Thread: 223 1:7 twist

Anyone running a 223 in 1:7?
How do they go?

Bang!

Originally Posted by John Duxbury

Bang!

A good bang is always a solid foundation for any rifle lol

I've got one, a CZ 600 , it's out on loan just now but will be back next week hopefully. It's been away a couple of years . . . It was fairly fussy as I recall but I've learnt a lot about 223s since then. I also have a "cross-over" weight custom that the gunsmith has assembled but is waiting on a range day to test, so maybe next week for that one too. It's a Mullerworks cut rifled barrel so I have fairly high expectations, hopefully it'll shoot well enough to annoy FTR people on the odd occasion I shoot against them.

Thanks Tentman, thought I saw you mention somewhere that you had one. I’ve Been mulling over a bunch of different 22 cal options. CM too expensive. ARC looks good, but not sure if the gains outweigh the convenience of 223 brass availability etc.
My current 223 is a great shooter, but with the 24in heavy varmint barrel, it’s not a lot of fun to carry around all day.
I’m thinking of rebarreling it with something along the lines of a 20in fluted barrel, Trueflite or similar, so thinking 1:7 might worth it to eek out a little more performance at heavier projectile end……..

The thing is most of us test at 100M. My understanding (recently learnt) is that longer projectiles like 75s-80s etc will often group nicely at 100M, showing no sign of instability. But as they get further out and become less stable that can have an effect on accuracy, but more importantly, the even slight instability has a large effect on BC.

So a 1:7 twist is a sort of insurance for running longer projectiles at longer ranges. A long time ago I used to run a 1:8 twist 223 in FTR, it had a Krieger 1:8 twist and was spectacularly accurate with Sierra 80 gn projectiles. I was able to shoot FTR possibles pretty regularly at 300 and 400, but never at 500/600 . . . possibly I now understand a little more about why!

If in doubt just go for the tighter twist.

If you plan on using heavier projectiles then there is no reason not to go for a 1:7.

Thanks for the info guys.

Side question....

Can anyone tell me about the Pros/Cons of 223 Wylde (might as well explore all options if we're going down the new barrel route)?

Looks like it just takes standard 223 brass.

223 Wylde has a longer freebore than a normal 223 chamber which means you can seat bullets further out of the case neck, down side is you need the magazine length to do this.
Everything else is the same other than you can load bullets to a longer COAL.

If you are only shooting 50-69gr bullets you probably don't need a longer chamber/freebore.
If you are planning to shoot 69-75gr bullets then the Wyle is a a good idea.
If you want to try the 75-90gr bullets then you probably need an even longer chamber.

For example the 88gr ELD-M is an insanely long bullet with a long bearing surface, you can seat this for a normal 223 chamber but the bullet will waste a lot of case capacity. If you go for a longer freebore then you can seat them out further and not waste case capacity but you'll need some very long COAL magazines and you wont be able to seat lighter bullets (50-69gr) anywhere close to the lands.

What weight bullet you plan on shooting?
I'm guessing you won't be trying anything over 80gr?

Originally Posted by Beetroot

223 Wylde has a longer freebore than a normal 223 chamber which means you can seat bullets further out of the case neck, down side is you need the magazine length to do this.
Everything else is the same other than you can load bullets to a longer COAL.

If you are only shooting 50-69gr bullets you probably don't need a longer chamber/freebore.
If you are planning to shoot 69-75gr bullets then the Wyle is a a good idea.
If you want to try the 75-90gr bullets then you probably need an even longer chamber.

For example the 88gr ELD-M is an insanely long bullet with a long bearing surface, you can seat this for a normal 223 chamber but the bullet will waste a lot of case capacity. If you go for a longer freebore then you can seat them out further and not waste case capacity but you'll need some very long COAL magazines and you wont be able to seat lighter bullets (50-69gr) anywhere close to the lands.

What weight bullet you plan on shooting?
I'm guessing you won't be trying anything over 80gr?

I think 75 or 80 ELDM will be the max. im guessing velocity will start dropping off drastically above that.... Using Tikka CTR Mag, which i know will take at least 2.42in COAL.
Lightest will probably be 55grain Fiochhi SP, although im handloading now, and can load 73ELDM for about the same price, so not sure how much of the 55s ill continue to run.

TBH the main reason for new barrel is to get the weight down a bit, Currently running the 24in Heavy Varmint barrel in 1:8, dont really want to cut shorter than 20in, but i feel like it will still be quite heavy at that. So that being said, if im going new anyway, just want to optimise it for 70-80 gr projectiles

Had one years ago. Savage model 10 with a truflight 1in7 barrel. Shot the 65gr gamekings and 75gr Amax very accurately and to the same POI at 100. Shot alot of goats and fallow with it, without any issues

I remember researching a while ago and 1:7 is apparently worse for copper fouling. Military rifles need it because some of the steel core stuff needs extra stabilisation. Bolt rifles used for hunting fire the denser lead core so manufacturers settle for 1:8 to keep it cleaner. Maybe not a problem with custom barrels with cleaner rifling.
Americans want 1:7 because they like to pretend they're special forces and also have access to bulk surplus ammo.

Wylde/556 is always nice to have to handle more pressure although apparently you lose some fps firing factory 223 since there is a smaller initial pressure spike

I have a 1:7 twist troy defence straight pull. I haven’t shot many heavy projectiles. Weirdly it likes the 55gr vmax and other 55gr bullets more than the 75gr hpbt. Accuracy is good and get very similar speeds out of the 16” barrel for the same ammo as I did out of the 16” 1:8 twist ruger ranch I had previously. Mostly used for longer range hare shooting where 55gr work well. I cant really make use of ultra heavy bullets like the 88gr eldms etc because Im quite limited by AR mag lengths, so make sure your mag and chamber allow for long bullets to get the most out of the 1:7 twist.

Wylde chamber should be ok for what you want then, CTR mags are pretty long.

1:7 twist would definitely be better if you are just using heavier bullets, safer for the 80 ELD-Ms in a shorter barrel.1:8 twist would probably be ok though.

Agreed with Beetroot.

Some 8 twists do and some 8 twist don't shoot with 80gr plus.

I have a 7 twist 223Ai and have no troubles stabilizing up to 88gr. I haven't put anything lighter than 73gr through it yet. I dont think the 60gr ish range would do too well though.