Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Ballistics and Barrel Length

  1. #1
    Member bigslim's Avatar
    Join Date
    Sep 2011
    Location
    OHIO

    Ballistics and Barrel Length

    5", 4.5", 4.4", 4.25", 3.9"?

    My top 3 choices for EDC are M&P40, SIG P22X, and Glock. I shoot all of them well and they all fit me without issue. I can get each one with a 5" barrel or 4" family save for the P229 with is only 3.9"(close enough right?)

    So the question is how much does barrel length play into ballistics and accuracy other than sight radius? Does it make sense to carry a 5" gun?

    Mike

  2. #2
    Murder Machine, Harmless Fuzzball TCinVA's Avatar
    Join Date
    Feb 2011
    Location
    Virginia
    If you're asking whether any of the shorter-than-5" barrel lengths you cite (4" is the standard for terminal ballistic testing) will neuter the good defensive load on Doc's list, the answer is no. At most, the 5" gun might develop a bit more velocity, but I doubt that the increase will be enough to cause a given JHP to over-expand and stop shallow or anything.

    All other things being equal (rarely are all other things equal) having a bit more barrel means the bullet gets to twist more (depending on the twist rate) which helps with stability in flight, which can be a boon to longer range accuracy. The longer sight radius helps with getting a clearer picture of the front sight's orientation to the rear sight. In practical terms (meaning the results you are likely to see when holding the firearm) these advantages may prove to be completely theoretical for your shooting. As a for instance, you're unlikely to find that the Sig P229 is significantly less accurate than a Glock 34 traceable to the shorter barrel on the Sig.

    Similarly, you are unlikely to find that a Glock 17 runs significantly differently for you than a Glock 34 in a manner that is traceable to the 34's extra barrel length. Those who are at higher skill levels might be able to tell a measurable difference in their performance with both guns.

    Does it make sense to carry a 5" gun? Well, if it's a 1911 the 5" gun with a standard barrel bushing seems to be the most dependable configuration. On the M&P, I've never seen a 5" gun that had the early unlock problem that plagues some samples of M&P...but I've only seen a fairly small number of 5" M&P's, so take that with a bucket or two of salt. In those instances if the 5" gun bought me a better shot at reliable function or the ability to dodge serious accuracy problems, I'd buy the 5" gun. If it isn't buying me that then it's not likely to buy me much and I'd stick with the gun that gave me a better shot at finding a good comfortable holster I could carry in every day.

  3. #3
    Member
    Join Date
    Feb 2011
    Location
    Seattle
    I'm not an expert I can't speak on the performance of ammo in soft tissue or anything to that nature but there is this cool website
    http://www.ballisticsbytheinch.com/
    Where they fire various rounds in various calibers through barrels of various lengths and then charge the muzzle velocity and energy. As you can see the length difference between 5" to 3.9" is really not going to change either in a significant manner.

  4. #4
    Member John Hearne's Avatar
    Join Date
    Mar 2011
    Location
    Northern Mississippi
    I carried a 5" P220 for a number of years and really liked the extra sight radius. I never sat down and quantified the difference at the Pistol-Form level but it seemed to be there when I think about tests like Dot Torture, the FBI bullseye, or my El Pres time. As best I can remember, both speed and accuracy increased by it was accuracy where it was most significant.

  5. #5
    Site Supporter DocGKR's Avatar
    Join Date
    Feb 2011
    Location
    Palo Alto, CA
    With high quality, robust expanding ammunition, there will be know significant terminal performance differences noted.

  6. #6
    Member bigslim's Avatar
    Join Date
    Sep 2011
    Location
    OHIO
    I have looked at ballistics by the inch and the data they site is in a form that I can't equate to real life performance. As the barrel gets longer velocity increases and that site does a great job of quantifying that but what does that mean on the street?

    Doc are the differences you speak of positive or negative? In an M&P 40 is there a significant reason to go with Pro 5" over the standard 4.25" model?

  7. #7
    Site Supporter DocGKR's Avatar
    Join Date
    Feb 2011
    Location
    Palo Alto, CA
    Only if you need the longer sight radius or if you are going to be using an X300 light a lot.

  8. #8
    Member bigslim's Avatar
    Join Date
    Sep 2011
    Location
    OHIO
    I do plan on mounting a light and I have heard that the G22 experienced issues with mounted lights, are the M&P's suffering the same fate? Is it the added slide mass that slowed it down enough for proper cycling?

  9. #9
    Site Supporter DocGKR's Avatar
    Join Date
    Feb 2011
    Location
    Palo Alto, CA
    Don't overgeneralize--that issue is confined only to 3rd gen G22's.

  10. #10
    Member bigslim's Avatar
    Join Date
    Sep 2011
    Location
    OHIO
    That sounds like it is a non issue in my case, if I went with a G22 it would be 4th gen. I think I have settled on either an M&P or Sig P22X. Not sure if the added cost of the Sig is justifiable or not.

User Tag List

Posting Permissions

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