Criterion barrels videos

[survivalshop]

 If you get emails from Criterion Barrels , you already saw this , but if you didn't , hear is a four part series on how to help get better accuracy from your rifle , builder or not . Most here know most of this stuff , but there are some things you may not .

 

Edited July 11, 2017 by survivalshop

[98Z5V]

This is good stuff.  Thank you Criterion. 

Oh, and ss! 

[survivalshop]

5 hours ago, 98Z5V said:

This is good stuff.  Thank you Criterion. 

Oh, and ss! 

Did you notice the Loctite 609 sleeve retainer they used on the Barrel extension ?  Your thoughts ?

[98Z5V]

1 hour ago, survivalshop said:

Did you notice the Loctite 609 sleeve retainer they used on the Barrel extension ?  Your thoughts ?

I did see that - I've never used that stuff so I'll have to check into it more.  I've heard of people stating to use red Loc-Tite installing barrels (Loc-Tite 271 permanent thread locker) and that's not a wise move...

 

EDIT - This might be worth trying...

Loctite ® 609™ Retaining Compound, Cylindrical bonding

Loctite ® 609™ is a low viscosity, rapid-curing anaerobic adhesive that augments the strength of press fit assemblies or slip fit assemblies up to 0.005"in diameter. Adds up to 3,000 psi holding power. Recommended for parts that will need subsequent dismantling, i.e., retention of bearings onto shafts and into housings.
Technical Data:
Typical applications: Augment press fits
Viscosity: 125cP
Cure Time: Fixture - 10 minutes Full - 24 hours
Max gap fill: 0.12mm
Temperature resistance: 150°C
Shear strength: 15.8 /mm2

Edited July 12, 2017 by 98Z5V

[survivalshop]

3 hours ago, 98Z5V said:

I did see that - I've never used that stuff so I'll have to check into it more.  I've heard of people stating to use red Loc-Tite installing barrels (Loc-Tite 271 permanent thread locker) and that's not a wise move...

 

EDIT - This might be worth trying...

Loctite ® 609™ Retaining Compound, Cylindrical bonding

Loctite ® 609™ is a low viscosity, rapid-curing anaerobic adhesive that augments the strength of press fit assemblies or slip fit assemblies up to 0.005"in diameter. Adds up to 3,000 psi holding power. Recommended for parts that will need subsequent dismantling, i.e., retention of bearings onto shafts and into housings.
Technical Data:
Typical applications: Augment press fits
Viscosity: 125cP
Cure Time: Fixture - 10 minutes Full - 24 hours
Max gap fill: 0.12mm
Temperature resistance: 150°C
Shear strength: 15.8 /mm2

 There are four videos in that series I posted , it goes from one to another , it was in # 3 that they talked about installing the Barrel . Makes me wonder about its use , they talk about Harmonic's & Vibration ( about the some thing ) , stiffer bond between two dissimilar Metals ?

 This is the Loctite I have & have used it on AR's , but not Barrel attachment , Maybe I should try it , Loctite 638 Retaining Compound . http://www.loctite.com.au/3320_AUE_HTML.htm?nodeid=8802627616769 

Edited July 12, 2017 by survivalshop

[98Z5V]

12 hours ago, survivalshop said:

 There are four videos in that series I posted , it goes from one to another , it was in # 3 that they talked about installing the Barrel . Makes me wonder about its use , they talk about Harmonic's & Vibration ( about the some thing ) , stiffer bond between two dissimilar Metals ?

I went straight through all 4 of them  - good stuff.  Pleasure to "meet" Josh, finally, and now Mike.    They've got it right, and used the terminology "308AR" when referencing the Large Frame ARs.  They knows what's up. 

It's awesome to see barrel manufacturers talking about this stuff, finally.  First the stuff from Nathan @ Faxon, and now this collection from CBI - all of it is invaluable information.  Excellent work, gentlemen. 

I think CBI is using this Loc-Tite 609 in the way that its intended - but for firearms.  It's for sealing bearings onto shafts, or into housings.  It fills a gap of up to 0.005", and makes the bearing more "solid" in an otherwise "loose" mount.  Bearings will last longer, because they're in a more solid mount, and won't suffer as much from vibration - which WILL kill bearings.

In the firearms-use instance, it's being used to create a solid bridge between a barrel and upper receiver, if such a need is there.  Tight barrels-into-receivers won't need this.  If you can drop your barrel right into your receiver, I can see this helping - cut down vibration.  Vibration is harmonics. 

I can see this stuff working, for exactly what they're using it for, and I'm going to try it on the Mk12 Mod 1.  I'll even try it on the 13.5" 308 3-Gun carbine.  I'll shoot both first, get those barrels worn in, and get accuracy groups.  I'll take them apart, use the 609, and get more accuracy groups.  I'm saying now, though - the Mk12 Mod 1 barrel is a tight fit in the AP upper receiver...

Edited July 13, 2017 by 98Z5V

[mineralman55]

I've got three Criterion barrels installed (two M1 Garands and an AR15). They are superb, no doubt about it.

A number of AR15 builders I know insist on using blue Loctite on the barrel when installing it, saying it takes up the gap between the barrel extension and the upper receiver. All mine have required a heat gun to expand the upper just enough to slip in the barrel, so I've personally never done it.

[survivalshop]

   I guess we could think that a tight fit may not need it , but now I may be thinking a little differently , why , because of two dissimilar metals with two different expanding qualities . Not only that but just because a Barrels extension goes in tight , doesn't necessarily mean it is tight the total circumference . Gaps may not let it expand uniformly , with a sealer /filler involved , it would be more uniform & more predictable with regards to expansion .

  Then you have the Vibration or Harmonics involved , opens up a whole new aspect . 

  I should of used this stuff on all the old four speed Tranny's I have rebuilt , with all their Ball, roller & Bushing type Bearings . I did use the Loctite 638 on Stainless Steel Revolver Cylinder Shims ( 0,004" )  I installed on the SI Defense Billet Upper to CMMG 308AR Billet lower Receives Pivot pion area , probably not the correct application , but it worked to hold them in place for assembly , because they Upper /Lower receiver fit was snug , but not tight & took out all play , not sure if they are still locked onto the Upper Receiver, because I no longer own the rifle , but a friend owns it, so I could look if he brings it back for any mods.or service.

Note , this was all to help the Rifle with the original gun. Mags ., which it did a little , but not completely , L 7's & Gen 3 PMags fixed the FTF  issue .

 

[mineralman55]

Isn't the red Loctite "permanent". Wouldn't you rather go with blue if you anticipate ever taking the barrel off?

[survivalshop]

  This can be removed by heat or their solvent , at least thats what their sight reads . If it was permanent , how would you replace a Bearing that this Retaining compound was used on , its for replaceable Bearings , Sleeves , Wearing Rings type applications . I have an Upper Receiver that I'm switching out this week for a Neighbor , going to use this product .

  This stuff is not Red , its Green in color .

Edited July 14, 2017 by survivalshop

[98Z5V]

11 hours ago, mineralman55 said:

Isn't the red Loctite "permanent". Wouldn't you rather go with blue if you anticipate ever taking the barrel off?

That's the red Loc-Tite 271 you're talking about.  242 is the blue stuff.  Both are for securing fasteners.   There's so damn many types of Loc-Tite it's not even funny.

[392heminut]

I don't know what number it was, but a friend of mine that ran an automotive machine shop used a green Loctite on cylinder liners when he drove them into the engine blocks. He swore by that stuff.

[Flabbergasted]

Joe Carlos who writes articles for the American Gunsmith Association has been using Loctite and shim stock when installing barrels for quite some time. He's conducted his own tests and has noticed accuracy increases when he uses it. 

I've used loctite 620 on one of my builds due to the barrel fitting loose in the upper. It shoots well. Not sure if it is due to the loctite or not. I have removed a barrel with after the loctite has cured. It sucked. Had to use a heat gun and beat the barrel out of the upper, but it came out.

 

[98Z5V]

I wouldn't piss around with any green loc-tite, no matter what the number on it - that's the shiit that the Japanese motorcycle manufacturers use on footpegs bolts - that you cannot get out without a healthy dose of MAPP gas.  I'm not putting that on a barrel, no way, no how. 

Suzuki had a footpeg bolt recall around 2012, and we had to replace all the footpegs bolts in GSX-R sport bikes - I've done enough of them that I can say I hope I never see another one again...

Edited July 20, 2017 by 98Z5V

[survivalshop]

  I used the LocTite Retaining Compound on my Barrel install with the 25-45 Sharps Barrel swap from my BRO Receiver set ,onto the FDE Aero Upper . The Extension was real tight at first , then after a couple test fits to see how many Shims I would need to align the Gas Tube hole for the Aero HG Barrel Nut ( ended up using none of the supplied Shims & went past their recommended max Torque  ) the fit was a little more snug then tight . I was going to use the Loctite anyway , so we will see how it works .