I realise that the 1x7 twist allows you to stabalise heavier bullets. Are there any andvantages of a 1x9 over a 1x7?
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I realise that the 1x7 twist allows you to stabalise heavier bullets. Are there any andvantages of a 1x9 over a 1x7?
It's my opinion that you're only gaining a marginal increase in accuracy at the expense of being able to shoot any type of ammo.
Your 1x9 might shoot 75 & 77 grain ammo, might not.
Your 1x7 will shoot anything. Period.
The 1x9 twist holds the same place in my heart as 16" carbines with M203 cuts...
Zydeco,
Might I also suggest that you use the search function and look at some of the posts here. Much of what you are asking has been talked about here many times over. Just a thought.
1:7 here.
It's just depends on the rifle... some 1/9" barrels can shoot up to 75's, some can't. Some are a bit more than 1/9, some are a bit less... My S&W M&P15T has a 1/9", but it actually measures out to be 1/8.8", and can shoot 75's just fine, haven't tried anything heavier though... it thrives on 68/69gr. loads though. It actually shoots the 75gr. Hornady Match BTHP's better than it does 55gr. V-Max/B-Tip/FMJ's.
If ALL you're going to be shooting is 75/77gr. bullets, get a 1/7, but if you want to shoot anything from 40 - 75gr., get a 1/9". My brother has a Colt LE6920 that my S&W just eats alive when comparing them with accuracy - he just bought himself a Noveske N4 16" that's just the sweetest carbine I've ever seen - and I'm going to be comparing it head to head this weekend, weather permitting - I don't expect to have better accuracy, just want to prove that you don't need a $2000 rifle to get sub-.75 MOA groups. IMHO, the BEST twist rate for the AR15 is 1/8", but unfortunately, it's hard to find any 1/8"s except for in heavy contour SS varmint/target barrels.. If there is a chrome lined 1/8" barrel thats either 16 or 18", someone please tell me!! :D
Check out these groups I shot yesterday doing some load development.
The 10 shot group on the top left is with 69gr. Sierra Matchkings.
The 10 shot group on the top right is with 68gr. Hornady Match BTHPs.
The 8 shot group (didn't have 10) on the center is 75gr. Hornady Match BTHPs.
http://i261.photobucket.com/albums/i.../Target_02.jpg
http://i261.photobucket.com/albums/i.../Target_01.jpg
All these groups were using my S&W, rounds loaded with various weights of Ramshot TAC, using CCI Small Rifle Magnum primers, and Winchester brass, loaded to a C.O.L. of 2.614" for all rounds. Shots were made from the prone position, off my Harris BRM bipod, at 100 yards, 60 degrees, no wind.
http://i261.photobucket.com/albums/i...747/MP_IOR.jpg
My Noveske is a 1:7 and it will easily nail stuff out to 200 yds. with 55gr. ammo. It also shoots the heavier ammo without a problem. Unfortunately, I don't have any cool guy data or targets to show off. But, I feel confident with 1:7.
Iraq I did look around a little albiet not in depth for the answer for my question. Usually twist rate questions are what weights can I shoot in what twist etc.... I am trying to find out if there is ANY advantage to having a 1x9 over a 1x7. You see the franken upper problem child in my other post is my paractice and three gun match upper. I will be building a serious upper aswell. I currently hace 2 uppers. One is the Franken upper and the other in a 20 inch HBAR bushy. I love the way the HBAR shoots. That kind of accuaracy with M193 out of chrome I did not believe was possible. However as I am sure you know it weighs as much as a SAW and handles like a sldge hammer. Definately sucks for 3 gun. So the franken upper is my education and practice upper. I want to build another carbine upper that I would bet my life on. Ofcourse I need to be able to afford it.
If you ammo is warm or you reload it that way and depending on barrel length, you can stabilize the heavy bullets in the 1n9. No sense in my opinion hot rodding the stuff to work if you don't have to. I would say go with the 1n7 or stay with what you can safely shoot with the 1n9.
I spent more than one occasion with my 10.5 LMT ringing the 12x12 at 400 with irons and 55 grain ball. I've also spent some time with 262 in a 1n9 Colt 20" shot it moa.
It was 400 feet!---no yards, I mean.
No it was 400 yards, in theory, that's 3 moa, nothing to brag about. Just mentioned it to say that the 1n7's will shoot the 55 grain ball fine.
It was 10 moa of drop with that short barrel, no worries with the LMT fixed rear, dial it up!
Thankfully I am not shooting varmints or I would have to scrap all of my guns.
not true ! my 16" carbines 1/7 will group 55 grain bullets in about 6" @ 100 yds. the same 55's from my 1/9 puts them in a 1 1/2".., both barrels are Colt.., from my 20" Colt barrels it is a whole different story for later publication.Quote:
Your 1x7 will shoot anything. Period.
one thing to keep in mind about barrel twist, is it is also interactive with bullet velocity. a longer (heavier) bullet needs to spin faster than a shorter bullet to maintain stability. firing a bullet faster at a slower twist can accomplish the same thing...
I've shot as low as 52gr out of a 1 in 7 barrel just fine. But really, the meat of the market for the 5.56 is 55 to 75 grains. In that range the 1 in 7 is perfect. My 1 in 7 barreled Colts shoot 55 gr all the time and group just as well as they do with 62 and 75 gr. If you want a dedicated varmint gun that shoots down into the 40 gr bullets, a 1 in 9 is good, or even a 1 in 10 or 12. But since the best performing defense loads are 55 or heavier, I'll go with a 1 in 7 every time.
Ok so for my purposes a 1x7 is better. A 1x9 would be better if I am going to do some small game hunting aswell.
I would get the 1:7 for either. If I were doing a dedicated varmint gun and wanted stainless I would get the 1:8.
I have a question. Not a challange or an argument... just a question.
If the 1-7 is typically considered the better overall twist rate, why is the 1-9 so much more common? Is this a cost to manufacture issue that makes 1-9 twist rates so prominant? I just wonder why the manufactures are not going with the 1-7 on a regular basis if everyone tends to agree that 1-7 is the more desireable twist.
Maybe its that the civilian AR clones are made 1-9 so that the true military guns have a distinct advantage over the off the shelf civilian rifles?
Anyone have a thought on this? It does not make sense to me.
The biggest advantage with going with a 1 in 9 over a 1 in 7 is that you don't have to argue with DPMS owners about which one is the best zombie stopper.
This statement is made half-jokingly. The fact of the matter is that most people that own and extoll the virtues of a 1 in 9 are unbudgable on their view-point whereas it seems that most people that own 1 in 7 twist rifles tend to own more duty-ready guns. I do not mean to imply proficiency or knowledge based off of a purchase, but a simple observation on who is more likely to interfere with your chi.
I don't buy this arguement at all. I read it all the time on the boards.
Here's why I don't believe it. Guys have purchased the Fed NT for shooting at their local indoor ranges. They shoot this ammo through their 1/9 16" barrels. The bullet is 50 grains and loaded pretty hot. The bullet is also about the same length as an M856 tracer. So you have a hot round with a long bullet and these guys are getting keyholes on their targets.
My opinion is that velocity doesn't make up for twist rate at all.
1/9 twist come on "bubba" guns such as Bushmaster, DPMS, etc, that are built for the "lowest common denominator"
They are designed to be compatible most cheap ammo that an amateur will use. This is why these guns have out of spec gas ports to handle such ammo as Wolf.
The rational behind the 1/9, as I understand it, was one of barrel life. I am not saying this was actually so, but I believe that when the govt went to 1/7, they were seeing drastically lower barrel life (which may have been more related to WHAT sort of ammo they were firing, tracers etc), at least at first, and the commercial makers decided that 1/9 worked better as barrels were supposedly lasting longer and when this became common, you did not have greater than around 68 grain bullets except in match type guns/ammo for service rifle etc competition so 1/9 would do the common 55gr and 62gr just fine and supposedly had longer barrel life.
This was how it was explained to me back 10 years ago or longer. Times change.
I honestly don't see why these companies keep ignoring the consumer. I would even be happy with 1/8 twist like what SDI is doing on their Match barrels, but 1/9 makes no sense on a fighting gun.
This makes little sence to me unless over stabalisation could cause keyholing. A
1x9 twist shoots 50 gn ammo very well by any measure. I have personaly had great results with 45 and 50 grain rounds in my lowly mini-14 1x9 barrel. In fact it is a proven fact that 1x9 would be better for this weight with a 1x12 being even better.
I also resent the bubba comments. As I type this response from my trailor in south MS with caloused hands from hard work. I certainly do not think we "bubbas" are driving the market for 1x9 barrels. Infact I will take my trailor trash bushmaster 1x9 twist barrel up against colts 1x7 version any day of the week with 55grn ammo. I have a redneck HBAR sitting right here that prints sub MOA with XM193 at 100 yards.All this being said I would like to offer a more realistic theory.
Tooling is expensive. When most of these "bubba" companies were tooling up the common ammo to be used was and still is M193 and M855. The 1x9 twist is better "if only marginaly" for these weights. This was also the twist that my
M16A2 jamatic was built on. Then the military went to the M4. As we are all aware the new carbine had issues the old rifle did not have. I have been told but not witnessed that some 14.5 inch barreled M4's were having trouble stabilizing the new M855. So they rolled out the new improved 1x7 twist. This eliminated the supposed issues with the short 14.5 1x9 barrels with the heavier 62gn M855. Your tax dolloars being as unlimited as they are there is no trouble tooling up a colt factory for the new twist. The civilian market however requires a financial reason to do so. Most "bubbas" or people that buy AR15's including those built for law enforcement do just fine with the 1x9 twist barrels produced on the now paid for tooling that builds them. Now we have new input from our soldiers in Iraq and Afganistan. They tell us the 62gn penetrator rounds showed no real improvement over the old 55gn M193. Infact from what I have read it is less effective on non barrier shots. However the 77grn smk ammo does show better results than either one. The thicker jacket on the higher quality projectile lends to holding the projectile together better through barriers retaining weight for impact on the otherside. Now we all want to be able to shoot 75 and 77 grain ammo. These rounds are "reported" to be more effective through barriers. They are certainly better for long range accuracy. The highpower crowd with their 1x8 barrels have known this for years while they sling 80grn rounds out to 600 with tight groups.
I certainly do want to own a quality 1x7 twist chrome lined barrel. I think 70-75 grain bonded or solid projectiles would be ideal for dealing with a bad guy shooting at me from behind a car door. The question is is it worth the $ for me to pay the cost for a barrel twisted on the new not yet paid for tooling. You see us bubba's have to factor in things like our childrens tuition at private schools, braces etc... with how much we can afford to spend on deffending them from badguys.
Most bubbas just get a more powerful hunting type arm similar to the ones they mastered while they were still little redneck kids shooting tin cans while barefoot. Those certainly were good days for me. I am also most profficient with my bubba pump action shotgun and would most likely grab that if I heard my back door getting kicked in in the middle of the night. My carbine is for 3gun matching and for the possibilty of another Katrina like event. At this point a carbine capable of holding 30 rounds and firing them with more precission than anything else in it's price class is certainainly a tempting proposition. Besides it looks cool hanging in my gunrack on my 4x4 with the really HUGE rebel flag flying behind it. Oh and yes my plate says BUBBA556. Not really but that would be cool.
Jeez Louise....I've only been here about 24 hours and already I feel like a smuckatelli bubba.............:D
My bubba gun will be delivered to Virginia Arms tomorrow...
The 1/7 twist was the product of a USMC PIP (Product Improvement Program) specifically to match the SS-109 round that was going to be used on the M-249. When M855/856 rounds are readily available...hell, you'd find yourself in Nirvana when sending rounds down range. During the PIP they discovered that a 1/8 was the best twist for temperate climates and wasn't too bad in the Artic to boot. We still had the M-249 and that musical piece of gear is very picky on what she'll play.
I remember when the A2s first hit the fleet in 84. We had a hell of a time matching our 25 yard BZO with the rifle range, so much that we started doing BZO at the 300 yard line which was a time/space/logistics nightmare. It took close to a year to get the 855s into the system, until that time we were stuck with the 193. When a weapon is made specifically for a round, other rounds will work but the true musical masterpiece will come from the round that it was made designed around. On a side note, for S&G we would use 60 ammo to reach out and touch with our 40s but those rounds were not as effective as the match rounds.
The 1/9 will fire the 855 and numerous other rounds, crap rounds included without any major problems. Full heavy barrel aid in accuracy, now using my bubba intuition I determined that the Colt 1/9 was the one for me.
If 855 rounds were readily available, I would have gone 1/7.....as most people know those rounds are very hard to get. Next option would be to hand load, with 7 people in this house, 3 of which are kids (15, 7, 5) and the 7 year old fighting leukemia when I have spare time, that time will be spent sending rounds down range not hanging out in the basement loading rounds.
When the 855 is flowing like manna again, I get a Colt 1/7...until that time I stick with my bubba gun that is a ford vice a ferrari.:D
M855 is out there but why? My 20inch barrel is more than adequately accurate with it. My 14.5 1x9 seems ok with it but have not put that one one a bench with a scope. I have a couple k of it but dont really see any advantage with it over the M193. All data I have seen show the ss109 projectile is not an improvement in a small arm. However in a saw I have seen the round take a out a sillouet at 800 from a saw with droping only one round in the feed tray.
I agree with you...I just needed to bubba ramble.......the 16.1 1/9 HBAR is exactly what I need at this juncture.
The SS109 isn't an improvement, it is the round that works best with the saw. The 1/7 twist works best with the SS109 because the fireteam is built around the saw, from a logistics point of view the M-16A1 PIP had to work with the saw. No matter how much you want it to, the saw don't sing with 193.
That's kinda the point of the question I asked yesterday.
If so many professional soldiers and match shooters know that 1-9 tends to be the least usefull overall twist but a 1-8 would be the very best of both worlds... you would think that any idiot at a gun company could figiure this out and start standardizing a 1-8 twist.
I'm not a big fan of the "Bubba" term because I picture a big fat hill-billy with rotted teeth from the front of one of those "Big Johnson" shirts or something. Kinda like your calling every average citizen stupid and ignorant. I may not be a trained soldier/warrior or a national or regional match champion.... but I try to be as good as I can afford to be with the time I can afford to spend not making money to feed my children. I am a soldier to my family. I am a hero to my wife. We are warm, we eat, and once in a while we have extra money to spoil each other with a night out or a special gift. That is a man doing his most important job.
Anyways...
I have a RRA stripped lower and I am going to be assembling my 4th M4 as a SBR over the next year as I can afford it. After this I am thinking of using a 1-8 barrel to be the best of both worlds. That sounds to me to be the wisest choice. Where does one find a 1-8 twist 12.5" barrel or complete upper for a SBR build?