.223 twist rate 1:9 or 1:7?

[chilldo]

Im thinking about getting a robinson xcr, id get an ar-15 but theyre restricted up here in canada.

Its available in both twist rates. From what ive read, 1:7 is more versatile especially wih heavier rounds. Is there any advantage to the 1:9?

[1983]

Originally Posted by chilldo

Im thinking about getting a robinson xcr, id get an ar-15 but theyre restricted up here in canada.

Its available in both twist rates. From what ive read, 1:7 is more versatile especially wih heavier rounds. Is there any advantage to the 1:9?

You sure about them being restricted.
Look a little deeper into it. As long as it's Semi-Auto has a barrel length 18" or longer and doesn't fire a round over .300 win mag it should be good to go as long as you don't have that scary carrying handle on top.

You may need a government stamped milled receiver as well.

Even Kalashnikovs are legal here as long as they're semi auto and have a milled receiver so it can only be semi auto only.

Al

[chilldo]

100% sure theyre restricted, in fact theyre one of the few long guns here that are restricted along with hand guns,

That doesnt mean i cant get my hands on one. Just that ill need to take another class, get another license, itll need to be registered with the government, and i wont be able to use it outside Of a shooting range

[HMC]

Its seems everyone is getting 1:7 but I have a 1:9 and never had any troubles with ammunition. 1:9 seems to do better with lighter 45 and 55 grain HPs but 1:7 may be slightly better with 69 grain loads and up.

I shoot 75 grain Hornadys from my 1:9 all the time and it is still one of the most accurate rounds in my rifles.

Its up to you but you will probably get more reccomendations for the 1:7.

[Spence_tron]

The 1:7 is more versatile than the 1:9 in that it can stabilize 75-77grain bullets (MK262 anyone?) without problems. 69 grain is as high as I'd go with a 1:9 (I have a 1:7.75 barrel and go up to 69-75gr). With the 1:7 twist, you can also stabilize any of the solid copper TSX bullets as they are longer than lead-core bullets and thus require more stabilization.

The only downside to a 1:7 that I've heard of is that with *some* 45 grain thinly-jacketed bullets the faster twist can actually rip the bullet to bits in the air from the extremely high rpm. But this wont be an issue with normally constructed, standard weight bullets.

Both the 1:7 and the 1:9 will do you just fine. But pick the 1:7 if you plan on shooting heavier rounds though.

[Ph0x]

Originally Posted by Spence_tron

The 1:7 is more versatile than the 1:9 in that it can stabilize 75-77grain bullets (MK262 anyone?) without problems. 69 grain is as high as I'd go with a 1:9 (I have a 1:7.75 barrel and go up to 69-75gr). With the 1:7 twist, you can also stabilize any of the solid copper TSX bullets as they are longer than lead-core bullets and thus require more stabilization.

The only downside to a 1:7 that I've heard of is that with *some* 45 grain thinly-jacketed bullets the faster twist can actually rip the bullet to bits in the air from the extremely high rpm. But this wont be an issue with normally constructed, standard weight bullets.

Both the 1:7 and the 1:9 will do you just fine. But pick the 1:7 if you plan on shooting heavier rounds though.

I've done that with speer TNT bullets.

VMAX will never do that. (In 223)

[Groundhog whacka]

I have shot 75gr A-Max's out of my 1:9 with no trouble.

[5.56 SS109]

I would just get a 1/7.

You are more likely to shoot heavier than 55gr ammo than you are to shoot lighter than 55gr ammo.

Not that 1/9 wouldn't do everything you need it to do, but the best quality barrels on the market just happen to be 1/7.

[Ph0x]

Originally Posted by Groundhog whacka

I have shot 75gr A-Max's out of my 1:9 with no trouble.

I would shoot 75g AMAX out of my 14.5 inch BBL M4.

But the Sierra 75g OTM would yaw.

[Ethan]

Newb question here, does a lower ratio produce better accuracy, and a higher ratio better range, generally speaking?

[944]

Originally Posted by Ethan

Newb question here, does a lower ratio produce better accuracy, and a higher ratio better range, generally speaking?

Heavier the bullet the longer it is, and different length bullets perform better with different twist rates.

[tuer502gt]

I'd get the one that shoots the lighter bullets better because you get more velocity and damage from the fragmentation from the lighter bullets. It's not a long range round. Well it isn't. 300m is pretty far for one of them and that's not long range. I reckon 150m would be far enough to shoot with one at speed with fast aquisition of targets.

I thought fast spin is for heavy bullets but I'm not sure, just relaying what a guy who used to shoot .50 Browning machine guns told me, that they spin hell fast and do right angles when they hit the water because of the amount of spin required to stabilise them.

[1983]

I called the RCMP and asked a few questions about the legality of some of the ARs and M4s... Waiting on a call back from them.

Al

[Spence_tron]

Originally Posted by tuer502gt

I'd get the one that shoots the lighter bullets better because you get more velocity and damage from the fragmentation from the lighter bullets.

This is incorrect, bullets which rely on fragmentation as their primary wounding mechanism (usually military loads due to the Hague convention) benefit from greater mass. The reason being that when the bullet fragments, a heavier bullet will disperse more fragments than a lighter one and will also disperse fragments of greater mass (and thus greater force per fragment).

Bullets which rely on expansion (most hunting/LE loads) do not benefit as much from increased mass. Because the bullet stays in one piece and the greater velocity of lighter projectiles allows deeper penetration and/or greater expansion. In many cases a lighter faster expanding bullet is preferred over a heavier and slower one, half the page down there's a pic showing the difference between 53gr TSX and 70gr TSX here

[tuer502gt]

Would a lighter bullet travelling at higher velocity fragment more and have increased lethality? I have no idea what I'm talking about.

Also, cored rounds.

[Spence_tron]

Originally Posted by tuer502gt

I have no idea what I'm talking about.

At least we can agree on something.

[tuer502gt]

So debating from your point of irredeemable knowledge, how the fuck are you right, genius?

The military knows what they are doing. Their job is to kill and incapacitate.

NOW, do tell.

[Spence_tron]

Originally Posted by tuer502gt

The military knows what they are doing. Their job is to kill and incapacitate

...within (for the most part) compliance to the Geneva convention, Hague convention, etc. The military cannot use "expanding" bullets due to the Hague convention so they have largely adopted projectiles which fragment and/or tumble upon impact (Ex: M193, M855, MK262). This does not include open-tip match bullets used by the military, as the hollow tip is there to shift the center of gravity rearwards improving the ballistic coefficient instead of initiating expansion.

Fragmentation relies on high velocity to be accomplished (decreasing effectiveness at a distance), expansion is less dependant on higher velocities and can be utilized with slower projectiles (like pistol rounds)... making expansion a more reliable wounding mechanism. The military's use of ammunition is confined by the Hague convention, law enforcement's is not. There is a reason why LE units almost always use soft point, hollow point, or ballistic tip ammunition instead of fragmenting FMJ or OTM rounds.

[tuer502gt]

Tell me about classified procedures. You can't, because you only know what you're spoon fed.

A wound canal is a much better injury to receive than an internal fragmentation wound.

You don't know shit. Accept it you fucking sheep.

[mizled]

Originally Posted by tuer502gt

Tell me about classified procedures. You can't, because you only know what you're spoon fed.

A wound canal is a much better injury to receive than an internal fragmentation wound.

You don't know shit. Accept it you fucking sheep.

Back on topic - Exactly what type of rifle chambering .223/5.56 do you have personal experience with?

Or are you just shooting with Google?

[Spence_tron]

Originally Posted by tuer502gt

Tell me about classified procedures. You can't, because you only know what you're spoon fed.

A wound canal is a much better injury to receive than an internal fragmentation wound.

You don't know shit. Accept it you fucking sheep.

Quit trying to save face.

And sure, a fragmenting bullet wound will be far more difficult to treat than a expanded bullet wound.... if the bullet actually fragments. As stated above, fragmentation is an unreliable wounding mechanism, M855 and less so M193 (because of the lighter weight and less complex construction) do not reliably fragment at all practical ranges. If a round fails to fragment and yaw, you're just getting shot with a glorified .22. Controlled expansion is more reliable and consistent round to round.

[5.56 SS109]

Originally Posted by Spence_tron

Quit trying to save face.

And sure, a fragmenting bullet wound will be far more difficult to treat than a expanded bullet wound.... if the bullet actually fragments. As stated above, fragmentation is an unreliable wounding mechanism, M855 and less so M193 (because of the lighter weight and less complex construction) do not reliably fragment at all practical ranges. If a round fails to fragment and yaw, you're just getting shot with a glorified .22. Controlled expansion is more reliable and consistent round to round.

This.

Also rounds that fragment readily tend to not penetrate enough to reach vital structures.

So it can fragment all to hell but if it lacks the penetration to push those fragments where they need to go, then it is worthless.

Plus heavy OTMs tend to have more wound volume than rounds designed specifically to fragment heavily.

[tuer502gt]

Originally Posted by mizled

Back on topic - Exactly what type of rifle chambering .223/5.56 do you have personal experience with?

Or are you just shooting with Google?

I've used civilian and military rifles chambered in 5.56. Does it matter in discussion of round effectiveness?

A better question, which I pose to you, is, have you got any experience using military ammunition that fragments and standard and hollow point ammunition on breathing targets?

E: Both my parents have worked and lived on bases, I've lived on, and I grew up with guns. You don't need to know any more than that on a public forum. And I also don't like you.

[tuer502gt]

Originally Posted by Spence_tron

Quit trying to save face.

And sure, a fragmenting bullet wound will be far more difficult to treat than a expanded bullet wound.... if the bullet actually fragments. As stated above, fragmentation is an unreliable wounding mechanism, M855 and less so M193 (because of the lighter weight and less complex construction) do not reliably fragment at all practical ranges. If a round fails to fragment and yaw, you're just getting shot with a glorified .22. Controlled expansion is more reliable and consistent round to round.

That's interesting to know, but my original post was about how lighter, higher velocity rounds are better and a civilian can choose what to feed their guns with.

[5.56 SS109]

Originally Posted by tuer502gt

higher velocity rounds are better and a civilian can choose what to feed their guns with.

Why?

[tuer502gt]

Flatter shooting, fragment easier and if your ammo is not issued you can use what you want.

[5.56 SS109]

Originally Posted by tuer502gt

Flatter shooting, fragment easier and if your ammo is not issued you can use what you want.

Heavier HP rounds tend to be flatter shooting because of the higher ballistic coefficient.

And their greater length causes them tumble upon impact, which causes them to fragment.

Because of their higher initial weight they tend to allow the fragments to penetrate deeper than a lighter weight round.

Wound ballistics research and testing puts 75gr match hollow points at the top of the list when it comes to a .223 projecile's ability to cause incapacitation.

[Ph0x]

Lighter bullets DO shoot flatter however longer bullets retain their velocity better.

[tuer502gt]

Originally Posted by 5.56 SS109

Heavier HP rounds tend to be flatter shooting because of the higher ballistic coefficient.

And their greater length causes them tumble upon impact, which causes them to fragment.

Because of their higher initial weight they tend to allow the fragments to penetrate deeper than a lighter weight round.

Wound ballistics research and testing puts 75gr match hollow points at the top of the list when it comes to a .223 projecile's ability to cause incapacitation.

Higher velocity, less weight = flatter shooting (less bullet drop).

Their high velocity causes them to shred upon impact, or fragment.

For hunting large game that is important. Human organs are not far beneath the skin.

*yawn*

So why is the military not using them? To save weight? I doubt it. If they were that awesome you could carry less as less follow up shots would be required.

[Spence_tron]

Originally Posted by tuer502gt

but my original post was about how lighter, higher velocity rounds are better and a civilian can choose what to feed their guns with.

Yes, and I stated that when it comes to fragmenting rounds (which is what you originally referenced) a bullet of greater mass is desired. Because when it fragments a heavier bullet will produce more fragments and fragments of greater mass than a lighter bullet... there is simply more material to be turned into fragments. Mk262>M193 you get it yet?

However when it comes to expanding bullets, the projectile having a greater mass is much less of a concern than with bullets which rely on fragmentation. Light and fast is sometimes preferred with expanding bullets, as is seen with TSX rounds in gelatin.

I have already stated all of this, pay attention.

Lighter bullets shoot flatter but heavier bullets retain their momentum better over a distance and are less effected by crosswinds.

[5.56 SS109]

Originally Posted by tuer502gt

So why is the military not using them? To save weight? I doubt it. If they were that awesome you could carry less as less follow up shots would be required.

The military is using them, dipshit.

They have been using MK262 which uses a 77gr Sierra bullet for quite awhile now. It is not as wide spread as NATO standard M855, but the US is fielding it for DMR use and to units that use stubby little barrels.

[tuer502gt]

Originally Posted by Spence_tron

Yes, and I stated that when it comes to fragmenting rounds (which is what you originally referenced) a bullet of greater mass is desired. Because when it fragments a heavier bullet will produce more fragments and fragments of greater mass than a lighter bullet... there is simply more material to be turned into fragments. Mk262>M193 you get it yet?

However when it comes to expanding bullets, the projectile having a greater mass is much less of a concern than with bullets which rely on fragmentation. Light and fast is sometimes preferred with expanding bullets, as is seen with TSX rounds in gelatin.

I have already stated all of this, pay attention.

Lighter bullets shoot flatter but heavier bullets retain their momentum better over a distance and are less effected by crosswinds.

With less weight it will fragment more reliably. You don't understand high school physics. I won't discuss this further with you.

[tuer502gt]

Originally Posted by 5.56 SS109

The military is using them, dipshit.

They have been using MK262 which uses a 77gr Sierra bullet for quite awhile now. It is not as wide spread as NATO standard M855, but the US is fielding it for DMR use and to units that use stubby little barrels.

Thanks for acknowledging they are being used for longer range shots, as they are being used by marksman. As already mentioned this in this very thread by yours truly.

They would be used in shorter barrels because of their weight they travel slower and use more powder before exiting and reduce flash. I honestly don't know why I am explaining this to you though.

You're a faggot. I will not respond to you or converse with you ever in future.

[5.56 SS109]

They are used in the 10.3s because they fragment more readily at the reduced velocities produced by the stubby barrel.

Don't worry about having to converse with me any longer because you have proven yourself to be nothing but an arguementive nuisance and your time on this forum is done.

[Spence_tron]

Originally Posted by tuer502gt

With less weight it will fragment more reliably. You don't understand high school physics. I won't discuss this further with you.

A higher velocity will increase the reliability of fragmentation (as well as an improved bullet construction). BUT bullets of higher mass are still preferred to lighter faster bullets when they rely on fragmentation for the reasons I have stated twice already (more/larger fragments, can't you read?). They have managed to make the heavier and slower 77gr MK262 fragment more reliably than the lighter M855 because of the bullet's construction, obviously not because of its weight. The fact that fragmentation is velocity dependent is most important in the aspect that the round's effectiveness dramatically decreases as the target's distance from you increases. Controlled expansion is not as velocity dependent and thus a more reliable wounding mechanism. Don't think that since velocity is more important for fragmenting bullets that faster and lighter is better, it simply isn't. You have already admitted that you have no idea what you are talking about and I have repeated myself three times now, stop wasting everyone's time with this BS.

[mizled]

Originally Posted by tuer502gt

I've used civilian and military rifles chambered in 5.56. Does it matter in discussion of round effectiveness?

A better question, which I pose to you, is, have you got any experience using military ammunition that fragments and standard and hollow point ammunition on breathing targets?

E: Both my parents have worked and lived on bases, I've lived on, and I grew up with guns. You don't need to know any more than that on a public forum. And I also don't like you.

You are so much less than stupid. L8R troll.