barrel, dabbing a small amount of Loctite 620 through the set screw hole, at a few different positions around the barrel. Then, spin the gas block around a few more times to spread out the Loctite. You’ll want to clean out the excess Loctite from the set screw threads before installing the set screws.

If you do it right, you’ll get a thin layer of Loctite behind and in front of the gas port that will seal everything up once cured.

EDIT: I also apply some Loctite 620 to the gas tube, behind the gas port hole, before sliding the tube into the gas block for pinning.

 

[TheOE800]

Giving away secrets in this thread now are we?

 

[Leicafan1990]

Giving away secrets in this thread now are we?

I think @Bigjake83 has also posted pictures or explanations of how he seals his gas blocks. This is just a simple method that has worked for me. If it doesn’t 100% seal everything up, it will get you 90% of the way there and carbon will quickly seal up any remaining leaks.

 

[TheOE800]

It was tongue in cheek. 620 is wicking grade though and you should be able to apply it through the front of the gas block and gas tube (if block has open front).