223 Bullet weights for 1:7 twist

[Robert]

Don't expect me to come back here and argue this issue.

I am right and you are wrong and I have the internet to back me up so I am taking my ball and going home. Very mature of you.

No one ever said that it was not possible to make a bullet come apart, or that a flawed bullet might not come apart. All we said was in spec ammo shot from an in spec rifle with more often than not function without issue.

 

[FlyinBryan]

i dont think we should be telling the o.p. that 55g bullets can fly apart when being fired from a 1/7 ar15 barrel.

it is truly a rediculous claim.

45? maybe
55? no way.

it is without a doubt the most common bullet fired from every 1/7 barrel in the hands of shooters.

 

[helotaxi]

helotaxi you seem to be under the impression that I just fell off the turnip truck. That's where people usually go wrong on these boards. You shouldn't make assumptions sir. They have a way of coming back on you.

You assuming that I assumed that pans out how?

You talk about "scientific analysis" but you don't offer any as proof. You just expect us to take your word for it. I talked about information from one of the most respected sites on the net. The link was posted by UKWildcats. If you have this scientific proof you refer to let's see it.

Brian Litz discusses this topic a good bit in Applied Ballistics for Long Range Shooting. His conclusion, based on extensive computer analysis is that over-stabilization is a myth.

Until you do the scientific information posted at the 6mbr site trumps your unsubstantiated claims. And I don't recall saying that the information at 6mmbr detailed a lack of accuracy with 55 gr. bullets in a 1:9 twist barrel. In fact I specifically said it was another site where I got that information.

Hornady and Speer each single out one bullet from their line that must be kept to reduced velocities to avoid an in-flight bullet failure. This is the 3rd time in this thread that I've said that.

As for my not working up a load with 55 gr. ammo in concert with barrel harmonics keeping me from determining that a 55 gr. bullet doesn't work well with my twist rate it sure as heck seems funny that the more I moved to higher weights the more accurate my shooting became. I didn't just up pick a box of Wolf .223 and decide that was the be all and end all of 55 gr. ballistics as you assumed that I did. I tested dozens of different loads. I do know how to arrive at a bullet that functions well for my rifle. And the funny thing is that all of the bullets I have used that worked well have all been heavier than 68 gr.. Now either that is a fantastic coincidence or there is something to the theory advanced by some that heavier loads are more accurate in a 1:9 twist barrel.

It's a fantastic coincidence. I've yet to encounter a 55gn FMJ factory load that shoots worth squat. The cheap bullets are the cause, not the fact that they happen to be 55gn. Funnt thing about the heavier bullets is that they are all match bullets and the factory loads that contain them are likewise match loads.

Do I have that information handy? Well yes I do In a scientific sort of way. I'll point you to this web page where you'll find this quote:

"Faster than optimum twists tend to exaggerate errors in bullet concentricity and may cause wobble."

That to me says that cheap bullets shoot poorly. Not a surprise. Quality bullets are extremely consistent and this is a total non-issue with quality ammo.

Wobble is not a good thing when it comes to accuracy. Apparently overstabilization only causes problems in a limited number of situations but I would bet that's what happens with my rifle using too fast of a spin. And just for the record I've seen other quotes that claim that overstabilization does cause problems such as:

"Howell feels one can overstablize a bullet. Ideally, the bullet's axis will keep tangent to the flight path, but overstablized, the bullet will instead remain pointing in the direction of the barrel."

Again this serves to show that over spinning a bullet can cause accuracy problems according to science (despite what you said). You did notice that the quote above said that the ideal was to have the bullet keep tangent to the flight path but when spun too fast the bullet will remain pointed in the direction of the barrel instead. right? You do understand that is a predictable cause of accuracy issues, right?

"Howell suspects..." Translation, he thinks that it might be the case but he doesn't actually have any scientific information to support his theory. Read Litz. This becomes an issue at ranges well beyond the effective range of whatever round you're talking about; a range that requires the rifle to be aimed at an extreme upward angle. This "adverse" yaw also only causes the bullet to lose velocity at a faster rate than normal ballistic analysis would normally indicate.

So it seems that science is indeed on my side.

Others' pontification hardly qualifies as science. Anecdotes don't equal evidence. If you want some more actual analysis beyond that of Litz, look at some of the analysis done by Molon over on AR15.com concerning 1:7 barrels and 55gn ammo.

 

[benzy2]

Jeff, I ask you again, have you ever seen a 55gr bullet come apart shot from a .223rem/5.56nato cartridge, regardless of twist? Have you heard someone claim they have had it happen personally? Plenty of people have shot 55gr rounds out of a .223/5.56 and if jacket failure is a problem, it must be documented, right? Has real life shooting matched the theories you quote as being true?

And I just read your "supporting material". Seems you may want to go back and read it. He said, and I quote " I haven’t seen a 55gr milsurp disintegrate from overspin in a 1:7 barrel." Hmm.

His entire article comes down to the point that cheap ammo shoots poorly and quality ammo shoots well. If you push the ultra thin jacketed bullets in the ultra fast twist barrels as hard as you can, you might have them go poof. If you use cheap ammo, it won't hit where you aim. If you use ultra long bullets in the ultra slow twists, it's going to key hole. Not much more than is commonly accepted.

 

[TonyAngel]

So...what was the question again?

 

[FlyinBryan]

So...what was the question again?

lol, best bullet weights for a 1/7 twist barrel

i think practically speaking 50ish and the sky's the limit from there (no pun intended)

 

[dalepres]

I haven't been able to get to email or the net for a week so I got behind. I have to say, though, thanks to everyone for a lively, interesting, and informative discussion on my question.

The most important thing is that I can expect to have a lot of fun with the 55 grain ammo I have on the shelf - even if I don't win competitions with it - and I can do so safely without bullets blowing apart and doing unexpected things. Now I can start planning that break-in trip to the range.

I'm looking for a good plinking gun and round. 2 MOA won't hurt my feelings a bit as a starting place. The factory rounds are really, to me, just once-fired-brass kits used to make brass for reloading. When I start reloading them I will take a lot of great ideas and information from this thread into consideration and will, hopefully, get a great round for my barrel. In any case, it seems like what I have will work for casual plinking.

Jeff, I have really appreciated your participation in the thread. Good debate helps strengthen the outcome. Please take this in the humorous way it is intended when I say, though, that science is a great thing but it tells me I can never travel faster than the speed of light (which has now been proven incorrect) but since I can't go over 75 on the ground and 700 in the air, the idea that I can't go over 186,000 in space is kind of meaningless to me.

I do accept your premise that it is possible to spin a bullet apart at high velocity and light weight and a fast spin. I'll keep that in mind when I start loading for accuracy. Thanks.

Thanks again to all who have participated so far.

Dale

 

[FlyinBryan]

I'm looking for a good plinking gun and round. 2 MOA won't hurt my feelings a bit as a starting place.

55's are pretty much the best plinking bullets regardless of twist simply because they are so cheap and load data for them is vast. if 2moa is all it takes to satisfy you, then you will be thrilled with the 1moa that a good barrel (1/7 or 1/9) will yield.

 

[TonyAngel]

Well, if a good plinking round is what you're looking for and 2 MOA won't hurt your feelings, I regularly pop clay pigeons and hit golf balls with enough regularity to keep it fun with just about any .223 or 5.56 55gr ammo. When I buy loaded ammo, it's usually some flavor (55 or 62gr) of Silver Bear or Lake City M193.

If you reload and want something a bit better without breaking the bank, Bryan is right about the Hornady 55gr FMJ projectiles. They are a step or two above milspec bullets. I load them in a progressive press with ball powder. 1000 rounds loads up pretty fast. If you want to step it up a tad from that, try Nosler 69 and 77gr bullets. They are a little more expensive, but less expensive than Sierra's offerings, although I stick to Sierra when accuracy is what I'm chasing.

I'd also like to throw this out there. Lots of guys get into an AR and start over thinking things, as though they think there's a lot of science or voodoo to it. There isn't. Just get out and enjoy the rifle. Odds are that 55gr is what you'll be shooting the most of because it's what's cheap and usually shoots straight enough.

What you should be asking about is what parts to keep on hand, like gas rings, cam pins and buffer springs. If you plan to shoot your rifle a lot, you should at least have some gas rings on hand. If/when your rifle starts to short stroke, change the rings.

 

[TonyAngel]

Jeff, if you are representing that you had 55gr bullets come apart when fired out of a 1:9 barrel (or 1:7 for that matter) and your premise is that the bullet must have come apart because you didn't see anything hit the target, I would suggest that you rethink your position. Maybe nothing hit the target because you missed the target.

Of course, it's still possible that there was something wrong with your rifle and/or ammunition and there could be other reasons that would cause the bullet to come apart; but to say that 55gr ammunition is inappropriate for a barrel with a 1:7 twist is just plain bad information.

If you came to your hypothesis as a result of shooting at 1/4 of a mile (440 yards), I'd have to say that you plain missed the target. Not because you can't shoot, but because that is pretty much pushing the envelop of what a 55gr projectile is capable of consistently shooting. There's a reason why shooters prefer 77gr and heavier projectiles at longer distances.

Have you ever had this result at less than 440 yards?

I would suggest that you get out to a class or similar setting and try to sell this to someone that knows what they're talking about and see what happens.

 

[Robert]

Sorry guys I was at a competition this weekend. And dang if those 55gr bullets work like a charm in my 1:7 barrel. I can say without reservation that my misses were a result of not remembering where I zeroed my scope in the spring. Once I figured my holds right I did ok. Did tank the 3rd stage though. But that was a shooter issue. Always room for improvement on my end too.

 

[FlyinBryan]

But it was like the bullet disappeared. And that's all you would notice if a bullet did spin apart. These guys seem to be laboring under the impression that you would "see" a bullet travelling well in excess of 3000 fps blow up in mid-air or something

you were just missing.

when a bullet flies apart you can see it.

 

[TonyAngel]

Jeff, you didn't kick my rear in any competition, did you? Still, you're wrong about the 55gr projectiles coming apart due to excessive twist and I know you're wrong. That's the reason that I've taken the position that I have.

I'm not trying to be less than civil, but the fact of the matter is that information such as yours is something akin to the lacquer coating on steel cased ammunition melting in your chamber. It's wrong, but someone is going to spread it.

 

[Bartholomew Roberts]

Because that's the only reason I can think of that you're being so offensive.

Pointing out that you are wrong on a factual matter like 55gr bullets at 3,000fps being spun apart by a 1:7 twist isn't offensive. It is pointing out an objective fact. Or were you saying that you found being corrected and/or objective fact offensive?

 

[Bartholomew Roberts]

Did you read my source material Bart? You should before you make blanket statements based on nothing but opinion. It is an objective fact that 55 gr. bullets do spin apart at 3000 fps. I provided proof, not opinion.

Yes, I did read your material Jeff - every link and I did not once see anything supporting a claim that 55gr bullets can spin apart at 3,000 fps muzzle velocity in either a 1:7 or 1:9 barrel. All I saw were general claims that with enough velocity and a fast enough twist, a light, thin-jacketed bullet could spin apart. However, none of those links appeared to believe that a 55gr bullet was light, thin-jacketed or that 3,000fps was sufficient velocity to spin one apart. Perhaps you could point me towards the specific part you believe supports your argument?

I've got something like 15,000 logged rounds through 1:7 and 1:9 barrels and most of it is 55gr. If you include the rounds I've witnessed fired at classes, training, and plinking with friends, it is a lot of 55gr downrange through 1:9 and 1:7 barrels.

Two things I have not yet seen: accuracy problems relevant to anyone outside benchrest shooting and 55gr bullets spinning apart.

I think you're being immature by demanding that I come here and endure your incessant arguments that I have shown to be wrong.

I realize you didn't direct that statement at me, Jeff; but from my perspective, a failure to admit when you are wrong is probably the most marked sign of immaturity. I eagerly await the opportunity to admit I was wrong and that off-the-shelf 55gr bullets at 3,000 fps in 1:7 or 1:9 barrels can spin apart; but I'm still not seeing support for that proposition in your posts and it runs counter to all of my experience with that combo.

 

[TonyAngel]

Jeff, I understand that you did a bunch of reading up, but I'm speaking from first hand experience. I'm not saying that I've seen it all, but I have sent tens of thousands of 55gr projectiles down range and all of them were fired out of rifles with barrel twists of 1:9 or faster, with most of them coming from 1:8 and 1:7 barrels.

Another thing to consider is the guys that shoot precision matches using ARs. I know quite a few of them that shoot the same rifles for the 200, 300 and 600 yard lines, but vary their ammo using some flavor of 50 something grain flat base bullets for the 200 and 300 yard lines, while saving the heavier stuff (77gr and over) for the longer distances; and as I said, they are doing all of this shooting from the same rifle, many of which are running 1:7 or 1:6.5 twists.

With regard to the links that you posted, and the information contained in them, they do make some statements regarding light bullets and their flying apart when fired from fast twist barrels, but I think that you may have missed applying some perspective. A 55gr .223 bullet is not a light bullet. A 35 or 40gr bullet is what is considered light in the realm of .223s. 55s are, in fact, the middle weights.

 

[ugaarguy]

I also said that those sites most certainly do suggest that a 55 gr. bullet could "wobble" when shot from a fast twist rifle and that causes accuracy issues. I have seen accuracy issues from just such a setup. I do not "know" that's the cause. But I at least have to consider it because I've read "many" articles detailing exactly that.

Back in post 27 of this thread I agreed with that.
I even dug up what THR member rsilvers (he's an engineer at AAC who's on the .300 AAC Blackout Dev Team) said about fast twist bbls:

http://www.thehighroad.org/showpost.php?p=7589416&postcount=11
More RPM can increase the dispersion of out of balance bullets. That is about the best reason to not spin much more than needed.

Without knowing specifics on balance of the 55 gr. bullets in the ammo that caused Jeff56's accuracy problems I can't assume anything.

On the other hand, based upon controlled testing done by the US Army (FM 23-9 previously linked in this thread), and ATK / Federal Ammunition (also previously linked in this thread) I'm willing to firmly say that a 1:9 or 1:7 twist barrel is not a problem for the 55gr projectiles loaded M193 and XM193 cartridges, nor are those twist rates a problem for equally or better constructed 55 gr bullets.

 

[Art Eatman]

I don't see how a .223 can drive a 55-grain bullet fast enough to come apart in a 1:7 twist. 35s and 40s, yeah, maybe, or one of the "Blitz" bullets intended for such as a Hornet. But the .223 ain't no Swift or .22-250. Medium power. Useful, of course, but not real impressive.

 

[CraigC]

What did I miss when firing 55 gr. and lighter bullets in a 1:9 twist? The target mostly.

Dang, you're on a roll, Jeff!

Wrong again my friend. All I use are 50-55gr bullets in my 1-9" twist S&W and it shoots them wonderfully. MOA or better.

How can one person 'know' so much that isn't true???

 

[Bartholomew Roberts]

I should qualify my "accuracy" remark by saying that I rarely shoot past 300yds with 55gr and when I do shoot past that distance, I am usually shooting at fairly large targets (IDPA/IPSC silhouettes or High Power bullseyes). So what I consider "practical" accuracy is probably different than what a High Power competitor would consider "practical."

From what shooting I have done, I can see where twist might make a difference past 300yds, although even there I tend to believe the difference is a small one and that the quality of most 55gr bullets plays a bigger role than the twist/length issue.

 

[Justin]

I might have seen a 55 gr. or a 52 gr. bullet spin apart from a 1:9 twist barrel. I mainly said I have read it's a problem at times and the sites I referenced weren't the places I saw it.

I've been running 55 grain bullets in 3 Gun and Tactical Rifle competitions almost exclusively for over five years.

I personally know many shooters who do the same.

The twist rate on my rifle barrel is 1:8, and it's highly likely that most 3 Gun competitors are running rifles with twist rates of between 1:7 and 1:9.

I have never, not once, ever seen a 55 grain bullet disintegrate at any of these matches, nor have I heard about it happening from another competitor, nor have I ever read an after-match online discussion where this has ever even been alluded to as an issue.

Absolutely none of my first-hand, second-hand, or third-hand experience taking part in this sport has ever even hinted that this "problem" even exists.


While I don't consider it to be outside the realm of possibility that a poorly manufactured or out-of-spec bullet might "spin apart," the fact that you can't point to any actual documented evidence that this has happened with anything approaching statistical regularity leads me to believe that it's about as much of an issue as worrying about whether you should take your shark repellent to the range, lest you be attacked by a Great White.

I also said that those sites most certainly do suggest that a 55 gr. bullet could "wobble" when shot from a fast twist rifle and that causes accuracy issues. I have seen accuracy issues from just such a setup. I do not "know" that's the cause. But I at least have to consider it because I've read "many" articles detailing exactly that. I can not find them at this point. I do not care to do a ton of research to prove my point to people who berate me constantly for one thing or another. Find it yourself. It's there.

It's generally well known that the lighter 55 grain bullets tend not to be as accurate as heavier bullets, but that doesn't mean that they are inaccurate. Like Bartholomew Roberts, I've shot 55 grain bullets out as far 550 yards and been able to make hits on steel IPSC silhouettes. That's good enough for the practical accuracy I'm looking for. Were I to go shoot High Power, I'd probably choose a heavier bullet, but then it's a matter of tailoring the ammunition choice to the situation in which it's being used.

From what shooting I have done, I can see where twist might make a difference past 300yds, although even there I tend to believe the difference is a small one and that the quality of most 55gr bullets plays a bigger role than the twist/length issue.

I'd consider it much more important to know your hold over and how to read the wind than to worry about whether or not the rifle's barrel is causing the bullet to "wobble".

 

[Bartholomew Roberts]

You clearly didn't read the source material. Those people would be using high quality ammo while the claim is that cheap ammo with thin jackets are the bullets that might possibly fly apart.

Again Jeff, there isn't anywhere in your "source material" that talks about 55gr bullets spinning apart at 3,000fps. In fact, in over ten years of reading gun forums at TFL, THR, AR15.com, and various others, this is the first time I've even seen someone claim this is possible.

An "an engineer at AAC who's on the .300 AAC Blackout Dev Team" said over spinning a bullet can cause accuracy issues. Guess who gets my confidence?

Accuracy is relative, Jeff. So far all of the sources you have quoted discussing overspinning as an effect on accuracy also describe it as having minimal practical effect on accuracy. In the same post, the same person mentions that he specifically set up a .22LR rifle for 60gr ammo and then mostly shoots 40gr ammo out of it. What would you infer from that?

And if you had read the articles I posted links to you would have read that poorly made ammo can fly apart and about any ammo can have accuracy issues from being overspun.

55gr ammo is perhaps the most common .223 ammo sold and the most common rifling twists are 1:9, 1:8 and 1:7. If 55gr ammo could be spun apart at 3,000fps from any of those barrels, I can't help but think that this wouldn't be the first time I'm hearing someone claim that. I couldn't begin to speculate why you were unable to account for all the rounds you fired; but I am skeptical that 55gr rounds being overspun is the answer.

In short, your initial post about 55gr off-the-shelf spinning apart was bad information (i.e. wrong). Alternatively, some 7-8 random posters who don't know you decided to team up on you for stating something that was objectively, scientifically true. Occam's Razor anyone?

 

[FlyinBryan]

You people think I just fell off the turnip truck.

that is not the truck i think he fell off of.

alright. i got a pm saying im on his ignore list, so he wont see this.

we all know that bullets of around 50g and up are fine for 1/7 barrels. ive never heard a single intance (other than from jeff) of there being a problem with such. its just a rediculous claim, and i think at this point, at least as far as im concerned, just letting him say it maybe???? i dont know. i guess i can see the point to getting accurate info available to people that are asking, but argueing with him seems to just get him crazier, so i will leave it to the authorities that be, and know that whatever is best for the board will be.

the o.p. must be about ready for that truck now trying to keep up with this.

 

[Justin]

You clearly didn't read the source material. Those people would be using high quality ammo while the claim is that cheap ammo with thin jackets are the bullets that might possibly fly apart.

Really? Well, perhaps you ought to define what "cheap ammo with thin jackets" is. Would you care to name some brands?

When I started shooting practical sports that involved the use of rifles, I was on a budget and ran the cheapest stuff I could find. Since then, I've acted as a Range Safety Officer at matches with competitors who were similarly on a budget and running cheap ammo. Not once have I seen the bullets "spin apart" even when shooting the cheapest crap ammo on the market.

If you're willing to list some brand names of ammunition with this problem, I'd be happy to pick some up and go conduct a few live-fire tests to confirm whether or not there's any truth to what you've posted.

I've never missed by 30 feet in my life.

I never accused you of such, so this is completely moot.

If you want to comment on my views please read what they are. I generally shoot 2" groups with heavier bullets. My posts here have been about the "possibility" that out of balance, cheap bullet can fly apart and even quality bullets can be overspun.

Bully for you. Lots of people have great success with heavier bullets, and in many instances they are indeed more accurate than lighter bullets.

However, that doesn't change the fact that your claims of

...buying off the shelf ammo those 55 gr. bullets are liable to rip themselves apart before they reach the target just as others have said.

do not match the experience of a lot of shooters here with a lot of rounds put down range.

An "an engineer at AAC who's on the .300 AAC Blackout Dev Team" said over spinning a bullet can cause accuracy issues. Guess who gets my confidence?

And I suppose that there is truth to this. But there's a difference between spinning a bullet at a rate that causes a slight drop in accuracy, and making claims that factory ammunition shot through barrels with fast twist rates with explode before hitting the target.

Furthermore, I would suggest that the accuracy issues resulting from over-spinning a bullet are probably negligible to the vast majority of shooters. (you are, of course, free to post sources that show what sort of accuracy impact results from this situation.)

I never said I had for sure seen bullets fly apart. I said I "may" have seen it.

An unscientific failure to show documentation of the hypothesized occurrence and therefore nothing more than irrelevant conjecture until proven otherwise.

You people can argue this until the cows come home. I've read a lot of expert opinions (people who build rifles and bullets - not shooters who shoot quality ammo) that say different. That's the end of it IMO. Obviously evidence from actual experts has no sway in any discussion on this board so why bother.

Evidence from actual experts is always welcome here. Taking what they've written and twisting it around to fit your preconceived notions is not.

You've presented no compelling or verifiable data, either first hand or second hand, that rifle barrels with fast twist rates cause bullets to "spin apart" in mid-flight, and for the rest of your claims, you do a fairly good job of actually hiding your claims by wrapping them around the truthful words of people who actually are authorities on the subject.

 

[Justin]

Jeff, I'll make this really easy. Answer the following two queries:

1.) If there are commercial brands of .223 Remington or 5.56x45mm ammunition that will regularly "spin apart" when fired from rifles with fast twist rates, please post the brand names and loadings. Furthermore, please post the model of rifle, barrel length and twist rate that is likely to cause this failure. If you can provide evidence of what the odds are of the bullet actually coming apart, that would be tremendously helpful.


2.) If shooting a .223 rifle bullet through a barrel with a twist rate that is faster than optimum causes issues with "wobble" or accuracy in hitting a target, please tell us, what weight of rifle bullet (or brand of ammunition), in what twist rate of barrel, and how significant the expected loss of accuracy actually is in group size rendered in inches.