223 twist confusion

[texasbilly]

My custom 223rem has a twist rate of 1:8. It stabilizes and shoot bullets of 69gr and heavier. I have been successful getting sub-minute of angle groups on a regular basis. The other day I shot some 55gr bullets to foul the barrel and got a 3" group, but that was to be expected from this gun and twist.

A friend of mine has a Tikka in 223rem also with a 1:8 twist rate. He shoots 50 and 55gr bullets and gets sub-minute of angle groups. How is that possible? How can that rifle stabilize the light weight bullets?

Thoughts?

 

[TAJ45]

Your shooter doesn't like that weight - load??? His does?

 

[IowaGeologist]

A 1-8 will stabilize light .224 bullets just fine. I shoot 40 gr vmax very well with mine. The upper end of the 1-8 is the 77-85 gr range. As long as you’re not overspinning and blowing up your bullets you’ll be fine. Not sure where you got the idea a 1-8 shouldn’t work well with 55gr.

 

[varmintshooter]

Fast twist shoot lite and heavy bullets, slow twist will only shoot lite bullets.

 

[stacy]

ONE OF MINE 1/9 TWIST WILL SHOOT BUGHOLES WITH 50GR V-MAX WITH H-4895

 

[Twicepop]

Barrels vibrate when you shoot them, each one has a sweet spot with bullet/powder/primer combination. Whatever load combo you had was outside the parameters of that sweet spot.

 

[nicholst55]

My 1:7" twist Colt HBAR absolutely loves 50 grain bullets - at least at 100 yards. Another identical barrel that I had shot patterns with the same loads, rather than groups. It's just individual (barrel/rifle) preference.

 

[jepp2]

The other day I shot some 55gr bullets to foul the barrel and got a 3" group

What specific 55 gr bullet where you shooting?

 

[texasbilly]

Perhaps my point was not well stated. I am not interested in shooting light bullets in my 1:8 twist 223rem. I was wondering how my friends rifle was able to violate the age-old rule about "slow twist for light bullets; fast twist for heavy bullets". Apparently there is no correlation. Thanks.

 

[Nick Caprinolo]

My custom built Remington too with a Bartlein 1/8 twist barrel loves Berger 80 gr. bullets. I load 21.8 gr's Varget powder. It shoots almost as good as my 6 PPC and that's saying something. Of course, if I were to shoot at longer distances, I would probably want a bit more powder to increase velocity. And another benefit of a lighter load is barrel longevity. I have 754 rounds down the tube and scoped it last night after a trip to the range. There is little sign of wear.

 

[biggun2869]

Perhaps my point was not well stated. I am not interested in shooting light bullets in my 1:8 twist 223rem. I was wondering how my friends rifle was able to violate the age-old rule about "slow twist for light bullets; fast twist for heavy bullets". Apparently there is no correlation. Thanks.

what varmintshooter said

 

[r bose]

Perhaps my point was not well stated. I am not interested in shooting light bullets in my 1:8 twist 223rem. I was wondering how my friends rifle was able to violate the age-old rule about "slow twist for light bullets; fast twist for heavy bullets". Apparently there is no correlation. Thanks.

If you believe in quick load and the optimum barrel timing associated with different barrel lengths and powder charges, then yes it's very likely one 8 twist will shoot better than another IF the barrel lengths are different. If barrels are the same length then I'd suspect you're using different powders and 223's in my experience will do very weird things when shooting different powders, one on top of the other. I've had to fire 5-20 shots to get a barrel "refouled" by switching to a different load/powder if using a different one from before. Then, I've had some shooters swear that by using different brands of bullets that have different copper jacket mixtures, they will shoot differently, if shot one after another. You see this in XTC matches where I'd shoot a cheaper projectile at 200 and 300 yards then switch to a premium bullet for 600 yards. That can cause problems. If that's not it then, the barrel itself, the amount of groves, type of material it's made out of, the difference in chambers!!!!!!, muzzle breaks, and even the crowning can make a difference in groups with the same ammo. There's a ton of things that might be going on and it all happens in micro seconds.

 

[Ned Ludd]

Using a faster twist rate [much] faster than necessary to fully stabilize a given bullet can have negative consequences such as increased torque and gun handling issues, increased aerodynamic jump (i.e. spin drift), and most importantly, bullet jacket failure. In contrast, using a [much] too slow twist rate will generally result in stability issues that show up as poor precision, oblong holes, or even keyholes on the target.

Of the two scenarios, a markedly slow twist rate (Sg </= ~1.1) is the much worse because you're practically guaranteed to have poor results. Until you reach the extreme of blowing up the bullets (i.e. jacket failure), a faster-than-necessary twist rate will usually work just fine, or possibly show up as just slightly larger groups. Unless the holes in your target showed some evidence of bullet instability, it is likely your rifle simply didn't approve of that particular 55 gr load, rather than the twist rate being excessively fast.

As an example of that, I've shot plenty of XM193 55 gr FMJ commercial ammo out of rifles with barrel twist rates ranging from as slow as 10-twist to as fast as 7-twist. In fact, I have yet to find a rifle in which it does shoot well. There is something inherent about that particular loading that doesn't shoot well in any of the rifles in which I have fired it. It may be the FMJ bullet, it may be the powder/primer/brass, etc., but I'm lucky to get 1.5 to 2.0 MOA groups at 100 yds with that stuff out of rifles that otherwise shoot sub-MOA with preferred types of ammunition. If you're not reloading so that you can optimize any necessary parameters to suit the rifle, the best you can do is purchase a box of ammo from that has the bullet weight range you're interested in of several different types and/or manufacturers and shoot groups to find out which gives the best precision. Having done this many times in the past, you can usually find at least one or two brands that work well out of a given setup.

 

[kevinbritvec]

My custom 223rem has a twist rate of 1:8. It stabilizes and shoot bullets of 69gr and heavier. I have been successful getting sub-minute of angle groups on a regular basis. The other day I shot some 55gr bullets to foul the barrel and got a 3" group, but that was to be expected from this gun and twist.

A friend of mine has a Tikka in 223rem also with a 1:8 twist rate. He shoots 50 and 55gr bullets and gets sub-minute of angle groups. How is that possible? How can that rifle stabilize the light weight bullets?

Thoughts?

FMJ's? Full metal jacket bullets are hideous. Try some varmint or match bullets weighing 50 to 55 grains.

 

[Texas10]

My custom 223rem has a twist rate of 1:8. It stabilizes and shoot bullets of 69gr and heavier. I have been successful getting sub-minute of angle groups on a regular basis. The other day I shot some 55gr bullets to foul the barrel and got a 3" group, but that was to be expected from this gun and twist.

A friend of mine has a Tikka in 223rem also with a 1:8 twist rate. He shoots 50 and 55gr bullets and gets sub-minute of angle groups. How is that possible? How can that rifle stabilize the light weight bullets?

Thoughts?

Slower twist barrels will stabilize lighter bullets at greater velocities without overspinning them and blowing them up, hence the light-slow rule of thumb.

Velocity x 720 divided by twist rate = bullet RPM. Although there is an optimal RPM for a given bullet to be fully stabilized at a particular velocity, that does not preclude other spin rates or velocities. In your custom and probably hand lapped barrel, you'll probably be able to greatly exceed recommended max PRM situations without experiencing jackets spinning apart. But a rough, rail road tracked factory barrel will be much less forgiving, sometimes blowing up bullets well below published max RPM's.

Your 8 twist should shoot 50 to 53 grain bullets perfectly well (mine does) in the 3350 to 3400 fps range, as well as 80 grain and perhaps slightly heavier. Nice thing about that twist rate, it covers the field pretty well, but bullet weight is not the only factor. Velocity, B.C., center of mass, boat tail angle, tip design, jacket thickness all factor into what makes one bullet shoot better out of YOUR barrel, as opposed another barrel. Barrel time is the biggest factor.

Of course, there's always the option of installing a barrel tuner, and seeing your groups shrink dramatically.

 

[Coyotefurharvester]

I have a case of factory 223 rem Nosler 40 gr bt. These run about 2.236 col. I made up some test loads with the same Nosler bullet seated to col of 2.240 to see if they would shoot in my factory Savage varminter( 1 in 9 twist). The loading just for kicks 26.0, 26.5,27.0 grs of benchmark. All shot well from the early 90's rifle with a 3.5# factory trigger(someday I will replace it). 26.0- 0.62", 26.5- 0.539", 27.0- 0.432"(suppressed). Will load at least 100 of the 27 gr load for a pd trip early July. Hard to beat the way 53 gr vmax shoot, but I need to see what the 40's will do to pd at about 3750.

 

[K22]

I got my 8" twist Tikka's to shoot 55 Nosler BT's in the 1/2 moa range by reducing the powder charge about 1 full grain over than used in my 12" twist 223's.

The 60 grain Vmax (flat base) shoot exceptional well in my 8" twist 223's.

Powder: H4895 in all my 223's.

 

[varmintshooter]

Think of it like this, 2 one gallon buckets but one has a hole half way up. They will both hold 1/2 gallon of water, but only one will hold a gallon of water.

 

[JAlfred]

My 1-8" WOA shoots 77 and 80 gr bullets great, but smallest groups are with 52 gr bullets. I'll stick with 1-7" in the future

 

[6MMsteve]

I'm running a 1n9 twist with 69gr smks 22grs of 4198 it will hit a half gallon water bucket at 100 yds. or a waterhead with duckfeet wearing alligator skin shoes..actually I had never shot a ms15 that's code till a few months ago it's the perfect utility rifle as I'm finding out.