I just recently had a 26 Nosler put together(1-8 twist) and I went with the 27" inch barrel thinking I might as well try to get the most out of it as possible when reloading for it. I've done some research and everything I've read says with that extra inch I might gain anywhere from + or - 20 to possibly 30 fps. In my mind, I'm thinking I should be able to load "hotter"?? But maybe not?? I guess it depends on wether there are any "signs of pressure" when I am working up a load for it. That will dictate what I can do with it right?
27” barrel
- Thread starter Sendero6
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That's correct. Charge weights will still be dictated by case volume, and seating depth,. Work up slowly and watch for signs of pressure. The increase in velocity is due to a little more time for powder to completely burn.
the nosler line is a overbore cartridge. Which means there is more powder in the case which can be burn in a typical barrel length. So having a longer barrel doesn't mean you can add more powder, just means a little more powder will burn before the bullet exits the barrel.
johnnyk
Well-Known Member
Sendero6, haven't had a chance to welcome you yet but glad your here. Welcome brother!
Here's an excerpt from Accurate Shooter.com
"In the simplest terms, a very big case pushing a relatively small diameter bullet is acknowledged as the classic overbore design. But it's not just large powder capacity that creates an overbore situation — it is the relationship between powder capacity and barrel bore diameter." Good read.
( https://www.accurateshooter.com/technical-articles/overbore-cartridges-defined-by-formula/ )
I'm of the opinion that it's not the longer barrel that will allow you to load a particular cartridge "hotter" but actually the chambers design. Think .257 Weatherby for a moment. Roy filled the case with the slowest burning powders that he could find and put some .378" of freebore in the lede of the barrel to keep the pressures down while still delivering substantially higher velocities.
Others are doing similar things, for instance; I used a Ryan Mantha reamer in my SAAMI .300 WinMag chamber and created a bit of freebore. This allows me to seat the 215gn Berger out to 3.7xxx" and with this extra case space I can incrementally bump up the powder charge to get more velocity. Hornady calls this "more head room" or I think it was them. Their Creedmore and PRC cartridges use this concept and let them market the 6.5 CM being better than the .260 Remington when using heavier (140gn) bullets. Do a search for "How to Increase you rifle throat length with a Chamber Uni Throating Reamer".
I've also read of shooters/reloaders doing the same thing with revolver cartridges. By extending the bullets to just shy of the beginning of the cylinder, this allows for more powder. The concept has been around for years though.
Good luck with your 26N.
Here's an excerpt from Accurate Shooter.com
"In the simplest terms, a very big case pushing a relatively small diameter bullet is acknowledged as the classic overbore design. But it's not just large powder capacity that creates an overbore situation — it is the relationship between powder capacity and barrel bore diameter." Good read.
( https://www.accurateshooter.com/technical-articles/overbore-cartridges-defined-by-formula/ )
I'm of the opinion that it's not the longer barrel that will allow you to load a particular cartridge "hotter" but actually the chambers design. Think .257 Weatherby for a moment. Roy filled the case with the slowest burning powders that he could find and put some .378" of freebore in the lede of the barrel to keep the pressures down while still delivering substantially higher velocities.
Others are doing similar things, for instance; I used a Ryan Mantha reamer in my SAAMI .300 WinMag chamber and created a bit of freebore. This allows me to seat the 215gn Berger out to 3.7xxx" and with this extra case space I can incrementally bump up the powder charge to get more velocity. Hornady calls this "more head room" or I think it was them. Their Creedmore and PRC cartridges use this concept and let them market the 6.5 CM being better than the .260 Remington when using heavier (140gn) bullets. Do a search for "How to Increase you rifle throat length with a Chamber Uni Throating Reamer".
I've also read of shooters/reloaders doing the same thing with revolver cartridges. By extending the bullets to just shy of the beginning of the cylinder, this allows for more powder. The concept has been around for years though.
Good luck with your 26N.
^^^ THIS! ^^^
nmbarta
Well-Known Member
pretty much what's already been said, you peak pressure will happen long before the bullet leaves the barrel. Careful working up.
Chamberman
Well-Known Member
Is the 27" barrel coming from the maker as 27"? If so the smith will usually remove 1 inch from the end of the barrel, because that last inch is considered for tool run- out when manufacturing the barrel and it is highly recommended it be removed.
del2les
Well-Known Member
Just a couple of mentions:
* Your barrel length will not effect your chamber pressures and ability to load "heavier" powder changes.
* Several are mentioning the longer barrel gives the powder more time to completely burn, which is not completely accurate. Most modern smokeless powders are completely combusted in the first few inches, and depending on several factors, often while in the chamber/throat area. The longer barrel may allow the gas pressure more time to push on the bullet before it leaves the muzzle, and in some smaller case capacities and projectile loads, too long a barrel can actual impede the projectiles' top velocity. I.e. no longer increases velocity or is actually slower than the optimum length.
* Your barrel length will not effect your chamber pressures and ability to load "heavier" powder changes.
* Several are mentioning the longer barrel gives the powder more time to completely burn, which is not completely accurate. Most modern smokeless powders are completely combusted in the first few inches, and depending on several factors, often while in the chamber/throat area. The longer barrel may allow the gas pressure more time to push on the bullet before it leaves the muzzle, and in some smaller case capacities and projectile loads, too long a barrel can actual impede the projectiles' top velocity. I.e. no longer increases velocity or is actually slower than the optimum length.
First question that must be answered for ever rifle question.......What are you using the rifle for.....hunting.......stationary, humpin' it, horseback, steel ringing, paper punching, distances? Longer barrel does add velocity, but that may not be overall for the best. Longer barrels have more harmonics and possibly lower accuracy. Todd Hodnett, military shooter and now Accuracy first owner and trainer for military, uses 20" down barrels for the rigidity and consistency. Velocity is a consistent ballistic characteristic that can easily be accounted for in consistent come up dialing. Extra weight, harmonics, longer length to get through brush/deal with in vehicles/cases, plus extreme length if a can is ever desired, et el, et el. may make the extra velocity a very marginal trade off.
