barrel twist for 223

[cocopuff]

Almost time to rebarrel my 223.......6000 rounds to date.
wanting to use heavier bullets,75 or up for f class class..
i hear some say they can shoot 75 gr hornady in their
9 twist with good results...not sure what good is..
my thought is either 7 0r 8 twist...Any thoughts on this?

 

[mac86951]

I'd recommend an 8. Does well with 80.5, down to 52. A 7 twist is really when you're getting serious in the 90s. That said I have a 7 and it does just fine with the lighter bullets too. I dont see many pushing 90s at 1000y, the 80s do well enough.

For Fclass I'd recommend a 28-30" barrel. You'll get another 100-150fps over a 24" barrel that way and as time goes on, it can be cut down.

 

[Mozella]

........ snip......... some say they can shoot 75 gr hornady in their
9 twist with good results...not sure what good is..
my thought is either 7 0r 8 twist...Any thoughts on this?

No doubt some people claim the can shoot 90gr bullets in their 1:12 twist. This is the Internet, ain't it?

I just went through this barrel twist choice for a .223 F/TR rifle I just finished. I elected the 1:7 because I didn't want to eliminate the 90gr bullets or, perhaps future skinny, high BC mid 80gr bullets which might need a faster twist.

I'm not sure a 1:8 will be all that much better for 80gr bullets even if you know you'll never shoot 90s. Of course I could be wrong, but I would ask myself if I would regret not being able to shoot 90s if the guy lying next to you in an F/TR match is shooting a bunch of Xs with 90gr bullets.

Remember, velocity is good, but BC is better 'cause one starts decreasing the moment the bullet leaves the muzzle while the other keeps working for you all the way to the target. I vote for 1:7.

 

[savagedasher]

I would pick a twist that is a faster then is recomended for the bullet you plan on shooting . The trend seems to be going the need for heavy bullets .
Over stabilator is better then under. Larry

 

[Lightload]

I've got an 8t and with 24.4varget, it shoots the 80's superbly. I'm making plans to change the barrel next year and I'm seriously looking at a 7.7 so I can shoot the 90's and maybe still do OK with the 55's. Ya know, trying to have my cake and eat it too which can get you in trouble but I'm still thinking about it.

 

[Snuggie]

Lightload, I have a 7.7 tw that shoots lights out with 80 SMK's. Wanted to try the 90's but Bryan Litz's twist rate calculator says they will only be marginally stable. Contradicts your results. Your thoughts please.

 

[r bose]

Before you commit to a barrel twist and make a purchase, you must decide if you plan on shooting 90's exclusively or not. "Trying the 90's some day" is not gonna work if you don't have the barrel set up properly to "just shoot" 90's.

I recently (400 rounds ago) re-barreled my 223 with a 7 TW. And, my OAL with a 90g Berger VLD was 2.640" touching the lands for my newly chambered barrel. I don't think I could touch the lands if I was using a 80-80.5-82 etc. bullet.

My point is shooting 90's have big advantages but only in a rifle set up for them.

 

[Lightload]

Lightload, I have a 7.7 tw that shoots lights out with 80 SMK's. Wanted to try the 90's but Bryan Litz's twist rate calculator says they will only be marginally stable. Contradicts your results. Your thoughts please.

My only results are with 80 SMK'S in an 8 twist. I'm thinking of going to a 7.7 so I can shoot 90's but it's not going to happen if 1. The gun will have to be 90's only and 2. The 90's would be only marginally stabilized.

 

[Fotheringill]

Just take a look at the outside of a box of 75 gr. A-Max. It says 1:8 twist or faster. 80's will need more. I suggest you contact Hornady and Berger and ask them.

 

[mac86951]

What barrel length are you wanting?

 

[r bose]

7.7 twist is simply not sufficient for the 90s, don't even waste your time. With that twist rate you'd be giving up so much BC, there wouldn't be a whole lot of difference from the 80-grainers. Put a 7-twist on it and you will be able to shoot any .224 bullet currently made. A 7-twist is not too fast for any of the 80-something gr bullets, and thus will give you the widest possible range of bullet choices.

If you want a rifle throated for the Berger 90 VLD, Dave Kiff at PTG sells a reamer: "223 Rem ISSF". It cuts .169" freebore, which is long enough to seat the 90 VLDs with COAL in the 2.64"-2.66" range, which will depend on your final seating depth. I have a rifle chambered with that reamer and it shoots extremely well. I have loaded dummy rounds with the 80.5 gr Fullbore in that rifle and it is absolutely possible to load/seat those all the way out to touching as well. I specifically checked because I just couldn't believe it wasn't too long for the 80.5, but it turns out it will work just fine. That also means the 82 gr Berger is another candidate in the 80-something category, if you have a rifle chambered for the 90 VLD. I believe the SMK 90 gr falls somewhere in between the Berger 90 VLD and the 80-somethings in terms of length, so that chamber should also work for those as well.

I've never tried the 80 something's bullets in my rifle knowing I was going to shoot 90 VLDs only. So knowing that info, I'd certainly use a 7 twist and shoot anything from 75's to 90's.

I'm using a 31" tube and jamming the 90's 20K in the lands.

 

[chevytruck_83]

Brian lititz's book applied ballistics for long range shooting will explain this in great detail. You cant really go wrong with a faster twist barrel. It was thought for some time that you can get greater velocity with a slower twist but they could not prove that from what i read. The length of the bullet is also a factor in twist rate. I played with the heavy 223 bullets but found that all the loads that shot well really beat up the brass. So i went with a caliber better suited for long range. 1x8 twist with 69 grainers out to 750 is money. Past that there are way better calibers.

 

[mac86951]

Brian lititz's book applied ballistics for long range shooting will explain this in great detail. You cant really go wrong with a faster twist barrel. It was thought for some time that you can get greater velocity with a slower twist but they could not prove that from what i read. The length of the bullet is also a factor in twist rate. I played with the heavy 223 bullets but found that all the loads that shot well really beat up the brass. So i went with a caliber better suited for long range. 1x8 twist with 69 grainers out to 750 is money. Past that there are way better calibers.

+2 on that. If utilizing 223 for magazine purposes, the 69 is a trade off of velocity vs BC of the 77, and the two are neck n neck as I've experienced. More than 77gr, start with different caliber for better results. Can 223 do it? Sure, but at a sacrifice of a lot that made 223 popular.

-Mac

 

[boltman223]

I believe the SMK 90 gr falls somewhere in between the Berger 90 VLD and the 80-somethings in terms of length, so that chamber should also work for those as well.

For anyone who is wondering, I just checked my rifle that was chambered with the .169 freebore reamer. I just eyeballed it real quick and the 90 smk's base is roughly in the the same place in the case as the 90 vld.

 

[Longtrain]

I have shot many 223 match barrels, all 1:8 twists, most have been 26" or 28". IMO they handled 52 grainers to the 80.5 without any hugh issues. The 80.5 is just on the cusp of being confortably stable according to Berger at normal 223 velocities. Their 82 is a little shy of that benchmark from a 223. But would these Bergers work in a 1:8, being marginally stable, sure, and some probably have success with them. Longer barrels certainly help the 1:8 vs. Service rifle lengths.

My 1:8's love the SMK and Nosler 80's and shoot them mid-range happily.

I do have a 1:7 26" on a Space Gun, shoots anything I want, very well. I would have chosen a 1:8, but it wasn't available.

So, another opinion, 1:7 for anything up to 90 grain, 1:8 everything else. It's really a matter of opinion.

FWIW, I'm building. 223 AI, for 80 grainers, 1:8, 30", I think the additional speed of the AI and a 30" barrel, will shoot any 80 I want, not interested in 90's at all.

 

[michael martin]

I would go with the 8, or 7.
The 8 will stabilize most anything, while the 7 would be good for the heavy bullets.
A guy at a 600 BR match once opined that you can't spin an 80 grain Berger fast enough. Could be true.

 

[manitou210]

I have been shooting F class for 9 years just for some observations I have found.Shooting f class
Rifle Barnard/30.5" 1/7 twist Broughton 1"at muzzle, this time. have shot Kreigers Tru Flight barrels, stock is a Robertson, jewel and a Star Shooter front Bi-Pod
Change barrels at 3400 to 3600 when firecracking shows the barrels still shoot great.
To win against the .308 win you have to use 90 gr Bergers even at 500 & 600 y just to much wind drift with 75 to 82 gr bullets. I have the same wind drift as the 185gr Bergers in .308win.
If your strong on using 80 gr get a 1/7 twist bvarrel.I had a reamer made by JGS that works with 90gr and 80 gr bullets.
for me the only powders you can use in a 223 with heavy bullets
#1 Varget
#2 H4895
#3 Vt N 150 so so
i have tried a lot of powders they all had good accuracy but all double base powders like Rl 15, VT 540 & 550 and many others double base are hard on throat and they just will get you in trouble spiking in the hot dog days of summer.
I shoot a lot at Connaught ranges in Ottawa Ontario home of the 2017 world f class championships.
Reading flags is a must but also understanding mirage is very important
I have shot the 80s to 1000k they okay in no wing conditions but when wind is twitching you will get smoked by guy using the 90 s.
there is a problem with Lapua brass when shooting 90 gr over 2750 fps primer pockets loosen up quick, but I have found away around that PM me if you would like any info
Cheers
Manitou
Happy New Years To All

 

[amlevin]

I would pick a twist that is a faster then is recomended for the bullet you plan on shooting . The trend seems to be going the need for heavy bullets .
Over stabilator is better then under. Larry

Amen. For that very reason I re-barreled my .223 Bolt action with a Benchmark 1:7 3-groove.

It shoots EVERYTHING well from 52's to 90's. I spend most of my shooting time with 75/80 gr A-max and Berger 80.5 Fullbores but will also use 90's when I can get them.

 

[WindSurgeon]

For FClass up to 80 gr go with an 8 twist. My AR shoots 62 to 80 gr bullets well. 7 twist might be hard on the lighter bullets and is only necessary for shooting the 90 grain bullets.