AR-? Help me decide!

[Dolomite_supafly]

If you are going to use a faster twist with heavier bullets you need a longer barrel to get your velocity up. The only reason why people are wanting 7 twist barrels is because that is what the military is currently using. It isn't because 7 twist is better than 9 twist. And the biggest reason for the switch to 7 twist is for NATO tracer use and hard target performance.

When you combine the short barrel with heavy bullets you reduce your range substantially because of the reduced velocity. 77 grain bullets are under 2700 fps out of a 16 carbine.

Unless you are exclusively going to be shooting 77+ grain bullets do not get the 7 twist. And if you are you should be using a longer barrel to take full advantage of the heavier bullets. A 9 twist will shoot everything up to 77 grain bullets just fine, actually better if you want terminal performance out of FMJ or target type ammunition. The reason is the bullets are more likely to tumble, increasing their effectiveness. You can take a 9 twist gun and shoot 55 grain FMJ's and those bullets are more likely to tumble and fragment acting like a soft point. Out of a 7 twist gun those same bullets are just going to pass through the target like a 22 lr unless you are at CQB distances.

Tumbling can reduce the velocity needed for fragmentation but if the twist is too fast the bullet will never tumble and in turn never fragment. This is why we are hearing of the problems overseas. We have reduced the barrel length which causes a reduced velocity, on top of that they have increased the twist. The combination of a slower bullet that is spinning faster results in a bullet that is too slow to fragment and spinning too fast to tumble. Which results in a 22 lr type wound.

Also, a 7 twist will not shoot the lightweight varmint type rounds. I know because I have watched them turn into gray mist 25-35 yards out of the muzzle of a 7 twist gun I own.

A 9 twist barrel will shoot 40 grain bullets and all the way up to a 77 grain bullet. A 7 twist barrel will not shoot anything under 50 grains without the risk of the bullet coming apart under its own centrifugal force. And just so you know 77 grain is the heaviest bullet that can be magazine fed, 80 and 90 grain bullets cannot. Why limit yourself with a 7 twist barrel when a 9 twist can shoot anything that will feed from a magazine.

We never heard of complaints from the military until they shortened the barrel to 14.5" and went to a 7 twist barrel. There is a reason for this.

And finally, Colt is no longer the gold standard for AR's. There are better for cheaper.

Dolomite

[JPR1959]

If you are going to use a faster twist with heavier bullets you need a longer barrel to get your velocity up. The only reason why people are wanting 7 twist barrels is because that is what the military is currently using. It isn't because 7 twist is better than 9 twist. And the biggest reason for the switch to 7 twist is for NATO tracer use and hard target performance.

When you combine the short barrel with heavy bullets you reduce your range substantially because of the reduced velocity. 77 grain bullets are under 2700 fps out of a 16 carbine.

Unless you are exclusively going to be shooting 77+ grain bullets do not get the 7 twist. And if you are you should be using a longer barrel to take full advantage of the heavier bullets. A 9 twist will shoot everything up to 77 grain bullets just fine, actually better if you want terminal performance out of FMJ or target type ammunition. The reason is the bullets are more likely to tumble, increasing their effectiveness. You can take a 9 twist gun and shoot 55 grain FMJ's and those bullets are more likely to tumble and fragment acting like a soft point. Out of a 7 twist gun those same bullets are just going to pass through the target like a 22 lr unless you are at CQB distances.

Tumbling can reduce the velocity needed for fragmentation but if the twist is too fast the bullet will never tumble and in turn never fragment. This is why we are hearing of the problems overseas. We have reduced the barrel length which causes a reduced velocity, on top of that they have increased the twist. The combination of a slower bullet that is spinning faster results in a bullet that is too slow to fragment and spinning too fast to tumble. Which results in a 22 lr type wound.

Also, a 7 twist will not shoot the lightweight varmint type rounds. I know because I have watched them turn into gray mist 25-35 yards out of the muzzle of a 7 twist gun I own.

A 9 twist barrel will shoot 40 grain bullets and all the way up to a 77 grain bullet. A 7 twist barrel will not shoot anything under 50 grains without the risk of the bullet coming apart under its own centrifugal force. And just so you know 77 grain is the heaviest bullet that can be magazine fed, 80 and 90 grain bullets cannot. Why limit yourself with a 7 twist barrel when a 9 twist can shoot anything that will feed from a magazine.

We never heard of complaints from the military until they shortened the barrel to 14.5" and went to a 7 twist barrel. There is a reason for this.

And finally, Colt is no longer the gold standard for AR's. There are better for cheaper.

Dolomite

I love reading your posts especially on the technology of the AR platform. You should write a book!!!

[Caster]

Also, a 7 twist will not shoot the lightweight varmint type rounds. I know because I have watched them turn into gray mist 25-35 yards out of the muzzle of a 7 twist gun I own.

And finally, Colt is no longer the gold standard for AR's. There are better for cheaper.

Dolomite

Yeah, me too. 50g SP Midway varmint bullets come apart out of my Spikes 1/7 I didn't know when I bought it. I have a 1/8 that does very well with them.

As for Colt....pffft, that's been true for a while now. There are other companies building much better stuff. MUCH better.

[Guest Huntaholic]

You know what they say, a little knowledge is a dangerous thing! Thats why Im asking my questions and thinking out loud here, so yall can agree or correct me when Im wrong. Ok, so a Colt might not be the best option after all, what is? Ive had my hands on the M&P sport, wasnt what Im wanting. I would still like to have a barrel longer than 16", but thats a tough critter to find in conjunction with the other stuff I would like. I dont really want to build a rifle for my first one, I want to get my hands on one and run it a while and get comfortable with the whole platform first. I would like for as much of it as possible to be "mil-spec", and tested.

[Dolomite_supafly]

I am PM'ing you my number. If you want to call you can if not that is fine to. I am on Verizon so if you are call anytime. If not then give me a call 9pm-10pm or on the weekends.

I am not selling anything, I do not work for a shop and not looking to gain anything by talking to you.

Dolomite

[RWF]

Originally Posted by Dolomite_supafly The only reason why people are wanting 7 twist barrels is because that is what the military is currently using. It isn't because 7 twist is better than 9 twist.

every one has there own ideas, and most well be perfectly happy with whatever they get. but i can very truthly say i do not agree with that part of your statement. in fact i go way out of my sometimes so my guns does not look like a tactical ted gun. and do not care what twist the military is using. i have see some 69's that would not fly at all from a 1 x 9.

for me i have to say 1 x 7 is better for the shooting i do. and i have never seen a manufacter of a 77 grain bullet recommend a 1 x 9 twist. i can not say for sure but i do not think most of the high end guns like , Laure, noveske and JP or even white oak do not even offer a 1 x 9 twist. but like i said most people will be happy with whatever they get.

i am not trying to step on toes or act like i know anything, jusy my 2 cents only.

thanks.

it was just the statement that i would want a 1 x 7 because the military is using it, for me (and me only) nothing could be farther from the truth.

[Dolomite_supafly]

Not stepping on any toes here, I enjoy healthy discussions. This is how ideas are exchanged and new discoveries are made.

Your gun is a purpose built gun with what I have always said is needed with a 7 twist, a long barrel. That way you get the most benefit out of those heavy bullets because of the extra velocity. And to keep those heavy bullets stabile at the longer distances a 7 twist is definitely what is needed.

A 9 twist will stabilize a 77 SMK grain bullet just not at the long distances most people are going to want to use 77 grain bullets for. Temperature also makes a difference on how far a 9 twist will stabilize a 77 grain bullet. If I were to use a 77 grain bullet for CQB it would without a doubt be fired out of a 9 twist. The reason is the bullet is because the bullet is going to tumble more readily in a 9 twist than in a 7 twist.

I am just saying you need to match your gun to what you intend to do with it and match the bullet to your gun.

The majority of AR owners I have talked to cannot give a reason why they bought a 7 twist barrel other than the military uses it or thats all the seller had. And I am just as vocal with people in person about AR's but I only bring up the twist if they do. And when they do I always ask why they picked a 7 over a 9. Rarely does anyone say anything about stabilizing heavy bullets and when they do they generally have a purpose built gun like yours with a longer barrel.

I am not saying a 7 twist is bad, it has its place and that place isn't on carbine length barrels if you plan on shooting heavy bullets. You are already at a velocity deficeit because of the heavy bullet and by using a gun with a carbine length barrel you are only exacerbating the velocity problem. Then add a fast twist and it negates any the advantages it did have. And if you never plan on shooting heavy bullets out of your carbine then why use a 7 twist in the first place.

The combination of a shorter barrel, which leads to slower velocity, and faster twist is what is causing all our problems with the cartridge overseas. The 5.56 was never designed to be anything more than a 300 yard cartridge. And the military has ruined its effectiveness by trying to make it into a long range cartridge. Ideally if we were only going to be shooting 55 and 62 grain bullets a 12 twist barrel would be even better than a 9 twist.

As I said for the average user the 9 twist has more advantages over a 7 twist. Both twists are going to work with what most people are going to be shooting which is 55 or 62 grain bullets. It is when you get on the extreme bullet weights, heavy or lightweight, of either twist where you run into problems. And a 9 twist will shoot anything that will feed from a magazine while a 7 twist will not shoot lightweight varmint type bullets.

Which 69's have you seen that will not work in a 9 twist? I have used every brand of bullet around that weight and never had an issue in my 9 twist guns.

We are a lot a like in your regard to having a tacticool gun. I just want a gun to do what I want it to. I don't care what it looks like or what is hanging off of it. To me my guns are tools and nothing more. As long as they work that is all that matters.

Dolomite

[RWF]

on the 69s i do not remember the brand he was reloading, but it was very long, even longer than the 75s i had.

and yes it is true that most buy a AR more or less just because they want one, with no thought on twist.

[mikegideon]

on the 69s i do not remember the brand he was reloading, but it was very long, even longer than the 75s i had.

and yes it is true that most buy a AR more or less just because they want one, with no thought on twist.

Even a Berger 70gr VLD will fly in a 9 twist, and it's a few thousanths shy of an inch long. I would like to know which one.

[Guest Huntaholic]

Excuse me just a sec, (putting on my flame suit cause it may get hot in here!) I took the plunge today. I looked at so many different guns with so many different options, that my head is still spinning. I just couldnt ever seem to put the things I wanted all together in one gun and stay under $1300 or so without having to buy it in pieces and assemble it myself. I didnt want to do that for my first one, so I looked for something as close as I could get to what I THINK I wanted. ANYWAY, I ended up getting a Colt 6920. The brand on the side didnt mean nearly as much to me as the components its made with. I didnt get my 20" barrel, and I didnt get the 9 twist I was looking for, but other than that, I think it will at least get me started in the AR world. Im a handloader, have been for almost 20 years, so when it comes to hunting ammo, I WILL be shooting handloads. I hope this gives me an edge in that department when it comes to finding a bullet that will perform on deer and hogs. The way Im looking at it right now, the worst case scenerio would be that I have to replace the barrel.

I sincerely hope I havent hurt anyone's feelings on here with my choice. I looked at everything I could find that you fine folks told me I should, but I still couldnt find what I wanted for less money than I gave for the Colt.

[Caster]

Well what did you get, you didn't mention what length or twist????

Why do you think anyone would be offended. If someone is offended by your personal choice, you tell them where to go and what to do when they get there!

Seriously, Colt builds a dang fine rifle. Take care of it and it will take care of you.

post pics man, we wanna see!!!!!!

[Caster]

If you got the faster twist, try the Barnes tsx. It should put them hogs in thier grave.

[Guest Huntaholic]

16" barrel, 7 twist. Just the basic bare bones 6920 I guess, but the price was as close to right as I could find for what I wanted. $945 for the gun, shipping and all it came to $961.

[Caster]

16" barrel, 7 twist. Just the basic bare bones 6920 I guess, but the price was as close to right as I could find for what I wanted. $945 for the gun, shipping and all it came to $961.

Awesome. Serious about the Barnes, they work and they work well in that 1/7.

[nb forrest]

Even a Berger 70gr VLD will fly in a 9 twist, and it's a few thousanths shy of an inch long. I would like to know which one.

They were Hornady 68gr bullets. They are .985 long and they would not group out of MY Bushmaster 16" gun with a 1 in 9 barrel. They shoot fine out of my 1 in 8 and my 1 in 7 guns.

[RWF]

many thanks NB Forrest for stating the correct bullet. i know the 68 did not work saw the results my self!

Caster is correct that 1 x 7 70 grain TSX barnse thinks it a 30 cal. on deer. they drop on the spot with a good size exit hole, shot through the head at 142 yards or shoulder heart shot at 150. this i what done this year on some cull bucks.

i use silver state 5.56.

[mikegideon]

They were Hornady 68gr bullets. They are .985 long and they would not group out of MY Bushmaster 16" gun with a 1 in 9 barrel. They shoot fine out of my 1 in 8 and my 1 in 7 guns.

Some folks are doing fine with them in 9 twist barrels.

[Dolomite_supafly]

I have also had issues with Hornady not grouping but I think it is the bullets and not the twist. They are very inconsistent lot to lot. I shot the smallest group ever with hornady and could never repeat it or get groups even twice the size. After I spent months chasing my tail I talked to a local competition guy who confirmed it was Hornady and not the gun or me. And since I have been told the same thing by several shooters.

Stabilizing a 77 grain bullet out of a 9 twit barrel has to do with velocity more than anything. If you can get the velocity up with a longer barrel it will be stabile longer.

Dolomite

[Dolomite_supafly]

Excuse me just a sec, (putting on my flame suit cause it may get hot in here!) I took the plunge today. I looked at so many different guns with so many different options, that my head is still spinning. I just couldnt ever seem to put the things I wanted all together in one gun and stay under $1300 or so without having to buy it in pieces and assemble it myself. I didnt want to do that for my first one, so I looked for something as close as I could get to what I THINK I wanted. ANYWAY, I ended up getting a Colt 6920. The brand on the side didnt mean nearly as much to me as the components its made with. I didnt get my 20" barrel, and I didnt get the 9 twist I was looking for, but other than that, I think it will at least get me started in the AR world. Im a handloader, have been for almost 20 years, so when it comes to hunting ammo, I WILL be shooting handloads. I hope this gives me an edge in that department when it comes to finding a bullet that will perform on deer and hogs. The way Im looking at it right now, the worst case scenerio would be that I have to replace the barrel.

I sincerely hope I havent hurt anyone's feelings on here with my choice. I looked at everything I could find that you fine folks told me I should, but I still couldnt find what I wanted for less money than I gave for the Colt.

Glad you got what you wanted and at a nice price as well. Resale , if it comes to that, will be nice also. One good thing about AR's, or is it a bad thing, is you can buy as many extra uppers as you need. That way you can swap them out as needed. So realistically you could have another really nice AR to fit another role for less than the cost of a complete firearm. 10 seconds to swap uppers and another 10 seconds to swap the buttstock and you have a completely new gun. And along with that upper change you can change calibers. There are so many calibers now it is amazing. 300 BLK or 458 SOCOM would be murder on hogs as wel as 223.

And because you mentioned your grand kids using it you need to buy one of the 22 lr conversions for it. CMMG makes a great kit, do not order anything from Ciener though. Makes shooting your rifle cheap and easy. My first conversion had over 15K rounds through it before I built a dedicated upper. The dedicated has over 10K through it now. You can setup deer targets and show them how and where to aim in order to get a humane kill.

Good luck with your new disease, Black Rifle Disease or BRD. It is very addictive and has no know cure. It causes sleepless nights as you invision how you are going setup your AR. Anxiety because you can't wait to go to the range to try out the newest component you just installed. The cost of treatment can also be quite high because the only known treatment of the symptoms is buying components. And as time goes on you will realize that any extra part, no matter how small, will lead to a completely new AR. And selling your AR will only lead to withdrawls and the purchase of a much nicer AR because you felt guilty.

Dolomite

[Caster]

Good luck with your new disease, Black Rifle Disease or BRD. It is very addictive and has no know cure. It causes sleepless nights as you invision how you are going setup your AR. Anxiety because you can't wait to go to the range to try out the newest component you just installed. The cost of treatment can also be quite high because the only known treatment of the symptoms is buying components. And as time goes on you will realize that any extra part, no matter how small, will lead to a completely new AR. And selling your AR will only lead to withdrawls and the purchase of a much nicer AR because you felt guilty.

Dolomite

YES! Herein lies a serious problem you need to consider. Use me for example. I like to keep extra parts. Minimum an extra bolt-carrier group for each AR. Toss in a few other things and you have a nice cache of spare parts should anything ever go wrong. Every time I get enough spare parts to suit me, the dang things begin to gravitate toward one another and before I can stop it, I have another finished rifle. Dangitt!!!

[Guest Huntaholic]

I should have it in my hands Wednesday I cant wait to put a few rounds through it!

[JPR1959]

You must post pics, or you're pulling our legs!!!

[Guest Huntaholic]

You must post pics, or you're pulling our legs!!!

Pics will follow as soon as I get it! I wanted to get by Dunhams in Cookeville today and pick up a few boxes of ammo, but I didnt make it into town. Went hog hunting instead. LOL No piggies today though. Oh well, maybe they are justwaiting to poke thier shouts out till Ive got a new toy to wipe their noses with!

[Guest Huntaholic]

Just to make sure you guys dont think I was just wasting your time with all my silly questions, I just sent Dolomite a pic of my newest editions! HOPEFULLY he can post it in this thread!

[Guest Huntaholic]

Doesnt look like Dolomite is able to add the pics for me. I wasnt sure if I could or not, but here goes!