Page 1 of 3 123 LastLast
Results 1 to 10 of 24
  1. #1
    Join Date
    Apr 2018
    Posts
    174

    Default SBS vs. 18.5" and Velocity Lost?

    When it comes to shotguns, we have all heard the "Don't get an SBS, it limits your range!" and then we have people chime in saying "No it doesn't, with equal chokes, you get nearly equal patterns, and with slugs, they are just as accurate", to which the rebuttal "But the velocity will be less and the shot/slug won't hit nearly as hard from your SBS as from a "full size" tactical shotgun barrel like an 18.5 or 20""

    Then we are left with a bunch of conjecture and confusion and very little real data and both sides kindof walk away without having actually unpackaged anything from the debate.

    I have long held the opinion that with at least low-recoil ammunition, the girth matters more than the length, when it comes to shotguns. Bore VOLUME is what matters, and considering the amount of powder in a shotgun shell vs. length vs bore ID, there has, in my mind, always been plenty of bore volume to make up for lopping off several inches of length because of the large ID of a 12 gauge bore.

    Regardless, conjecture is what we want to get away from, so I decided to actually test the theory and see if the bore ID of the 12 gauge made up for the bore shortening in the case of the SBS. Today, I tested low recoil ammunition, since it's so popular. Tomorrow, or soon, I will also test full-power ammunition, and see if the trend changes because of the larger amount of powder involved.



    Average velocity of 14" firing LEB127LRS (rated velocity, 1300fps)
    1180.6fps, calculated kinetic energy (assuming 438gr), 1356ft-lb

    Average velocity of 18.5" firing LEB127LRS (rated velocity,1300fps)
    1215.2fps, calculated kinetic energy (assuming 438gr), 1436ft-lb

    Average velocity of 14" firing LE13200 (rated velocity, 1145fps)
    1088fps, (energy per pellet, assuming 50gr pellet weight) 131ft-lb

    Average velocity of 18.5" firing LE13200 (rated velocity, 1145fps)
    1125.25fps,(energy per pellet, assuming 50gr pellet weight)141ft-lb

    With the slugs, the 14" SBS gave up 34.6fps, and 90ft-lb of kinetic energy. With buckshot, it gave up 37.25fps, and 10ft-lb per pellet (90 total) of kinetic energy. This is the equivalent of 6 yards in distance of flight travel, presuming a G1 BC of 0.07.

    Across Federal's low-recoil LE ammunition, this is a very uniform result, and I have a high level of confidence in its accuracy due to this.

    Thank-you for watching, and I hope this answered any questions you may have had on the topic.

  2. #2
    Join Date
    Jan 2012
    Location
    NW Washington
    Posts
    2,908
    Good data.

    However, I think it's important to realize that comparing "low recoil" or other light loads almost always shows the smallest difference in barrel lengths out of all the loads you could test. Personally I think a 14" barrel is fully adequate for it's intended role, and maybe the low recoil loads are the best choice for that setup, but if you compare a number of full power loads you will see a much larger velocity difference with some of them. That's not an argument for or against short barrels, just something that should be understood before thinking that testing the two loads above tells everything you need to know.

  3. #3
    Join Date
    Apr 2018
    Posts
    174
    Quote Originally Posted by Yondering View Post
    Good data.

    However, I think it's important to realize that comparing "low recoil" or other light loads almost always shows the smallest difference in barrel lengths out of all the loads you could test. Personally I think a 14" barrel is fully adequate for it's intended role, and maybe the low recoil loads are the best choice for that setup, but if you compare a number of full power loads you will see a much larger velocity difference with some of them. That's not an argument for or against short barrels, just something that should be understood before thinking that testing the two loads above tells everything you need to know.
    Correct. I am testing full-power ammunition later this week in an identical manner to determine the amount of variance, there, to see if full-power ammunition offers an advantage in power over LR in an SBS, and if so, how much, vs an 18.5" barrel.

  4. #4
    Join Date
    Jan 2016
    Location
    Prescott
    Posts
    696
    all of this data and time spent and i feel the need to remind folks it is not relevant to us in this group. Federal flight control will and absolutely does hold the group together out to 25yds. after that your pattern may start to spread but you can still put pellets on target at 50 and beyond, because staff and students have done it. velocity in relation to barrel length in this context is an absolutely irrelevant topic

    Do NOT call me an armorer
    Si Vis Pacem Para Bellum
    Now I am become Death, the destroyer of all worlds
    People have asked me if I consider myself a good or bad person. The truth of it is, I don't know or care. I have been called both. I like to think I have saved more lives than I have ended. Either way, I can still sleep at night.
    SEMPER FI

  5. #5
    Join Date
    Apr 2018
    Posts
    174
    Quote Originally Posted by ShopMonkey View Post
    all of this data and time spent and i feel the need to remind folks it is not relevant to us in this group. Federal flight control will and absolutely does hold the group together out to 25yds. after that your pattern may start to spread but you can still put pellets on target at 50 and beyond, because staff and students have done it. velocity in relation to barrel length in this context is an absolutely irrelevant topic
    That's another subject entirely, and unrelated to this thread. It depends heavily on individual bores, as to what patterns your Flite Control will throw, and if they do or don't have constriction, etc. Velocity and powder burn efficiency, etc./whatever you want to call it is something different from patterning efficiency.

  6. #6
    Join Date
    May 2000
    Location
    Beyond The Wall
    Posts
    44,261
    I can take any out of the box 18 inch 870, load it with the right ammo and hit a man in the chest out to 25 yards...I can do the same with a 14" barrel.

    I think we have even shown the patterning on video once or twice. The power issue in practical terms is a non-issue as any buckshot from any barrel will have a devastating effect on a man.

    So other than an interesting scientific measurement...I dont think this is going to cause anyone to change already carefully chosen ammo.
    Gabriel Suarez

    Turning Lambs into Lions Since 1995

    Suarez International USA Headquarters

  7. #7
    Join Date
    Feb 2009
    Location
    Colorado
    Posts
    7,150
    At the very least its interesting data that can be referenced and its better than some recent threads lol.
    Geek Warlord
    Dungeons & Dragons & Deadlifts

    Muscle Wizard Casts: Fist


    CRG-1 DPS
    CRG-2 CRG x 2
    SGF-1 Shotgun Gunfighting
    Trauma care under fire
    Spetsnaz Sniper
    HRO-5 Terrorist & Active Shooter Interdiction
    HRO-6 CQB: Fighting in Structures
    CRG-4 Force on Force
    HRO-5 Terrorist & Active Shooter Interdiction - 3 day
    TWOTU edition
    Trauma Medicine for the CCW Operator
    Pistol Ground Fighting (Taint Shooting Progressions)

    TWOTU since May 2015

  8. #8
    Join Date
    Apr 2018
    Posts
    174
    Quote Originally Posted by Gabriel Suarez View Post
    I can take any out of the box 18 inch 870, load it with the right ammo and hit a man in the chest out to 25 yards...I can do the same with a 14" barrel.

    I think we have even shown the patterning on video once or twice. The power issue in practical terms is a non-issue as any buckshot from any barrel will have a devastating effect on a man.

    So other than an interesting scientific measurement...I dont think this is going to cause anyone to change already carefully chosen ammo.
    No, I doubt it will, but I am curious if the 14" barrel gains much from using full-power ammo. That will be seen today. If it gains only 25fps...and you load full-power in it...it would likely get you to change to LR, if it's reliable, because the muzzle flash is far less, recoil is less, and you lose nothing meaningful. It's a 2 part experiment, with LR ammunition as the first part. I personally think it will gain more than 25fps, but we will see.

    I have found actual velocities interesting. For example, Hornady's 1600fps in an 18.5" gun runs low 1400's. Federal's 1325fps buckshot averages very high 1300's. Federal's 1600fps bukcshot runs 1450+. All of the people running the Hornady stuff are trading 1 pellet, and likely better patterns, for a whopping 75fps, while thinking they are getting nearly 300 out of the deal. That's the kind of stuff I'm looking to discover, otherwise, it makes for good entertainment, as you say.

    The slug data should be useful for those who also hunt.

  9. #9
    Join Date
    Aug 2014
    Posts
    2,921
    For me, the issue is to what degree reduced velocity affects penetration ((of animal hide, leather coats, human skulls and such) and how it affects what happens once the pellets get inside.
    Warrior for the working day.

    Es una cosa muy seria. --Robert Capa

    "...I ride the range in a Ford V8...Yippy Yi Yo Ki Yay." --Johnny Mercer

    "Can I move?...I'm better when I move."

    1, 4, 10. And a wakeup.

  10. #10
    Join Date
    Jan 2012
    Location
    NW Washington
    Posts
    2,908
    Quote Originally Posted by Papa View Post
    For me, the issue is to what degree reduced velocity affects penetration ((of animal hide, leather coats, human skulls and such) and how it affects what happens once the pellets get inside.
    Yes, that.

    Uno, I'm interested to see the rest of your results. Keep us posted.

Posting Permissions

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