20" AR different enough from 16" middy to justify buying?

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TrailWolf

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Hi all,

Looking for some next AR purchase advise.

I have an 11.5" and a 16" lw middy and just sold a second 16" standard profile middy due to an offer I couldn't pass up.

This leaves me with $$$ to pick up a third AR.

I originally got a second 16" middy because I thought having a backup AR to my other 16 " would be nice.

Now I'm thinking maybe variety is the spice of life and I should do a 20" rifle built as opposed to doubling up on 16" middies.

I have never shot a 20" ar but have read about how sweet shooting they are.

With that said, I have also read a lot that the extra 4" only gives a few hundred fps boost and that the difference is only worth it for shooting 400 meters plus. I also read that it's not that much softer than a 16 middy.

What say you guys? Is a 20" different enough than my 16" middy to make it worth it?

I don't really ever shoot past 100 yards, but I guess I am intrigued by the classics.

Not interested in other lengths or calibers.
 
IMO: if you don't have a 16" pencil barrel, light weight carbine?
Like a Colt SP1 carbine?

You don't have a 'classic' AR-15 yet.

rc
 
Well personally the 20 is my favorite AR size. I like to shoot irons and irons are all about sight radius. Plus it is nice to give the little bullet all the steam possible and to have the forearm room to stretch out a little.

I prefer a collapsing stock and floating handguard on my 20.
 
rcmodel said:
IMO: if you don't have a 16" pencil barrel, light weight carbine?
Like a Colt SP1 carbine?

You don't have a 'classic' AR-15 yet.

rc
Click to expand...

I guess I'm not really a purest - honestly the 16" length w carbine gas system does nothing for me - classic or not it doesn't give any advantage over midlength w 16".
 
Welding Rod said:
Well personally the 20 is my favorite AR size. I like to shoot irons and irons are all about sight radius. Plus it is nice to give the little bullet all the steam possible and to have the forearm room to stretch out a little.

I prefer a collapsing stock and floating handguard on my 20.
Click to expand...

Good to know - this is what I was thinking of doing - a C7 clone w the carbine receiver extension. Maybe go the vltor route.
 
I qualified expert on an M16 a few years ago, and I mean a few, eight to be precise. 300 meters (simulated on paper) I hit pretty well with irons. Now I have a heavy barrel 20" rifle. It's only an A2 now but I have a flat top ordered and on the way. Soon it will have an Aimpoint M2 that I've had sitting on a suppressed Savage Mk II of all things.

I started a thread a few days ago questioning the origins of the upper my wife and I built this rifle on. It shoots a foot high, but it shoots 1.5 inch groups at 100 yards with some reloads I have.

The 5.56 was made for the 20" barrel. Why not let it use it?

I figured I'd leave a picture here, everyone loves a picture.
Top to bottom:
Tikka T3 .270
Rem 700 30-06
M1 Garand
(Wife built) A2 HBAR 5.56 (awesome rifle!)

imagejpg1-1.jpg
 
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Well, variety does add spice to life, but for me it was more than merely buying a 5.56mm AR with a 20" tube attached. I've got a 9" SBR, 16" carbines of various makes, and an 18" SPR.

It was the old-school ("retro") look of this one, along w/ the 20" pencil barrel, that made the decision easy.

It's 1965 again, sort of ... :D

RetroAR-4.gif

:cool:
 
I think I don't even have a 16" AR, in 223 put together right now. I use e 18 and 20" AR's for a lot of stuff unless I want a "short" one the use the 10.5" because it is he same length as a 16" (with the suppressor) and doesn't require hearing protection.
 
I have a SP1 made in 1964 Serial # range low 6,000. Got it second hand in 1966. Years later picked up a 16 inch barreled carbine. Sold it as it just did not feel right, still have the black rifle, and would not own another shorty.
 
You will never get 3300 + fps from a 16 inch barrel. The smaller calibers are much more sensitive to barrel length and the 5.56 drops off a surprising amount between a 16" and a 20" barrel.
 
You will never get 3300 + fps from a 16 inch barrel. The smaller calibers are much more sensitive to barrel length and the 5.56 drops off a surprising amount between a 16" and a 20" barrel.
Click to expand...

.223 is affected about the same as other well balanced cartridges. Within the range of "normal" barrel sizes, you'll gain or lose about 25 FPS per inch. The charts above demonstrate this perfectly.

Below 12", the changes become a little more drastic. Likewise, longer than 24" will produce more modest gains. 18" to 22" is ideal for 55 or 62 gr 5.56 loads, and the average velocity difference from a 16" to 20" tube is about 100 FPS.

Also, you most certainly can hot rod the 5.56 to get 3,300 out of a 16" with 55 gr. Whether or not it's a good idea is a separate debate, but it can be done, and I have done it. So while it's really pushing the round and won't happen with factory ammo, to say never is foolish.
 
The 5.56 round was designed for a 20 inch barrel and that is optimum for many loads. It gives you the most range supersonic. I have both. For close range it is mostly preference. I like having both a 16 carbine and a 20 rifle. I like the rifle more as mine happens to be more accurate and gives me a little more effective range. Also the rifle has a smoother and more reliable action. Less problems with extractors and timing issues.
 
I like my 20" I put together. But I have never tried to clear rooms with it either. For a pure compromise I would go 16" with 62gr.
 
Also, you most certainly can hot rod the 5.56 to get 3,300 out of a 16" with 55 gr. Whether or not it's a good idea is a separate debate, but it can be done, and I have done it. So while it's really pushing the round and won't happen with factory ammo, to say never is foolish.
Click to expand...

This is also true.

When I was a kid, I loaded a 357 magnum to 41 mag levels, now that I have a kid I load a 44 mag to 41 levels.
 
The rifle length gas system in a 20" AR with a properly matched buffer weight in a rifle length buffer tube will be the softest shooting AR. Not that 5.56 has much for recoil, but when you are shooting a LWHV caliber then velocity is everything for maximizing fragmentation range and also minimizes bullet drop over long distances.

I've got a pair of 16" AR's and an unused lower that I'm thinking of building into a 20" A2.
 
In addition to all the practical issues mentioned, a pure M16A2 style 20" AR with government profile barrel is a dream to shoot. It is aesthetically pleasing and there are some intangible qualities that make it just nicer than many other configurations. It is heavy enough to be able to shoot well but light enough to carry easily. I would cheat on the trigger, though, and get a RRA match trigger. Nobody has to know.
 
You will never get 3300 + fps from a 16 inch barrel. .....
Click to expand...

I get 3300+ with 53gr TSX with CFE223 from a 16" Rainier Arms 5r polygonal barrel. I have chrono'd those velocities many times and consistently. It depends on load. I dont recall the exact charge, but it is on the high end of the safe charge. I dont get any signs or over pressure and i get very tight groups.

I do agree that it is less likely to get 3300 with 55gr and up from a 16".

I do like 20" ARs, but i found that they became safe queens. I sold my last one earlier this year. I now have 2 16" and a 10.5". My 20" ARs were National Match and the matches were so rare around here. If i wanted to build a precision AR, it would be a 20" heavy profile.
 
to me a 20" government profile is still heavy and profiled wrong. It has its weight at the end of the barrel. I would prefer a straight profile or pencil barrel. And this is for a carrying gun not a heavy varminter. For the heavy guns you lay on the hood, heavier the better.
 
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