Ar15 twist rate question

[lesharris]

I am considering buying a new or used AR 15 semi auto rifle.
I plan to shoot 50-60 grain jacketed and of course cast bullets with the rifle.
I have some Lyman and Ideal and the Lee 22 cal bator moulds.
My question is: "what would the best twist rate"?
I will be punching paper with this rifle. I will not be hunting with it.
My choice is heading in the 1:7,or 1:9, twist rates rather than the 1:12.
Thanks in advance for your replies. Les.

[357 Voodoo]

I would say go with the 1:9. it will be a good all around twist rate for what you plan on shooting. 1:7 is good for the long heavy jacked bullets and not so good for the lighter shorter boolits.

[seanhagerty]

What he said!!

1X9 sounds like your best bet.

[EOD3]

Use caution with boolets, lead fouling is very bad for the gas system. :groner:

[lesharris]

Thank you for your input.
I currently shoot lead in my M1,and M14,and SKS.
Not a constant diet of lead,but enough.
I do clean right after shooting either lead or jacketed.
I understand the gas tube and system can become clogged with lead.
I will clean the entire system.
I carried the M16 in Vietnam and i am familar with the cleaning.
Thanks again.

[82nd airborne]

Use caution with boolets, lead fouling is very bad for the gas system. :groner:

I have AR's in a dozen or more calibers and shoot cast out of them all. I have not once had a problem with fouling the gas system, even with volume shooting, considering, even less maintnance than I consider necessary for jacketed. Im not sure what I am doing wrong, but I see that posted alot. You may try working with your alloy.
Regards,
Aaron

[Larry Gibson]

The 12" twist will be the best. It will do ferry nicely with J bullets of 50-60 gr and is the best twist of the 3 mentioned for cast bullets. Very acceptable accuracy with 100% functioning is easily obtained at 2000-2200 fps with cast of 50-60 gr. with the 9" twist it is done in the 1750 - 1950 fps range and with the 7" twist accuracy can be problematic when 100% functional reliability is attained.

I currently have 3 ARs; a 7" twist, a 9" twist and a 12" twist. I also have shot cast in 8 and 10" twist gas guns. I also have .223 bolt and single shots with 9", 11", 12" and 14" twists. The 14" twist gives the best accuracy with 40 - 60 gr cast bullets at 2200 - 2350 fps of so.

It all has to do with slowing down the RPM if accuracy with cast bullets is to be maintained with functional reliability in gas guns. Been there, done that numerous times with various twist .223s in ARs, Mini 14s, single shots and bolt actions. Get the 14" twist in the AR if it's an option (it is available from some barrel makers) as you will shoot J bullets of 50 - 55 gr as well as any other twists and you will have the best twist for cast bullets with that cartridge in the AR.

Larry Gibson

[mike in co]

I have AR's in a dozen or more calibers and shoot cast out of them all. I have not once had a problem with fouling the gas system, even with volume shooting, considering, even less maintnance than I consider necessary for jacketed. Im not sure what I am doing wrong, but I see that posted alot. You may try working with your alloy.
Regards,
Aaron

see aaron we agree sometimes.......

glad you posted first..otherwise i'd get called on the carpet for being insensitive...


mike in co

[82nd airborne]

haha, Im glad we found some middle ground. Maybe we should hug?

[mike in co]

follow larry's advice...he knows cast boolits...and if you want to shoot lite jacketed 12/14 is the way to go.
my hart bbl's target is 1/14....52/53 only.....

mike in co

[NickSS]

I agree with Larry if you stick to 50-55 gr Jacketed or Round nose 60 gr jacketed and cast bullets. The 1 in 9 twist came as a in between twist for people who want to shoot 60 to 75 gr pointed bullets and the 1 in 8 and 1in 7 twists are for vld heavy bullets. They work really well with bullets like the 69, 77 and 89 gr Sierra matchkings.

[songdog53]

All my AR's are 1 in 9 and my bolt gun is 1 in 12. The one in 12 is tack driver as long as stay 60gr or less. The AR's shoot anything well. I never have shot any lead in mine...just haven't gotten around to it but it is coming.

[EOD3]

see aaron we agree sometimes.......

glad you posted first..otherwise i'd get called on the carpet for being insensitive...


mike in co

Not by me, you fellas are welcome to share your opinion. I'm a firm believer in empirical evidence so I presume neither of you have ever seen barrel leading before. I'll stick with my "I've seen it" as opposed to your "I don believe it cuz it aint never did hapin to me"

Now you can call me insensitive. I've got broad shoulders, I can take it.

[82nd airborne]

Oh no, I definatly believe in leading, and have had it happen alot. However, I have found that once I get all my stuff together to where a load is not leading, it seems to not effect the gas port, in my experience.

[Moonie]

Not by me, you fellas are welcome to share your opinion. I'm a firm believer in empirical evidence so I presume neither of you have ever seen barrel leading before. I'll stick with my "I've seen it" as opposed to your "I don believe it cuz it aint never did hapin to me"

Now you can call me insensitive. I've got broad shoulders, I can take it.

Um, I don't see where they said anything about barrel leading, they were talking about leading in the gas system's of the AR's.

And I for one have yet to see any leading in my AR, not saying it doesn't happen, of all the problems I've had with it and cast, barrel leading and lead fouling in the gas system just isn't one of them.

I am aware that it can and does happen however (barrel leading, haven't had anyone prove to me about the lead fouling in the gas system, but lots say it will happen if you try it)

[mike in co]

Not by me, you fellas are welcome to share your opinion. I'm a firm believer in empirical evidence so I presume neither of you have ever seen barrel leading before. I'll stick with my "I've seen it" as opposed to your "I don believe it cuz it aint never did hapin to me"

Now you can call me insensitive. I've got broad shoulders, I can take it.

the trick is to create a load that does not lead....untill then the combo is just test data....

no leading in my 26"/1/14 twist with the bator...no lead in gas system......

it could be your port or your bbl....ut not all ar's lead, nor deposit lead in the gas system...
there are atleast 2 of us that know that, and i suspect many more...

mike in co

[EOD3]

I am considering buying a new or used AR 15 semi auto rifle. I plan to shoot 50-60 grain jacketed and of course cast bullets with the rifle.


I have found that once I get all my stuff together to where a load is not leading, it seems to not effect the gas port

Absolutely true.


Um, I don't see where they said anything about barrel leading, they were talking about leading in the gas system's of the AR's.

Pretty much speaks for itself, doesn't it? Last I checked, ALL of the gas tubes in my rifles are attached to the barrel in one way or another. You'll break open your rifle to clean the CRUD out of the gas tube and bolt assembly and then stand there arguing that lead doesn't get into the gas system.

This has degenerated into an idiotic pile of meadow-muffins. I have better things to do...

[mike in co]

Absolutely true.



Pretty much speaks for itself, doesn't it? Last I checked, ALL of the gas tubes in my rifles are attached to the barrel in one way or another. You'll break open your rifle to clean the CRUD out of the gas tube and bolt assembly and then stand there arguing that lead doesn't get into the gas system.

This has degenerated into an idiotic pile of meadow-muffins. I have better things to do...

no i don't clean the gas tubes on my ar's......where did we say we did ...you did..not us.
i have checked them( 7ar15's, 2 ar10) enought times over the years to determine that fouling of any kind is not an issue in the gas tubes of MY ar's.


mike in co

[45r]

don't need to clean the tube on my AR.I use Vitt-133 and it burns so well in .223 that its never needed.

[EOD3]

no i don't clean the gas tubes on my ar's......where did we say we did ...you did..not us.
i have checked them( 7ar15's, 2 ar10) enought times over the years to determine that fouling of any kind is not an issue in the gas tubes of MY ar's.


mike in co

I presume that the "royal we" you're referring to.

So, if you absolutely have to make yourself look like a total idiot simply to continue an argument where any "rational" person would have cut his losses long ago, I'll help you along one LAST TIME.

The IDIOTS that originally fielded the M16 rifle to the kids serving in Viet Nam had the same opinion. Literally hundreds of kids died as a DIRECT cause of **** CRUD & CORRUPTION building-up in the rifle to the point of catastrophic failure of the rifle. You may think a stoppage is not catastrophic. Join the ARMY and put your money where your mouth is. I've scraped more CRUD out of more rifles than you've ever had in your hands, let alone fired.

Now, you'll have to carry-on without my help. Bye Bye Mike

[mike in co]

I presume that the "royal we" you're referring to.

So, if you absolutely have to make yourself look like a total idiot simply to continue an argument where any "rational" person would have cut his losses long ago, I'll help you along one LAST TIME.

The IDIOTS that originally fielded the M16 rifle to the kids serving in Viet Nam had the same opinion. Literally hundreds of kids died as a DIRECT cause of **** CRUD & CORRUPTION building-up in the rifle to the point of catastrophic failure of the rifle. You may think a stoppage is not catastrophic. Join the ARMY and put your money where your mouth is. I've scraped more CRUD out of more rifles than you've ever had in your hands, let alone fired.

Now, you'll have to carry-on without my help. Bye Bye Mike

well since you cannot stay on topic...you looooossse
no one mentionsed m16's

the subject was lead in the gas system of ar's( not m16's)..........you brought it up as an issue...and we( arron and i) disputed your claim....
and then you started traveling all over the world...everything but lead int he gas system..as in your latest post......
and you are wrong there to by the way...itwas dirty chambers the were not chrome lined as designed, not shot with the correct powder as designed( both to save money), and the cleaning kits was left out by design..it was not needed when the rifle was built as originally designed.

ohh and why don't you show us some "facts" on the claim of 100's killed???

and as we pointed out...you were no help, you were a hinderance...its good you left.

( ps can you show me how to clean "CORRUPTION" from my gas system.....)

[DCM]

I would say go with the 1:9. it will be a good all around twist rate for what you plan on shooting. 1:7 is good for the long heavy jacked bullets and not so good for the lighter shorter boolits.

Well stated! Good call. The 1-9 will stabilize everything except the long match bullets. Check the Greenhill formula for MINIMUM twist rates for your boolits. Over spinning will cause some projectiles to come apart, mostly varmint bullets.

http://kwk.us/twist.html