Quantcast
  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

How much accuracy is gained by an inch of barrel?

Discussion in 'Handguns: Autoloaders' started by Potatohead, May 5, 2013.

Thread Status:
Not open for further replies.
  1. Potatohead
    • Contributing Member

    Potatohead Member

    Joined:
    Mar 9, 2013
    Messages:
    5,371
    thanks guys. ive gota thick head but im gettin it:)
     
  2. VetPsychWars

    VetPsychWars Member

    Joined:
    Jun 30, 2011
    Messages:
    101
    My question would be, does that extra inch really enhance your ability to conceal it? With some holsters, like horizontal carry under the arm, perhaps so. Inside waistband? Not so much.

    Tom
     
  3. Potatohead
    • Contributing Member

    Potatohead Member

    Joined:
    Mar 9, 2013
    Messages:
    5,371
    good point, i hope..because i really want the 5"
     
  4. olderguns

    olderguns Member

    Joined:
    Jun 3, 2010
    Messages:
    203
    Location:
    Florida near Orlando.
    We know its sight radius that gives the extra accuracy, but to have that longer radius you Must have a longer barrel, so in a way it is the length of the barrel that helps you aim.
     
  5. pockets

    pockets Member

    Joined:
    Apr 27, 2010
    Messages:
    1,134
    Location:
    in my own little world
    Many target pistols have been made with sight extensions and a barrel shorter than the sight radius.
    I seem to recall S&W including an extendable front sight on some of their model 41 pistols. It rode in a groove on the slide and could be extended well past the muzzle.
    .
     
  6. Blackstone

    Blackstone Member

    Joined:
    Oct 30, 2011
    Messages:
    722
    Location:
    United Kingdom
    Not disagreeing with anything that's been said, but would the extra twisting from the extra rifling have a greater stabilising effect on the bullet?
     
  7. Roadking Rider

    Roadking Rider Member

    Joined:
    Jun 12, 2012
    Messages:
    466
    Hard to come up with a definitive answer to your question. I guess that would depend on the pistols in question and the person pulling the trigger.
    Speaking only for myself,I shoot my CZPO-1 every bit as good as my CZ75b with the inch longer barrel and seem to shoot my G26 as good as I do the longer barrel Glocks. Having said that when It comes to 1911's I shoot the full size much better than I do the shorter barrel models. I think the answer is always going to be is what gun works best for the shooter and not so much as the length of the barrel if we're only talking an inch.
     
  8. Infidel4life11

    Infidel4life11 Member

    Joined:
    Nov 28, 2011
    Messages:
    621
    Location:
    Where the Army puts me
    This^ longer well made barrels tend to shoot with more velocity, shorter well made barrels are more accurate. Sight radius is king.
     
  9. Walt Sherrill

    Walt Sherrill Member

    Joined:
    Jan 1, 2003
    Messages:
    5,107
    Location:
    Winston-Salem, NC
    Possibly. But the original question was about the effect of an extra 1" of barrel length. If you read through everything below, and the links, you might get the idea that there is likely to be little difference in that effect unless the barrel length is greatly changed -- and then mostly when the barrel is shortened to a point that stability isn't imparted. It's hard to assess how much extra accuracy/precision is gained from that additional barrel length.

    Until someone does Ransom Rest tests of two guns that are very similar except for barrel length, this discussion boils down to our understanding of THEORY and our interpretation of that theory. Ransom Rest tests do away with the "human element" -- and the need to actually see the target or squeeze the trigger properly. Ransom Rest tests assess the gun's innate ability to put shots fired consistently in a small group. Sight radius is irrelevant.

    American Rifleman apparently did this back in the 70's using a .44 magnum handgun round in a rifle. They shortened and recrowned the barrel, and tallied the results. They continued down until they were testing what was the equivalent of a short barrel, and then to the point that the round started to keyhole. Their results -- there wasn't a great difference until the barrel got so short that stability was impaired. Somebody out there may have these test results stashed away, somewhere.​

    If you go to Wikipedia, you'll find that twist rates tend to be optimized for a given bullet's weight, shape, and length -- and that makes me wonder whether shooting the same round in different length barrels would offer varying results with some guns -- but I've seen nothing about firing the same round in handguns that have 4" - 6" barrels. Here's the link: http://en.wikipedia.org/wiki/Rifling One interesting point made in the Wiki article concerns bullet size and weight. It says,

    "Large diameter bullets provide more stability, as the larger radius provides more gyroscopic inertia, while long bullets are harder to stabilize, as they tend to be very backheavy and the aerodynamic pressures have a longer "lever" to act on."​

    Reading that, I wondered if that explains why BULLSEYE shooters seem to love .45 ACP -- and explains why some of the most impressive long-distance sniper shots have been made using .308 and .50 caliber rounds.

    There is a formula for selecting the twist rate in the Wiki article -- and I wonder if the twist rates of a 4" pistol barrel differs from that used with a 5" or 6" barrel. We might find that different weight/bullet shaps/loads might make a difference, if the twist rates are the same. (The Wiki article also mentions the use of twist rates that change in a single rifle barrel -- that was something I had never heard of...)

    In some tests I've found on the net (very precise, but focusing on air guns with rifled barrels), the relationship between velocity and twist rates seems to vary with lower power settings (corresponding to less powerful loads) doing better with lower twist rates, and higher power settings doing better with higher twist rates. That series of tests, however, uses a single projectile design and weight. None of the differences were significant until the target was pushed out to 25 yards or more -- and most of us would LOVE to be shooting the groups they were getting at those distances!!

    A participant on another forum made the following observation; I added the underlining, below. Keep in mind, this participant describes accuracy as the ability of the shooter to shoot a gun well enoough to hit what's being aimed at, while precision describes the gun's ability to shoot small, consistent groups (ignoring the human element). That's not layman terminology, because we tend to call both things "accuracy" -- but there is a difference, and it's good to understand that difference. One has to do with the gun's innate ability to deliver, while the other has to do with the shooter's ability to take advantage of that innate ability. When we started this discussion some were talking about accuracy and some were talking about precision. I think the Original Poster was asking about precision, which is NOT the same as accuracy. This other commentator went on to say:

    Shortening the length of a barrel will have a small effect on precision, which relates to the ability of a gun to shoot consistent, tight groups. Shortening the barrel length (within reasonable limits) will insignificantly alter the grouping ability of a gun, which means it will have an insignificant affect on precision.

    Accuracy relates to making the point of impact the same as the point of aim. Since bullet velocity is highly affected by barrel length the bullet will drop more over a given distance as the barrel is shortened. Thus accuracy in hugely affected by barrel length because the point of impact will drop relative to the point of aim as the barrel length is reduced, IF THE SIGHTS ARE NOT ADJUSTED. If the sights are properly adjusted after shortening the barrel, the point of impact can be restored to the point of aim, thus restoring the accuracy.​

    Much longer barrels (rifles), as noted in this discussion, can bring with them their own problems, due to a lack of rigidity, expansion from heat, or barrel movement from vibrations (harmonics, etc.).

    We do know that the extra sight radius of a longer barrel can help the shooter manage the gun better. As can a better trigger, and better-fitting grips, etc. Those are all things that make the SHOOTER more ACCURATE -- but the gun doesn't care. The gun's PRECISION is likely to remain the same, or close to the same unless the barrel length is greatly changed.


    .
     
    Last edited: May 10, 2013
  10. 918v

    918v Member

    Joined:
    Mar 16, 2006
    Messages:
    3,931
    Walther PPQ factory test target at 15m:

    [​IMG]
     
  11. 918v

    918v Member

    Joined:
    Mar 16, 2006
    Messages:
    3,931
  12. 918v

    918v Member

    Joined:
    Mar 16, 2006
    Messages:
    3,931
  13. 918v

    918v Member

    Joined:
    Mar 16, 2006
    Messages:
    3,931
  14. 918v

    918v Member

    Joined:
    Mar 16, 2006
    Messages:
    3,931
  15. 918v

    918v Member

    Joined:
    Mar 16, 2006
    Messages:
    3,931
    Can't find any PPQ 5" test targets.
     
  16. Potatohead
    • Contributing Member

    Potatohead Member

    Joined:
    Mar 9, 2013
    Messages:
    5,371
    wow thats nice 918..beautiful gun..i assume you like it? feel free to offer any details
     
  17. Potatohead
    • Contributing Member

    Potatohead Member

    Joined:
    Mar 9, 2013
    Messages:
    5,371
    thats very interesting..and surprising to a newb like myself
     
  18. Potatohead
    • Contributing Member

    Potatohead Member

    Joined:
    Mar 9, 2013
    Messages:
    5,371
    wow! nice post Walt Sherrill
     
  19. PRM

    PRM Member

    Joined:
    Apr 14, 2008
    Messages:
    2,060
    Not sure an inch would have a lot of impact on accuracy or performance - hasn't for me. I will say the three inch heavy barrel on my Model 36-1 tames the recoil and makes shooting it more of a pleasure over my two inch snubs. Concealment is not a noticeable factor in my carry. I usually carry a pancake style holster on my strong side. I have carried my two inch guns in ankle holsters. Don't have one for my three inch. If there is any difference, I would say it would probably be in this type of carry.
     
  20. Bovice

    Bovice Member

    Joined:
    Sep 27, 2009
    Messages:
    1,593
    What's the point of 8 million posts of walther factory test targets?
     
  21. leadcounsel

    leadcounsel member

    Joined:
    Jun 5, 2006
    Messages:
    5,365
    Location:
    Tacoma, WA
    My practical experience tells me that there is a world of difference in my practical accuracy between a 2 or 3" barrel and a 5" barrel. Perhaps a combination of:
    1. Longer sight radius
    2. Effectively doubling the length of barrel to double the stablization and spin on the bullet, which we all agree makes a bullet more inherently stable and accurate. It's not just 1" difference, it's a percentage. The increase from 2" to 4" DOUBLES the time in the barrel and adds more spin to the round, which must add some power and stability to the round as it exits a 4" barrel.
    3. More powder behind the bullet, and more energy, rather than wasted energy escaping from the muzzle in a 'flash.'

    I think there is a sweet spot of deminished returned for a pistol in size vs. compactness at 4" for a standard carry gun, and 5" for a home duty gun. Of course, the pistol cartridge probably performs best from a rifle, but if you're going to go with a rifle, then use a rifle cartridge.
     
    Last edited: May 10, 2013
  22. brickeyee

    brickeyee Member

    Joined:
    Feb 25, 2005
    Messages:
    3,135
    you must have some pretty funny rifling, like gain twist.

    Once the bullet enages the rifling the spin rate per length traveled is set.

    Having a longer barrel with the increased in velocity that usualy results meas the spin rate per unit time will increase, but it is a losing battle on the stability side.

    The higher velocity results in increased overturning force.
     
  23. Potatohead
    • Contributing Member

    Potatohead Member

    Joined:
    Mar 9, 2013
    Messages:
    5,371
    I wondered that myself
     
  24. herkyguy

    herkyguy Member

    Joined:
    Jul 31, 2009
    Messages:
    1,364
    here's a twist...... get a shorter barrel but put some high-quality target sights on it. i have a few guns with longer barrels but have more or less maxed out their practical accuracy due to the large size of the front dot. now that messes up the whole conversation!
     
  25. Vern Humphrey

    Vern Humphrey Member

    Joined:
    Dec 30, 2002
    Messages:
    18,569
    Location:
    Deep in the Ozarks
    Use Patridge sights, not dot sights on handguns. The Patridge, with it's wide, flat front sight is sighted to place the bullet just on top of the front sight, centered,
     
Thread Status:
Not open for further replies.

Share This Page