I have a Tikka T3x 223 Remington which has a 12"twist.

Today I got another one which has an 8" twist.

Apart from this, these two rifle are twins.

I was wondering if any of you have any idea if this will make a difference ?

I have bullets in weight from 40 to 80 grains.

I think it well on the heavy end of bullets.

Yes, you are right that the 12 twist will not stabilize the heavier bullets.

What I was wondering is if anyone has seen any appreciable difference on the lighter bullets.

It might be a new project for us.

Got a number of rifles I am installing scopes and sighting in right now.

All Sako 85 in various models.

3 Long Range 338 Lapua Magnum
2 Long Range 300 Winchester Magnum
1 300 Win Mag
1 7mm Rem Mag
1 375 H&H Mag

And the Tikka T3x mentioned earlier.

A friend was here yesterday when I was shooting one of the 338 Lapua rifles.

I had a box of our own 280 grain Walterhog bullets, and I set the powder measure to drop 86 grains of H1000.

I fired one shot, landing slightly low and to the left.

I fired another one and it went into the same hole!

All he said was “This is ridiculous. These are hunting bullets”

I have a 1-7 223 that is a sub .5 rifle with 52gr match kings. I haven't seen a fast twist difference.

Berger's manual has, for years, indicated that the best accuracy is attained when the bullet is marginally stabilized.

That said, most of us won't be able to tell the difference in accuracy between, say a 10-twist that "marginally stabilizes' bullets of a particular length and a 6-twist that over-stabilizes the same bullets.

Regarding velocity, the probably real differences in velocities between barrels with different twist is lost in the noise in variations in velocity between otherwise identical barrels.

One can calculate the rotational velocity for a fast twist and a slow twist barrel with the same barrel. That energy can then be used to back-compute the likely change in velocity resulting from changing twist rates.

I once shot 5 Identical Mannlicher rifles, in 270 Winchester.
Using 150 grain Norma ammo.

Velocity difference between the slowest and fastest barrels was 150 FPS??!!

What I have heard (never proved it myself), the slower twist barrel will have higher velocity than the faster twist barrel. Supposedly it's because the slower twist barrel will have less rotational energy because the faster twist barrel has to convert some of it's kinetic energy to rotational energy.

But, like you have observed, "identical" barrels could have enough variations in velocity to where this is not provable.

Saeed, I have a Tikka in 22-250, and admittingly I don’t know the twist. I am shooting Hornady factory 55gr v-max and at 100 yds the bullets are basically the same hole with my bad eyes. It has a Zeiss 3x9 x40 older model on it. Just a superb rifle, a perfect varmit killer.

I recently re-barreled 3 rifles for a local Park Police Dept. They had purchased Rem 700 PSS rifles in 223. They had 7 twist barrels from the factory. The Park Police planned on using these rifles to cull the deer overpopulation problem. The Dept. chose 40 Gr. V-max ammo to cull the deer, at night, with headshots. The fast twist barrels shredded the thin skinned bullets before they got to the target. I installed 14 twist Hart barrels and the problem was solved. Bullet choice could have solved the problem as well but they were adamant about using the frangible 40 Gr. V-max.

I'm trying to finish up a Stiller Tac30 in 223. I chambered 2 barrels. One is an 8 twist and the other a 12 twist. I'm probably a month away from shooting it.

quote:

Originally posted by butchlambert:
I'm trying to finish up a Stiller Tac30 in 223. I chambered 2 barrels. One is an 8 twist and the other a 12 twist. I'm probably a month away from shooting it.

It would be very interesting to see your results.

I have installed identical scopes on both the Tikka rifles I have, and will test them.

Well, the fun started earlier than I had expected.

Rifles are Tikka T3x, with 24 inch barrels.

One has an 8 inch twist and one has a 12 inch twist.

Both have Swarovski Z6i 5-30 scopes.

I started with the Hornady V Max 35 grain bullet.

I will post photos of the targets later, but here is the velocity readings.

Federal brass, RWS 4033 primers.

1. 23.0 Reloader 7
8 = 3458 fps
12 = 3469 fps

2. 23.7 Reloader 7
8 = 3594 fps
12 = 3601 fps

3. 24.4 Reloader 7
8 = 3849 fps but no bullet touched the target!! They all blew up.
12 = 3822 fps. 3 hit the target, 2 blew up.

I am shooting the Berger 40 grain bullets now.

Getting quite impressive groups.

A lot of us are following this. The results may counter some thoughts on twist.

Looks like both barrels could have an accuracy node around 3550-3600 and maybe another at close to 3900? Did the upper end charges show higher pressure on the fast twist barrel?

Funny enough both rifles seem to digest the same loads same way.

I stopped increasing charges once I can see that the primers are looking that any increase might flatten them.

This is not a scientific test, but I am using my past experience.

I am shooting 60 grains now - I have two types.

A Sierra HP and a Hornady V Max.

I will try both, as they are different lengths.

So far there has not been any significant differences, that could not be attributed to two different rifles.

When I was reloading for my .223 I got pretty good results with 25 gr. H335. This was for a standard factory Remington 223 with a 12 TW. barrel. For the 12 TW. 52-55 gr bullets work pretty good in my barrel. Hornady and Berger are good.

I haven't used it for the .223 but LT32 works good for my .220 Beggs Russian with a 12 TW (Shilen) barrel. The case capacities are similar with the .223R @31.4 gr. h2o and .220 BR @30.1 gr. h2o

Of course bullet seating depth will always give better results in everything I reload for. Usually just off the lands will give better groups for me.

Saeed

I've used Seafire's recipe for RL-7 in the .223 and found that 26.0-27.0 grains on a 40g Nosler BT is maxed out for most guns.

One Rem 700 .223 with a 22" barrel would handle the 27.0 g load and another Rem 700 .223 with a 26" bull barrel and a suppressor on it would choke on that load and backed it off to the 26.0 load. Out of the 26" bull barrel I was getting 3903-3034 fps and great accuracy. I had one group like yours at .358 at 100 yards.

I shot that 26.0g load out of an AR-15 with a 16" barrel and get 3612 fps. Deadly on coyotes and smaller deer.

I love that RL-7 and 40g combo.

Sierra 60 grain HP is 0.780" long.

Hornady 60 grain V Max is 0.873".

I just fired a group of 5 shots with the Hornady in the 12" rifle, using 24.0 grains of H4895.

It looks like just one hole!!

My experience with different twists has been with 300 Winchester and 358 STA and several rifles.

The 358 STA was an interesting one. I got on done and after seeing results several others got one. One bloke bein Blair 338 RUM who posts on AR.

The 358 STAs had a 1 in 14 twist which is the equivalent of 1 in 13.2 in 338 and 1 in 14.66 in 375. On a switch barrel bench style rifle and with barrels of same profile and from same barrel make and in 358 STA, 338 Winchester and 375 H&H and with the 338 and 375 having their standard 10 and 12 twists. If you took the most accurate load for each there was nothing in it. However, if you looked at accuracy across a range of loads then the 358 STA won with ease. Also, more inclined to shoot first shot from clean cold barrel, or with cold hard fouling into the group.

I have found the same with 300 Winchester with 10, 12 and 13 twist. One thing I found interesting was with light bullets 125/130 grain. Accuracy was fine with 10 twist but wind drift much greater.

Based on my own use and observing others I would say the slowest twist possible will provide accuracy that is easier to obtain and over a wider range of loads.

However, for an out of the box factory gun I don't think much difference would be seen with a Howa/M70 etc. if in 300 Winchester with 1 in 10 or 1 in 13. One the things with "accuracy" rifles is apart from being more accurate they are usually tested far more on paper so differences become more obvious.

My test is done, and I will post the results as soon as I finish shooting the 75 and 80 grain bullets in the 8" twist rifle.

69 and 70 grains will not stabilize in the 12" barrel.

So that rifle is done.

But, I am continuing with the heavier bullets to see how they perform in this particular rifle.

I have not seen any meaningful difference in either velocity or accuracy between these two.

What differences have been are no different than those one might get from two different rifles.

But, I am getting reports that penetration is better with faster twists.

I might run a test on that sometime in the future.

One thing to remember Saeed is 1 in 8" and 1 in 12" in 224 is the same as 1 in 11" and 1 in 16.5" in 308 bore size.

I have a Rock River 1/8" twist that shoots 50-55 grain bullets very well. The last test of 3-3 shot groups with 55 grain Noslers averaged right at 0.3" groups at 100 yds.

Clarence

quote:

Originally posted by ClaMar:
I have a Rock River 1/8" twist that shoots 50-55 grain bullets very well. The last test of 3-3 shot groups with 55 grain Noslers averaged right at 0.3" groups at 100 yds.

Clarence

Pictures please.

This is a sewer of long making. Mr. Ackley wrote in his books that rifling twist consumes 35% of the bullet's energy. I politely inquired if this was a misprint. He most generously gave me the name of the man, mathematician, who wrote the section and said, "yes" it is accurate. He also pointed out that speeds of 6000 fps were achieved but with smooth bore barrels. Obviously, the sharper twist is a bit harder on the jacket material too.
The original .22 cartridge, .22 short, only required a 1 in 22 twist. I believe with the .22 long rifle it needed to be 1 in 16. Then came the hot rods. 1 in 14 was common to perserve velocity. Then came Uncle Sam and his ".22." He wanted a bullet that would tumble and cause greater "wounding" in enemy soldiers. The 55 grain FMJ's needed 1 in 12 or 1 in 10... No enough knock down so they made the bullets heavier and now needed 1 in 7 or 1 in 8... Fred Barnes worked with this long ago. Mr. A. wrote of 125 grain .224 bullets out of a 1 in 6 twist barrel. Preserved velocity well, just hard to get them going to fast.
---Accuracy is a balancing act. You find the combination that a gun likes. Yes, the 1 in 8 may be a bit slower but the target won't know if hit well. Where the slower twist just might last a few more accurate rounds. Luck. Happy Trails.