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.38 SPL accuracy load for a .357 magnum Colt SAA

Discussion in 'Handloading and Reloading' started by Stimovsky, Jan 4, 2020.

  1. Stimovsky

    Stimovsky Member

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    I have difficulties developing a .38 SPL accuracy load for a .357 magnum Colt SAA 7 1/2".

    My ingredients are new Starline brass, CCI Small Pistol #500 primers, HP-38 and 158 gr Hi-Tek coated LSWC.
    I experimented over the whole range of powder amounts from 3.1 to 3.7 grains according to Hogdon website and got all over the place. Ugly.

    The "best" results, in terms of grouping were achieved with 3.7 grains and nothing to be proud of anyway, especially if you consider I was using a sandbag rest.
    My chrono reported those at 631 fps (SD 13, spread 42 over 10 rounds). That's 200 fps slower than what I expected but I understand there are many reasons why it may be so.

    Point of impact is definitely 2" below and 2" left of point of aim. I can put up with a POI higher than POA, but not lower.

    Would it be possible to get a higher POI, and (I'm afraid to ask…possibly less... leftward?) with another case/powder/bullet combination?

    If not, would it be a crime to consider performing surgery on a 2nd Gen Colt SAA?

    Thank you for your help,
     
  2. Barry loyd

    Barry loyd Member

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    884B126E-54F9-408D-B45A-EE9B2DF949B9.png 631 FPS from a 7 1/2in barrel is awfully slow. More velocity may stabilize the bullet better. Hodgdon’s load data for .357 with HP-38 gives more wiggle room as far as powder charge.
     
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  3. Mr_Flintstone

    Mr_Flintstone Member

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    Loads with reduced velocity and/or reduced recoil lower the point of impact of a certain weight bullet when compared to higher velocity/increased recoil loads. I would imagine a .357 revolver of that size would have the sights set for a 158 gr lead bullet at about 900-1100 FPS. A bullet traveling just over 600 FPS could definitely account for the lower impact point.

    Using .357 magnum cases and appropriate .357 charges as stated by Barry Loyd above would give you a better chance of hitting on target. You can use .38 special cases and a variety of other powders with your 158 gr bullets to get you there as well. You can still shoot reduced loads, but you should work them up to see which powder/bullet combinations work for your gun.
     
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  4. Stimovsky

    Stimovsky Member

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    If in the end it is merely a question of velocity, I'll try lighter bullets.
    I'll come back here after I've run my tests. Thank you both.
     
  5. Mr_Flintstone

    Mr_Flintstone Member

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    If what I’ve read is right, it’s a little more than just velocity. See here.
    If you use lighter bullets, make sure you keep a high enough recoil to raise the point of impact.
     
    Last edited: Jan 4, 2020
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  6. GooseGestapo

    GooseGestapo Member

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    Actually, #3 and #4 are backwards.

    It’s a matter of recoil and barrel transit duration.
    A 158gr bullet is typically slower (longer barrel transit time) than a lighter bullet,
    A heavier bullet going slower is going to exit the barrel at a higher deflection point.
    With a revolver, recoil begins before the bullet exits the barrel. A bullet doesn’t reach exit velocity instantly. Most of the recoil felt is induced after the bullet exits due to acceleration having to overcome inertia.
    Increasing speed causes the bullet to exit at a lower deflection point even though weight of bullet remains constant. The bullet velocity increases at a greater rate than recoil as the firearm, and hands and arms holding it are a much greater mass.
    Take note as to how tall the front sights are on a S&W Model 24 and 25.

    So, a heavier bullet is needed in order to raise point of impact. You can also file the front sight in order to raise impact.

    Windage is a little trickier. You can:
    Rotate barrel to move the front sight,
    Increase or decrease bullet weight as heavier bullets induce greater rotational force engaging rifling,
    Or; bend frame by rapping the the barrel while frame is held tightly in a padded vice.
    I’ve had to do all of the above to get S&W service revolvers to “hit where they look”.
    This is the reason I don’t hold all the old fixed sight revolvers in reverence like many here do.
    All my single action revolvers have adjustable sights, as do most of my d/a revolvers and s/a pistols.

    I was so thrilled when my agency traded in the Model 65’s for M686’s! And switched from Winchester 158gr SWC’s to Winchester 145gr SilverTips...

    As to the OP’s issue with accuracy, I suggest a softer, fatter bullet, with a higher charge weight to achieve obturation of the bullet to the cylinder throats.
    Slugging the cylinder throats seems to be in order...
     
    Last edited: Jan 4, 2020
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  7. Stimovsky

    Stimovsky Member

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    Thought so and I expected box of 180gr XTP to be delivered today, unfortunately those are still on the way tonight.
    Interesting article Mr.Flintstone, thanks for sharing.Obviously I need to get me some 125 gr too.

    Yet, bullet weight effects case volume, so also pressure development, then velocity, then recoil, which depends on the gun itself and my grip... Changing a single variable shuffles them all.

    I now realize no one else but me can answer my question. I only explored powder amounts for a given bullet weight and wasn't satisfied. I just need to go through the same process with different bullet weights until I find what's right for my gun and me.

    This is the first time I'm confronted with such a picky gun. I'm glad I can still learn. We'll come to terms someday.
     
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  8. Mr_Flintstone

    Mr_Flintstone Member

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    Not if you read closely. Everything you’re saying is true, but statements 3 and 4 assume the same recoil between the two loads. Same recoil means that the muzzle rise will be the same between the two shots; meaning that the two bullets leave the barrel at the same angle. If they leave at the same angle, the faster bullet will reach the target faster; thus with less drop. I had to read this twice as well. When read in context with the article, the statements make more sense.
     
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  9. Mr_Flintstone

    Mr_Flintstone Member

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    Load development is key to finding the most accurate load. Although it sounds like the ammo might be the issue, there could actually be an issue with the gun as well. Only experimentation will tell. Good luck.
     
  10. Shak3s1977

    Shak3s1977 Member

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    I would also up the charge as GooseGestapo mentioned to increase bullet obturation. I run a 12 brinell, hi tek coated bullet in my 357 magnum. This is soft enough that with a decent charge, bullet obturation happens. This gives me accuracy and no leading in the barrel.
     
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  11. frankmako

    frankmako Member

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    you need to up your charge a little and do some chronograph work.
     
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  12. Stimovsky

    Stimovsky Member

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    There's something interesting there. Among those widely spread out impacts I'm confronted with, groups of 2 or 3 were connected. That dumbfounded me until I read your answer.
    I'm shooting 13 brinell HT-SWC. My charge may just be on the verge of "decent".
     
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  13. Mr_Flintstone

    Mr_Flintstone Member

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    Are your cases really dirty after shooting these rounds? If so, the load is too light to seal against the cylinder walls and prevent the back flow of gas. I have run into this with light .38 special before. It makes them erratic. A few will be accurate, and some will be flyers.
     
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  14. Shak3s1977

    Shak3s1977 Member

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    Stimovsky I am currently chasing a similar problem in 44 magnum loads now. I have one 44 load that is accurate and zero leading. My other load was going to be a softer load but it's not accurate and I'm getting massive leading. I got my 357 dialed in after alot of rounds downrange. Poor accuracy, leading, made me research about bullet hardness and how much psi is needed to obturate the bullet into the grooves.

    So many companies sell super hard bullets that alot of the time aren't needed, and in fact hinder the reloading experience.
     
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  15. Stimovsky

    Stimovsky Member

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    I just took a look at the rounds I shot today. Most display a soot ring near the mouth, with a smudge. Some are really clean :
    824447-cecea69ca3f131c545ee9066af7da1fd.jpg
     
  16. RON in PA

    RON in PA Member

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    I think your loads are too wimpy. HP38 is the same powder as Win. 231 and when Winchester published loading manuals they suggested a load of 4.5 grains of 231 with a 158 grain lead bullet to duplicate a normal .38 special load. The suggested +P load foe the 158 grain lead bullet was 4.7 grains.
     
  17. film495

    film495 Member

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    the Hodgdon's website and manual lists 3.1 - 3.7 with 158 LSWC for regular .38 Special loads and Win 231 .. thinking of doing some for the first time, so was just looking this up recently.

    are you using .38 Special or .375 Brass? if you are set up for both, I'd load both with the exact same charge and components and compare to see if shooting .38 Special brass is your challenge. If it is, why not just use the .357 brass and work up some mild target loads?
     
  18. murf

    murf Member

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    let us know how much better those 180 grain xtps shoot. a slower powder, like unique, will work better for that bullet, but hp38 should do fine.

    luck,

    murf
     
  19. Mr_Flintstone

    Mr_Flintstone Member

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    That looks like a ring of unburied powder on the left case. That and the amount of soot down the side indicate too light of a charge. If I’m not mistaken, HP 38 doesn’t like light charges very well either. Do you have other powders or .357 cases available to test?
     
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  20. murf

    murf Member

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    bullseye does much better with light loads in the 38 special cartridge.

    murf
     
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  21. Stimovsky

    Stimovsky Member

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    Also, I noticed an unusual amount of unburnt flakes on my mat.
    I have both, and I will do just that.
    I also have other powders to experiment with. I'll keep you updated with my results. I have some handloading to do now !
     
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  22. RealGun

    RealGun Member

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    If possible, you should try those same loads in a different gun. That could indicate whether the gun is a negative factor in your results.
     
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  23. Mr_Flintstone

    Mr_Flintstone Member

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    Years ago when I used to work in IT, we had a saying; check the simplest thing first and work toward hard. I think that could be applied here.

    Easiest check would indeed be to try the suspect ammo in another gun of known quality, and/or try known good ammo in the suspect gun. Intermediate would be to try load development and check in this and another gun. The hardest (and potentially most irreversible) would be to start tinkering with the gun mechanics.
     
  24. mavracer

    mavracer Member

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    No 3 and 4 are still backwards.
    The slower the velocity the higher the gun will be in recoil when the bullet exits and the higher POI will be in relation to POA.
    Don't fret it's not the first time Chuckie's been dead wrong.
     
  25. Stimovsky

    Stimovsky Member

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    I don't have another .38 and I won't ask another shooter his gun to test my reloads.

    Yesterday, I cleaned my revolver thoroughly, measured all throats with a vernier caliper for what it's worth, all .360".
    I dropped a .358 HiTek LSWC through each throat. It stuck inside the throat, and required to be pushed with reasonable force in 4 chambers, and I had to push just a little bit harder on the last 2, but it wasn't excessive though.

    I prepared several dozens .357 magnum cases. I now have a box of 125gr JSP, another of 180gr XTP and plenty 158gr LSWC.
    It took me some time to decide on what loads to test.

    I decided to give HP-38 another chance but with magnum loads this time.
    I plan on exploring various ranges :
    • from 7.5 to 8.5gr with 125gr JSP
    • from 4.0 to 5.0gr with 158gr LSWC . Hopefully my revolver will like one.If not, I'll change powders rather than bullets.
    • Hodgdon doesn't list HP-38 as a suitable powder for 180gr .357magnum. I'll try 6.0gr Bullseye.
    I'll be back.
     
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