Home Forums Hunting & Shooting Ask The Gunwriters Ask John Barsness Questions About "1-12 vs. 1-9 Twist in .223's"

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"Modern Rifle Powders"

"Seating Bullets Straightly"

"Cartridges and Bullets for Whitetails"

"Rifle Cartridge Overall Length"

"The .300 Weatherby: The Best .30-Caliber Magnum?"

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Thanks again, John!

"For centuries rifle shooters had been wary of using bullets that were too long for the twist in their barrels. This was because the bullets then became "over-stabilized," and accuracy went downhill." Emphases added.

Is that a typo for too short or for "under-stabilized" ?

FREX in the original 6mm Remington days it was said for game bullets - longer and heavier than the lighter varmint bullets - the shorter round nose was better stabilized and the too long spitzer was under stabilized?

Similarly at one time some accuracy advantage with medium weight bullets for the .308 Win over the .30-'06 Springfield was attributed to the 12 inch twist of the .308 Win and the failure of the .308 Win to handle the longest and heaviest bullets was attributed to under stabilizing with the slower twist.

Perhaps I misunderstand over and under usage?

That's a typo. It should have read too short.

The beauty of the Internet ... I'll fix it.

rb

Yeah, it's not like you just sent out 50,000 magazines!

I've got a new .223 Broughton bbl on order for my light-weight walking varmint rifle. It is a #3 contour bbl with a 12 twist. I intend to shoot 40gr-50gr bullets exclusively. Shots rarely exceed 250 yards. Is there any benefit to using a 9 twist?

I'm looking at building a .22-250 Improved, using a long neck by sizing down .243 brass and leaving it full length. I want to use a 60 grain solid copper (Barnes-type) bullet. This will be a spitzer boat tail, approaching the VLD profile. Will a 1:9 twist be fast enough, or do I need to go to 1:8?

So, what is the 1 in 7 twist in my colt upper good for? Or should I ask, why did Colt bother making 1 in 7 inch barrels for the M4?

John,

What's the heaviest bullet you've shot in a 1/9 223 Rem and out to what distance?

This was posted on Snipers Hide by Brian and I agree

Keep your 1:12.

I wouldn't go below a 50 grain bullet in a 22 cal, if you want to shoot 40 grain bullets get a 20 cal because they have a much high BC and achieve the same velocity.

I believe your accuracy will deteriorate with a 1:9 twist at the range and bullet weights you specify (more so for the 40 grain than the 50 grain). This is because it takes a while for the bullet to "settle down" in flight, like a football will start off with a small wobble but then stablise during mid flight (and then begin to wobble again toward the end of its flight). Below is a table that shows the approximate relationship between bore twist and bullet weight (based on using plastic tipped bullets in a 24 inch* barrel).

50gr 60gr
100 yards 1:12 1:12
200 yards 1:12 1:12
300 yards 1:12 1:9
400 yards 1:9 1:9
500 yards 1:9 1:9

Personally I have a 1:12 twist barrel and shoot 50 grain (foxes) and 55 grain (wild dogs). However if I was going to shoot 60 grain bullets exclusively I would go for a 1:10 twist. I don't think the 223 has enough grunt to push the 60 grain bullets fast enough. These are better left to higher powdered 22 centrefires (a 22-204 anyone?).

* John's article didn't talk about the assault weapon influence on twist rates. These weapons typically have shorter barrels and so obtain lower velocities, which require a faster twist rate to spin a bullet at the same revolutions-per-minute speed delivered from longer barrels. Therefore barrel length also needs to be considered (the longer the barrel the slower the twist should be). This explains why traditional 200 meter long-barrel target shooters chose the slow 1:14 twist for both 22 cal and 6mm bore sizes.

Matt

Most of the 20's 40 grainers don't have that meaningful of a BC advantage over the 40 gr NBT and the 223 will throw it faster than a 204 ruger using printed data.
Timely article though not the most in depth. Not that it was meant to be. Just an observation.

John,

Thanks for the article on the 223 and twist rate. I have read so much on the campfire about the 223 and deer that I would like to try the .224 on for deer hunting myself.
From you article I understand that a faster twist rate can stablize a heavier/longer bullet and also the short/ light bullets. You mentioned that your wife may try using a 22-250
for deer. Why the 22-250? Does the speed of the 22-250 change the twist rate required to stablize heavier/longer bullets or does speed play any role in that?
What is the standard twist rate for the 22-250?

Thanks
Keith

Let me start by saying again that, yes, velocity does have an effect on the twist required for any given bullet. I have gotten very fine accuracy with 60-grain spitzers in .22-250's and .220 Swifts with their standard 1-14 twists.

My wife is thinking of going to a .22-250 for as lot of her hunting because of several reasons:

1) She dislikes recoil more and more the longer she hunts.

2) She hardly ever shoots at more than 300 yards, even on pronghorn, and likes a flat enough trajectory that she can aim in the middle of the chest and hit the lungs. A .22-250 with a 60-grain bullet shoots just as flat more conventional "deer" cartridges out to 300 yards.

3) She knows from experience that it will do the job for most of her hunting, having used a .220 Swift some back when the 60-grain Nosler Solid Base was one of the best "deer" bullets. Nowadays we have even better .224 deer bullets.

The heaviest bullets I've used in 1-9 .223's have been boattails in the 70-grain range, and they have shot very well out to 600 yards. I also like to shoot 40-grain bullets, however, and do quite frequently, because of lower recoil and higher "lift" on prairie dogs at normal ranges. A 40-grain Ballistic Tip at 3700 or so is a very fine varmint load, except on windy days. Luckily, I have also found that most .223's will shoot various bullets weights to similar points of impact at 100 yards, so often carry handloads with various weights of bullets for different conditions.

The .204 with 40-grain bullets is indeed a little less susceptible to wind drift than a 40 in a .223, but not all that much. I also tend to take a .204 as well as a .223 when shooting PD's and have found that the .204, like the .223, tends to shoot different bullet weights to the same POI. Unless the wind is blowing I shoot lighter bullets in the .204, anything from 26-33 grains, again because I like the low recoil and "lift," but if the wind kicks up I switch to 40's.

I have never noticed any consistent difference in accuracy between 40-50 grain bullets shot in 1-12 or 1-9 barrels in a .223. That was one of the major points of the article. Somebody else may have had different experiences, but I have shot a LOT of .223's and while some rifles shoot better than others, I haven't seen bullet weight being the major factor.

Bryan at Berger really knows what he is talking about. He does more intensive research into what really happens with bullets at longer ranges than 99% of the people in the business.

JB...is Eileen thinking about using the 60 gr. Nosler or the 62 gr.TSX in the .22-250 , or whichever one shoots best for her....
Ingwe

The 60-grain Nosler Partition.

Great article JB!

So take it one step further

How about a 1 in 8? Surely 50gr+ will shoot great in a 1 in 8?

Specifically a Tikka 223 1 in 8 if I can find one...

The 1 in 7" twist of a mil spec AR is due to the 63 grain tracer bullet and it's length due to an 800M burnout requirement. 50's and 62's shoot just great in a 1 in 9 or a 1 in 8. Sierra thinks 70's shoot fine in a 1 in 8 or 9 too according to the box. I have seen 50's and lighter varmint bullets come apart from a 1 in 7" Delta HBAR Colt. 55 grain FMJ shoots just fine from them IME.

Not to get off track in this thread....but I've owned both an 1-8"twist 223AI and 1-8"twist 22-250. Both rifle's shot the 40 and 50gr Vmax's very well. 90% of the bullets fired through those rifles are 75Amax's though and I run them all the way out to 1000yds. I've burned up just shy of 4000 75Amax's over the past 2 years in those rifles so I've spent more than a little time behind them.

MuleDeer, thanks for writing that one, I enjoyed reading it!!!