Barrel Length Matters!

Barrel Length Matters!

This is a discussion on Barrel Length Matters! within the Defensive Ammunition & Ballistics forums, part of the Defensive Carry Discussions category; TL;DR - Don't use high velocity ammo in short barrels. You won't achieve the velocity and will only add recoil. Does Size Really Matter? When ...

View Poll Results: What barrel length is your CCW?

Voters
207. You may not vote on this poll
  • 1-2 Inches

    14 6.76%
  • 2-3 Inches

    31 14.98%
  • 3-4 Inches

    119 57.49%
  • 4+ Inches

    43 20.77%
Page 1 of 6 12345 ... LastLast
Results 1 to 15 of 89
Like Tree226Likes

Thread: Barrel Length Matters!

  1. #1
    Member Array usmc9688's Avatar
    Join Date
    Sep 2013
    Location
    USA
    Posts
    141

    Exclamation Barrel Length Matters!

    TL;DR - Don't use high velocity ammo in short barrels. You won't achieve the velocity and will only add recoil.



    Does Size Really Matter?

    When choosing which defensive ammunition to carry many folks forget to consider their barrel length. This is a costly mistake which can lead to a diminished performance of your defensive ammunition. In order to understand why barrel length matters, we must first explain how barrel length affects velocity.




    Experiment



    • Background


    In order to demonstrate this topic, we took two calibers of ammunition (Liberty 357 Mag and 38 Special), and fired them through the same weapon (S&W M640). We chose the Liberty line because we have previously tested this loading in 9mm. We found that it performed just as designed when fired through a full length barrel. We also wanted to use a bullet design that depends on high velocity in order to function properly.

    • Thesis


    Shorter barrels will result in a catastrophic loss of performance for ammunition that relies on velocity to perform.

    • Results


    38 Special
    Barrel Length: 2in
    Max Penetration: 13in
    Max Permanent Cavity: 0.75in
    Max Temporary Cavity: ~5in
    Diameter of Fragmentation: N/A

    9mm
    Barrel Length: 4in
    Max Penetration: 11in
    Max Permanent Cavity: 1.5in
    Max Temporary Cavity: ~5.75
    Diameter of Fragmentation: 5in

    357 Magnum
    Barrel Length: 2in
    Max Penetration: 12in
    Max Permanent Cavity: 2.0in
    Max Temporary Cavity: ~4in
    Diameter of Fragmentation: 3.9in


    • Conclusion


    We found that both rounds performed terribly. The loss in velocity made the 357 Magnum loading fail to fragment completely. The 357 Magnum, which usually outperforms 9mm easily, fragmented in a pattern roughly half the diameter of the 9mm. The 38 Special completely failed to fragment. Its performance was similar to a FMJ in this caliber.

    Ammunition performance depends on barrel length. Barrels that are too short result in a loss in performance. High velocity loadings are not as effective with shorter barrels due to the lack of velocity reached.

    Cartridge Physics and Barrel Length


    When you fire a bullet from your firearm, you are actually dealing with a controlled explosion. The primer ignites the gunpowder that is encapsulated by the casing. This burning of powder creates pressure that drives the bullet through the barrel. The barrel acts as a confined space which directs the force onto the projectile (bullet). Without the barrel the bullet will have a significant loss in velocity.

    An ideal barrel is only long enough for all of the powder in the case to burn. A barrel that is too short will result in unburnt powder igniting outside the muzzle. Once the bullet passes the muzzle, the powder is no longer accelerating it, therefore; powder that burns after leaving the barrel is wasted. In contrast a barrel that is too long can also result in lower velocities. Shortly after the powder has finished burning the force being applied to the bullet quickly diminishes. After a certain distance the frictional force applied to the bullet from the barrel will overcome the pressure behind the bullet. In this case the barrel length has resulted in a loss of velocity.


    How Velocity Applies to Compact Pistols

    Handguns are naturally under powered. We carry them because they are conveniently sized. A compact pistol is much easier to conceal than an AR-15. What we gain in conceal-ability is lost in firepower.

    In order to get the most firepower out of your handgun you need to keep these tips in mind:

    1. Ammunition that relies on high velocities require full size barrels to reach optimal performance. Don't kid yourself. If you are carrying ammo that advertises a 2000fps velocity in a 2in barrel, you won't see anything close to that.


    2. Most ballistic testing is conducted with full length barrels. When considering a specific type of ammo try to find a gelatin test with your barrel length. I'm sure most hollow point loadings would do well out of a carbine barrel. What will it do in a compact?

    3. Don't add unnecessary recoil to your weapon unless you are guaranteed better performance. A high pressure loading (+P) might perform the same as a standard load with your barrel length.

  2. #2
    VIP Member Array OldVet's Avatar
    Join Date
    Nov 2009
    Location
    Hiding inside a bottle of Jim Beam Black in S. FL.
    Posts
    20,429
    If I'm going to get all wrapped up about barrel length in a CC handgun, I'll just dump it and carry a rifle.
    Retired USAF E-8. Lighten up and enjoy life because:
    Paranoia strikes deep, into your life it will creep. It starts when you're always afraid... Buffalo Springfield - For What It's Worth

  3. #3
    Member Array usmc9688's Avatar
    Join Date
    Sep 2013
    Location
    USA
    Posts
    141
    Quote Originally Posted by OldVet View Post
    If I'm going to get all wrapped up about barrel length in a CC handgun, I'll just dump it and carry a rifle.
    It's hard walking around with AKs in my pants all day, but it gets the job done! :)

  4. #4
    Senior Member
    Array hick63's Avatar
    Join Date
    Jul 2014
    Location
    Fox Valley Illinois
    Posts
    945
    This is a great site for info on pocket guns including ballistic gel test on dozens of different brands and calibers of ammo.

    Pocket Guns and Gear
    usmc9688, gatorbait51 and Katana1 like this.
    I know little on the subject so I'll speak at length.

    If you have an excuse for failure, you will.

  5. #5
    VIP Member Array lchamp's Avatar
    Join Date
    Oct 2012
    Location
    Florida's Space Coast.
    Posts
    2,129
    Quote Originally Posted by OldVet View Post
    If I'm going to get all wrapped up about barrel length in a CC handgun, I'll just dump it and carry a rifle.
    Yep!

  6. #6
    VIP Member
    Array ShooterGranny's Avatar
    Join Date
    Aug 2013
    Location
    Southeast USA
    Posts
    3,498
    In contrast a barrel that is too long can also result in lower velocities. Shortly after the powder has finished burning the force being applied to the bullet quickly diminishes. After a certain distance the frictional force applied to the bullet from the barrel will overcome the pressure behind the bullet. In this case the barrel length has resulted in a loss of velocity.
    I am not trying to argue, but am legitimately confused. I thought that a .22lr bullet would have much more velocity (power) coming out of a rifle barrel than coming out of my .22 revolver with its 2" barrel. How does that compute with the above? Can anyone enlighten me here?
    Getting old was not on my list of "things to do" in the Golden Years!

    ==================

    Talking to each other here is good, but taking action is better.

  7. #7
    VIP Member Array Harryball's Avatar
    Join Date
    Jun 2009
    Location
    Lansing Mi
    Posts
    9,099
    Quote Originally Posted by ShooterGranny View Post
    I am not trying to argue, but am legitimately confused. I thought that a .22lr bullet would have much more velocity (power) coming out of a rifle barrel than coming out of my .22 revolver with its 2" barrel. How does that compute with the above? Can anyone enlighten me here?
    He said a barrel too long Granny.
    gatorbait51 and Aceoky like this.
    Don"t let stupid be your skill set....

    Never be ashamed of a scar. It simply means, that you were stronger than whatever tried to hurt you......

  8. #8
    Member Array usmc9688's Avatar
    Join Date
    Sep 2013
    Location
    USA
    Posts
    141
    Quote Originally Posted by ShooterGranny View Post
    I am not trying to argue, but am legitimately confused. I thought that a .22lr bullet would have much more velocity (power) coming out of a rifle barrel than coming out of my .22 revolver with its 2" barrel. How does that compute with the above? Can anyone enlighten me here?
    It's a really good question.

    Let's say you fire a bullet. The powder burns and runs out halfway down the barrel because it is too long. After that there is still high pressure behind the bullet. It continues down the barrel still accelerating. As it moves down the barrel the volume behind it increases which drives the pressure down. This in turn lessens the force pushing it towards the muzzle. At some point the frictional force between the barrel and bullet, which is pushing the other direction, will overcome the force from the expanding gases. At this point the bullet begins to slow down.

  9. #9
    Senior Member
    Array hick63's Avatar
    Join Date
    Jul 2014
    Location
    Fox Valley Illinois
    Posts
    945
    The friction of the barrel rifling against the bullet works against the expansion of the propellent. Think of a squib load. It's caused by an insufficient expansion of the propellent which causes the bullet to stop in the barrel.

    Optimal performance of a bullet is dependent on both barrel length and diameter. (If the diameter is too big the expanding gases escape around the bullet instead of propelling it.)
    gatorbait51 likes this.
    I know little on the subject so I'll speak at length.

    If you have an excuse for failure, you will.

  10. #10
    VIP Member Array Stevew's Avatar
    Join Date
    Oct 2009
    Location
    Mississippi
    Posts
    3,654
    For your testing to really tell us the effect that the short barrel had we would need some comparison with a long barrel. Would also need some chrono comparison of a short barrel and a long barrel. When I compare my S&W Model 60 with a 2.25 inch barrel to my GP100 with a 4 inch barrel, I am getting 60fps difference. With the short barrel, I am still getting over 1400 fps.
    hick63, AzQkr, Bad Bob and 2 others like this.
    Good people do not need laws to tell them to act responsibly, while bad people will find a way around laws. Plato

  11. #11
    VIP Member Array LimaCharlie's Avatar
    Join Date
    Mar 2013
    Location
    Oregon
    Posts
    6,828
    It is difficult to carry my 10 1/2" Ruger Super Blackhawk IWB.
    I carry a gun, because a Cop is too heavy.

    Second Amendment: The difference between politicians and rulers.

    U.S. Army, Retired
    NRA Benefactor Life Member

  12. #12
    VIP Member Array maxwell97's Avatar
    Join Date
    May 2013
    Location
    Minnesota
    Posts
    5,110
    Some good points, but if you're feeling more recoil, you ARE getting more velocity for the same bullet weight. Maybe not as much as you would like, but a .357 from a 2" barrel stills beats the snot out of a .38 from a 2" barrel.

    I'm also a bit confused as to why fragmentation is being used as a measure of performance.
    Eric357, Aceoky and Paladin3840 like this.
    "...there is no arguing with such snivelling puppies, who allow superiors to kick them about deck at pleasure."

    Captain Bellamy

  13. #13
    VIP Member
    Array ShooterGranny's Avatar
    Join Date
    Aug 2013
    Location
    Southeast USA
    Posts
    3,498
    Quote Originally Posted by usmc9688 View Post
    It's a really good question.

    Let's say you fire a bullet. The powder burns and runs out halfway down the barrel because it is too long. After that there is still high pressure behind the bullet. It continues down the barrel still accelerating. As it moves down the barrel the volume behind it increases which drives the pressure down. This in turn lessens the force pushing it towards the muzzle. At some point the frictional force between the barrel and bullet, which is pushing the other direction, will overcome the force from the expanding gases. At this point the bullet begins to slow down.
    Thank you for your post. I still do not understand - MOSTLY because of the use of the term "barrel too long"........which tells me nothing that I could possibly use when choosing a gun or ammo.

    HOWEVER - I do not shoot rifles because of my eyes and because I can't hold most of them anyway. So I guess I will continue to stay with my more or less carry gun size collection and trust that IF and WHEN I need a gun it will do what I need it to do. They all do a great job of hitting paper and steel in the proper places!

    Again, thanks even though I still don't understand it...........but I bet my dearest better half Gramps does because he knows a lot about guns and shootin' stuff.
    Getting old was not on my list of "things to do" in the Golden Years!

    ==================

    Talking to each other here is good, but taking action is better.

  14. #14
    VIP Member Array Dangerfield's Avatar
    Join Date
    Oct 2012
    Location
    USA
    Posts
    3,367
    Speer Gold Dot manufactures "Short Barrel Personal Protection" cartridges with specially designed bullets as follows;

    Part Number 23611 = 9mm Luger +P, 124gr, Bullet Type GDHP-SB
    Part Number 23921 = 38 Special +P, 135gr, Bullet Type GDHP-SB
    Part Number 23917 = 357 Magnum, 135gr, Bullet Type GDHP-SB
    Part Number 23975 = 45 Auto, 230gr, Bullet Type GDHP-SB

    Get you some!
    usmc9688 likes this.
    ALWAYS CARRY - NEVER TELL
    NRA MEMBER
    Friend of Bill

  15. #15
    VIP Member Array OldVet's Avatar
    Join Date
    Nov 2009
    Location
    Hiding inside a bottle of Jim Beam Black in S. FL.
    Posts
    20,429
    Quote Originally Posted by LimaCharlie View Post
    It is difficult to carry my 10 1/2" Ruger Super Blackhawk IWB.
    Not without drawing a lot of the ladies' attention, I bet.
    Retired USAF E-8. Lighten up and enjoy life because:
    Paranoia strikes deep, into your life it will creep. It starts when you're always afraid... Buffalo Springfield - For What It's Worth

Page 1 of 6 12345 ... LastLast

Remove Ads

Sponsored Links

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Search tags for this page

size of barrel for ccw
,

when size barrel for hi velocity ammunition

Click on a term to search for related topics.