Relation in between powder weight and barrel length
- Thread starter Chatrbaz84
- Start date
Sample : a rifle in 308 barrel length 24 inch 1:10 shoots .5 MOA with 168gr SMK , varget 43.5 g
Do you think if we had exact same rifle with 20 inch barrel shoots the same group .5 MOA with the same load?
Maybe! Even two rifles of the same make and model may prefer different loads.
coleman1495
CGN Ultra frequent flyer
- Location
- Whitecourt
Totally depends on where your accuracy nodes fall.
What I think your referring to is barrel harmonics.
I would be surprised if 2 identical rifles would print the same group . with the same round with out that round being tuned to each individual rifle .
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- Location
- Prince Albert, Sk
Barrel harmonics and burn rates and how they related to barrel length and velocity , which could be the equation and how it related to a PARTICULAR rifle.
A shorter stiffer barrel MAY be more accurate than a longer more flimsy barrel.
A shorter stiffer barrel MAY be more accurate than a longer more flimsy barrel.
If anything, would expect the shorter barrel could shoot a smaller group if everything else is equal. But that is not guaranteed.
No two rifles shoot the same. When they do, go buy a lottery ticket.
Thats why we reload - to tailor loads to a specific rifle to obtain the best accuracy - performance depending on the use of the load. To obtain a better group - get good components and develop your load for the barrel you have.
Choosing a powder is made for a cartridge not barrel length, up to a point.. in shorter barrel you might want the fastest of the powder listed for that bullet - powder charge, and longer barrel the slowest, but again not a fixed rule.
Usually pick up the powder the data for that cartridge that show, the best velocity for the bullet you use.
Thats why we reload - to tailor loads to a specific rifle to obtain the best accuracy - performance depending on the use of the load. To obtain a better group - get good components and develop your load for the barrel you have.
Choosing a powder is made for a cartridge not barrel length, up to a point.. in shorter barrel you might want the fastest of the powder listed for that bullet - powder charge, and longer barrel the slowest, but again not a fixed rule.
Usually pick up the powder the data for that cartridge that show, the best velocity for the bullet you use.
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Probably not. Each rifle is different.
Even if the 2 rifles had the same barrel length, each would have its own best load.
However, the load that worked well in the 24" would probably be close to the best load in the 20"
uncledillers
Regular
- Location
- Comox Valley
take a read on Dan Newberry's Optimal charge weight load development, it seems to be the the bush your trying to sniff out.
Munkey1973
CGN frequent flyer
- Location
- Regina, SK
Not sure what you mean.
But one premise that is widely accepted (empirically tested) is that for a given load, there will exist a positive correlation between muzzle velocity and barrel length.
I would have to look for it, but I found an article years ago, where an F Class shooter in New Zealand (maybe Australia) took a 308 with about a 28" barrel and used highly consistent reloads.
He measured muzzle velocity at various lengths from 28" to 20" (he actually cut his barrel at the range with a saw).
In a nutshell, it was discovered that there was big increase in velocity (something like 160 fps) from 20" to 26".
But the increase in velocity diminishes after you add inches beyond 26".... basically 28" is still faster than a 26" but not by too much
As for accuracy, you should try different powered loads to see what groups best ... that is true of any rifle of any barrel length
FYI: This guy did a similar experiment with a shot out 6.5 Creedmoor... looks like 300 fps gain from 16" to 24" !
Pay particular attention to the column in the chart that reads CHG 24.
https://rifleshooter.com/2019/05/6-c...zzle-velocity/
But one premise that is widely accepted (empirically tested) is that for a given load, there will exist a positive correlation between muzzle velocity and barrel length.
I would have to look for it, but I found an article years ago, where an F Class shooter in New Zealand (maybe Australia) took a 308 with about a 28" barrel and used highly consistent reloads.
He measured muzzle velocity at various lengths from 28" to 20" (he actually cut his barrel at the range with a saw).
In a nutshell, it was discovered that there was big increase in velocity (something like 160 fps) from 20" to 26".
But the increase in velocity diminishes after you add inches beyond 26".... basically 28" is still faster than a 26" but not by too much
As for accuracy, you should try different powered loads to see what groups best ... that is true of any rifle of any barrel length
FYI: This guy did a similar experiment with a shot out 6.5 Creedmoor... looks like 300 fps gain from 16" to 24" !
Pay particular attention to the column in the chart that reads CHG 24.
https://rifleshooter.com/2019/05/6-c...zzle-velocity/
