Barrel cut and velocity testing.

[Smokinyotes]

Originally Posted by Chargerguy

Cat, I'm not sure if you're joking or being serious about a bullet speeding up once it leaves the barrel.

Cats joking. Think about it, how could a bullet increase in speed after its left the barrel. What would be propelling it?

[elkhunter11]

Originally Posted by Chargerguy

Cat, I'm not sure if you're joking or being serious about a bullet speeding up once it leaves the barrel.

I sincerely hope that you are jokiing.

[catnthehat]

Originally Posted by Chargerguy

Cat, I'm not sure if you're joking or being serious about a bullet speeding up once it leaves the barrel.

The Post was directed at a particular member not as a general statement ,referencing another forum member with a big ol' smiley at the end of it .
Yes it was made as a joke , but I'm sure we have all heard silly statements llke that before so I can understand your post !
Cat

[couleefolk]

Interesting thread. Now I'm waiting for the talk about how the cylinder gap on a revolver fits into all this, and barrel lengths on those.

[roger]

Originally Posted by catnthehat

The Post was directed at a particular member not as a general statement ,referencing another forum member with a big ol' smiley at the end of it .
Yes it was made as a joke , but I'm sure we have all heard silly statements llke that before so I can understand your post !
Cat

i don't know how I got brought into the vortex of all this....
im not knowing offhand but apparently I made reference to this at some point or where the bullet not dropping until 500 yards came from. but hey we are all suckers to marketing gimmicks and sales pitches in our own way...with suitable evidence im open to new ideas.
for the average hunter guy, neither higher muzzle velocity or cloverleaf accuracy makes no difference to animal at 300yds and under. the real only obvious difference being the rainbow-like trajectory of the slowest bullets vs a laser like path.


in ultra high velocities like im typically running, shortening by 1" equates to about 50 ft per second, 2" equals 100fps, I cant say if that is exponential though
and as far as I know freebore in a factory wby pipe is lets say, is not more than 3/8".

[BackPackHunter]

I interested in the felt affects to the shooter in a shorter barrel?
How much accuracy would be lost say too 500 yards? going from a 24 to 18"
Would recoil or muzzle blast increase ?
Or should one think more about balance of a rifle vs the length of the pipe?

[catnthehat]

Originally Posted by BackPackHunter

I interested in the felt affects to the shooter in a shorter barrel?
How much accuracy would be lost say too 500 yards? going from a 24 to 18"
Would recoil or muzzle blast increase ?
Or should one think more about balance of a rifle vs the length of the pipe?

Balance is everything in my book , 24" to 18" is not that larger a thing at 500.
I have shot some very good groups at 500 meters with a 20" barrelled rifle with a heavier profile in a well made rifle with a Krieger barrel.
Cat

[Salavee]

Originally Posted by BackPackHunter

I interested in the felt affects to the shooter in a shorter barrel?
How much accuracy would be lost say too 500 yards? going from a 24 to 18"
Would recoil or muzzle blast increase ?
Or should one think more about balance of a rifle vs the length of the pipe?

Depending on the cartridge/propellant it would be safe to say you would lose 20-30 fps per inch of length reduction with a given load.

Muzzle blast at 18 inches would be increased significantly. Accuracy potential would be the least affected, if at all.

Assess your cartridge potential and determine an optimum barrel length for that cartridge before reducing barrel length. Usually there is a trade-off involved between barrel length, all-up weight and balance.

[Chargerguy]

Originally Posted by Smokinyotes

Cats joking. Think about it, how could a bullet increase in speed after its left the barrel. What would be propelling it?

I never questioned if it was true. I questioned if Cat thought it was. Some people actually believe this. I just wanted to make sure.

[Chargerguy]

Originally Posted by catnthehat

The Post was directed at a particular member not as a general statement ,referencing another forum member with a big ol' smiley at the end of it .
Yes it was made as a joke , but I'm sure we have all heard silly statements llke that before so I can understand your post !
Cat

Oh I have heard some good ones. And I saw the smiley. I just wasn't sure if it pertained to the whole post. My apologies. It was a little early in the morning for me lol.

[ramonmark]

Did anyone else actually look at the velocity changes vs barrel length? It appears that sometimes a shorter barrel is actually faster. This is obviously directly related to components being used and even the cartridge and size of bore. The whole caboodle. Either way its kinda neat to see the velocity slightly climb with a few inches cut off the barrel.

[Nyksta]

Some shorter barrels can be faster if the rifling starts earlier and has a resulting higher pressures than a longer barrel with long jump and low pressures.. but if you cut the barrel shorter it will be slower than what is used to be because there is less time for the powder pressure to push the bullet faster.

[Salavee]

One way that a shorter barrel could "increase" velocities is when the barrel is much too long for the burn rate of a specific powder/bullet combination in the first place.
The additional inches of bullet travel after the pressure loss in the barrel will create major drag and deceleration on the bullet. The bullet would be travelling on momentum only. Cut the barrel back to accommodate the burn rate and you show "increased" velocity. I's probably more about bullet deceleration than velocity gain. I have never heard of, or experienced, this situation so this is just my guess.

All ears.

[Nyksta]

Ive heard of that with 22lr being fastest at 16" barrel and 12 gauge slug fastest at 14" barrel, but I've never tested that. Those are both much lower pressure than rifles. I think a bottleneck rifle cartridge would need to have a very very long barrel before the friction of rifling would be greater than pressure but this one i havent read too much on.

[Nyksta]

http://riflebarrels.com/barrel-lengt...racy-question/

Says common rifle cartridges stop increasing muzzle velocity at about 40" of barrel.

[Salavee]

Originally Posted by Nyksta

http://riflebarrels.com/barrel-lengt...racy-question/

Says common rifle cartridges stop increasing muzzle velocity at about 40" of barrel.

That makes sense. I just ran this scenario thru Quickload. It doesn't have a drag function for barrel length. I ran a barrel length to 150 " and velocity was still increasing with a mild load. I want one of those.

[Nyksta]

http://www.popsci.com/technology/art...supplies-space

[t.tinsmith]

I am a barrel chopper and I chronograph my handloads. I do this routinely and find a shorter barrel loses muzzle velocity and usually gains some accuracy. I like the results I get.Often I will shorten both ends of the rifle.

[roger]

Originally Posted by BackPackHunter

I interested in the felt affects to the shooter in a shorter barrel?
How much accuracy would be lost say too 500 yards? going from a 24 to 18"
Would recoil or muzzle blast increase ?
Or should one think more about balance of a rifle vs the length of the pipe?

bph,
I can offer a little on this having owned a ruger frontier in 300wsm with a 16" bbl, scout style 2.5 ier leupold and with 180gr bullets, I called it "loudmouth' . intending to take it on an upcoming trip to Africa were the shots are supposedly 150 and under. I found it easy to carry and balance to shoot but it has violent muzzle jump, obnoxious blast, more recoil than my comfort zone (comparing my 257wby) and other foul words that you cant say on tv. being the muzzle was only 20" from your nose when it touched off, there isn't enough safety gear to wear to avoid the punishment.
i did manage to finish the Drayton Valley rifle competition in third or fourth overall that year with it, however after the 60 or so rounds i had exceeded my threshold for being beaten up.
ballistically it was comparable to a 30-06 so I had at least some idea of suitable results could be at 500yds but being a purpose built gun for short range pplications, the steel coyote target at the DV shoot at 300 is nothing more than a speck in 2.5x scope and offhand to boot i was surprised to hit it 2/3 times.
putting a standard style scope on this creature could have lead to forehead area bloodloss..specifically, my blood.
I had had enough of it. forever.

[Nyksta]

There is physical recoil momentum where the muzzle velocity times bullet weight divided by the weight of the rifle is the amount it hits your shoulder. This will not really noticably change with cutting your barrel shorter. However the other sensation of recoil is noise, flash and airpressure. Unburnt powder will exit the muzzle behind the bullet and this is the flash and some sound, and all the high pressure in the barrel pushing behind the bullet now escapes to the air around the muzzle. This is the concussion blast, if there is a muzzle brake then all this pressure sound and flash is even more so redirected to the feeling on the shooter.

Longer barrels have less unburnt powder, and lower remaining pressure when the bullet exits. That is why short barrels are louder and more straining feeling than longer barrels of the same cartridge.

[Nyksta]

Barrel length may change rifle balance and a shorter barrel will be more rigid than a longer barrel of the same thickness. It all comes down to what overall features are important to you.

[Jeron Kahyar]

A article was done at the University of Southern California using a Mosin Nagant. Looks at velocity and muzzle report changes from shortening a barrel.

https://www.google.ca/url?sa=t&sourc...9xu-fgJYW06lYQ