# 100 yards,, 1-7 or 1-9 twist?



## budgetprepp-n (Apr 7, 2013)

Hi
Hey I'm still gathering parts for my buddies build and he is not a long time shooter or 
an expert shooter. The main shooting he will be doing for enjoyment will probably be about
100 yards. From what I have red it looks like a 1-9 twist with a lighter bullet like maybe 55Gn 
would be more accurate than the 1-7 with a 62gn bullet. Is this true?

Also on ammunition when it's listed as "match grade" does that mean that it's better than
regular production ammo for accuracy? 

I know that some of my questions may sound really basic but I like to confirm what I learn
as I go. So if you don't mind bear with me. I don't want to be one of those guys that 
don't have a clue but for some reason don't want to ask a simple question.

He wanted to know what I wanted for helping with his first AR- I told him I wanted
him to join the NRA. One more voice


----------



## Kauboy (May 12, 2014)

At 100 yards, twist won't matter much. You'll hit what you aim at.

When dealing with twist, you also have to consider the length of barrel. What are you putting in this build?


----------



## budgetprepp-n (Apr 7, 2013)

Kauboy said:


> At 100 yards, twist won't matter much. You'll hit what you aim at.
> 
> When dealing with twist, you also have to consider the length of barrel. What are you putting in this build?


Just a 16" maybe a wylde barrel 
And when shooting longer than 100 yards which would be best 1-9 or 1-7 ?


----------



## Hemi45 (May 5, 2014)

Twist correlates more to weight than distance. If shooting 69-77 gr bullets, you'll want to go 1/7. If you'll not be shooting below 55 gr bullets that 1/7 should still serve you well enough but the 1/9 will be more accurate at longer ranges.

I'll add that when looking beyond AR's and into 'precision' .223 rifles, you'll see a lot of 1/9, some 1/8 and nearly no 1/7. If I wanted a precision AR and was building it from the ground up, I'd use a 1/8 bull barrel and split the difference.


----------



## Operator6 (Oct 29, 2015)

Basically the heavier the bullet the faster the twist rate.


----------



## dsdmmat (Nov 9, 2012)

Go for 1-8 you won't stabilize 77-80 grain bullets but you will be good for almost everything else you find.


----------



## GrumpyBiker (Nov 25, 2015)

Up 62gr bullets 1:9 will do just fine !
Over that weight 1:7 is the preferred twist.
The National Match barrel in my Predator AR is 1:8 stainless with a Wylde chamber.
Super tight at 300yds . 
But I don't use anything over 62gr in any of my ARs.


----------



## AquaHull (Jun 10, 2012)

1:12 will stabilize 62 gr FMJ,not SS109, 1:9 is good up to 69 gr SMK's.
My 1:12's are more accurate at 100 yds than my 1:7 with M193( 55 gr FMJ). All 3 are 20" Colt barrels


----------



## Slippy (Nov 14, 2013)

I actually set up a bench vice for this experiment some time a while back. At 100 yards there was very little noticeable difference and I wish I had been able to do this experiment at 300 yards. But I didn't. I did come away feeling better about only using 62 grain 5.56 in my 1-7 barrels...but by no means wouldn't turn down some .223 55 gr if someone were to give them to me free.

Below is a short article conducted by the Lucky Gunner Labs. I think Smitty or someone posted some military stats on this a while back too.

Good luck
https://plus.google.com/+LuckyGunner/posts/ZZPNiRXyqYm


----------



## AquaHull (Jun 10, 2012)

Slippy said:


> I actually set up a bench vice for this experiment some time a while back. At 100 yards there was very little noticeable difference and I wish I had been able to do this experiment at 300 yards. But I didn't. I did come away feeling better about only using 62 grain 5.56 in my 1-7 barrels...but by no means wouldn't turn down some .223 55 gr if someone were to give them to me free.
> 
> Below is a short article conducted by the Lucky Gunner Labs. I think Smitty or someone posted some military stats on this a while back too.
> 
> ...


That sums up my experience


----------



## bigwheel (Sep 22, 2014)

A hundred yards if for pistols. Straighten up.


----------



## txmarine6531 (Nov 18, 2015)

At 100 yards, the difference between the two doesn't amount to a hill of beans. The determining factor should be the purpose of the rifle. A 1:7 will let you use heavy bullets, up to around 80gr, anything higher than that a 1:6.5 or better is needed. A 1:9, I wouldn't take it past a 69gr. A 1:8 is a good all around twist rate, you'll be able to shoot a wider variety of bullets. The heavier bullets will get you better ballistic coefficients. A Berger 55gr has a BC of .210, a Berger 90gr has a BC of .551 which is awesome for a .224 bullet. Match grade ammo is of higher quality than standard ammo. The components are better and more attention is paid to putting it all together.


----------



## AquaHull (Jun 10, 2012)

I have a pre-order in for a 1:14 20" pencil barrel


----------



## Farva (Aug 26, 2015)

As others have said, at 100 yards it probably isn't going to matter, annnnndddd, it's a weight thing.

I personally wouldn't go under 50gr on a 1/7
and wouldn't go over 55gr, maybe 62 on a 1/9

Not dangerous or anything like that, just useless. In either case your POI will change enough to notice.

I got my .224 education on,
.223
220 swift 
22-250
22 hornet

Doesn't mean I know bupkus, just what I saw during my varmint reloading days.


----------



## M118LR (Sep 19, 2015)

budgetprepp-n said:


> Hi
> Hey I'm still gathering parts for my buddies build and he is not a long time shooter or
> an expert shooter. The main shooting he will be doing for enjoyment will probably be about
> 100 yards. From what I have red it looks like a 1-9 twist with a lighter bullet like maybe 55Gn
> ...


XM193 Ammo, 55 Grain FMJ for the AR Rifle. Circa 1960's, was considered Inhumane.(Killed to well inside of 100 Yards)With a twist rate of 1:14 or 1:12. But the NATO Standard M855 required a twist rate of 1:9 to stabilize and puncture a NATO Helmet. Need to make a 5.56 round perform (not quite a 7.62 NATO Round) in an arena dominated by 7.62 NATO folks?
About your "Match Grade" question? Can we discuss a "Match Grade Shooter"? 
Did you mention terminal effects? 
I might have forgotten your Original question.


----------



## shooter (Dec 25, 2012)

i have an Ar in each of the 3 "fast twist rates" 1:9 1:8 1:7 The 1:9 and 1:7 are both 16" barrels the 1:8 is a 20" barrel. 

The 1:9 is a tac driver for (sub moa) 55g rounds at 100 yard and can shoot the varmint round that are 45 and 36 grains pretty well, the 62g rounds hold up but I do see a small widening of the group, 1.5 - 1.25 moa) but its not enough to worry about unless you want nothing but clover leafs. The groupings seem to hold up at longer rangers 200 and 250 yards. (on this rifle i have a 3-16 scope so its easy to see the target at longer ranges which helps keep the groups tight) I have not shot much of my hand load 69g or 77g stuff from this rifle but the manuals all say that as long as it has a 1:10 or better it should shoot the 69g okay and a 1:9 should shoot a 77g okay.

The 1:7 has a red dot w/ a 3X magnifier on it. It shoots the 62g well and if I put a real scope on it I am sure it would be a tac driver with those 62g rounds. the 55g rounds seem to be a bit wider but nothing to major. the 36 and 45gr stuff some to really not hold up well. But when I fired my handload 69g and 77g stuff the groups are really tight. At least for a red dot with a 3x on it. Sorry can't really give you moa here as the red dots don't allow the accuracy of the more powerful scopes.

My 1:8 20" barrel loves the 69g and 77g stuff. I have noticed that the cheap 223 55g stuff shoots a little over 2 moa and the 55g 5.56 cheap stuff shoots 1.75 moa which is more then good enough, for most plinking and training. The 62g 5.56 shoots about 1.5 to 1.25 moa (and I am sure with hand loads both could shoot better...) I bought some Nosler SSA 77g and it shoot near clover leafs with this stuff. And some Hornady 75g stuff shot around 1 moa. My hand loads for 77g and 69g are cloverleafs. I once tried shooting some 45g stuff and it was not pretty. I think it was 3 to 4 moa and I never really tried it again after that. 

So what does all this mean. If you shooting the cheap milsurp 556 or cheap 223 stuff any one of those twist rates works. If your shooting varmints alot with the 45 or 36g stuff from time to time look at the 1:9 if you like shooting some heavier stuff from time to time look at the 1:7. If you see one at a super great price buy it, unless your a sharp shooter or are wanting to shoot over 300 yards it probably wont matter as all the groupings would hit a 18"x24" target which is all that matters....


----------



## budgetprepp-n (Apr 7, 2013)

M118LR said:


> XM193 Ammo, 55 Grain FMJ for the AR Rifle. Circa 1960's, was considered Inhumane.(Killed to well inside of 100 Yards)With a twist rate of 1:14 or 1:12. But the NATO Standard M855 required a twist rate of 1:9 to stabilize and puncture a NATO Helmet. Need to make a 5.56 round perform (not quite a 7.62 NATO Round) in an arena dominated by 7.62 NATO folks?
> About your "Match Grade" question? Can we discuss a "Match Grade Shooter"?
> Did you mention terminal effects?
> I might have forgotten your Original question.


Sure we can talk about a match grade shooter if you want to but,,

My question was what is match grade ammo? Is that like the best for companionship events?

I want to thank everyone for there input,, Very helpful while learning. Thank you


----------



## Montana Rancher (Mar 4, 2013)

My understanding is 1:8 is the the military standard, then you can shoot the 55gr or the 62gr with little or no sight adjustment


----------



## AquaHull (Jun 10, 2012)

Montana Rancher said:


> My understanding is 1:8 is the the military standard, then you can shoot the 55gr or the 62gr with little or no sight adjustment


And


----------



## dsdmmat (Nov 9, 2012)

budgetprepp-n said:


> Sure we can talk about a match grade shooter if you want to but,,
> 
> My question was what is match grade ammo? Is that like the best for companionship events?
> 
> I want to thank everyone for there input,, Very helpful while learning. Thank you


Match grade ammo is designed to be consistent. Usually loaded with a bullet that has a good ballistic coefficient (BC) and good quality brass cases. It is supposed to be the most accurate load that the manufacturer offers. YMMV


----------



## LunaticFringeInc (Nov 20, 2012)

For what its worth to you....My 1-9 twist barrel will stabilize and accurately shoot most 53 gr bullets and those up to and including the 69gr SMK. Beyond those 2 extremes accuracy starts to fall off considerably as the bullets deviate from those two extremes more. Although not a AR...my 224 TTH build on a Mauser Action with a 28 inch barrel has a 1-6 or 1-6.5 twist rate and wont stabilize anything under 75grs very well at all. But load it with a Lost River Ballistics 80gr bullet and push it out at 3600 fps and its a tack drive out to 400 yards. Its pretty over bore for a 22 though so I don't think the barrel will last very long and its pretty demanding on the bullets you use making it a pretty pricey option to shoot much.

I would look more at the ammo you plan to shoot and then get a barrel with a appropriate twist rate based off that criteria and go from there. That being said if I was going to shoot bullets from 55 to 69 I would go 1-9. Not gonna shoot anything over 62grs go with a slower twist. Wanna shoot bullets heavier than 69grs I would opt for 1-8 or possibly 1-7. But that's just my opinion.


----------



## Smitty901 (Nov 16, 2012)

If you want to punch holes in paper at 100 yards maybe the 1-9 is for you. If you want the rounds you shoot to stop a man then 1-7. The twist also effects how the bullet acts. Often the one that punches the best hole does not do the best job of stopping the target.


----------



## M118LR (Sep 19, 2015)

budgetprepp-n said:


> Sure we can talk about a match grade shooter if you want to but,,
> 
> My question was what is match grade ammo? Is that like the best for companionship events?
> 
> I want to thank everyone for there input,, Very helpful while learning. Thank you


dsdmmat gave you a pretty good answer. Match grade ammo will be constructed from the upper tier components and will be designed to be as consistent from round to round as possible. That isn't to say that it will be the most accurate ammunition for your particular rifle at a particular distance. But Match Grade ammunition will have the lowest deviation rates that the manufacturer can design within cost factors. When it comes to which twist rate and chamber (Since we are talking about 5.56/.223) a Match Shooter will select based upon the style of match and distance. Yes there is a specific match chamber (PTG 223 Reminngton Match) and it is usually mated to a twist rate that is optimum for the projectile that will be used within the selected competition. Since NATO has made the M855 (62 Grain) 5.56 round a standard the arms manufacturers have attempted to optimize 20 inch barrels with a 1:9 twist rate. Back when the XM193 (55 Grain) 5.56 round was used 20 inch barrels had either the 1:14 twist used by bench shooters in rifles of 20 inches or more, or the 1:12 twist rate which became standard for 20 inch barrels. The general rule of thumb today is to go with the fastest (1:7 vice 1:14) twist rate available as long as you don't use extremely low weight highly frangible projectiles that could be adversely effected by the higher rotation stress.This will allow longer heavier projectiles to stabilize along with standard weight projectiles. As long as you use 55 grain to 77 grain standard rate fragment-able projectiles the 1:7 twist rate will allow you the greatest variety of standard weight Military style projectiles. All that being said, the tightest groups shot with 55 grain .223 ammunition came from 20+ inch 1:14 twist rate barrels at the 50 and 100 yard range. 300 and 600 yard matches regularly have perfect rounds shot with 62-63 grain projectiles, and at distances beyond 600 yards 77 grain projectiles or heavier are usually used. Hope that helped.


----------



## alterego (Jan 27, 2013)

Please note the grain weight of average rounds at your average store for reasonable price. Most that I have observed are 55 grain


----------



## txmarine6531 (Nov 18, 2015)

55gr and 62gr are the most commonly available commercial rounds that I've seen. Just about every other bullet weight is going to be sold as reloading components. Right around the $10 mark for a 20 round box of 55gr.


----------



## RedLion (Sep 23, 2015)

My understanding and take is that you can not go wrong with 1/7 twist regardless as most barrels in 1/7 will shoot pretty much all .223 bullets well.


----------



## AquaHull (Jun 10, 2012)

69 SMK's out of a 1:12 will ruin someones day for sure

Yes I've tried getting them to group on paper. Tried.


----------



## txmarine6531 (Nov 18, 2015)

RedLion said:


> My understanding and take is that you can not go wrong with 1/7 twist regardless as most barrels in 1/7 will shoot pretty much all .223 bullets well.


It will pretty much. If you shoot too light weight of a bullet, like less than 45-50gr, you can start running into over stabilization.


----------



## Hemi45 (May 5, 2014)

txmarine6531 said:


> 55gr and 62gr are the most commonly available commercial rounds that I've seen. Just about every other bullet weight is going to be sold as reloading components. Right around the $10 mark for a 20 round box of 55gr.


Actually, I've been buying several brands of 69, 75 and 77 grain online lately. Usually $20-25 for a box of 20 cartridges. Not cheap but the better things never are.


----------



## txmarine6531 (Nov 18, 2015)

Hemi45 said:


> Actually, I've been buying several brands of 69, 75 and 77 grain online lately. Usually $20-25 for a box of 20 cartridges. Not cheap but the better things never are.


Those are naturally going to be more expensive, the heavier bullets are going to be of better quality. I was just talking about basic ammo for training/plinking. Where do you buy yours online? I'm an admitted fan boy of Midway USA. They carry the new IMI ammo. Prices aren't bad at all IMO.

IMI Ammo 5.56x45mm NATO 62 Grain M855 SS109 Penetrator Full Metal


----------



## Hemi45 (May 5, 2014)

^^^ The last few places I bought heavyweights from and even hit sales were:

Cabela's
Joe Bob Outfitters
PSA


----------



## GTGallop (Nov 11, 2012)

Twist rate and bullet weight are more related than distance. Next is barrel length.


----------



## RedLion (Sep 23, 2015)

txmarine6531 said:


> It will pretty much. If you shoot too light weight of a bullet, like less than 45-50gr, you can start running into over stabilization.


I guess that the lightest that I ever shoot is 55grn and that is not too often. Mostly 62grn and up.


----------



## txmarine6531 (Nov 18, 2015)

55 would be the minimum for a defensive round for me. I have some 40 and 45's that I was testing for varmint loads for my Savage bolt action 223. They were actually pretty durn accurate, just don't trust them for a long distance shot. I have some 70gr Berger LVD's and Nosler 69's I need to load up.


----------



## SecretPrepper (Mar 25, 2014)

You can use the Greenhill formula or there are others out there. Berger has a calculator on thier site but I don't know what formula it uses.


----------

