Is a 1:7 twist too much for 55g .233 ammo?

[carbonrod]

Both guns have disadvantages, and disadvantages. They will both likely shoot OK though. I would go the other way and find out which one had the longer magazine so I could shoot 90grs from a mag, and buy it. If either are long enough that is.

I suspect that they would both be similar with lighter bullets.

 

[beltfed]

Depending on the bullet(s) you are planning on using... the 8 twist may not work well with the 90s. If you plan on stripping rounds from a magazine, this likely isn't an issue.
I had a Savage 12VLS with a 7 twist. While it shot well, feeding was a issue.
I sold it before I could make the mistake of pouring money into it to make it something it wasn't.

 

[Boomer]

I wanted a fast twist barrel for my .222 so I got a 1:7 Gaillard. That rifle shot like a house on fire, with a 12X scope I could cut the link of a 3/16" chain and call which side of the link I would cut and that was with 52 gr MKs. So the answer to the OPs question is that short bullets work fine in fast twist barrels. The exception to the rule are thin skinned bullets of the non-ricocheting variety. At the time I tried Sierra Blitz and Hornady SX, neither of which would take the fast spin the 1:7 barrel induced, and probably four bullets out of ten didn't make it to the target. Here's the thi8ng about a fast twist barrel though, while it shoots short bullets very well, it shoots long ones very well also, but a standard or slow twist barrel won't shoot long, heavy for caliber bullets. Case in point, on a recent trip to the city I stopped at wholesale and Cabelas to find some .224/45 TSXs. I loaded some 53s for his .22-250 and they wouldn't stabilize, so I wanted to try the 45s. Not only didn't they have any of the light weight TSXs, the only ones they did have was .224/70s! It won't take long for the TSXs to develop a bad reputation selling those.

 

[agent_mango]

It seems the consensus is a fast twist will be fine for shooting high quality 55 gr rounds. However, is there a loss in velocity? How much slower will a 55 gr be out of a 7, 8, or 9 twist compared to a 12 twist?

My only 223 is an 8 twist, as for now I'm interested in 69-80 gr projectiles.

 

[kevin g]

I started out with the 69 gr Scenars in my 8 twist Tikka 223. Found the perfect load for the 100 yd game. .250 ....A little while back, I done some initial testing(70 rds total) with some Varget and the 80 gr A-Maxes. Gettin jiggy with it...awesome at 100 yds very...very close to the Scenars. I only used 5 shots at 200 yds (having too much fun and forgot to save a few) ....less than 3/4"....a little blustery and very hot conditions that day!!...Can't wait for further load developement PITA tho feedin that friggin "baby Tikka" by hand.

 

[icedragonmx]

Sako. I gave up on both Remington and Savage (700P an 12LVS) when I came to the realization they are crappy money pits.


sure you do....

My money pit before I work a load for it. Using my AR load on this target Will do a much longer OAL with the AI mag feed in the Savage 223 when I have time to do it proper...

77gr in 1-8 twist-

AR in 1-8 twist shooting 77gr SMKs Different day (I know you will razz me on the full page, but its the best so far)

 

[beltfed]

What's to razz? Those are some nice starts to some groups
There is no question Savages can shoot out of the box, but the quality just doesn't compare to the Sako and Tikkas. IMHO.

 

[Bolivar]

It seems the consensus is a fast twist will be fine for shooting high quality 55 gr rounds. However, is there a loss in velocity? How much slower will a 55 gr be out of a 7, 8, or 9 twist compared to a 12 twist?

My only 223 is an 8 twist, as for now I'm interested in 69-80 gr projectiles.

I am not aware of any velocity loss associated with barrel twist, only barrel length length. The bullets go just as fast, and the tighter twist causes them to have higher RPM.

 

[Trotter]

i never had any keyholes or anything but nice round holes in targets at 200 with the tikka 1:8. the AR will eat anything up to 100, just never tried it at 200 (its a 1:7 - 16"bbl.).

 

[AlexF]

I am not aware of any velocity loss associated with barrel twist, only barrel length length. The bullets go just as fast, and the tighter twist causes them to have higher RPM.

Normally around 3% of a bullet's energy is in rotational energy while 97% is in the form of kinetic energy.
If you double the rotational speed of the bullet, it's rotational energy is quadrupled to around 12% of the bullets total energy.

E total = E rotation + E translation
E bullet = 3% rotation + 97% kinetic (for a normal spin rate)
= 12% rotation + 88% kinetic (for 2 x normal spin rate)

This means that:

1. if total energy is the same, kinetic energy drop from 97% to 88% and you get a 10% loss in kinetic energy therefore a 5% drop in muzzle velocity,
2. the muzzle velocity is the same, total energy is 9% higher, therefore chamber pressure increases by around 9%,
3. or a mix of (1) and (2) and you lose only some velocity but chamber pressure increases somewhat.

Alex

 

[wagnerb]

I have a Savage 12VLP in .223 with the 1/7" twist. It "patterns" any 55grain factory load (I've tried a bunch), but it'll place consecutive shots out past 1100 yards in a 10" or so bull. Your results may vary, but I'm sticking with my Savage 12. Only thing it needs is more scope elevation...at 1100 yards the holdover gets a bit ridiculous.

 

[ArtyMan]

I have a Colt AR-15 with a 20" 1:7 bbl and it shoots bulk 55gr FMJ rounds really well. At 200m I have yet to see any keyholing or issues. At 100m rested with MFS 55gr it will do 2" all day.

 

[Sakonut]

20 inch TRG is 10.25lbs. 20inch Remington LTR is 7.5. I'll lug the LTR around for the 3 lbs of fit and feel, and potential accuracy loss.

But yes, a Remintgon will take nearly the same $ and more dicking around then the commie rifle.

Quick little history lesson, ain't no commie finns, they kicked them out over 90 years ago...just sayin' Besides, no commie country ever produced anything sako quality

 

[saskcop]

I am tagging this one for interest. I have shot tonnes of 55 grainers through a 1 in 7 twist with nary and issue. I have run my fair share of 52 grain match bullets through the 1 in 7 as well with good accuracy out to 300 yards. Can something be "over-stabilized", or is it just simply spinning faster?

 

[beltfed]

I have a Savage 12VLP in .223 with the 1/7" twist. ...but it'll place consecutive shots out past 1100 yards in a 10" or so bull.

Wow! With that consistency you should consider competing in F-Class. If it is truly shooting like that, you'd be winning pretty much every match out there....

 

[carbonrod]

Quick little history lesson, ain't no commie finns, they kicked them out over 90 years ago...just sayin' Besides, no commie country ever produced anything sako quality

As much as I like the Finnish, they are still commie.

 

[Miltiades]

I am tagging this one for interest. I have shot tonnes of 55 grainers through a 1 in 7 twist with nary and issue. I have run my fair share of 52 grain match bullets through the 1 in 7 as well with good accuracy out to 300 yards. Can something be "over-stabilized", or is it just simply spinning faster?

Whether a bullet can be over stabilized or not is still an open question. The "physics" behind rotating objects (like bullets from rifles) being much more accurate over longer distances than non rotating ones is based on conservation of angular momentum, the same principle as gyroscopes. In principle, then, a bullet spinning too fast compared to the norm, say a 55 gr from a 1/7" compared to that from 1/12", tends to resist change of trajectory more than the slower spinning one. So, over short distances, until the bullet slows down due to air drag, it resists following the ballistic trajectory dictated by gravity and can lose some accuracy. This is one reason also that some long match bullets shoot better MOA scores at 300 m, say, that at 100 m. However, where over stabilization plays more of a role is in the wound channel of a 55 gr out of 1/7" exactly because it resists flip over rotation and tumbling more than the same bullet from 1/12".

I've seen ballistic gel results with 55 gr from the two twist rates above and indeed the bullets from the slower twist created a large permanent cavity than the ones from the faster twist.