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Thread: Pressure Signs in Revolvers

  1. #1
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    Default Pressure Signs in Revolvers

    What are the pressure signs when handloading revolvers, like my 44 Magnum? Flattened Primers?? Hard extraction?? ??

    Nope, I don't think I have any, but I'd like to know what to look for, like I do when handloading for a rifle.

    Thanks

    Smitty of the North
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  2. #2

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    It's tricky because there are so many variables. Primers and extraction are partial indicators, but you can be led astray by things like dirty chambers. I also watch resizing effort, but overall I'm pretty conservative. Over the years I've shot too many revolvers "loose" with a steady diet of the hottest loads.

    I read about some pretty astronomical loads here and elsewhere both for handguns and rifles, but I never see any sign how the folks determined that pressures were really okay. For max loads I now only rely on "book" loads that have been pressure tested. Even then I'm really altert for indications of excess pressures in my own guns, due to the many dimension variables even between the same models from the same production run.

  3. #3
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    If I could add to what BrownBear said and be in full agreement with his post.

    The brass for rifle and pistol is made of the same stuff...brass. Rifles operate at around 60 to 65,000 psi and revolvers such as the 44 mag operate at about 36 to 40,000 psi. Excessive pressure for the 300 mag will expand primer pockets and expand the webb of the case a little. For those signs to show up on revolver cases they would have to be at rifle pressures. This is way beyond the design pressure of the cartridge. Most of us load the 44 mag too hot. Taking loads from a manual with pressure numbers and velocity numbers is the safest way then match up the velocity with the same bullet or at least same construction and weight, giving consideration to barrel length.

    What I have found for subtle pressure signs in a revolver is the slight expansion of the webb of the case will slightly stick the extractor. On DA revolvers this is more obvious as we are pushing all six of them out but with single actions it is a very slight extra push. This expansion will keep a case from falling out just from gravity. But as BrowwnBear said, a dirty cylinder will also stick a case in the same way. Primers will flatten and top hat in some revolvers even at or below normal pressure. This is a headspace thing. Also a dirty gun will stick the cylinder when we try to swing it out on a DA, just the way excessive pressure does. The body expansion of a case from excessive pressure will push the case back against the recoil face and bind a cylinder and not allow it to rotate, just like a dirty cylinder.

    Get to know the personality of your guns. If it always sticks cases after a few rounds because it's dirty then clean more often. If it never sticks cases until a 100 rounds and they stick after one cylinder, this could be a problem. S&W's tend to need the cylinder and particularly the extractor, cleaned more often than the Ruger RH/SRH. A SA can go for much longer because the ejector is more powerful than with DA's.

    Nowadays the Ruger RH/SRH's are much stronger than needed for the 44 mag. That same gun is made in 454 and 480 and they operate at higher pressures. It's true that we can get by with more high pressure loads in these guns. This isn't to say that we can do anything we want but they are more forgiving.

    There is a big safety valve built into the 44 mag. If we use the small handful of powders appropriate for the caliber for heavy loads, we can't get enough in the case to do much damage. Powders such as W296/H110, (they are the same powder) H4227, N110, 2400, and Lil'Gun, will do all that can be done and will get all out of the caliber it was designed for.

    My recent loads with this Lil'Gun powder are derived from the Hodgdon's annual loading manual. There is a BT 325 grain WFNGC with 20.0 grains of Lil'Gun gives a pressure of 38,600CUP. I have not exceeded that load with any of my loads, but I've played all around it. My heaviest load was 20.0 grains with the 320 WFNGC. My velocity was less but the test barrel was 8 3/8", mine were all shorter. Now I extrapolate from this load and use say 21.0 grains with a 300 grain WFNGC. But that is staying within reason. I don't think I exceeded the published pressure or if I did, not by much.

    It is always good to be able to trace your load back to some normal, legitimate, testing laboratory.
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    Thanks, you guys:

    A bunch of stuff there, that I needed to know.

    I'm glad I got around to asking now.

    Smitty of the North
    Walk Slow, and Drink a Lotta Water.
    Has it ever occurred to you, that Nothing ever occurs to God? Adrien Rodgers.
    You can't out-give God.

  5. #5

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    Thanks for elaborating on the point Murphy.

    I can add one more indicator that I use. I shoot mostly DA, and primer drag is immmediately apparent (and cumulative) when you're well acquainted with a particular gun. I don't even need to open the cylinder to confirm it, but I'll sure stop shooting if the gun doesn't have a history of doing it with reasonable loads.

    And that brings up the most important point, which you introduced tangentially: If you have several 44's, you need to keep all your loads tuned for the least capable or else religiously label them to allow you to restict their use to specific guns.

    I have both Smiths and Rugers, and loads developed for the Rugers can easily be too hot for the Smiths. But why own the Rugers if you restrict all your loads to suitable levels for the Smiths?

    If a box of reloads sits around for a few months or years, can anyone really remember which gun it belongs in? I sure can't without good labeling.
    Last edited by BrownBear; 06-06-2007 at 07:56.

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    Member RANGER RICK's Avatar
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    Unhappy

    This is one way to know if your pressures are too high !!!!!
    Ouch !!!!!!!!!!!!!!

    By the way the guy only had a small scratch after this pressure test .He was very lucky to say the least .

    RR




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    Perfect Practice makes perfect !!!!!!!!!!


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    Rick,

    That looks like an obstructed barrel to me. Maybe first shot left the cylinder and waited in the barrel then the second shot got it out. Do you have details on that one? Nice pictures.
    Is there nothing so sacred on this earth that you aren't willing to kill or die for?



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    Default

    I've seen parts of case heads melted, blown primer pockets, and I've seen barrels expaned from stuck bullets due to primer only. I have a 1960's Python barrel with six in it cut in half. But I never saw one with a burst barrel. That's a first Rick.

    How come you don't sell big meplat bullets for the .44mag like you do for the .500 S&W Rick? You do make good bullets, Rick!

  9. #9
    Member RANGER RICK's Avatar
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    Murphy

    You are most correct .
    From what I remember this guy was new at reloading and missed a cartridge with powder , only had a primer .
    When he shot the squib the bullet did lodge in the barrel .
    He inspected the cylinder and yep bullet was gone so he let another one fly and you can see the results of not checking the barrel .
    I wonder if warranty would cover that ???? NOT !!

    RR
    Practice does not make perfect !!!!!
    Perfect Practice makes perfect !!!!!!!!!!


    USS SARATOGA CV-60

    http://img.photobucket.com/albums/v5...ex_2-1-1-1.gif

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