AR build

1.) I am thinking of getting a 1/7 twist so I can use a heavy bullet if needed, is there alot of difference between the 1/7 and the 1/9?
2.) Midlength vs. Carbine - I have heard that the midlength is easier on the gun than the carbine thus making the parts last longer. I am leaning toward the midlength, I also like the look and the distance between the sights. I like to use irons instead of scope, there are no batteries that die at inopportune times in the irons.

I am debating between Palmetto upper and a Del-Ton upper as of right now, great prices for either of these.

Rich

 

A lot of holes in the desert, and a lot of problems are buried in those holes. But you gotta do it right. I mean, you gotta have the hole already dug before you show up with a package in the trunk. Otherwise, you're talking about a half-hour to forty-five minutes worth of digging. And who knows who's gonna come along in that time? Pretty soon, you gotta dig a few more holes. You could be there all fuckin' night.

I love this!

 

14.5" right? and also the standard mil round for 5.56 is a 62gr bullet, the proper twist for that is 1/7

1/9 twist is more of a commercial grade and can use lighter bullets. 55gr is the norm for this.

your on the right track. 1/7 twist midlength upper the midlength is suppose to run a bit smoother than the carbine.
http://palmettostatearmory.com/2533.php

what?

 

that's not true.... i've got a 11.5in bbl'd AR that's 1/7 twist and it shoots just as good as anything out there, it has nothing to do with barrel length

OP i wouldn't really worry that much about the twist rate, i have a few that are 1/7 twist, chrome lined and one that's 1/9 twist non CL they all shoot good, you can shoot 62gr no problem out of a 1/9 gun, 1/7 is good if you reload and want more head room to step up to say 69gr or mabye 77gr bullets

 

That was in someones sig that posted in this thread and it made me laugh.

 

Thank you all for the help so far!

 

This.
That post by WileyC is candidate for the TW Misinformation Hall of Fame.
If you're going to have a collapsible buttstock and combat optics, 69gr or 77gr are like tits on a boar....same for 1/7 twist.

 

you dont like tits on your boar hogs?

 

I can tell you this - all things being equal, you're going to have an easier time selling a 1:7" twist AR than a 1:9". 1:7" is the new hotness, and 1:9" is as old an outdated as a DPMS gun.

Whether or not it's a true advantage, it's seen as such, and therefore a benefit in the resale market.

 

unless you are selling it at a local gun show...dpms, bushmaster, stag, and armalite rule the roost when it comes to people who are uneducated about black rifles...and i doubt they will ever even think twice about what the barrel twist is.

 

misinformation, ..how so?...

1/7 is what the US military uses...

 

no, it's simple physics.. spin rate = function of twist rate of the rifling, and muzzle velocity... longer barrels are generally conducive to higher muzzle velocities, which, for a given twist rate, would produce higher spin rate (RPM)... thus, ...to stabilize a given round at a certain spin rate, ...the shorter barrel would need a higher twist rate than the longer barrel...

 

1) w/ a 1:7 you can shoot 55gr up to the heavier rounds 69gr, and some use even heavier for match competition.. 1:9 is good too, but not recommended for the heavier rounds (not enough stabilization, or spin rate - see my "contentious" post about the relationship between spin rate, twist rate and muzzle velocity.. 1:9 should be fine for the recreational shooter, especially if you hoard 55gr like i do

2) i have an AR in carbine lenght gas system, and one in midlength - so i will give you my opinion based on direct comparision.. go w/ the midlength! the midlenght is very pleasant to shoot, and the benefit of the longer sight radius is important to me!

 

I don't know how old you are but some of us bought our Bushmaster when all you had to choose from was Bushmaster, Colt or Armalite. My old A2 still puts rounds out the spout every time I pull the trigger. Only problems I have ever experienced is with particular magazines. I throw those away and use the ones that work consistently.

YMMV

 

I realize that

now days there are tons of companies that make AR's but your average joe doenst realize that. All they see is what you can buy at the big box stores and gun shows and that is usualy the above listed. therefor thats all they know of and if they havent heard of it then they probably wouldnt want it...


I bet I could go to a local gun show and sell a base model bushmaster faster than I could sell a BCM in the same configuration and same price.
the same goes for 1/7 twist and 1/9 twist...your average joe wouldnt think twice about what the twist rate is.

 

So to get this straight:
1/7 shoots anything you throw at it
1/9 shoots anything up to 69gr.
1/12 not recommended for 16in.

that about cover it?
Thanks,
Rich

 

That's why Remington sells so many more 770s than 700s. They are sold where people buy.

 

Ive never even seen a 1/12 barrel for an AR.

yup.
supply and demand. People want low cost with a name they know

This link is in regards to your bushmaster post.
http://www.m4carbine.net/showthread.php?t=7376

with this quote being the underlying statement

 

i'd say 1:7 is best for 55gr and up. i've heard of people trying to shoot fragmenting varmint rounds 50gr, and they disintegrate from the centripetal force caused by overspin (too high spin rate for the materials used)...

1:9 good for 55gr to 62gr, ..probably 69gr ok too.. ..and for fragmenting varmint rounds..

1:12 may only be available on certain 20" barrels... not sure about that.

some manufacturers may make a 1:8, ..that would be good..

 

I think 1:12 was used on the veitnam-era M16, ...since then they've gone to 1:7 on the M4 and M16A2, i believe..