S&W M28-2, 357 Magnum, High Pressure, Locked Action,

Discussion in 'Handloading and Reloading' started by 243winxb, May 10, 2022.

  1. murf

    murf Member

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    the early 686's had the same problem with primer flow on the high power loads. the factory had a recall and replaced the firing pin and pin hole insert. maybe s&w will do the same for the m28. other than a thicker primer cup, that seems the only solution.

    luck,

    murf
     
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  2. 2ndtimer

    2ndtimer Member

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    I think it looks like bad primers. Have you tried some CCI or Remington? I have had some disappointing experiences with Winchester components (and rim fire ammo) over the past few years. In the past I have loaded .357 Magnums with Accurate No. 9 with heavier charges and similar bullets and CCI primers without issue.
     
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  3. jmorris

    jmorris Member

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    I don’t really have a “system” other than gathering as many data points as I can, resource or first had but I prefer to learn from the mistakes of others.

    Some stuff .2 gn is the difference between MAX and MIN.

    465B8918-2790-4406-A904-4F0EB27905CD.jpeg

    Other stuff like 50 BMG, with a ~220gn charge, .2 gn is nothing.
     
  4. 243winxb

    243winxb Member

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    I dont have other primer brands available. I have used close to 3000 WSPM, same lot, without any issues, loading 13.0 grs of Alliant 2400. Same components. Will test later with ammo loaded with 2400.

    Looking at the gun now.
    Found the strain screw had backed out almost 2 turns. Should be tight. The main spring is producing 56 oz + now. On firing, the hammer nose may not have stayed in contact with primer long enough. Extra hammer bounce.

    End shake is .008" Will be adjusting that when Power Custom Bearings get here.

    Powder - Hand weighted the first patch. 2nd was droped from the measure & every 5th check on scale.
    Run a 20 drop test into brass. Weight checked each one. Perfect at 11.2 grs No. 9 . Not loading any till repairs are made & test fire with 2400 powder.

    Thought about test firing with factory ammo, not at $1.00 a shot.
     
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  5. tightgroup tiger

    tightgroup tiger Member

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    Accurate 9 has a faster recoil impulse than 2400 so 2400 should be a little easier on the brass than AA9, may not show up as profound as AA9 problem is.

    I'm wondering about the looks of the hammer nose dents on the brass. It may be lighting conditions but some of the dents look deeper than other.
    Powder not burn consistantly? Has your hammer nose been tuned in to the gun after it was staked on the hammer.
    When mine was replaced we had to work it down a little because the pin was a little to long when it was new. It would pierce a primer now and then and with the harsher recoil of some powders and loads.
    I also noticed that the dents are everywhere from center of primer to off to the side of primer and I don't remember either one of my 28s ever doing that.
    The strikes were dead center of the primers. I may just not be remembering correctly.
    I'm not in a position to test my guns for that because I'm laid up right now. Trying to go from memory. The dents don't look round either.

    Are these things just lighting conditions or am I seeing an accurate view of the case heads?

    Not really sure what to think of the primers that look deeper than others. I would also lean toward the powder not burning consistently on that one to start with but if the hammer nose is striking off sides of the bushing it also could be inconsistent with the strikes. Any side to side movement of the hammer?

    Just trying to wrap my head around this. Definitely try the 2400 though and see what shakes out of that.
     
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  6. 243winxb

    243winxb Member

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    The strain screw had backed out, causing lighter then normal strikes. The hammer bounce makes the indent in the primer, oval.

    Powder is burning ok. The firing pin protrusion is on the long side, but in spec.

    Brass- The brass trim length that i check before loading was well under 1.290" The fired brass sized a little harder then normal. The trim length was now to long on some by .003" A high pressure sign. But brass did fit back into the chambers, after firing.
    Have a speedy recovery.
     
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  7. Walkalong

    Walkalong Moderator Staff Member

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    I never had good luck with AA # 9 in .357 Mag, does great in .44 Mag.
     
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  8. WrongHanded
    • Contributing Member

    WrongHanded Contributing Member

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    I just saw your previous post regarding the strain screw, and then this one. And as soon as I read "strain screw" it clicked.

    I just had an issue with my new 686, and the strain screw backing out was the cause. Light strikes, and primer flow into the fire pin hole. No pierced primers for me, but between the primer flow and the extractor rod simulataneously beginning to unscrew, I had an interesting time.

    I'm glad you figured it out!
     
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  9. AJC1

    AJC1 Member

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    I've learned to qualify my statements here because of exactly this reason. If using my plan for my cases makes sense then why not... the smallest case I currently load is 38spl.... if loading a 25acp then you may need different rules...
     
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  10. 243winxb

    243winxb Member

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    S&W M28-2

    After a closer look, installed one .002" Power Custom Bearing to remove some sligth end play. Was not really needed or the cause of primers blanking.Imo.

    Cylinder gap is now .007" Headspace is .009" Firing pin protrusion is .058" (hammer nose),

    Primer pocket depth was uniformed. Little to no brass removed. Same primers seated with Ram Prime, using cam over on RCBS press. Seated hard, not smashed.

    The 2400 loads will be fired first, then the reduced loads of Accurate No. 9 powder. Reduced because it seems to be a high pressure problem??

    Off to the range for test fire.
     
  11. 243winxb

    243winxb Member

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    High pressure produced from a heavier, different bullet then Hodgdon data? 10.6 grs looks ok. The 10.1 gr loaded felt light.

    Accurate No 9 B.jpg No 9 357 info.jpg No 9 and 2400.jpg
     
  12. 243winxb

    243winxb Member

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    Last edited: May 25, 2022
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