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Old September 5, 2017, 06:43 PM   #1
Astocks2622
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Flash can muzzle slightly short of handguard

I'm putting together my first AR pistol, and have to into a slight problem. I have a KAK 8.5" 300BLK barrel, Micro Flash can, and 10" ALG handguard. The handguard hasn't arrived yet, but when I threw the flash can on the barrel, I'm only measuring about 9" from the barrel shoulder to the muzzle of the can. If I've done my math right, including the .45" it upper barrel threads with are also covered by the handguard, this will put the handguard forend about 3/8" forward of the flash can muzzle.
1st, did I forget anything in my dimensions that means the can will end up flush out beyond the guard?
2nd, assuming the can muzzle is slightly (3/8") short of the handguard, do I actually have an issue? The flash can is designed as a forcing cone, directing blast and gasses forward, not up or sideways. I've seen pictures of guys blowing their handguards apart with a compensator under it, but will a flash can do the same thing over time?
Worse comes to worst, I can buy the standard length Slimline flash can and have a full inch beyond the guard.
Thanks for your help!

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Old September 5, 2017, 10:59 PM   #2
44 AMP
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I freely admit I don't know the specifics of the parts you are talking about, but, consider this, powder gas erodes STEEL. It eats steel barrels, over time.

Anything projecting beyond the muzzle will eventually be damaged by powder gas, and if its not steel to begin with, the process could happen fairly soon.
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Old September 6, 2017, 12:39 AM   #3
Astocks2622
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I know. That's what's got me worried! I wouldn't even think about it if it were a normal muzzle device. Watching videos of the KAK flash cans, it looks like almost all of the gasses are forced into a cone beginning several inches from the muzzle. Anyone have experience with this issue specifically?

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Old September 6, 2017, 06:50 AM   #4
stagpanther
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Carbide tipped radial saw blade from home depot and 10 seconds later your handguard problem solved.
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Old September 6, 2017, 08:21 AM   #5
zukiphile
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The issue I foresee isn't the safety of an aluminium handguard (another of which can be purchased), but the safety of peoples' hands. That it is a "handguard" will suggest to people that it is reasonable to place one's hands anywhere on the guard.

You would not like to hand this to someone only to have him place his hand in a manner that would leave him injured.
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Old September 6, 2017, 08:38 AM   #6
Fishbed77
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Quote:
Carbide tipped radial saw blade from home depot and 10 seconds later your handguard problem solved.
Or just order a longer muzzle device.
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Old September 7, 2017, 06:22 AM   #7
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Don't let your digits overhang the handguard!!!!!!!!!!
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Old September 7, 2017, 06:23 AM   #8
stagpanther
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Don't let your digits overhang the handguard!!!!!!!!!!
Unless you want to convert one to a front sight.
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Old September 7, 2017, 10:49 AM   #9
Astocks2622
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Originally Posted by stagpanther View Post
Unless you want to convert one to a front sight.
Or a rear peep sight, if you use a small enough cartridge...
I ordered a longer flash can. We'll see how close the shorty comes to the end if the guard when it gets here.

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Old September 8, 2017, 01:10 PM   #10
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Ive personally blown plywood apart with a brake, take a 4" chuck out of one layer at a time. An aluminum handguard would fair better but not by much. Get the longer muzzle device once you get the handguard in...hand.

Btw, I did this when building my AR9. Oops.
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Old September 8, 2017, 02:55 PM   #11
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I would say to go for the longer slim flash can, if you need the slim one that is. Otherwise you could just get the standard kak flash can.

If you are correct and the micro ends up being a bit short and ending slightly inside the hand guard, not only will you have "concerns" regarding safety and possible damage to the hand guard, but it will just look funny too. If you spend the $20-$30 to buy the longer one you wont have to worry about anything and it will look better.

If you decide to do that, let me know, I might buy your micro from you if you want to get rid of it cheap
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Old September 9, 2017, 12:28 PM   #12
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Yeah, it's definitely too short. The longer can and buis should be here Monday.

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Old September 9, 2017, 05:26 PM   #13
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ditch the rail for a proper length one.
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Old September 9, 2017, 07:14 PM   #14
Astocks2622
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Originally Posted by stagpanther View Post
ditch the rail for a proper length one.
Nope. This is the shortest rail if this design ALG makes, and is the style I want. I'll just throw on the flash can that's 3.25" instead of the 1.75" one. That will put the muzzle 1" forward of the rail.

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Old September 9, 2017, 10:28 PM   #15
stagpanther
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Nope. This is the shortest rail if this design ALG makes, and is the style I want. I'll just throw on the flash can that's 3.25" instead of the 1.75" one. That will put the muzzle 1" forward of the rail.

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Proper length rail seems to me to be a better alternative than "compensating length" compensator or suppressor--but I have no experience with such arrangements. I have also never seen a weapon configured that way, either. Good luck.
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Old September 10, 2017, 12:12 AM   #16
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You could save yourself the $ from the new muzzle brake and just buy a suppressor, of all the reasons to buy one, this seems pretty high up there.
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Old September 10, 2017, 10:11 AM   #17
Astocks2622
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Hmm, I don't think the wife will buy that one...
"Honey, I saved $35 by buying a $600 suppressor, (plus $200 for the tax stamp)"

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Old September 11, 2017, 01:55 PM   #18
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Ive got a kak blast diverter laying around Ill sell ya. Pretty sure its the long regular sized one, ie not slim.
1/2 36 iirc
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Old September 12, 2017, 08:30 PM   #19
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All set with the new flash can. It looks better and no worries about blowing my rail apart. I also put on an afg, mostly to prevent unintentional perforation of my digits. I'll throw pics up when I get home. I did have some failures to feed with the new pistol, but I'll start a separate thread on troubleshooting that.

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Old September 12, 2017, 08:58 PM   #20
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Here are the pics.

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Old September 12, 2017, 09:19 PM   #21
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Looking good, Astocks2622

https://www.youtube.com/watch?v=XtKydtoLucc
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Old September 14, 2017, 12:22 AM   #22
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My 8 1/2" barrel 300 Blackout pistol with a full length hand guard and Faxon " loud mouth" brake is quite enjoyable to shoot and I have never come close to putting my hand too far forward on the guard. The top of the rail is raised and has a sight on it the bottom has a rail section for the adding of accessories, both let the hand know how far forward it is.
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Old September 14, 2017, 02:44 AM   #23
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What does a "flash can" do, anyway?
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Old September 14, 2017, 09:40 AM   #24
Astocks2622
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Originally Posted by armoredman View Post
What does a "flash can" do, anyway?
Mostly just directs the sound and flash forward instead of up or back like a compensator or flash hider.

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Old September 14, 2017, 10:59 AM   #25
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Hmmm--kinda counter-intuitive for a short-barreled AR no?
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