Question Pin and welded CA legal SBR

[KH7500]

I have been wanting to build an AR with less than a 16” barrel. For example: a 11.5” barrel with a pin and welded KAK industries slim extended flash can which is 5” bringing it to about 16.5” OAL does anyone have experience doing something like this with their rifles? Are there any cons to it?

 

[Stratego]

The cons are typically incredible muzzle blast and poor ballistic performance from a shorter barrel. Otherwise it’s great fun. Highly recommend doing this with modern cartridges that can get decent performance out of a shorter barrel such as 300blk.

 

[KH7500]

The cons are typically incredible muzzle blast and poor ballistic performance from a shorter barrel. Otherwise it’s great fun. Highly recommend doing this with modern cartridges that can get decent performance out of a shorter barrel such as 300bl

The cons are typically incredible muzzle blast and poor ballistic performance from a shorter barrel. Otherwise it’s great fun. Highly recommend doing this with modern cartridges that can get decent performance out of a shorter barrel such as 300blk.

Thank you, taking that into consideration I decided to try it on my 9mm rifle just to make it a home defense/ fun range gun

 

[Mongoose913]

You could also build a pistol lower and run any length at that point. There are a few FFLs that specialize in AR pistol lower builds.

 

[Ryan Gosling]

I have been wanting to build an AR with less than a 16” barrel. For example: a 11.5” barrel with a pin and welded KAK industries slim extended flash can which is 5” bringing it to about 16.5” OAL does anyone have experience doing something like this with their rifles? Are there any cons to it?

cons - stuck with a certain gas block unless you use a clamp on or use a smaller diameter muzzle device, pick the right one beforehand. Stuck with a muzzle device. Significantly reduced internal fragmentation (see chart) on target at range, and penetrative power on armor/cover. Turns into a flashbang for those around you. louder. Worse recoil due to shorter gas tubes, also causing significantly more wear and carbon on your internal parts (gun needs to get as much gas as it can, faster, before bullet leaves barrel)



Pros- less weight, possible better balance, much easier to work inside a vehicle or doorway. Those long ass retro KAK flash hiders make an AR sound like an AK

My verdict- Short barrels are not so nice in this state since we cant use suppressors here (yet) and making a pistol is expensive. An inch or 2 is not gonna be the difference keeping you from navy seal type performance. stick with a 16 unless you have a specific use case in mind.

 

[Funjeff]

I would suggest a 13.7" p&w build for a rifle, and/or purchase a pistol register semi-auto lower if you want to build a pistol.

 

[Stratego]

If you are doing a 9mm build, just do it as a pistol and make it a 7-9” barrel. Braces work great. Don’t bother with 11”+, you get nearly all of your velocity by 9”: http://www.ballisticsbytheinch.com/9luger.html

 

[Plenty_Pack_556]

Get it done by someone that can walk the talk.

I had my 10.5 7.62x39 upper p/w by a well-known socal gunsmith, and through reddit gunowners, realized the 7" brake was angled downward off end of barrel by about 10 degrees because the bubba decided to use a used crush washer.

 

[AR15barrels]

I have been wanting to build an AR with less than a 16” barrel. For example: a 11.5” barrel with a pin and welded KAK industries slim extended flash can which is 5” bringing it to about 16.5” OAL does anyone have experience doing something like this with their rifles? Are there any cons to it?

Make sure you check your math.
Thread length is typically 5/8" so that 5" long muzzle device overlaps the barrel by 5/8".
To figure out your actual length, use the barrel length minus thread length and then add muzzle device length.
Using your 11.5" and 5" example, you are about 1/8" short of 16".

I do perm attach jobs if you need someone to make your upper legal.

 

[AR15barrels]

Get it done by someone that can walk the talk.

I had my 10.5 7.62x39 upper p/w by a well-known socal gunsmith, and through reddit gunowners, realized the 7" brake was angled downward off end of barrel by about 10 degrees because the bubba decided to use a used crush washer.

10 degrees is a LOT.
Like a lot more than normal thread fit would even allow.
Did someone thread your barrel with a die?
That's the only way I have seen threads cut so crooked on a barrel.

I have had lots of people send me barrels that were screwed up after being threaded with a die.
The fix is to shorten the barrel some more and then lathe cut proper threads on the barrel that are concentric with the bore.

 

[ar15robert]

imo if your gonna pin and weld to bring it to 16 inches might as well go with a 14.5 and a muzzle device. You’ll get the full effect of the longer barrel and either way you’ll need to be 16inches minimum.

Not sure if pistol build is a go in ca anymore unless you know something.

I have a 10.5 sbr and I wanted it short so chose the 10.5 since it’s about as short as you wanna go with 5.56. But there is quite a bit drop off vs a 14.5 too.

 

[Ryan Gosling]

Get it done by someone that can walk the talk.

I had my 10.5 7.62x39 upper p/w by a well-known socal gunsmith, and through reddit gunowners, realized the 7" brake was angled downward off end of barrel by about 10 degrees because the bubba decided to use a used crush washer.

dm who

 

[Walmart_AR15]

Ah, its no longer a SBR if the fixed barrel length is > 16". Unless you are going for looks, why would you intentionally give up a few inches of barrel performance when the end result is still > 16". Now of course if you want EXACTLY 16" then pin and weld is the way to go. And AR15 Barrel is your guy if you are in SoCal.

If you really want a short barrel, then spend the time and money and find a pistol lower and build yourself a pistol. (Remember to follow the AW chart).

 

[AR15barrels]

dm who

Stop protecting bubba and protect forum users from bubba instead.
Post his response publicly.