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  #61  
Old 11-14-2017, 08:46 AM
fish_e_o fish_e_o is offline
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Originally Posted by densa44 View Post
I calculated the rpm of bullets exiting the barrel once and they were extremely high and it is hard to believe that a higher rpm makes them more stable.

Maybe the different twists rates are just a marketing tool? As others have said, its how they shoot that counts.
you can see the results of an unstabilized bullet in the B.C.
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  #62  
Old 11-14-2017, 02:38 PM
Pathfinder76 Pathfinder76 is offline
 
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And the keyholes in your target. My goodness.
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  #63  
Old 11-14-2017, 03:11 PM
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Originally Posted by chuck View Post
And the keyholes in your target. My goodness.
lol ya that would typically be a sign
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  #64  
Old 11-14-2017, 09:36 PM
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Originally Posted by RickF View Post
With that combo you aren't anywhere close to enough velocity to make a V-Max come apart. It is possible you have an incredibly rough or flawed bore that is causing that thin-jacketed bullet to fail.
Don't remember stating velocity.....
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  #65  
Old 11-14-2017, 09:57 PM
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Originally Posted by 6.5 shooter View Post
Don't remember stating velocity.....
This isn't exactly voodoo. 6BR ... 87 V-Max. 3100 fps? 3200 if you are standing on it. At least that's what can be reasonably expected, and is also what my 8T 26" 6BR gives. Sorry if I'm bucking any trends on here and speak from actual experience.

Many hundreds of fps less than velocities that will grenade a V-Max.

Last edited by RickF; 11-14-2017 at 10:03 PM.
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  #66  
Old 11-15-2017, 07:31 PM
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Originally Posted by RickF View Post
This isn't exactly voodoo. 6BR ... 87 V-Max. 3100 fps? 3200 if you are standing on it. At least that's what can be reasonably expected, and is also what my 8T 26" 6BR gives. Sorry if I'm bucking any trends on here and speak from actual experience.

Many hundreds of fps less than velocities that will grenade a V-Max.
Hench why all reloading manuals state that your rifle may produce different results then our rifles...SO work up your loads carefully and be careful of following loads on the internet........
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  #67  
Old 11-15-2017, 10:38 PM
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Generally speaking, the longer the bullet the faster the twist required to stabilize it properly .. not necessarily the reverse.
If you plan to use heavy for caliber bullets primarily, get a faster twist.
Nominal factory twist rates are built to suit the bullets most commonly used in them.
For eg , a .308 Win does not handle large for caliber bullets well and is usually twisted a 1-12 or 1-14. A 30-06 does handle the larger bullets well and has a normal twist rate at 1-10.
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  #68  
Old 11-15-2017, 10:59 PM
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Best advice has to be ... select a twist rate compatable with the bullet(s) you will use. Think about the wisdom of choosing a proper fitting box-end wrench instead of visegrips. Both are capable of doing the job, but the proper fit will probably serve you better.
Seriously, most shooters are fine with the performance they get from a fast twist barrel. I always choose a 17:1 twist for 115gr 30 cal to be shot in a 30BR. I have no doubt that bullet would perform “OK” when shot from a 12:1 twist barrel...but I would not expect sub 1/2 MOA groups....which I know will be a reality for the 17 twist.
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  #69  
Old 11-16-2017, 05:30 AM
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I can see a 17:1 twist being a little hard on bullets. Talk about fast!
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Old 11-16-2017, 09:28 AM
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Turning those 115’s once every 17” is “just right”. I always look to what the top dogs are doing to get results. Don’t think there are any competition shooters chambering 30 BR with a significantly faster twist because turning shorties faster is not getting them close to the winners circle.
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  #71  
Old 11-16-2017, 09:36 AM
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Quote:
Originally Posted by 260 Rem View Post
Turning those 115’s once every 17” is “just right”. I always look to what the top dogs are doing to get results. Don’t think there are any competition shooters chambering 30 BR with a significantly faster twist because turning shorties faster is not getting them close to the winners circle.
Think you missed the joke lol you typed 17:1 instead of 1:17

Last edited by dogslayer403; 11-16-2017 at 10:00 AM.
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  #72  
Old 11-16-2017, 09:55 AM
Don_Parsons Don_Parsons is offline
 
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I had to double read the 1:17.

1:10 is fast, 1:7 is faster.

Most bullet manufactures have suggested twist rates for each of their bullets. Of course there is window on either side of the suggestions.

Don
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  #73  
Old 11-16-2017, 10:04 AM
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Quote:
Originally Posted by dogslayer403 View Post
Think you missed the joke lol you typed 17:1 instead of 1:17
Ahh... you’re right.
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  #74  
Old 11-16-2017, 10:07 AM
elkhunter11 elkhunter11 is offline
 
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Quote:
Originally Posted by Don_Parsons View Post
I had to double read the 1:17.

1:10 is fast, 1:7 is faster.

Most bullet manufactures have suggested twist rates for each of their bullets. Of course there is window on either side of the suggestions.

Don
And 1 in 17" is a lot slower.
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  #75  
Old 11-16-2017, 10:39 AM
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I think the slow twisted barrels used to shoot short 30 cal bullets in the score game is a good example (in answer to the OP) of why manufacturers continue to offer the slower twist rates.
The OP suggests that fast twisting short bullets works “just fine”. My argument is that there is a big difference between “just fine” and “optimum”. I have no doubt that over spinning a bullet could make little difference hitting game. Nor do I have any doubt that matching a bullet to its optimum spin will produce “the best” accuracy results on paper.
I am a shooter that needs every advantage I can get to produce the results I strive for ...every little bit helps.
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  #76  
Old 11-16-2017, 11:14 AM
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Manufacturers offer slow twist .224 barrels probably because traditionally 90% of people shooting them use bullets under 55 grains and most don't shoot past 3 or 400 yds. It's slowly changing and more and more companies are offering faster twist barrels but it is mostly a rifle looney driven thing. Those into the long distance shooting using the heavy high ballistic coefficient bullets usually buy custom barrels. If you asked 80% of .223 or .22-250 shooters they couldn't tell you off the top of their head what twist their barrel is even if it is stamped right on it. You point it out and they say "huh... so what does that mean?". Basically the market for these guns is for people who want to shoot light bullets fast. My tikka in 1-8 twist and a 1-8 Sako I had in .223 don't shoot light bullets as well as any of my 1-12 twist tikka, remingtons or browning do.
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  #77  
Old 11-16-2017, 01:28 PM
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I'm surprised that this thread is still going.

260Rem is pretty much preaching from the Bible when it comes to twist rates. If you want the best accuracy, you should match the twist rate to the bullet that you will be shooting.
Berger, as an example, suggests a twist rate for each of their bullets.
http://www.bergerbullets.com/products/varmint-bullets/
Similarly, barrel makers will make the same recommendations.

In my experience, if you take a rifle to a gunsmith to be rebarreled, they will ask you what bullet you plan on shooting. They have all said that if I'm going to shoot only light (short) bullets I should use a slow twist barrel. They also cautioned me that if I select a slow twist barrel that I will not be able to to shoot the longer, heavier bullets. My conversations with barrel makers have been pretty much the same.

I've owned factory barrelled 223's with twists of 12, 9 and 8. With light bullets (40's and 50's), the order of accuracy from highest to lowest was 12 (Rem), 8 (Tikka) and 9(Weatherby). All shot well, but the 12 twist was clearly better. To be fair to the Weatherby, the load development for it has been near zero. I mostly shoot it at the range to practice shooting from field positions. It's load is an old favourite that can be found on the label of a can of Hodgdon powder. I did post groups from the Weatherby on one of the challenge threads.

I've owned and shot custom 223Rem barrels in twists of 14 and 12. That would be their order of accuracy using light bullets.

I will be the first to admit that my results are only anecdotal and prove little to anyone but myself. The aftermarket barrels were not all from the same maker, so my findings lack that consistency.
As well, I am mostly interested in shooting gophers rather than punching paper. As a result, my load development goes rather quickly. If I put more time into it and tried more powder/bullet/brass/primer combo's would my results be different? Maybe, but I'd rather prefer to spend my time shooting gophers.

My final thought is that the manufacturers offer good advice. Fast twist barrels are needed for heavy bullets and can also provide fine results with lighter bullets. But if you want to get even better accuracy, you're more likely to achieve it with a barrel that matches the weight/length of the bullet.

260Rem has hit the nail on the head.
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  #78  
Old 11-16-2017, 02:59 PM
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I think the original point is that fine accuracy is had with fast twist barrels and short bullets. You can't accurately shoot long bullets in slow twist.

People are arguing short bullets explode coming out of fast twist barrels.

Ive shot enough 40-50gr varmint bullets at 4100+ in 1:9 twist barrels I dont buy this.
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  #79  
Old 11-16-2017, 03:11 PM
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And only on the Internet will guys tell you that an 8lb unmodified factory varmint rifle with a #2 contour barrel that shoots groups a dime will cover can be improved upon.
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  #80  
Old 11-16-2017, 03:57 PM
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Quote:
Originally Posted by chuck View Post
And only on the Internet will guys tell you that an 8lb unmodified factory varmint rifle with a #2 contour barrel that shoots groups a dime will cover can be improved upon.
IMO, any factory rifle that groups consistently under a dime at 100m is exceptional, and the driver is also to be commended.
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  #81  
Old 11-16-2017, 04:30 PM
lclund1946 lclund1946 is offline
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Quote:
Originally Posted by duceman View Post
here's the follow up question:
what the hell is the draw toward dink bullets with high powder capacity cases; for example 50 gr bullet in a 40 gr powder capacity 22-250.
The vast majority of people have no idea about ballistics or why your 222 is much more fur friendly at close range yet gets the job done at 400 yards. I have talked to many people who rave about their pet 22-250 coyote load only to qualify by saying "I can't shoot more than 2 or three rounds without blowing primers though". Hornady show a max of 3800 fps with the 50 V-Max and my Ballistics program shows 3680 for a Factory 55 HP bullet yet many of these same people believe that pushing these bullets 200 fps faster is Ok as they shoot so flat.

However if you go to a 39/40 grain bullet in a 20 caliber at 3650, which can be done with 22.2-22.4 grains of powder in a properly designed cartridge with an 11"twist barrel, the PBR is very close and the 20 will do better in the wind. The problem with going to a 20 caliber is that no manufacturer makes anything but the standard 12" twist barrel, which do not work very well with the 39/40 grain bullets, unless they are pushed to over 2700 fps. Most 20 cartridge designs require pressures of 63,000 PSI to get there accurately and then some think it OK to find an accuracy node at 3900 fps.

The main reason that manufacturers have not been in a hurry to go to faster twist barrels is marketing but Cartridges like the 20 Var-Targ and 20 Tactical do not lend themselves to running 39/40 grain bullets, with in Saami standard pressures as they are either too small or too large, in capacity, and they will not fit in standard magazines without running well off the lands.

I realized this early on and decided to design my own 20 caliber that had none of these problems. I also realized that a 40 V-Max would stabilize nicely at 3470 fps and run the same trajectory as a 22-250 with a Factory 55 HP
bullet which the Leupold VH Reticle was calibrated. I was elated to find that this low pressure load was better in the wind as well. The 22-250 trajectory is in yellow and is virtually covered by the 40 V-Max trajectory to 500 yards.
[IMG][/IMG]

When IMR 8208 I was able to get the 39/40 grain bullets to 3650 fps which does make the 22-250 look a bit anemic, with 50-55 grain bullets, even when pushed to the max. Going to a 9" twist with the 55 Berger and Varget really make the 22-250, or any of the other 20 Calibers with 12" twist look rather sick. Duceman, you will be really pleased when you get to try this load out on a few coyotes, when you get the time, and I look forward to a complete review.
[IMG][/IMG]

The 11" and 9" twist barrels have no problem stabilizing, or shooting accurately, good loads in 32 (3850 - 4000 fps) and 39/40 ( 3500 -3650 fps) grain loads in all rifles.
[IMG][/IMG]
[IMG][/IMG]
[IMG][/IMG]

Last edited by lclund1946; 11-16-2017 at 04:37 PM.
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