Powder Burn Rates and Felt Recoil Test

Discussion in 'Reloading' started by George Kaplan, Jan 25, 2020.

  1. George Kaplan

    George Kaplan emeritus

    Messages:
    1,482
    Likes Received:
    1,970
    Joined:
    Dec 27, 2015
    Loaded three batches of .38 Special. All starting weights. Identical components except for the powder used. Of course each powder charge was different but nearly identical in published pressure and velocity.

    AA #2: Felt like a +P load.

    Sport Pistol: Very mild recoil. Similar burn rate to HP-38/231.

    VV N350: Extremely mild recoil.

    Interesting that the VV is way slower burning than SP but felt recoil was similar when fired back-to-back. I read that slower burning powders have less felt recoil than the faster burning powders. Didn't hold true in the SP/VV test. The difference is noticeable but not as much as I thought it would.

    Fired out of 642 J-Frame. 158gr. LSWC. No trace of leading. As a matter of fact, I've never cleaned a gun after a range trip that was so clean.
     
    Taterhead likes this.
  2. fredj338

    fredj338

    Messages:
    31,835
    Likes Received:
    10,713
    Joined:
    Dec 22, 2004
    Location:
    so.cal.
    No slower powders dont have less felt recoil as a rule. I find powders burning characteristics often determine felt recoil. So not how fast or slow but how the powder reaches peak pressures. WST is one such powder. It is about the same burn rate as tg but with same vel, WST offers less felt recoil.
     
    Last edited: Jan 25, 2020

  3. Taterhead

    Taterhead Nightshade

    Messages:
    5,638
    Likes Received:
    2,375
    Joined:
    Dec 13, 2008
    Location:
    Boise
    One big data point that's missing is the actual bullet velocities. That will have a far more sugnificant influence on felt recoil. It would be useful to try the experiment after loading the ammo to common velocity.
     
  4. fredj338

    fredj338

    Messages:
    31,835
    Likes Received:
    10,713
    Joined:
    Dec 22, 2004
    Location:
    so.cal.
    Which is what I have done with some 9mm & 45acp. I know it sounds wierd, but with identical vel, the WST load feels softer. I know that is subjective but my experience. I have shooters that reload tell me their fav tg load feels snappy compared to my wst loads.
     
    Lagamor and Taterhead like this.
  5. Taterhead

    Taterhead Nightshade

    Messages:
    5,638
    Likes Received:
    2,375
    Joined:
    Dec 13, 2008
    Location:
    Boise
    I've done the same thing in 38 spl where 452AA felt much softer vs the same bullet/velocity propelled by Green Dot and 700-X. I will get to my containers of WST at some point. As I've mentioned before, I have too many partial bottles open that I've committed to using before opening anything new. Progress has been made.
     
    Intolerant and fredj338 like this.
  6. fredj338

    fredj338

    Messages:
    31,835
    Likes Received:
    10,713
    Joined:
    Dec 22, 2004
    Location:
    so.cal.
    I thnk I mentined this, but 452aa is pretty much wst. It was all I shot in 45acp in the 80s. The switch is seemless as powder charges are virtually identical.
     
    Taterhead likes this.
  7. sciolist

    sciolist On the Border

    Messages:
    13,268
    Likes Received:
    14,216
    Joined:
    Nov 11, 2009
    Location:
    PNW
    I think duration of the impulse has a lot to do with it.

    In order to be able to shoot well at speed with traditional irons, you need to be able to look through the distractions of flip and recoil. Compressing the distractions into a shorter time frame makes that easier.

    Even highly advanced shooters have all sorts of little mechanical imperfections in their process much of the time. It's important to be able to arrange a series of events in time, so you can understand where the gun is pointed at the actual time of discharge.

    I'm coming mostly from the minor power perspective, but slower powders and higher charges tend to draw the distractions out into dominant aspects of the shooting process. Whereas faster powders/lighter charges/heavier bullets tend to do the opposite.
     
    George Kaplan, Taterhead and SARDG like this.
  8. SARDG

    SARDG Florida's Left Coast

    Messages:
    8,052
    Likes Received:
    510
    Joined:
    Nov 12, 2006
    Location:
    Florida's Left Coast
    Don't know if that's all true, but I'm buying it!
     
  9. Taterhead

    Taterhead Nightshade

    Messages:
    5,638
    Likes Received:
    2,375
    Joined:
    Dec 13, 2008
    Location:
    Boise
    Yessir, and why I have some on deck.
     
  10. sciolist

    sciolist On the Border

    Messages:
    13,268
    Likes Received:
    14,216
    Joined:
    Nov 11, 2009
    Location:
    PNW
    Shooting at speed is about vision and mechanics. What you can't do with the latter, you have to make up with the former.

    All shooters, even the most elite, have subconscious compensatory reactions to discharge. This is not something that can be risen above - it can only be coped with. It fundamentally resides below your conscious control.

    Equanimity of observation is critical in that regard. It's much easier to sort things out and remain unreactive if you slow down the rate of engagement.

    You can't learn to shoot at speed by building up from slow fire, it's a completely different thing. That's one reason it's so poorly understood by intermediate shooters.

    Continuity of observation as a fluid process is essential.
     
    SARDG likes this.
  11. OXMYX

    OXMYX

    Messages:
    4,494
    Likes Received:
    6,127
    Joined:
    Oct 4, 2014
    If I want less recoil I just load minimum spec . And I save a hell of a lot of money.
     
  12. SARDG

    SARDG Florida's Left Coast

    Messages:
    8,052
    Likes Received:
    510
    Joined:
    Nov 12, 2006
    Location:
    Florida's Left Coast
    Well... that could be affecting your accuracy significantly.
     
  13. Lagamor

    Lagamor

    Messages:
    401
    Likes Received:
    465
    Joined:
    Dec 12, 2018
    I used to love this conversation, especially when talking about 12 guage. Then I saw burn rate chart for actual burn rates. ....two millionths of a second was the actual difference. Now I think those differences are just in my head.
    The only difference I know to be true the speed a bullet enters rifling. To fast a powder and too soft a lead bullet and the rifling will strip the bullet, ruining accuracy. A little slower powder allows the bullet to “conform” to the rifling making a much more accurate bullet.
     
  14. unclebob

    unclebob DFC, MSM, 12 Air Medals.

    Messages:
    9,508
    Likes Received:
    2,894
    Joined:
    Oct 14, 2000
    Location:
    Mary Esther FL
    Then what about Andrea and Tony they shot some real real light Bunny Fart loads.
     
  15. sciolist

    sciolist On the Border

    Messages:
    13,268
    Likes Received:
    14,216
    Joined:
    Nov 11, 2009
    Location:
    PNW
    You might be surprised at how accurate lighter loads can be, even with heavy bullets.
     
  16. SARDG

    SARDG Florida's Left Coast

    Messages:
    8,052
    Likes Received:
    510
    Joined:
    Nov 12, 2006
    Location:
    Florida's Left Coast
    I remember speaking with Tony about his loads, but have since forgotten exactly what he was using. I think TG powder though. Wonder if he's making PF as he and Andrea also shoot Action.

    When I drop my 320 load by .2, the groups open up wide. Had some tumbling back when I was developing a load. If I adjusted OAL with that lighter load, it may save it, but each time I've tried to lighten up to reduce recoil, accuracy has gone to pot. This is with 147s. Tried and developed an accurate 124 load for my race gun, but that load always had a higher impulse.
     
  17. sciolist

    sciolist On the Border

    Messages:
    13,268
    Likes Received:
    14,216
    Joined:
    Nov 11, 2009
    Location:
    PNW
    320 and WST group about as well for me with 147's at 17 yards at 120 PF as they do at 130 or 140 PF.
     
    Last edited: Jan 25, 2020
    fredj338 and SARDG like this.
  18. unclebob

    unclebob DFC, MSM, 12 Air Medals.

    Messages:
    9,508
    Likes Received:
    2,894
    Joined:
    Oct 14, 2000
    Location:
    Mary Esther FL
    PM sent.
     
    SARDG likes this.
  19. newglocker10mm

    newglocker10mm Texas Born & Bred

    Messages:
    2,704
    Likes Received:
    5,505
    Joined:
    Mar 29, 2017
    Location:
    Texas, Oklahoma and anywhere with Oil!
    Fred I have a question. I have some Colt .45 ACP loads (not the DoubleTap stuff but loaded somewhere) 185 SCHP that has a very sharp (and I mean sharp!) recoil. It is commercially loaded but has a very fast sharp recoil versus any other 185's I shoot, including +p 185's. I've been shooting .45 for a long time, but this stuff actually has more FELT recoil than any of the .357 magnum or even some .44 mag loads I've shot. All the comparisons have been in the same pistols, a Sig 220 and a Springfield RO. I theorized the powder burn rate might have something to do with it but didn't know how to explain it. Not to over emphasize it, but the recoil with those Colt loads HURT!
     
  20. SARDG

    SARDG Florida's Left Coast

    Messages:
    8,052
    Likes Received:
    510
    Joined:
    Nov 12, 2006
    Location:
    Florida's Left Coast
    I am now routinely shooting to 25 yds, but PF no longer important anyway. Would be happy to cycle gun and lob bullets to target accurately.