Let’s hope they make the varmint in 1~8” twist as well.
Tikka changed twist rate for .243?
- Thread starter Farmer_J
- Start date
I have t3 223's in 1-8, and 1-10. I haven; t seen a 1-12" in years.
Faster twist rates shoot 53 grain VM really well. ~Muir
This isn’t the case. I have used and seen used at least half a dozen 1-8 twist .243 semi customs. All shoot 55gr varmint bullets phenomenally well, then handling all the way up to 105-108gr for long range. In 6mm a 1-8 twist DOES NOT compromise use with the lightest for caliber bullets. It’s about time factory rifles were given a sensible twist rate
I have seen 6.5 mm bullets dust from 6.5x284 fairly heavy ones when i was into F class . The above might well be true and i cannot dispute what i personally haven't done but lets put it this way " i would not be brave enough to build such a rifle , if it had to do service with the light stuff " such a bullet would be close to 4000 fps as a full stacked load ( thats some fast spinning , faster rotation than what i have already seen dust with a higher frangibility than those 6.5 target bullets that did ) . wont happen every time ( alitude, temp , humidity, air pressure etc etc ) all play a part . Sort of still got an itch for another 243 win , will let others do the crying before i personally do the buying of a fast twist .243 though ! If fast twist worked with everything we would make nothing but fast twist , those who walked this path before us didn't do things as they did on a whim .
Well, all I can say is that you are wrong. There is no crying involved! Fast twist .243s are the go to rifle for me and my friends, with litterally thousands of foxes and crows taken with 55 and 58gr. It’s fact, they handle them fine. In all weathers, conditions and speeds that we could shoot them.
Smellydog
Well-Known Member
Your forgetting bullet construction and it's ability to take or not take high RPM.
Ronin
Distinguished Member
As others have posted - the faster twist 6mm tend to handle most bulket classes
The slower twist have limitations to approximately 90 g class then become erratic above
Yes you can “overspin” the bullets causing explosive fragmentation in the air
But this can be overcome by tuning the load down (reducing VO ) if you wanted or “must” use such bullets
This isn’t new - there are many accounts of bullets not reaching target due to centrifugal forces
The trend towards faster twist is manufacturers responding to customers asking for this so they may use heavier class bullets
The slower twist have limitations to approximately 90 g class then become erratic above
Yes you can “overspin” the bullets causing explosive fragmentation in the air
But this can be overcome by tuning the load down (reducing VO ) if you wanted or “must” use such bullets
This isn’t new - there are many accounts of bullets not reaching target due to centrifugal forces
The trend towards faster twist is manufacturers responding to customers asking for this so they may use heavier class bullets
Plenty of foxes killed by my mates fast twist .243 and 58grn bullets.
Not wrong at all , just you have yet to experiance it ! A lot depends on a lot air pressure , actual velocity , actual twist rate etc . However not all will dust but frankly speaking as Ronin has suggested slowing them down works but why buy a .243 and shoot the light bullet class 55/58 etc through them ? The purpose of the light end 6mm varmint bullets in to blow up fast even at extended ranges. For the record i think a fast twist 243 shooting 100-120 copper would make an awesome all uk deer round longer and sleeker than a 6.5mm in the same weight range that i use myself through the 260. That sort of animal needs taming for the good of the light fast and frangible though ( which of course is the reason the 243 has been so popular 100 grain heavy deer bullets , maybe partition types even ! the next day out splating crows two fields away with 55 / 58 grain vamint bullets . out on Fox and smaller deer with say a 70 grain nosler BT .
Well how long do you expect us to wait for a bullet blow up? If it hasn’t happened in the last 10 years over thousands of rounds through multiple rifles in all weathers with several different hot homeloads and standard factory ammo then I think you can safely say that it isn’t an issue.
a lot depends on a lot , like the actual velocity and air pressure etc . However it is a real thing, i wonder how many folks assume a bum shot when it occurs ? with a heavy target rifle shot off stands, benches with rear bags you actually see it though ! Your last post , totally dismissed it could even happen but those with experience in long range competitive F class are well aware of it with heavier bullets not even designed to expand . Remember when your really steady in the rests and rear bags you can catch bullets letting go and one off paper ( after sighters) is rare when your looking for a 5 shot sub 5" group at 1000 yards to place, you sort of notice more and don't put such events down to a pulled shot or wind change . A thousand yard target is kind of large compared to the a4 paper at a couple of hundred yards . I understand your defending your original incorrect quoting of my statement but surely there is here something to enter your knowledge bank and learn from . You could shoot a std twist high velocity , lightweight , frangible varmint bullet from a std twist 243 win for a lifetime without it happening but you wont when you go to the fast twist rates , next time you call a bad shot think on eh ?
What BTW are you calling a fast twist ?
norcan
Well-Known Member
It’s not magic; things like temperature and air pressure only matter to the degree that they affect the muzzle velocity and therefore the rotational velocity.
When the bullet spins faster than the jacket can withstand, it disintegrates. If you want to know how fast it’s spinning, the formula is:
MV x 720/twist = RPM
Consider a 55-grain bullet exiting at 3900 fps from a 1:8”-twist barrel:
3900 x 720/8 = 3900 x 90 = 351000 rpm
This near or beyond what most thin-jacketed varmint bullets can take, so if you have a 1:8” barrel, you’re probably going to want to use either stronger-walled bullets, or choose something other than the absolute lightest weights.
When the bullet spins faster than the jacket can withstand, it disintegrates. If you want to know how fast it’s spinning, the formula is:
MV x 720/twist = RPM
Consider a 55-grain bullet exiting at 3900 fps from a 1:8”-twist barrel:
3900 x 720/8 = 3900 x 90 = 351000 rpm
This near or beyond what most thin-jacketed varmint bullets can take, so if you have a 1:8” barrel, you’re probably going to want to use either stronger-walled bullets, or choose something other than the absolute lightest weights.
1-8 twist. And I never said it couldn’t happen, I know for a fact that it does in certain calibres and twist rates. What I did say is that it won’t happen in a 1-8 twist.243 with hornady v max bullets. I don’t need preaching to about long range shooting, im not just an average stalker who shoots 150m, I shoot past 1000m weekly on my own ground. I will change my original statement to this: Although I cannot guarantee that anyone else would replicate my experience, i have seen at least 10,000 55 and 58grain projectiles pushed through 1-8 twist barrels chambered in .243win. At no point have I seen any problems due to over stabilisation. This includes a lot of target work at what is extended range for these projectiles. In my own opinion and experience, it is completely safe to fit a 1-8 twist barrel to a .243 that is going to be used with light bullets, despite the opinions of certain internet experts who have zero experience with that bullet weight, caliber and twist rate combination purely because they have seen a bullet breakup in a different caliber/twist/bullet combination.
Fin_Bainbridge
Member
Does anybody know what year and or date that the Tika T3X .243 changed from 1-10 to 1-8 twist
Many thanks Fin.
Many thanks Fin.
You’d need to be running a .243 at max pressure with a double length barrel to shed the jackets off a 58gr
Poor quality bullets and hyper velocity cartridges are the reason this scare mongering story exists
Its not relevant to your widely used stalking and vermin cartridges using quality bullets.
The smaller bullets/calibres are most prone to it, not least because 4-4500fpa is very achievable but also because the jackets get thinner and thinner as you get into a 30-40gr bullet range
As for 120gr copper in a .243…
Firstly youd need to find one
Then you would suffer the exact same issue of massive velocity drop compared to the lower weight class and remove the efficacy of the non lead round by doing so
Either stick to the .243 and 58-90gr/108gr if you have the barrel)
Or get a 6.5
Poor quality bullets and hyper velocity cartridges are the reason this scare mongering story exists
Its not relevant to your widely used stalking and vermin cartridges using quality bullets.
The smaller bullets/calibres are most prone to it, not least because 4-4500fpa is very achievable but also because the jackets get thinner and thinner as you get into a 30-40gr bullet range
As for 120gr copper in a .243…
Firstly youd need to find one
Then you would suffer the exact same issue of massive velocity drop compared to the lower weight class and remove the efficacy of the non lead round by doing so
Either stick to the .243 and 58-90gr/108gr if you have the barrel)
Or get a 6.5
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