Barrel Twist

[Gomer Pyle]

I know what it's for and understand it but I have some questions...

I have ordered the stainless steel, 20in, 1:8 twist, threaded barrel from rock river to build my AR... It's the only stainless barrel they have to offer that is threaded.

Now my questions are....

Is a 55 grain bullet going to be able to handle/catch the 1:8 twist grooves or will it just bounce around?.... Today I spoke to someone who had a 1:7 twist and said he got rid of it because the 55 grain bullet wouldn't take to it and it was pointless shooting it.... I have also seen and shot a 1:9 twist with 55 grain with extremely good accuracy at 100yds.

Will the 55 grain shoot well with the 1:8 twist???

Any experiences with long range shooting as well as 100yd and under.... This gun is meant for target both short and long.

I am real nit-picky with accuracy. I have my 30-06, 3 shot spread to a dime at 100yds haha.

My other question is:

Will I possibly need a heavier/lighter grain for long distance shooting (over 100yds).

In other words, how does weight effect accuracy over long distances? Do I need lighter or heavier? (I know weight has to effect the accuracy, just not which way to go).

Thanks.

[mrnyman]

Yes the 1-8 is a Target twist, nobody in Combat uses 1-8, I would not recommend 55 grns. in a 1-8 , your friend is right , its pointless.

Get some 68- 77 grains Black hills and have fun, great for Coyotes too .

To really learn more go to www.ar15.com and look at the www.ammooracle.com tons of info.

Nyman

[sid]

This is a good question I was wondering the same thing.

sid

[sid]

Yes the 1-8 is a Target twist, nobody in Combat uses 1-8, I would not recommend 55 grns. in a 1-8 , your friend is right , its pointless.

Get some 68- 77 grains Black hills and have fun, great for Coyotes too .

To really learn more go to www.ar15.com and look at the www.ammooracle.com tons of info.

Nyman

You posted before I did. Guess I should have refreshed more often lol.

thanks,
sid

[Tomcat088]

I know what it's for and understand it but I have some questions...

I have ordered the stainless steel, 20in, 1:8 twist, threaded barrel from rock river to build my AR... It's the only stainless barrel they have to offer that is threaded.

Now my questions are....

Is a 55 grain bullet going to be able to handle/catch the 1:8 twist grooves or will it just bounce around?.... Today I spoke to someone who had a 1:7 twist and said he got rid of it because the 55 grain bullet wouldn't take to it and it was pointless shooting it.... I have also seen and shot a 1:9 twist with 55 grain with extremely good accuracy at 100yds.

Will the 55 grain shoot well with the 1:8 twist???

Any experiences with long range shooting as well as 100yd and under.... This gun is meant for target both short and long.

I am real nit-picky with accuracy. I have my 30-06, 3 shot spread to a dime at 100yds haha.

My other question is:

Will I possibly need a heavier/lighter grain for long distance shooting (over 100yds).

In other words, how does weight effect accuracy over long distances? Do I need lighter or heavier? (I know weight has to effect the accuracy, just not which way to go).

Thanks.

First off, I think that you have a bit of a misunderstanding about bullet weight and rifling twist. It doesn't matter what weight the bullet is, if it's the proper diameter and it is a factory barrel in spec, the bullet will ALWAYS catch the rifling. The weight of the bullet of a certain caliber is usually related to how much lead/copper it contains, and the length of the bullet. they will all be .223 (technically .224) caliber. So your question isn't related to if the bullet will "bounce around" down the bore, but is related more to will the bullet be over stabilized too much or not. You should do some searches on twist rate and stabilization, as there are LOTS of very detailed threads on it, and how a bullet being over stabilized can affect accuracy. You really should search to learn this information for your own benefit.

For what you are talking about, the minimum recommended twist rate for a 55 grain .223 bullet at conventional velocities is 1:12. Going over that a bit will not necessarily hurt accuracy and will give you some other options. If you will search for the threads that I'm talking about, you will understand more how twist rate influences accuracy and why a 1:8 twist rate might shoot a little less accurate than your friend's 1:7 twist rate with a 55 grain bullet. In the other threads, you'll find that velocity, barometric pressure, air density, temperature, altitude and lots of other things effect require twist rate. If you can't find those threads, AFTER you have searched for them I will be happy to post up some links so that you can read. Typically for a .223, 1:8 twist is for 80 grain bullets or lighter. You'll learn what over stabilizing a bullet can do, depending on certain conditions, it might still shoot pretty accurately.

If you consider over 100 yards to be long range shooting, you should be fine shooting 55 grain bullets even out to just over 300 yards. If you want reliability and a bit better BC, you'll probably want some heavier and longer bullets to go to 500 and beyond. Best of luck to you and hope that helps.

[Gomer Pyle]

Yes the 1-8 is a Target twist, nobody in Combat uses 1-8, I would not recommend 55 grns. in a 1-8 , your friend is right , its pointless.

Get some 68- 77 grains Black hills and have fun, great for Coyotes too .

To really learn more go to www.ar15.com and look at the www.ammooracle.com tons of info.

Nyman

So do not expect tight groupings at 100yds with 55gr? It's gunna suck wasting money on ammo trying to find the right one.

Does anyone know what to expect (grouping wise) at different distances with different weights?

Like... 55gr at 100... 200... 300

68gr at 100... 200... 300

and then the 77gr 100... 200... 300.

As mrnyman suggested?

Or if I just stuck with the heavier 68-77 grain will the grouping be consistent throughout the range...

In other words.... its better to go with heavier grain off the bat, to get the better accuracy as distance increases.

I know this is annoying but I feel like this question is for experienced target shooters and/or those who have actually seen and/or performed weird tests like this.

In a great state such as PA with all the hunters and this website someone has to know haha.

Thanks Guys!

[knight0334]

So do not expect tight groupings at 100yds with 55gr? It's gunna suck wasting money on ammo trying to find the right one.

Does anyone know what to expect (grouping wise) at different distances with different weights?

Like... 55gr at 100... 200... 300

68gr at 100... 200... 300

and then the 77gr 100... 200... 300.

As mrnyman suggested?

Or if I just stuck with the heavier 68-77 grain will the grouping be consistent throughout the range...

In other words.... its better to go with heavier grain off the bat, to get the better accuracy as distance increases.

I know this is annoying but I feel like this question is for experienced target shooters and/or those who have actually seen and/or performed weird tests like this.

In a great state such as PA with all the hunters and this website someone has to know haha.

Thanks Guys!

A 55gr slug will be stabilized by a 1:8. A 1:12 is capable of stabilizing a 55gr slug. If you go with bullets longer than 55gr slugs, but shorter than 80gr slugs - a 1:8 will suffice.

There are too many variables to project results for given weights-to-accuracy at given ranges. If given enough elevation, no wind, a superb rifle and shooter - a 55gr could give sub MOA groups at terminal range of a mile or more.

[Gomer Pyle]

First off, I think that you have a bit of a misunderstanding about bullet weight and rifling twist. It doesn't matter what weight the bullet is, if it's the proper diameter and it is a factory barrel in spec, the bullet will ALWAYS catch the rifling. The weight of the bullet of a certain caliber is usually related to how much lead/copper it contains, and the length of the bullet. they will all be .223 (technically .224) caliber. So your question isn't related to if the bullet will "bounce around" down the bore, but is related more to will the bullet be over stabilized too much or not. You should do some searches on twist rate and stabilization, as there are LOTS of very detailed threads on it, and how a bullet being over stabilized can affect accuracy. You really should search to learn this information for your own benefit.

For what you are talking about, the minimum recommended twist rate for a 55 grain .223 bullet at conventional velocities is 1:12. Going over that a bit will not necessarily hurt accuracy and will give you some other options. If you will search for the threads that I'm talking about, you will understand more how twist rate influences accuracy and why a 1:8 twist rate might shoot a little less accurate than your friend's 1:7 twist rate with a 55 grain bullet. In the other threads, you'll find that velocity, barometric pressure, air density, temperature, altitude and lots of other things effect require twist rate. If you can't find those threads, AFTER you have searched for them I will be happy to post up some links so that you can read. Typically for a .223, 1:8 twist is for 80 grain bullets or lighter. You'll learn what over stabilizing a bullet can do, depending on certain conditions, it might still shoot pretty accurately.

If you consider over 100 yards to be long range shooting, you should be fine shooting 55 grain bullets even out to just over 300 yards. If you want reliability and a bit better BC, you'll probably want some heavier and longer bullets to go to 500 and beyond. Best of luck to you and hope that helps.

I'll search the threads and take a look. I figured this was posted before. I'm interested in this stuff alot so I'll def be reading them.

Thanks.

[Gomer Pyle]

A 55gr slug will be stabilized by a 1:8. A 1:12 is capable of stabilizing a 55gr slug. If you go with bullets longer than 55gr slugs, but shorter than 80gr slugs - a 1:8 will suffice.

There are too many variables to project results for given weights-to-accuracy at given ranges. If given enough elevation, no wind, a superb rifle and shooter - a 55gr could give sub MOA groups at terminal range of a mile or more.

Ya... I'm pretty sure I was a little confused about the twist of a barrel and how it affects the bullet.

I guess this thread means nothing until you go to a range and see/do it yourself.

[Tomcat088]

So do not expect tight groupings at 100yds with 55gr? It's gunna suck wasting money on ammo trying to find the right one.

Does anyone know what to expect (grouping wise) at different distances with different weights?

Like... 55gr at 100... 200... 300

68gr at 100... 200... 300

and then the 77gr 100... 200... 300.

As mrnyman suggested?

Or if I just stuck with the heavier 68-77 grain will the grouping be consistent throughout the range...

In other words.... its better to go with heavier grain off the bat, to get the better accuracy as distance increases.

I know this is annoying but I feel like this question is for experienced target shooters and/or those who have actually seen and/or performed weird tests like this.

In a great state such as PA with all the hunters and this website someone has to know haha.

Thanks Guys!

This question isn't necessarily for "experienced target shooters", it's for shooters that know a bit about how twist rate and bullet weight play with each other. There are lots of medium experienced shooters that know this information. Since you already ordered a 1:8 twist barrel, you have pretty much commited yourself to weights that are in the medium to heavy range. So no, the 55 grain bullets will probably not group all that well for you. I would again advise you to search around and learn some information that makes you a more experienced shooter, or at least a more knowledgeable one.

The comparison that you're asking "experienced shooters" to make about distance and bullet weight, related to stabilization is a can of worms, and for the most part can't be measured objectively. As distance increases, group size will always increase. On rare occasions it does not, and most people attribute that to bullets being over stabilized and not "going to sleep" until a greater distance. That phenomenon is still debatable, and is debated alot. Other than that phenomenon, group size will generally increase as the distance increases, no matter what bullet weight you are using.

Accuracy is related to MANY other things than bullet weight, even at distance. There are always trade offs between velocity, accuracy, drop, wind drift, etc. In a factory gun, many times it'll just depend on what ammunition fits closest to a node for your barrel. There are plenty of us to know, but judging from your responses, it sounds like you will need to learn a bit more information before any of those answers will make much sense to you. This is the reason that I won't go into the accuracy over distance thing until a bit more knowledge is covered. Hope this helps.