Pacnor barrel importers

[Ro6.5]

Does anyone no who the uk importers for pacnor barrels are?

 

I am after a 1 in 8 twist 20 cal barrel. Or does anyone no where there is one? It's a ten month wait for a krieger from prs and I could do with one quicker than that. Dolphin only have 1 in 9 twist.

 

it needs to be a 1in 8 to stableise 55grain bergers. Any advice welcome.

Rob

[Shuggy]

Neil McKillop (Dasherman) likes to use Pacnor barrels and seemed to have a decent stock the last time I was at his workshop.

[Ro6.5]

Neil McKillop (Dasherman) likes to use Pacnor barrels and seemed to have a decent stock the last time I was at his workshop.

Thanks. Have you any contact details for him? If you could pm me them that would be appreciated.

[garyw]

go to the home page [ukv] scroll down and on the right hand side-Mckillop engineering.Neil is yer man.

[Big Al]

Does anyone no who the uk importers for pacnor barrels are?

 

I am after a 1 in 8 twist 20 cal barrel. Or does anyone no where there is one? It's a ten month wait for a krieger from prs and I could do with one quicker than that. Dolphin only have 1 in 9 twist.

 

it needs to be a 1in 8 to stableise 55grain bergers. Any advice welcome.

Rob

 

What are you building?

[gunner]

Prs you mean callum ? Precision rifle services ? Thats where i got my krieger 9twist , what 20 you building ? A 20 BR in a 9 iv read will stabilize , or even 20 PPC , the latter being unbelievable accuracy

[Ro6.5]

Prs you mean callum ? Precision rifle services ? Thats where i got my krieger 9twist , what 20 you building ? A 20 BR in a 9 iv read will stabilize , or even 20 PPC , the latter being unbelievable accuracy

 

Yes callum. That's where my last one came from. The Berger website said it would only just stabilize in a 1-9 at 4100 fps and I didn't want to risk it.

[Ro6.5]

What are you building?

Not a new build just re barreling my 20x47lapua. It's not shot out yet but started to crack so just want to be prepared.

[Big Al]

Not a new build just re barreling my 20x47lapua. It's not shot out yet but started to crack so just want to be prepared.

 

The is lots of evidence that a 9 twist will stabilise these 55r Bergers, I have a 20BR pushing them at 3550 and a 20Tac pushing them at 3175, both are stable. Laurie brought up a valid point though that even if they are stable there may be a small drop in efficiency and the BC may not be optimised. I have yet to look into this.

 

I guess if you have already had an 8 twist then that would be the way you would prefer to go again, when looking to build a 20BR at Christmas I rang all the names in the UK without any success, an 8 twist .20 barrel is such an oddball for UK shooters.

 

Good luck.

 

ps, out of interest what load were you running in the 20x47 and how many rounds did you get out of the barrel?

[gbal]

Al,if you have not checked it out: Berger Twist Rate Stability Calculator is the place to start.

 

I don't know how the 'efficiency'/possible loss of BC would be field checked 'locally',as it would need at least two near identical rifles,one fully stabilised and the other not,and shot side by side.

And the first one needs a 7.75 twist,good luck sourcing that!

B Litz though is generally on the ball.

I suppose though,shooter experience with 1in 9/whatever would be good enough to see if bullets perform well enough,whether or not to full potential.

 

g

[Si-Snipe]

Al,if you have not checked it out: Berger Twist Rate Stability Calculator is the place to start.

I don't know how the 'efficiency'/possible loss of BC would be field checked 'locally',as it would need at least two near identical rifles,one fully stabilised and the other not,and shot side by side.

And the first one needs a 7.75 twist,good luck sourcing that!

B Litz though is generally on the ball.

I suppose though,shooter experience with 1in 9/whatever would be good enough to see if bullets perform well enough,whether or not to full potential.

g

I'm not sure how much I trust the stability calculator especially in smaller cals. Sub 0.224. If you run 17 Rem: 25g vmax at 4000 through a 1:9 it comes out at 0.951 (unstable).

A .204 with the 32g bullets it was designed to shoot and doing 4000 fps through the 1:12 it was based around is 1.09 (just marginal)

[Big Al]

I'm not sure how much I trust the stability calculator especially in smaller cals. Sub 0.224. If you run 17 Rem: 25g vmax at 4000 through a 1:9 it comes out at 0.951 (unstable).

A .204 with the 32g bullets it was designed to shoot and doing 4000 fps through the 1:12 it was based around is 1.09 (just marginal)

 

Agreed.

 

There are lots of examples of perfectly performing bullet weights and twists that come up as marginal or even unstable using the Berger stability calculator, it errs very much on the cautious side from what I can see.

[Big Al]

I don't know how the 'efficiency'/possible loss of BC would be field checked 'locally',as it would need at least two near identical rifles,one fully stabilised and the other not,and shot side by side.

And the first one needs a 7.75 twist,good luck sourcing that!

B Litz though is generally on the ball.

I suppose though,shooter experience with 1in 9/whatever would be good enough to see if bullets perform well enough,whether or not to full potential.

 

g

 

 

Surely if I verify my MV then find out my real drop at say 300yds that will tell me if my BC is as it should be or not George?

 

We all have software that will predict bullet drop from a known MV and if mine drops more than expected and if the MV is correct it can only be the BC that isn't right?

[Sherlock]

 

Agreed.

 

There are lots of examples of perfectly performing bullet weights and twists that come up as marginal or even unstable using the Berger stability calculator, it errs very much on the cautious side from what I can see.

 

Yes the Berger stability calc - It even places Bergers own bullets , using the twist rate they recommend for them ...... in to the just marginal stability range. LOL

[gbal]

Al,that's pretty much what my last sentence says.

 

Your last sentence hints at some of the issues too-if it doesn't shoot right,where is the 'error'- given the less than perfect ballistic engines being used with some dubiuos assumtions ,some hard wired,and distinctly dodgy input data-include chrono errors- it all gets a bit iffy....

The Litz/Berger output is probably conservative,and the actual effects are not quantified,in any case.

 

Hence my pragmatic conclusion,if it seems ok,you will never know just how efficient it is compared to optimised potential,and it's not going to matter if it works on 400y crows.

 

All this stuff is guidlines for the wise.

 

I'm not sure if my 17 rem was perfectly efficient or not-I don't think BC (rather BCs) had been discovered/invented at the time,but it did a pretty effective job,within it's real world range and conditions envelope. There weren't (m)any chronos either,so that may have helped reduce noise in the system!

(though a reliable chrono -with regularly checked calibration-is very useful,like any precision tool.I'd trade read out of SD,rather than actual velocities most days-variation affects POI,consistent velocity doesn't.)

 

Since they all simply have to be verified by careful real world shooting to distance,and that data is definitive,software predictions are secondary to practise...and practice! (at gongs).

 

:-)

g

[Ro6.5]

So! The gist of this is you guys think I can get away with a 1 in 9 twist barrel?

[Si-Snipe]

Yes the Berger stability calc - It even places Bergers own bullets , using the twist rate they recommend for them ...... in to the just marginal stability range. LOL

It's weird and doesn't make sense.

[Ro6.5]

ps, out of interest what load were you running in the 20x47 and how many rounds did you get out of the barrel?

I settled on a accurate load of 37.5 grain of reloader 17 @3890fps and it has done 800 rounds ish

[gbal]

So! The gist of this is you guys think I can get away with a 1 in 9 twist barrel?

Well, some claim ok performance-but what does Berger Stability Twist predictor say-

 

You need a velocity,of course for the 55gBergers.

 

It seems to say 1.2-marginal stability.....(as I input/read it) but read on ...'you may shoot good groups,but BC is compromised'

 

Alas,"good" and "compromised" are somewhat vague-as they have to be around boundaries-on a continuous scale....

Note_Berger are not denying good groups might be found,they are saying that even with good groups,marginally stabilised bullets may have compromised ballistic performance-the drop/drift might be worse than the BC predicts...but not quantifiable in general...

 

I can't read it as a guarantee that you will be delighted,nor that you will know what,if any,improvement might have come from a faster twist....and that's true of actual shooting by users also...."might shoot good groups" means also 'might not"....Seems to be saying 'you might be OK,but you won't know if it could have been better,and it just might not be good....",which is I think,where you came in...?

 

Elsewhere there are examples of allegedly the same twist shooting ok in one rifle,not ok in another-which is not unexpected near a cut off boundary-some do,some don't.Tough call for the buyer-but you know that.

 

gbal

[Big Al]

So! The gist of this is you guys think I can get away with a 1 in 9 twist barrel?

 

Duplicate post - see below.

[Big Al]

So! The gist of this is you guys think I can get away with a 1 in 9 twist barrel?

 

If you take a look on suabier.com there are lots of guys using 9 twists, as I said earlier, Ive had 1/2 groups at 200yds from my 20BR and it regularly shoots 1/4 at 100 providing I do my bit. I spoke too Callum Ferguson about this recently and he wasn't keen on using a 9 twist so make of that what you will?

 

I guess its a risk, if you end up with a 9 twist that won't shoot the 55's then your stuck with a pig in a poke as you won't have much chance to drive 39/40's at the speeds the 20x47 would be capable of due to the overly fast twist, they start to blow up at much over 4000fps, Ive seen this myself with my own 20BR.

 

20x47 is the extreme end of the 20's, can I ask what you were using it for?

[gbal]

Al,not disagreeing-note that Berger say good groups are possible-it's drop/drift that might suffer....that will not likely be much of an issue at 200y,might start to show as distance increases....but it might not be much...BC is overrated in relatively short range varminting...except at the extremes,for those super slim ones... :-)

Bullet break up certainly compromises-the 17 was the worst shotgun I can imagine!

 

g

[Ro6.5]

If you take a look on suabier.com there are lots of guys using 9 twists, as I said earlier, Ive had 1/2 groups at 200yds from my 20BR and it regularly shoots 1/4 at 100 providing I do my bit. I spoke too Callum Ferguson about this recently and he wasn't keen on using a 9 twist so make of that what you will?

 

I guess its a risk, if you end up with a 9 twist that won't shoot the 55's then your stuck with a pig in a poke as you won't have much chance to drive 39/40's at the speeds the 20x47 would be capable of due to the overly fast twist, they start to blow up at much over 4000fps, Ive seen this myself with my own 20BR.

 

20x47 is the extreme end of the 20's, can I ask what you were using it for?

Predominantly foxes and long rang vermin! I no a 22.250 will do that job but I enjoy the caliber and having something a little different. It's a lovely caliber to shoot with good velocity and high bc. it's a excellent round on foxes never had one move a muscle after the shot.