I have owned/built at least 3-4 varmint style ARs in the past. They have all been sold.

I am decideing want to do another one.

I like shorter rifles, and would like to do an 18", but I also want the best accuracy that I can get out of an AR......

Would my best option be an 18", 20" or 24"........don't really want to go bull barrel diameter, would rather go heavy.

I am thinking 1 - 8 or 1 - 9 twist.

What will the longer barrels do what the 18" won't......help me decide which way to go.

Thank you!

Added: I plan to do alot of shooting at 100 yards, but also want the best it can be out to 300-400 for critters.

Between the 1 in 8 and 1 in 9 twist, i would go 1 in 8.  It will stabilize heavier bullets better than the 1 in 9.  I'm not sure if that's a concern to you but it's something to think about.

What is better for wind resistance at longer ranges, a heavier bullet that may be in flight longer, or a lighter bullet that will spend slightly less time in flight?

I am thinking that an 18" will do everything I want at the 100 yard mark, but I think (please correct me if I am off base) that the ballistics from the 20" and 24" may come into play at 300, 400, etc??

IMHO...20" barrel with 1x9 twist. for 62 grn or less bullets. Why do you need a heavy bullet to shoot ground hogs, prarie dogs, etc?? I got an AR with a 1x9 and it shoots 1/2" at 100yrds. off bench with iron sights, I have shot 75 grn Horn. also and they shoot well also. JMHO

Barrel Length has no direct affect on accuracy.

What a longer barrel gets you is a more velocity and therefore, longer effective range before the projectile slows down to below the speed of sound and becomes unstable.

Base your decision on barrel length on how far you want or need to shoot combined with your need for portability and intended use.

I have been doing alot of reading both hear and other sights on this, and have decided on an 18" barrel with rifle length gas system.

Would 1 in 7 or 1 in 8 be the best.......I plan to do alot of plinking with cheap old 55 grainers as well as work up some loads from 45 grain up to 60......I have no interest (now anyway) to go above that.

I am looking into the following barels....sorry for all the links:

Spikes Lothar Walther SPR barrel

WOA SPR barrel....down a few on the page

Rainier Arms Ultra Match

BCM 18" SS410

What do you think?

I'd go with a SS 18" 1/8 twist barrel.  Very versatile.

+1 on this.  I like to walk when I shoot and I got tiered of the length(weight didn't bother me) of the 24" rifles.  I have 16, 18 and 20" but I like the 20's the best-all have colapsible stocks.  My go to varmint round is 55gn Nosler Ballistic Tips over 25gn of H335 and I get an average of about 3050FPS on the chrono.  1in9" barrels seem to love this load on several differnt rifles I've tried it in.  The Pdogs, coyotes and deer in South Dakota HATE this setup!

I have the Rainier Arms Ultramatch 18" and am happy with it.  I have got about moa out of it without much load develpment.

From recent reading (more and more reading) it looks like I need 2 different uppers or barrels for two specific roles?

Varmint - Most highly explosive bullets designed for exploding prairie dogs are in the 40-55 grain range (with some exceptions) and from the info that I am seeing, a 1-12 twist would be perfect if that is what you want to shoot with the absolute best results. I assume the barrel length can still be 18" to 24"?

Long range Target - The best bullets that people rave about for getting out and touching someone are the 69 and 77 grainers. These bullets don't seem to be designed for much else then target (not great for prairie dogs). It sounds like you can do 1-7, 1-8 or 1-9, but 1-7 or 1-8 would be ideal.......again, it doesn't sound like barrel length is much of an issue....18"-24" should be great.

Would 1 -9, be a good all around gun that should do well with 50-77 grain bullets? I assume there is no magic answer that is PERFECT for 50 grainers and PERFECT for 69-77 grainers????

I have information overload.

+1.  I have well over 1k rounds thru my Rainier Ultramatch.  I'm not a great shot but I get MOA or better with off-the-shelf Fiochhi VMax 50.   With the right loads, the barrel is definately capable of sub-MOA.



Mega Monolithic Upper
Rainier 18.5 Ultramatch
Leupold Mark AR 3x9-40
UBR stock


Fiocchi VMax 50 at 100 yards.

I Shoot Yotes and Beldings.
I Prefer 1:8 or 1:9
I am an RRA fan, have had three and will be ordering anothe this week.
The Predator Pursuit and Coyote both have 20" HB, not Bull, so packing it around is not bad at all.
The Predator has a SS 1:8 and the Coyote a Moly 1:9
Both shoot well under MOA with 55gr. loads and under MOA with 40gr.
I have not shot any loads with bigger than 55gr. bullets so I can really commint on them, but 1:8 or 1:9 should handel up to 69gr. fine
If I was going to assemble the upper from scratch I would get  the "AR 15 Varmint Tactical" Lothar walther barrel atraight from LW.
I may just go this route instaed of the RRA Upper

LW Varmint Tactical Barrel


This is from my RRA Predator Pursuit:

What does this mean? Or did you leave something out....???

Your 1-8 should love heavy bullets......evidently they can shoot lighter ones well too.

Sorry, Forgot the "M"  in  "MOA"
Shoots the 40gr. under MOA, just not as well as the 55gr.

That is what i thought, but wasn't sure.

Well, before I buy anything (barrels......) I am going to load up some 40 to 69 grainers and run through my 16" 1 in 9 twist barrel and see if it shoots all of them accurately......at least try them at 100 and 200 yards.

Thanks.

tag for info... I want a 16 or 18 short barrel tack driver and I am currently overwhelmed with options...

Good Plan, however what Chambering are they ?
.223, 556, Wylde, this will make alittle difference.
If you plan to shoot the shorter lighter bullets, they will usually perform better from a 223, then Wylde chamber.
My have all been Wylde chambers.

18"Lothar Walthar.

There is a reason LaRue uses them. I have on in my SPR, its amazing!

The one I have is just set up as a carbine SHTF type M4ish.....good description

It has a 16" 1-9 YHM barrel with a 5.56 Chamber. I don't expect it do do anything great.......

Problem is that I live in ND and it is not a lot of fun to go bench shooting for another 4 months from now.

Where at in ND are you?

I wanna blast some critters...