Barrel lengths, twist rates, actions, effects on accuracy??? 🥴

[Jvoelcker]

Morning All,

I'm planning a new rifle to be used as my main rifle and am trying to get my head around all the different factors affecting accuracy and robustness. I have spoken to a few custom rifle builders with mixed success from straight arrogance/rudeness to hesitant secret squirrel approach. Either way it is evident that I need to know a lot more about the subject before approaching them again.

I'm starting to understand the relationship between barrel length, twist rate and bullet stabilisation - I'm going for a 6.5PRC so all quite important.

But, what about the action? Being able to feed the rounds cleanly is the most obvious thing, but beyond that how much difference do they make to accuracy?

At the end of the day I want something accurate, strong and as light as is practical, I dont' really care too much about what it looks like.

Thanks

 

[Lateral]

Is this a stalking rifle ? shooting out to circa 300m, of further ?

Will you use factory, or home loaded ammunition ?

I have an R8 6.5PRC, 22" barrel. Twist is 1 : 8.66". I home load Hornady ELD-X 143gn, which suits the barrel spec' perfectly. My load gives 3070fps, and it's very accurate.

As for rifle, unless you particularly want a custom rifle, I would have thought a Tikka T3 lite, or carbon would fit your requirements perfectly.

 

[Jamie020]

I'm hoping to get a 6.5 this year as well and have been considering the PRC variant. The PRC utilises long / high BC bullets and the barrel twist rate is important. Most bullet weights for the PRC are between 120gr to 150gr. If you’re wanting to shoot lighter bullets, you’ll need a faster twist rate (1:7 or 1:7.5) for the bullet to stabilise, if you’re intending to shoot heavier bullets (+140gr) then 1:8 twist should be suitable. I’d recommend using Berger’s twist rate calculator before deciding.

Barrel length will affect bullet velocities. Have a think about whether you’ll be using the rifle mostly for hunting and would prefer a compact barrel, or whether the extra velocity with a longer barrel is valuable for targets.

The 6.5 PRC is a short action round, will you be top feeding or using a magazine mostly? Once the bullet is chambered, I’d say the accuracy of the rifle will depend on your ability, the consistency of the ammo, and how good the barrel is?

 

[Trigger260]

Use a different smith!

 

[DRN]

Hi Jamie020 , you might want to edit your post and switch the "lighter"and "heavier"

 

[Dave_45]

I would 2nd the , talk to a different smith motion.

Ronin gets my vote

 

[Jamie020]

Is this a stalking rifle ? shooting out to circa 300m, of further ?

Will you use factory, or home loaded ammunition ?

I have an R8 6.5PRC, 22" barrel. Twist is 1 : 8.66". I home load Hornady ELD-X 143gn, which suits the barrel spec' perfectly. My load gives 3070fps, and it's very accurate.

As for rifle, unless you particularly want a custom rifle, I would have thought a Tikka T3 lite, or carbon would fit your requirements perfectly.

This is interesting, I asked Blaser to confirm the twist rate for the PRC and they confirmed their barrel was 1:8. I know their 6.5 Creed, 6.5x47 Lapua and 6.5-.284 Norma barrels etc. are alleged 1:8.66.

This makes quite a big difference according to the twist rate chart mentioned previously with regards to bullet stability. Taking your round from 'stable' to 'marginally stable', but if your rifle's accurate that's all that matters!

Have you tried any lighter bullets? If so, we're they accurate?

Do you mind sharing your load data please for the 143gr ELD-X? I'd imagine that's a pretty hot round if you're able to achieve 3070fps out of a 22" barrel? Your achieved velocity is greater than that suggested by Hornady for 5 powders (max load) out of a 26" barrel! Very interested. Have you had any experience with RL-26?

 

[Jamie020]

Hi Jamie020 , you might want to edit your post and switch the "lighter"and "heavier"

Not so sure bud? Just relaying information from what I thought was a reputable bullet manufacture. Try their twist rate calculator and see please. The results indicate lighter bullets need greater twist to stabilise compared with heavier bullets.

Edit: assuming the bullets are of equal length and speed

 

[Jvoelcker]

Is this a stalking rifle ? shooting out to circa 300m, of further ?

Will you use factory, or home loaded ammunition ?

I have an R8 6.5PRC, 22" barrel. Twist is 1 : 8.66". I home load Hornady ELD-X 143gn, which suits the barrel spec' perfectly. My load gives 3070fps, and it's very accurate.

As for rifle, unless you particularly want a custom rifle, I would have thought a Tikka T3 lite, or carbon would fit your requirements perfectly.

Wasn't going to go in to specifics, more general info, however.

Stalking and foxing.
300+ when required.
Essentially home loads.

Looked at R8, but they were recommending the 650mm barrel.

Want to finalise specs before looking at branded or custom builds.

 

[cjs66]

Is this a stalking rifle ? shooting out to circa 300m, of further ?

Will you use factory, or home loaded ammunition ?

I have an R8 6.5PRC, 22" barrel. Twist is 1 : 8.66". I home load Hornady ELD-X 143gn, which suits the barrel spec' perfectly. My load gives 3070fps, and it's very accurate.

As for rifle, unless you particularly want a custom rifle, I would have thought a Tikka T3 lite, or carbon would fit your requirements perfectly.

Hi, I’m in no way doubting your facts but that’s very impressive. I’ve never come across the PRC but that’s cracking on. My Swede, (hat on) R8 does 2800 fps max with a Nosler 120 bt and I thought that was quick, my 140g SSTs with N160 are doing about 2700 and the Nosler140g with RL 22 are a tad slower. Do you use this just for punching paper or stalk with it too?
I’ve the 22/250 barrel for the same rifle so I’m a bit of a speed freak, hence the interest.

cjs

 

[Jvoelcker]

Use a different smith!

Spoken to a few and rejected a few, but feel I need to learn a bit more about the subject before talking to more so I end up with what I want rather than what someone is selling.

 

[sh1kar]

Spoken to a few and rejected a few, but feel I need to learn a bit more about the subject before talking to more so I end up with what I want rather than what someone is selling.

talk to Callum Ferguson or Neil McKillop Both very knowledgeable and personable people

S

 

[Jvoelcker]

I'm hoping to get a 6.5 this year as well and have been considering the PRC variant. The PRC utilises long / high BC bullets and the barrel twist rate is important. Most bullet weights for the PRC are between 120gr to 150gr. If you’re wanting to shoot lighter bullets, you’ll need a faster twist rate (1:7 or 1:7.5) for the bullet to stabilise, if you’re intending to shoot heavier bullets (+140gr) then 1:8 twist should be suitable. I’d recommend using Berger’s twist rate calculator before deciding.

Thanks, Useful info. Will look up that calculator.

Barrel length will affect bullet velocities. Have a think about whether you’ll be using the rifle mostly for hunting and would prefer a compact barrel, or whether the extra velocity with a longer barrel is valuable for targets.

Purely hunting, but able to get out to 300-400yards.

The 6.5 PRC is a short action round, will you be top feeding or using a magazine mostly?

Prefer to swap magazines.

Once the bullet is chambered, I’d say the accuracy of the rifle will depend on your ability, the consistency of the ammo, and how good the barrel is?

Well obviously I am a crack marksman and all ammo is 100% consistent, hence just asking about the barrels and actions

 

[Jvoelcker]

talk to Callum Ferguson or Neil McKillop Both very knowledgeable and personable people

S

Thanks. Will add them to the list when I have a clearer idea of what I want.

 

[Jamie020]

Not so sure bud? Just relaying information from what I thought was a reputable bullet manufacture. Try their twist rate calculator and see please. The results indicate lighter bullets need greater twist to stabilise compared with heavier bullets.

Edit: assuming the bullets are of equal length and speed

I'd agree in practical terms that wouldn't likely be the case as lighter bullets normally have a reduced length as well as BC.

I’ve just compared the 143gr ELD-X with 130gr ELD:
143gr ELD-X @ 2,950fps, length of bullet 1.48inch, 1:8 twist the stability factor is 1.42 (recommended barrel twist is 1:7.75)
130gr ELD @ 3,100fps, length of bullet 1.45inch, 1:8 twist the stability factor is 1.39 (recommended barrel twist is 1:7.5)

Hopefully we can agree it's not as straight forward as heavier bullets need greater twist than lighter, vice versa. As before, my suggestion to @Jvoelcker to use the calculator before deciding on barrel twist seems valid..

 

[jcampbellsmith]

This is a little dated - Custom Actions Worthwhile also browsing what actions the PRS guys are currently using. I personally favour the Borden Alpine, but there are a lot of comparable actions out there.
Regards
JCS

 

[Jamie020]

Wasn't going to go in to specifics, more general info, however.

Stalking and foxing.
300+ when required.
Essentially home loads.

Looked at R8, but they were recommending the 650mm barrel.

Want to finalise specs before looking at branded or custom builds.

I was going to check with Blaser to see if they'll still be producing 650mm barrels going forward for the 6.5 PRC. On their 2022 calibre overview the 650mm barrel is shown as an option (and there's a few kicking about on Guntrader) but when I picked up the 2023 calibre overview from the shooting show this year it's been removed.

 

[HonestJohn]

I'd avoid anything custom these days, even if you think it's your 'for life' gun, 9/10 times in a couple years you want to move on, and you will find your fancy 'custom' has zero resale value.

as for PRC, unless you're a target shooter, why bother with having very limited access to loaded ammunition? you are also not really using the 6.5's inherent ability to shoot heavy for caliber bullets up to 156g.

personally, I'd start back at the drawing board and think about 'why' you want a certain cartridge if it's just for hedgerow hunting.

 

[jcampbellsmith]

I'd avoid anything custom these days, even if you think it's your 'for life' gun, 9/10 times in a couple years you want to move on, and you will find your fancy 'custom' has zero resale value.

I wouldn't agree with that. The rifle below was a 6XC, it's now a 260 Rem, it could become another 260 Rem in the future, or a 308 Win. I have the stock, action, trigger and bottom metal. I've a fair amount of choice in Short Action each time I need a new barrel.
Regards
JCS

 

[HonestJohn]

I wouldn't agree with that. The rifle below was a 6XC, it's now a 260 Rem, it could become another 260 Rem in the future, or a 308 Win. I have the stock, action, trigger and bottom metal. I've a fair amount of choice in Short Action each time I need a new barrel.
Regards
JCS

true, but you're the exception rather than the rule John