AR barrel length

A suppressed 18" barrel will kill just as effectively as a suppressed 24" barrel out to 300 yards... there's nothing to debate. Anyone familiar with internal ballistics is aware barrel length effects velocity... there is no uniform formula to apply as each individual barrel can be different for obvious reasons. Personally, I've found the 18" barrel in the AR15 to be my sweet spot for weight, length, performance, and I love the overall look and feel of an 18" rifle.

The terminal effects are scientific in numbers and basically worthless in the field (edited to mean within the defined range of 300 yards).

A suppressor on a 22" barrel makes for a long stick... like mentioned earlier, how you will deploy the rifle might matter or it might not.

Congrats on the new can... what kind did you get? It should help increase accuracy, it's not uncommon to see a little improvement in the accuracy department, rare to see a loss of accuracy.

Look forward to a range report once you get it all together.
 
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alf said:
10-4.....

Another thought, there's tests done in the past cutting off a barrel an inch at a time, and the loss per inch in not linear in fashion. Some cuts lost very little, while others took a big jump. Who knows why, but it happens.
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Yep, kind of a "won't know until you do it" results.
 
Well back in the 80's I did run into a few guys running around with the Remington XP 100's shooting off the hood their trucks
Nothing wrong with that ...
 
old sparky said:
As I age things change. I have a 20" heavy barrel predator pursuit. I quit carrying several years ago. I started carrying a 16" A4 because it is light and quick. Then got a can for it. Back to not enjoying it. I just built a 11.5" AR pistol. My hope was to end up with a SBR. I built the pistol first to be sure it would be for me before getting a tax stamp. After getting it put together I am really happy with it! After sight in the first 100 yard groups were 1/2" and just under 3/4" with a really bad mil spec trigger. I know there will be a velocity loss and I am ok with that. I will shoot thru a chronograph to satisfy my curiosity.
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i was told by my local gunsmith that mil spec barrels will heat up pretty quick and some will start spreading groups because of the thin barrel. i switched to my heavy 223 wylde and my groups improved dramatically.

when sighting in a thin barrel he said its best to shoot a few rounds then wait 5 to 10 minutes to cool the barrel. when i did that my groups also stayed decently tight.
 
bohunr said:
i was told by my local gunsmith that mil spec barrels will heat up pretty quick and some will start spreading groups because of the thin barrel. i switched to my heavy 223 wylde and my groups improved dramatically.

when sighting in a thin barrel he said its best to shoot a few rounds then wait 5 to 10 minutes to cool the barrel. when i did that my groups also stayed decently tight.
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I wish I got into coyotes where I had to worry about heat. That would be cool
 
Ive hunted with 12.5" to 24" and it depends on where im hunting as to which rifle i take.
Slowly consolidated down and now i have 12.5" and 20". Seems like that was the best of both extremes.
 
joe777 said:
Forget about cutting the barrel, especially if its a known accurate barrel. You can buy a shorter barrel/upper for relatively cheap if needed, probably the same amount as cutting/re-crowning. Velocity loss and bullet drop will have essentially a negligible difference for hunting inside 300 yards. An 18" vs 24" 5.56/223 barrel could only have about 100fps difference.
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This is exactly what I'm doing. My 20" upper is way too accurate to mess with the barrel, and is also a little longer with my suppressor than what I prefer for carrying around the woods. I'm having a 16" upper being built now by Matt at DTECH that will be a very lightweight build. The vast majority of my shots are inside of 100 yards.
 
I just don't notice the difference between 18" barrel and 22" weight wise. I do notice a difference between types of stocks when adding a can to the barrel, mostly when on the shoulder/sling. Most of my winter day shooting is prone/bipod, barrel mass helps alot.
 
Like many have posted I've got several AR's from 24" to 14.5" in HB to M4 barrel profile weights. All but one is setup for a suppressor (the 24" HB setup for CMP competition).
Depending on what I'm actually doing drives which one I grab. The 14.5" M4 clone is handy for truck usage and walking through the PD fields. The 24" dedicated 1-12" twist PD gun is deadly on the PD's. Just a bit too long and heavy for field walking.
(and yes the HB don't walk as much under quick firing regiment as pencil barrels do)
Personally I would tell you to try with a open mind before a barrel swap and see if it actually needs to be shorter.

Although I am considering a BCA bolt action 10.5 upper to be re calibered in .221 with a SLeD device to add a top the 14.5" M4 clone (SBR)
 
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Barrel length and fps is dependent more on powder than the barrel. Most factory rifle loads are for long barrels, only part of the powder burns in the barrel for the 'shorties'. Thus lots of fps loss. Yes long skinny barrels have worse harmonics but that's accuracy, not fps.
 
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