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

[Jvoelcker]

A Tikka T3 action will be perfectly adequate and as light as they come - it's probably worth comparing any custom options with this benchmark and assessing whether it's worth the considerable extra cost for very little practical gain. If you prefer the bottom metal and magazine options that a Remington 700 based custom action offers then go with that.

You seem to know what barrel you want. Choose a stock and magazine / bottom metal that you want then that will narrow down your choice of action.

Thanks. Not fully settled on a barrel yet, but have a reasonable idea and a debate for another day.

Yes, plenty of actions out there, just trying to work out main differences/benefits. Not looking for a 'pretty' one, just want one that cycles the 6.5PRC rounds well from a magazine.

 

[badmolassesaccident]

Twist Rate - I'd recommend Googling this where it is explained better than I can. Plus there are calculators. How I understand it is that this is not a compromise, its blank or white, either a twist rate will stabilize a bullet of a given length and speed or it won't. Generally the standard twist rates are that way for a reason, manufactures know they will stabilize the range of ammo for a particular calibre. BUT longer copper bullets (for a given weight) has changed things slightly.

Actually there is some greyness in twist rate. If a bullet is marginally stable, it will not tumble and it will make a clean hole in a target. However is will wobble as it heads downrange and that wobble will increase drag. This will manifest as a more rapid loss of downrange velocity/energy and reduced BC.

 

[Jvoelcker]

Barrel Length - You preferred barrel length is a series of massive compromises.

Yes, a seperate headache to deal with - thought I would just start on the action today

Will you fit a moderator and if so what weight and type?

Yes, can't remember the brand, but over barrel one and light weight.

If so you'll want shorter for stalking / ease of carrying / mounting and longer for the type of foxing distances you're talking about, where every fps counts.

Yes, it will need to be a compromise. I think my current Howa is a 24" barrel. That is part of the appeal of something like an R8 with the shorter action making a longer barrel more manageable.

But you reload so can fine tune things. Somewhere in between maybe?

Yes although assumed I would be around the 25" mark.

Actions - Sorry I don't have much to say about this. All modern mauser-style bolt actions work really well.

I know nothing about them, but it appears to be quite a 'thing' that we can spend hours debating about.

Twist Rate - I'd recommend Googling this where it is explained better than I can. Plus there are calculators. How I understand it is that this is not a compromise, its blank or white, either a twist rate will stabilize a bullet of a given length and speed or it won't. Generally the standard twist rates are that way for a reason, manufactures know they will stabilize the range of ammo for a particular calibre. BUT longer copper bullets (for a given weight) has changed things slightly.

The twist rate side of things is pretty straight forward and plenty of info online to follow - 1:8 seems to be the recommended one for the 6.5PRC and no doubt there will be 101 exceptions to that rule.

Thanks.

 

[Jvoelcker]

39 posts (Before mine) and hardly any addressing the OPs initial question.
Bit of criticism too.
Ken.

Yes.

 

[Jvoelcker]

I spoke to a few aswell, like you say, some, 1 in particular, was very arrogant. I ended up going with dave wilde, very pleasant to talk to, and listened to what I was after.

Yes, quite astounding the responses. Have heard good things about Valkyrie. Best response so far from a local chap to me, but think I really need to get a better idea of the requirements myself so I have atleast a vague clue about what he is talking about.

 

[Twodogs]

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

Apologies if any repeats.

With regards the action, the more metal in it the stiffer it will be and will therefore help with accuracy, less body flex, though not so important with front locking bolts. A heavier action will absorb more recoil than a corresponding lighter action potentially further increasing accuracy.
Assume the action will be a short action.

Possibly if using a large diameter scope body or a fancy scope the height of the bolt lift (the height the bolt handle raises to on opening) may be important. The action choice may also direct whether you can feed through the breech opening or whether it can be mag fed only.

Push feed v controlled feed?

Scope mounting options I.e. built in picitanny rails, Any moa inclination on any inbuilt scope rail?

Also consider the barrel to action fit. Some barrels are press fitted, some screw fitted and some interchangeable. Consideration should be given as to whether you may want to change the barrel in due course. The 6.5 is allegedly heavier going on the barrels, than the likes of the Creedmore, but if used as a hunting rifle is not likely to be an issue, but if used for sustained fire in target shooting it could mean barrel replacement sooner than you expect.

When considering actions also consider build and after market accessories. Anything built on a Remmy 700 action will have many more options than say something built on a Sako action.

As I understand it a gain or reduction of 1” of barrel length will correspondingly increase or decrease muzzle velocity by about 25fps. Choice of propellant must be suitable for barrel length, no point in shooting a powder burning flame out the muzzle. Will you be using a muzzle brake and/or a moderator, this could influence, partially at least, barrel length.

With regards chambering. Have you considered any chamber details, lead or throat dimensions? Possibly all irrelevant.

 

[Jvoelcker]

Apologies if any repeats.

No worries.

With regards the action, the more metal in it the stiffer it will be and will therefore help with accuracy, less body flex, though not so important with front locking bolts. A heavier action will absorb more recoil than a corresponding lighter action potentially further increasing accuracy.

OK

Assume the action will be a short action.

I believe so, just.

Possibly if using a large diameter scope body or a fancy scope the height of the bolt lift (the height the bolt handle raises to on opening) may be important. The action choice may also direct whether you can feed through the breech opening or whether it can be mag fed only.

OK. Currently mainly using a Drone Pro and occasional a S&B 8x56. The Drone is a bit of a lump and I am keen to get it sitting lower if possible, but at the same time want to have a good rail setup so that I can more easily swap scopes - the Blaser setup appeals a lot for that reason.

Push feed v controlled feed?

You have lost me there....

Scope mounting options I.e. built in picitanny rails, Any moa inclination on any inbuilt scope rail?

See above. I don't need any moa inclination although doesn't that depend a bit on the action? I remember being cauught out with it when I first got one of my scopes, but worked around it.

Also consider the barrel to action fit. Some barrels are press fitted, some screw fitted and some interchangeable.

Yes. Just assumed you got a barrel to match the action with fine tuning by the gunsmith.

Consideration should be given as to whether you may want to change the barrel in due course. The 6.5 is allegedly heavier going on the barrels, than the likes of the Creedmore, but if used as a hunting rifle is not likely to be an issue, but if used for sustained fire in target shooting it could mean barrel replacement sooner than you expect.

Yes, the PRC is considered to be a bit of a barrel eater, but hopefully shouldn't be rushing out to get replacements that often.

When considering actions also consider build and after market accessories. Anything built on a Remmy 700 action will have many more options than say something built on a Sako action.

OK. But my confusion is what is the difference between the Remmy 700 and a Sako? A straight pull like the Blaser is obviously different, but are the differences between the others that great? Someone further up posted a link to a page with loads of them, some at rediculous prices, but hard to tell the differences and benefits that I should be looking for.

As I understand it a gain or reduction of 1” of barrel length will correspondingly increase or decrease muzzle velocity by about 25fps.

OK, so going longer will give a bit more speed I guess up to a point?

Choice of propellant must be suitable for barrel length, no point in shooting a powder burning flame out the muzzle.

Yes, that will be up to the magician that cooks my rounds for me. He has done a good job with my .243 rounds.

Will you be using a muzzle brake and/or a moderator, this could influence, partially at least, barrel length.

Looking at a light weight over the barrel mod. Currently using Wildcat Evolutions so want something similar, but lighter if possible and have found someone that should be able to deliver what I need.

With regards chambering. Have you considered any chamber details, lead or throat dimensions? Possibly all irrelevant.

Ah, lost me there. That will be the gunsmiths job.

Thanks for the thougths.

 

[Lateral]

Warm side!? Ha. I’m not sure I’d want it any warmer!

With your COAL at 2.950 and 59.2gr is the load compressed? Surprised the bullet fits in the case to be fair

That helps explain the numbers though if you’re putting 59.2gr of RL-26 inside. Hornady indicate 57gr is max load for RL-26 and that’ll push a 143 ELD-X out of a 26” barrel around 3,150fps.

Being able to nearly achieve that out of a 22” barrel is pretty incredible.

RL-26 is slow burning, does QuickLoad show 100% burn rate out of your 22” barrel? Or is it a bit of a flamethrower?

It's not nearly as bad as it sounds

 

[Twodogs]

Push feed v controlled feed, good explanation in the link below

Controlled Feed vs. Push Feed Rifles - What's the Difference?

Chris from the Lucky Gunner Lounge team examines the differences between push feed and controlled feed rifles.

www.luckygunner.com

Lead/throat dimensions may or not be important for a 6.5 PRC, I do not know. In general if the lead is too short then you may not be able to load some of the super slippery ELD bullets without jamming and possibly causing pressure issues (Jamming is quite normal with ELD target rounds, in 6mm BR, PPC etc anyway) if the lead is to long then you may get to much jump which will effect accuracy. If you have difficulty sleeping read up on seating depth and its effect on performance, another rabbit hole to disappear down.

Re different actions, even within brands different models might not necessarily fit in other models stocks. As I understand it a Tikka T3 and a T3X will fit each others stocks but will not fit their predecessors the M595/695 And vice Vesta.
The differences can be many such as different recoil lug positioning, different recoil lug methodology and so forth, never bothered to study the differences just need to know if A fits B.

 

[Jvoelcker]

Push feed v controlled feed, good explanation in the link below

Controlled Feed vs. Push Feed Rifles - What's the Difference?

Chris from the Lucky Gunner Lounge team examines the differences between push feed and controlled feed rifles.

www.luckygunner.com

Ah, now I get it. My Howa is push feed and can get stuck occasionally if I feed slowly which is irritating, but more to do with ramp angles, etc.

Lead/throat dimensions may or not be important for a 6.5 PRC, I do not know. In general if the lead is too short then you may not be able to load some of the super slippery ELD bullets without jamming and possibly causing pressure issues (Jamming is quite normal with ELD target rounds, in 6mm BR, PPC etc anyway) if the lead is to long then you may get to much jump which will effect accuracy. If you have difficulty sleeping read up on seating depth and its effect on performance, another rabbit hole to disappear down.

I have encountered some info on this usually with reference to copper bullets. As and when I start reloading is when I'll need to dust off the books for that.

Re different actions, even within brands different models might not necessarily fit in other models stocks. As I understand it a Tikka T3 and a T3X will fit each others stocks but will not fit their predecessors the M595/695 And vice Vesta.
The differences can be many such as different recoil lug positioning, different recoil lug methodology and so forth, never bothered to study the differences just need to know if A fits B.

Yes, can see the link between action choice and stock, I guess as long as I end up with a popular action there should be plenty of choice.

Thanks again.

 

[MGD]

Talk to dave Wylde at valkyrie rifles ,I have had two rifles made in the last year a 224 valkyrie and 7mm saum and he could not be more help full and if I suggested something he didn't think was right it got discussed. Very reasonably priced the valkyrie shoots well under half minute at 600 yards saum yet to be shot,I will be back later this year for 308

 

[NP435]

If you say so. Would putting 0-400 yards be easier for you to digest?

Shouldn't you always?

Indeed yes!

 

[Scuffy]

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.

I would disagree. I’ve had my custom .243 Ackley for 10 years, and a .300 RUM for 8 years, and would only very re barrel in same calibre. However I would agree on terrible resale value, but didn’t invest in them for high future resale value.

 

[PhilRS03]

If you’re looking for a great off the shelf rifle, you won’t go far wrong with a Bergara (as long as it’s a short action non magnum!).

If you’re going custom, a potential option would be buy something like a Defiance Ruckus action and a Pre-Fit Proof research barrel. They do steel or Carbon pre-fits, all screw cut too. Just screw it on, tourque it and get it proofed. Then just choose a stock and a trigger. Personally I think the Trigger tech primary two stage is outstanding. Not the cheapest way to do it, but by far not the most expensive way either. I have a 6mm Creedmoor that I did the above with.

 

[GrizZLy9]

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?

Probably zero measurable difference providing everything is machined true/square and the ignition mechanism is consistent.

 

[Jvoelcker]

If you’re looking for a great off the shelf rifle, you won’t go far wrong with a Bergara (as long as it’s a short action non magnum!).

If you’re going custom, a potential option would be buy something like a Defiance Ruckus action and a Pre-Fit Proof research barrel. They do steel or Carbon pre-fits, all screw cut too. Just screw it on, tourque it and get it proofed. Then just choose a stock and a trigger. Personally I think the Trigger tech primary two stage is outstanding. Not the cheapest way to do it, but by far not the most expensive way either. I have a 6mm Creedmoor that I did the above with.

Thanks Phil, sounds sensible, will look those names up.

Did you build yours yourself or use someone local?

 

[Jvoelcker]

Probably zero measurable difference providing everything is machined true/square and the ignition mechanism is consistent.

Thanks

 

[PhilRS03]

Thanks Phil, sounds sensible, will look those names up.

Did you build yours yourself or use someone local?

No worries mate. I mean I use the term build loosely, you literally just need a good vice, an action wrench and some barrel clamps. All mega cheap. Defiance even sell an action wrench. You definitely don’t need a smith to do it, it’s literally just a case of screwing a barrel on and fitting a trigger (two solid pins as I’m sure you know!). Off the top of my head it probabaly cost me about 2.5k all up. A Damn sight cheaper than a custom job, whilst still being a custom job.. I’d recommend it to anyone. I also just used a Magpul bottom “plastic” and then just .308 P-Mags.

In my opinion Defiance and Proof are two of the best names in the business, you won’t get much better!

 

[Jvoelcker]

No worries mate. I mean I use the term build loosely, you literally just need a good vice, an action wrench and some barrel clamps. All mega cheap. Defiance even sell an action wrench. You definitely don’t need a smith to do it, it’s literally just a case of screwing a barrel on and fitting a trigger (two solid pins as I’m sure you know!). Off the top of my head it probabaly cost me about 2.5k all up. A Damn sight cheaper than a custom job, whilst still being a custom job.. I’d recommend it to anyone. I also just used a Magpul bottom “plastic” and then just .308 P-Mags. View attachment 298798
View attachment 298799
In my opinion Defiance and Proof are two of the best names in the business, you won’t get much better!

Thanks. Sounds like a sensible option. I run my own specialist garage and have been stripping and tweaking most guns I have had in the past, so had toyed with building my own.

Are you at Tac Coatings? Did a good job on my Howa last year.

 

[Utectok]

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

Material density is the same more or less and diameter is the same so basically lighter bullets are shorter and less prone to twist instability. The calculator is correct but you must put accurate information in regarding the bullets… Heavier copper bullets are the problem usually but a 1:8 twist usually suffices (copper being a less dense material hence longer bullets per weight )