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

Tried Accurate No 9 powder in my S&W M28-2 357 mag. 164.5 gr lswc Seaco 382 mold. , WSPM, Starline brass. Shot rounds @ 11.5 grs, Hodgdon starting load for 158 gr. . Primer extruded into the firing pin hole. Locked action, cylinder jammed forward.

1 round at maximum 12.4 gs did it first.

After a complete gun/ammo check up, an adjustment to end shake was made with a .002" bushing. Strain screw came loose, tightened it. Head space check, OK. Firing pin protrusion measures .053"

11.2 grs No 9 still blanked the primer. Now shooting 10.6 grs. This seems to be my guns maximum?

All hand loads checked, not an ammo problem.

If your loading No 9 in 357 mag with 158 gr lswc or heavier, whats your powder charge & velocity?

Thank You.


See more photos here- https://www.thehighroad.org/index.ph...ed-action.371/

https://www.thehighroad.org/index.ph...hole.4486/full

My Hornady manual says MAX of 11.5 grains for 158 grain (Maximum, not starting load) and MAX 10.5 grains for 180 grain bullet. Your bullet is 164.5 grains, so your 10.6 grains of Accurate No. 9 is about right.

You can always start low and work up. Your components will probably not match the book loads.

Bullet weight is but one variable in the equation. Seating depth is a significant factor as well.

I quit using Accurate powders after experience at Ruger in pressure testing mostly in .357, lot to lot variation was far excessive and charge establishment firings had to be repeated every time we changed powder lots. Great fertilizer for growing impressive Roma tomatoes.

I prefer Alliant Bullseye, WST, AutoComp, IMR4227, depending upon. application.

How is the firing line bushing in the frame? If it’s oversized compared to the pin it allows for flow.
Early 357 magnums had issues with this. I remember 66s or 686s had to be recalled and bushed properly.

Might not be the load but the bushing tolerance

Looks like you need a smaller firing pin bushing or a bigger firing pin. If the firing pin is much smaller than the bushing it allows the primer to flow into the bushing.

Been shooting gun with 2400, for full power load, since bought new. Never a primer issue for the most part. Had a pierced primer now and then.

Changing to Accurate No 9 started the problem. High pressure is my guess.

The 2 blanked & 2 pierced primers have pock marked the hammer nose. Pin seem a good fit in the hole?

Getting photo..........

Thank you.

sound like looks like high pressure go back to 2400 or lower load

Quote:

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Originally Posted by bruce381

sound like looks like high pressure go back to 2400 or lower load

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Lowered to 10.6 No 9. Yes, looking for Alliant 2400. Hoping for a notification that an 8 pounder is available.

Check the end of the firing pin for erosion from previous pieced primers. There could be rough spots from jetting of hot gasses causing rough spots so the tip grabs the surface and stretches the primer surface instead of letting it slide on the tip.

Check data and primer combo in book. Switch to a different (tougher) primer and work back up.

Based on the simulation data I just ran, something isn't adding up.
Was the AA #9 a fresh pound that you purchased or something preowned that you traded for?
Long ago there was AA#9-C ( C for canister grade)on the surplus market that was stated to be 10% faster than the AA #9 sold on the shelves.

Quote:

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Originally Posted by JAC43

Bullet weight is but one variable in the equation. Seating depth is a significant factor as well.

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Not really. With slow powders, seating depth doesnt move the pressure needle much. I suspect the mag primer with aa#9. In 357sig, much smaller volume case, going with max book loads & std primers was fine. Switching to a mag primer caused excessive pressures. Lots of factors; bore size, cyl throat size, but book says max with 180 lead at 11.6gr? I would certainly be verifying my scale with check weights.

I am thinking magnum primer as well. I don’t think number 9 needs that. I had a similar problem once with a different powder in 357 magnum when I inadvertently used some cci mag primers. I pulled all the remaining bullets.

Hodgdon uses my primer in their data. WSPM.

Quote:

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Originally Posted by johnly

Based on the simulation data I just ran, something isn't adding up.
Was the AA #9 a fresh pound that you purchased or something preowned that you traded for?
Long ago there was AA#9-C ( C for canister grade)on the surplus market that was stated to be 10% faster than the AA #9 sold on the shelves.

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Got 2 one pound containers from Midsouth Shooters . Ordered on 4/9/22. Got here on 4/22/22, along with W244, 2- 1 pound containers.
No 9 was sealed. Looks nornal.

The main difference is the bullets. Hodgdons 158 gr bb. Mine 164.5 grs, with longer bearing surface, i think? Both lswc. Hodgdon lists a 170 gr jacketed, SAME POWDER DATA. Very strange.

Total cost with hasmat, shipping , was $ 40.13 per pound.

I am thinking, its a very HOT batch. Will try in 44 mag next.

Thank you.

Quote:

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Originally Posted by Michael J. Spangler

How is the firing line bushing in the frame? If it’s oversized compared to the pin it allows for flow.
Early 357 magnums had issues with this. I remember 66s or 686s had to be recalled and bushed properly.

Might not be the load but the bushing tolerance

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if its an early 686/586 look on the underside of hammer,if its had the recall on the firing pin it will have an M on it

cci primers have harder cups .

S&W revolvers will not stand up to a steady diet of heavy loads.

M28 was my first modern revolver. Early 1970's.
Shot a lot of 38 special unique loads in it and didn't clean as much or as often as I should have. The crud build up in the front of the chambers caused it to blow primers with factory .357 loads. Belatedly started cleaning regularly, but the ghost of the crud is still there to haunt me. Cleaned and shot with .357 cases, no problem.