Fast twist 223 - Ruger Precision

alanmc

Gents and gentettes,

So I've had enough of my Rem700 223 and I'm looking to change it for a fast twist 223. 7" twist preferably.

Do any of you have a RPR in 223?

I was also thinking of a Savage F/TR 223. Can't find any for sale on the interweb at the moment though.

The alternative is always to buy another Tikka with 8" twist, which if I'm honest I'd be delighted with as well.

Any other options?

crosshair1

Tikka t3x tac if you can find one, there aren't really any factory ammo offerings that require a 7 twist anyways.

123shooter

I think Tikka varmint heavy barrels had a 1:8 twist as well.

Cass

I'd be weary of going so fast. Most rifles or barrels with 1:7 are designed for the ultra heavy bullets and i've seen thsi first hand. A mate has a 1:17.25 twist and it won't shoot anything under 75gr. He uses his for long range target shooting and can reload for it, but he is running 90gr VLD.

Some of the 75gr factory stuff works just fine, but as i have found out finding a good supply and consistent supply of heavy ammo can be hard.

Even 1:9 can be troublesome. Some bolt actions work the 55gr stuff well in them, but others don't. The ideal weight range is 60 - 69gr for the 1:9 and one of my rifles is 1:9 so i know the hardship of finding a constant supply of ammo in that weight range.

Just an FYI.

alanmc

Cass wrote: »

I'd be weary of going so fast. Most rifles or barrels with 1:7 are designed for the ultra heavy bullets and i've seen thsi first hand. A mate has a 1:17.25 twist and it won't shoot anything under 75gr. He uses his for long range target shooting and can reload for it, but he is running 90gr VLD.

Some of the 75gr factory stuff works just fine, but as i have found out finding a good supply and consistent supply of heavy ammo can be hard.

Even 1:9 can be troublesome. Some bolt actions work the 55gr stuff well in them, but others don't. The ideal weight range is 60 - 69gr for the 1:9 and one of my rifles is 1:9 so i know the hardship of finding a constant supply of ammo in that weight range.

Just an FYI.

Thanks Cass.

I was in Lakelands yesterday and they always seem to have a good supply of 69g SMKs. They also have 75g Hornady and I thought I saw some 77g Bergers as well.

The 69g used to shoot unbelievably well in my 8" twist Tikka. Regularly and happily shot tight groups out to 300m.

None of this heavier stuff will work in my current rig.

Cass

alanmc wrote: »

The 69g used to shoot unbelievably well in my 8" twist Tikka. Regularly and happily shot tight groups out to 300m.

They run a treat in my 1:9 too, but people often confuse 69gr with being on the heavier end of the scale. It's not really.

If its a 1:9 i'd go to a max of 69gr, but not under 60gr for best results.
If its a 1:8 go to a max of 75gr, but not below 62gr.
If its 1:7 or faster then up to 90gr, but not below 75gr.

None of this heavier stuff will work in my current rig.

This is where reloading is needed.

The 75gr factory stuff is slower because of the longer, hence heavier, bullet. However all factory stuff is done to SAMMI spec meaning its seated to the standard OAL. As the OAL is not increased the amount of propellant is limited. Superformance get around this by using a seriously hot, and hence fast, burning propellant, but the results can be varied.

If you could reload you could seat the bullet out further and hence increase the charge making the round hotter and bullet travel faster. This would increase your rifles perforamance with this round. Of course that is somewhat over simplified as you need to test the loads, see which seating depth works best, if it likes jammed or jumped loads, different propellants, etc.

However for factory its usually lawyer friendly and hence slow. So while it maintains it's speed over longer distances better than lighter bullets the heavier bullets won't really work well until out at distance, if at all.

tikkamark

My 1:8 t3 tactical will Group anything from 50gr up to 75gr really well,it loves 55gr vmax in fact I’d reckon the faster twist makes the bt heads expand more explosively because of the higher rpm.
The only stuff it doesn’t like is fiocchi hp’s the bulk box and that steel case wolf Ammo

gunny123

What happens if you put a light bullet through a barrel with a fast twist , eg. 1:7 ?

crosshair1

I have a t3x tac 8 twist and it groups well with any quality ammo available here.
It wont group well with cheap ammo, wolf, tulamo, umc etc.
Having recently read bryan litz's take on the subject that poor quality/out of balance heads group worse the further the twist rate increases, i swapped the heads from 55gn umc and 55gn vmax.
The umc with v max heads shot good groups and the vmax cases with 55umc fmj heads shots 2moa groups
You need to pick your ammo first and then the gun to shoot it.
JBM ballistics stability calculator will answer a lot of questions and should be above 1.5 for boat tails to gain full use of their listed bc.

alanmc

Thanks lads. I think in the New Year I'm going to get a Tikka T3x.

I think Dom Byrne does them.

tikkamark

gunny123 wrote: »

What happens if you put a light bullet through a barrel with a fast twist , eg. 1:7 ?

There’s a chance the bullet can come apart mid flight

123shooter

tikkamark wrote: »

There’s a chance the bullet can come apart mid flight

Why if it has a copper jacket?

Cass

tikkamark wrote: »

My 1:8 t3 tactical will Group anything from 50gr up to 75gr really well,....

crosshair1 wrote: »

I have a t3x tac 8 twist and it groups well with any quality ammo available here.

Its a rule of thumb more so than a steadfast law, but there are a few reasons, imo, why bullets stablise/perform well in a twist rate they probably shouldn't.

1. Bullet design
2. Bullet type
3. Wrong twist rate
4. Amount/type of grooves/lands
5. Propellant
6. Seating Depth

1. Bullet design - Some bullets are made longer than the average bullet in the same "weight" category" from various other manufacturers. The twist rate ratio to bullet weight is actually incorrect. I explained this before that the actual ratio is bullet length to twist rate however as weight is easier to remember and discuss it's used in lieu of the length. So a 55gr V-Max bullet may be longer than say a 55gr HP, or FMJ. The longer bearing surface means more of the bullet engages with the lands and grooves and hence acts more like a heavier bullet. So a 55gr can act the same as say a 69gr depending on the bullet.
2. Bullet Type - The various types of bullet can effect performance. As was noted the Fiocchi HPs don't run as well as the V-max and both act diffently to the FMJ. They have causal effects on the external ballistics of a bullet. So too does the base of the bullet. Flat base can perform worse than Boat Tail in some rifles and in others cause no difference. All this means that a 50gr V-Max BT bullet may perform much better than a 50gr HP Flat Base bullet in the same rifle.
3. Wrong twist rate - Depending on the quality of the rifle/barrel and the process of manufacturing some rifles may not actually be what they say they are. I've seen rifles that were marketed as 1:9 that were actually 1:8.625 and a 1:7 that when measured was 1:7.75. I have also seen a 308 that had three different twist rates. It started as 1:11.25, went to 1:12 then finished as 1:11.5. This is down to poor quality control and will definitely have an effect on how a bullet acts in relation to internal ballistics.
4. Grooves/Lands - The amount of grooves and lands and the type or design of them will effect the internal ballistics. This is also down to the process used in manufacturing. This debate is constantly on going and there is no definitive answer on the actual effects but the theory held by some is that the more lands/grooves the more of the bullet bearing surface makes contact and the slower the bullet travels. Also whether the lands/grooves are standard, 5R, etc. So standard is cut "straight" edged while 5R have a "sloped" side meaning less surface to make contact which improves speeds, etc.
5. Propellant - Various manufacturers use various types of propellant. Look at Superformance. Burns hot, and is on average 10% faster than the equivalent in another brand. Its why people have such different opinions on their quality. Faster is not always better and if you have a certain twist with the "right" weight bullet the hot propellant can cause destablisation regardless because of the speed the bullet exits the barrel at. Its why you might get the 55gr superformance going poorly or not grouping and a 55gr V-max doing 300fps less working excellently. Effectively the same bullet, but the "excessive" speed causes stability issues.
6. Seating Depth - One of the most important aspects of any round, the depth at which the bullet is seated. I have first hand experience of this from reloading for F-Class and can personally say how a change of only four or five thousands of an inch can cause a 2.75 inch group at 1,000 yards to go to 19 inches. Depending on the quality control of the manufacturer and the rifle itself the SAMMI spec they [the manufacturer] use can cause some rounds to perform better than others and in some cases the same round to perform differently from batch to batch.

You have all experienced this at some point, possibly without even knowing it. Have you ever had a mate tell you a certain bullet runs perfectly in their rifle and because your rifle is the same caliber and twist rate you try them only to find them average to poor. That difference in performance is caused by one of the above (if we exclude shooter error).

gunny123 wrote: »

What happens if you put a light bullet through a barrel with a fast twist , eg. 1:7 ?

It may not stablise and you'll get inconsistent and unpredictable groupings. You may in worse case scenarios get anything from keyholing (where the bullet does not stablise at all and tumbles rather than goes tip first into the target) to bullet destruction where the combination of heat, friction, and centrifugal force can cause jacket failure and bullet “blow-ups” if you spin your bullets too fast.

clivej

Don't forget the CZ range of rifles.

My CZ .223 varmnt 1-9 twist will shoot the VMax 40gr very well. The main fodder I feed it is the Vmax and VShock 55gr. The foxes never complained with any of the rounds that hit them.