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

How much power is lost with a 2" barrel?

Discussion in 'Handguns: Revolvers' started by vito, Apr 4, 2013.

Thread Status:
Not open for further replies.
  1. vito

    vito Member

    Joined:
    Jun 29, 2004
    Messages:
    658
    Location:
    Northern Illinois
    Probably my favorite gun is the one I have owned the longest, a Model 19, 4-inch barrel that I keep loaded with 38+ Speer ammo for home defense. Despite my old, somewhat shaky hands, I can shoot this gun fairly accurately at self defense distances, i.e., under 10 yards or so. But in anticipation of concealed carry coming to Illinois, I purchased a S&W 640 a few years ago. Being a J-frame it is not nearly as nice to fire as my 19, but it certainly is easier to conceal. My question is about stopping power and how much of that I give up by firing the same ammo from a 2 inch barrel instead of a four inch barrel. I know I don't want to load it with 357mag since even at the range I find that caliber painful to fire, but I am assuming that with 38+p I still have enough stopping power to end a threat.
     
  2. Radagast
    • Contributing Member

    Radagast Moderator

    Joined:
    Dec 24, 2002
    Messages:
    8,148
    Location:
    Australia/OZ
  3. Billy Shears

    Billy Shears Member

    Joined:
    Mar 16, 2008
    Messages:
    1,004
    My dad tells me a story from his days on the Norfolk Police Department (the same department I now work for). He said one day when he went to qualify, they had an FBI agent at the range giving a demonstration. The agent borrowed one of the detectives 2" barreled chief's special, placed the barrel almost against the windshield of an old junker car they had towed out there, and fired. From a distance of only about two or three inches, and almost a 90 degree angle, the .38 bullet failed to penetrate. This was back in the 60s, when Super Vel was out, but almost all police, including Norfolk, were still using round nose lead, 158 grain bullets in their .38s.

    Of course, even out of a 4 or 5 inch barrel, the .38 firing that load was no powerhouse, but it does lose a lot of velocity out of a 2 inch barrel.
     
  4. Greg528iT

    Greg528iT Member

    Joined:
    Mar 10, 2010
    Messages:
    1,220
    If he did this knowing it'd not penetrate that's pretty ummmm brave. That slug was going to go somewhere and to hold the gun that close, HE was that close.

    Did he then try and get a 38 slug to penetrate with a 5" barrel???
     
  5. jmr40

    jmr40 Member

    Joined:
    May 26, 2007
    Messages:
    10,444
    Location:
    Georgia
    Look at it this way, the ballistics published for most revolver rounds are from 8" test barrels. Most published centerfire rifle ballistics are from 24" test barrels. Most people would not be surprised to find a 30-06 with a 6"-12" barrel is going to produce velocities well below what the ballistics charts say, but are surprised to find revolvers with 2"-4" barrels do.

    Shorter barrels can still be effective with proper ammo choices. The lighter 110-125 gr bullets at fast speeds from longer barrels work, but they need speed. If I were using a short barrel I'd be loading bullets on the heavier end of the spectrum since they are less dependent on speed to work.
     
  6. rcmodel

    rcmodel Member in memoriam

    Joined:
    Sep 17, 2007
    Messages:
    59,082
    Location:
    Eastern KS
    That is just pretty hard to believe!!

    We had an Ford old truck cab in a ditch on the farm a good 200 yards from the barn, and I put enough holes through it at that distance with a 2" S&W it looked like swiss cheese.

    rc
     
  7. natman

    natman Member

    Joined:
    Feb 11, 2007
    Messages:
    3,534
    A 38 Special will lose from 150-300 fps from a 4" to a 2" barrel. That may seem like a lot, but remember a 2" barrel is only half as long as a 4" barrel.

    You should only use a 2" if you really need that short a barrel to carry concealed. Otherwise go with the 4".
     
  8. Certaindeaf

    Certaindeaf member

    Joined:
    Jan 16, 2012
    Messages:
    5,170
    Location:
    Wet Oregon
  9. Billy Shears

    Billy Shears Member

    Joined:
    Mar 16, 2008
    Messages:
    1,004
    Apparently the agent had done this enough times to know the bullet was going to get stuck in the windshield. I don't think he repeated the performance with a 5" bbl.

    Actually, I find it pretty easy to believe. Look at the ballistics data: a 158 RNL bullet coming out of a 2" bbl isn't moving at much over a paltry 600 feet per second. I find it very easy to believe that will fail to penetrate a car windshield. I find it especially easy to believe since my department, just a few years ago, used 9mm S&W 6906s, and issued 147JHP ammo. The first sergeant I had was involved in a shooting, and he fired at the driver of a vehicle, his bullets struck the windshield and also failed to penetrate. This was not point blank, I believe it was a bit under ten yards away, but the 147 grain 9mm load was specifically developed, with input from the FBI after the infamous 1986 Miami-Dade shooting, to have better penetration than the 9mm silvertip that the agents had used in that shooting. An automobile windshield is pretty tough. It's two layers of tempered safety glass with a plastic sheet laminated between them to keep everything held together in the event of an accident. A bullet will go through the sheet metal of the car body a lot easier than the windshield. And remember, the .38 super and .38/44 and .357 magnum were all developed in the depression era partly because police were complaining that their .38 revolvers weren't doing a very good job penetrating the car bodies of the era.

    Edit: I came across this site, and while I can't vouch for the accuracy of the data, the author looks to have been fairly methodical in his testing. If this data is correct, I may actually have overestimated the velocity of 158gr RNL .38 ammo from a 2" bbl at somewhere just north of 600fps.

    http://www.yankeegunnuts.com/2012/07/30/38-special-ballistics-snubnose/

    His data for Federal American Eagle 158gr RNL, standard pressure .38spl ammo shows an average velocity of about three hundred feet per second when fired from a 2.125"bbl! Wow. Now the old '60s vintage ammo would have been loaded a bit hotter, since they downloaded standard pressure .38s a bit in the early '70s when they developed the +P loads, but still...
     
    Last edited: Apr 4, 2013
  10. Certaindeaf

    Certaindeaf member

    Joined:
    Jan 16, 2012
    Messages:
    5,170
    Location:
    Wet Oregon
    I guess the moral of the story is to not use 158 grain RNL.. for about 100 years.
     
  11. Radagast
    • Contributing Member

    Radagast Moderator

    Joined:
    Dec 24, 2002
    Messages:
    8,148
    Location:
    Australia/OZ
    Depends on if the wreck predates safety glass in cars or not. I would fully expect it to penetrate the older style of windows, and it would probably penetrate a modern window.
     
  12. beatledog7

    beatledog7 Member

    Joined:
    Jun 18, 2011
    Messages:
    5,093
    Location:
    Tidewater
    I invite you to look at it this way:

    If a gun with a 2" barrel has a "power coefficient" of 100, and you can carry it concealed because of its short barrel, you're carrying power 100.

    If a gun with a 4" barrel has a "power coefficient" of 120, but you can't carry it concealed because of its longer barrel, you're carrying power 0.
     
  13. rcmodel

    rcmodel Member in memoriam

    Joined:
    Sep 17, 2007
    Messages:
    59,082
    Location:
    Eastern KS
    .38 Spl LRN failed to penetrate windshield glass because it glanced off the sloping surface of the windshield glass.

    But the OP said the officer giving the demonstration held the gun at nearly a 90 degree angle to the windshield.
    I call Shenanigans.

    Either the demo officer was using very downloaded ammo to prove his point?
    Or the story got distorted in the retelling.

    Again, I shot enough long range .38 Chiefs Special on the farm 50+ years ago against an old Ford truck body to be a true skeptic.

    Stupid kids shot a hole through the back window of my wifes Dodge Durango from the street with a CO2 pellet pistol 5 years ago.

    As well as one door skin of my Dodge RAM.

    A 158 LRN at even 500 FPS will penetrate a car windshield at 90 degrees.
    But it won't at 45 degrees.

    rc
     
  14. Certaindeaf

    Certaindeaf member

    Joined:
    Jan 16, 2012
    Messages:
    5,170
    Location:
    Wet Oregon
    I think he forgot to tell the part where the car was going backwards at 400mph.
     
  15. tipoc

    tipoc Member

    Joined:
    Mar 9, 2006
    Messages:
    2,950
    I have to say I believe this to be inaccurate. A story told as an amazing one and retold and became even more amazing in the retelling, most likely.

    I say this because I personally have fired through modern windshield glass from a S&W M640 Centennial with a 1 7/8" barrel from 4 feet away and seen it penetrate with a Remington 158 gr. LSWC +P round. I've also seen the same at 60 yards or so from a Colt Cobra with a 2" barrel.

    I also dispute the information in the link posted earlier here...

    http://www.yankeegunnuts.com/2012/07/30/38-special-ballistics-snubnose/

    Here Yankeegunnuts reported average mean velocities from a snubby of 457.86 fps for CCI Blazer 158gr. +P TMJ ammo. And under 300 fps from Federal 158 gr. LRN ammo.

    I believe these figures to be inaccurate.

    If we look at the more believable figures here from Brassfetcher shown here...

    http://www.brassfetcher.com/38 Special/38 Special Summary Table.pdf

    We see a few 158 gr. loads moving at 900 fps and above from the same snubby barrels. A 158 gr. load from Remington is shown at 893 fps and another from Federal at 789 fps.

    If we look at Ballistics by the inch, while they have no 158 gr. loads listed we do see other loads from short barrels and none are in the 300 fps range Yankeegunnuts mentions. Possibly his machine was off.

    http://www.ballisticsbytheinch.com/38special.html

    tipoc
     
  16. Billy Shears

    Billy Shears Member

    Joined:
    Mar 16, 2008
    Messages:
    1,004
    Uh, no smartass it's merely the retelling of an anecdote not a carefully controlled scientific experiment designed to eliminate every variable. The agent, as the story was told to me, was standing in front of the passenger side of the vehicle, body brushing up against the vehicle, holding the gun in his right hand, shooting at a point roughly consistent with the passenger position, thus, an angle of close to 90% in the horizontal plane. However most windshields, even in the 1960s, have a backward rake, which varies from model to model, but which means that in the vertical plane, there will be a signficant but unknown angle. Now I know my own father, and he's not a liar. If he says it happened, then it happened, as far as I am concerned. I don't know what specific variable combined to make it happen. But I do have independent data showing how unexpectedly low the power of the .38 RNL load was, particularly from a short barrel -- not just the date from yankeegunnuts, but the established fact that the .357 round was developed partly at the request of law enforcement, who were finding .38 revolvers inadequate against the cover provided by (gasp!) car bodies!

    And as for the chronograph data: sure it's possible his machine was off. It's also possible it's perfectly accurate, and if people find that difficult to believe that's their problem. What's more likely, that a machine is wrong or that human perception is? You can decide, but a lot of what people think they know isn't so, and a lot of commonly held ideas are bunk. I've heard countless people tell me a .45 slug would "knock you on your ass" but if you know anything about physics, you'll know that's not so. It's entirely possible that the .38 slug could move at around 300fps, and the fact still not be all that noticeable because a .38 snubby is a belly gun, used the vast majority of time at bad breath distance against unarmored opponents, where even that low a velocity is adequate to inflict lethal wounds. After all, a Remington .41 rimfire Remington derringer would kill you across a card table, despite firing a 130 grain bullet at a measly 425fps. So why should it be any surprise that a 158gr .38 bullet moving somewhere between 300 and 500fps is deadly at similar ranges? And why should it also be any surprise that such a bullet would have a marked difficultly penetrating car bodies -- especially when this was a fact recording during the Depression era, and which led to the development of at least three cartridges designed specifically to address this shortcoming?
     
  17. Certaindeaf

    Certaindeaf member

    Joined:
    Jan 16, 2012
    Messages:
    5,170
    Location:
    Wet Oregon
    Uh, that was a joke, dillweed.
     
  18. Billy Shears

    Billy Shears Member

    Joined:
    Mar 16, 2008
    Messages:
    1,004
    Alright, let me ask you a serious question: how am I to know that? In face to face conversation, one has body language and tone of voice to make it clear. Even over the telephone, one has tone of voice. Over the internet, you have words on a screen, nothing else. Words which can, and very probably will, be taken simply at face value. What is it about that that clearly differentiates jocular good humor from sneering sarcasm? What makes it clear? Absent other cues, people tend to take words at their face value; it's the simplest course of action, and people tend to take it. So how am I to know that I should make an exception in this case? Given that I don't know you or what kind of sense of humor you have, and I can't see your body language or hear your tone of voice, what would inform me that you are joking as opposed to sneering?

    I have as much sense of humor as the next guy, but when it looks like I am receiving sneering dismissals or ridicule, I will respond with as much asperity as the next guy also. And I won't apologize for it either. People should keep a respectful tone. I try to. And if the situation is such that derision and sarcasm can't be clearly distinguished from good-natured humor, they ought to be careful in their wording so as not to give offense where none was intended.
     
  19. rcmodel

    rcmodel Member in memoriam

    Joined:
    Sep 17, 2007
    Messages:
    59,082
    Location:
    Eastern KS
    Guys!

    It is hard to read a persons comments or intentions on-line.
    And that sometimes leads to hard feelings.



    You & I didn't agree on that .38 Spl windshield deal either.
    But it didn't escalate to dillweed or smartass now did it?
    Not here on THR anyway.

    Can we all agree to disagree, and Just all get along??

    rc
     
  20. JRH6856

    JRH6856 Member

    Joined:
    Dec 5, 2011
    Messages:
    3,828
    Location:
    Flower Mound, TX
    Anybody have any pet loads they would like run through QuickLoad for a comparison of FPS in 2" and 4" barrels? I'll be glad to run them. YMMV in actual use but the differential should still be close.
     
    Last edited: Apr 5, 2013
  21. rcmodel

    rcmodel Member in memoriam

    Joined:
    Sep 17, 2007
    Messages:
    59,082
    Location:
    Eastern KS
    O.K.
    Just for arguments sake.

    CAUTION = OVER CURRENT SAAMI .38 SPL PRESSURE STANDARDS.
    One load I have used for about 50 years in 2" (actually 1 7/8") J-Frame S&W's is a 158 grain Keith SWC over 5.0 grains Unique.

    I can GayRonTeeYa it will punch through a car windshield from anything except a glancing angle.

    rc
     
  22. Certaindeaf

    Certaindeaf member

    Joined:
    Jan 16, 2012
    Messages:
    5,170
    Location:
    Wet Oregon
    Maybe the part about a car going backwards at 400mph would be a clue.
     
  23. JRH6856

    JRH6856 Member

    Joined:
    Dec 5, 2011
    Messages:
    3,828
    Location:
    Flower Mound, TX
    That load charts at:
    2" barrel: 594 fps 124ft/lbs 16326 psi
    4" barrel: 859 fps 259ft/lbs 16326 psi

    difference: 265 fps 135ft/lbs

    FWIW:
    1 7/8"barrel: 563 fps 111ft/lbs
     
  24. tipoc

    tipoc Member

    Joined:
    Mar 9, 2006
    Messages:
    2,950
    Stephen A. Camp passed away awhile back but his books and his website, operated by his family, go on. In addition to being an advocate for the Browning Hi-Power he was also a large fan of J frame S&Ws. He wrote a book on them and much of it is at his website.

    He chronographed a good many rounds. He mentions here...

    http://hipowersandhandguns.com/Snubnose.htm

    and here...

    http://hipowersandhandguns.com/Feedingthe38Snub.htm

    That he tested more than once both Federal and Remington 158 gr. +P LSWCHP rounds from his model 42 and 642. Both with the standard sub 2" barrels. He averaged about 900 fps from the Federal and 838 fps or so from the Remington. There was variation of course. But well above the 300 fps reported above or 600 or so fps. What Camp reported is in line with Ballistics by the Inch, Brass Fetcher and other sources as well as readings I've seen.

    tipoc
     
  25. JRH6856

    JRH6856 Member

    Joined:
    Dec 5, 2011
    Messages:
    3,828
    Location:
    Flower Mound, TX
Thread Status:
Not open for further replies.

Share This Page