M&P 340 Bullet jump, now what do I do?

307-Niner

307-Niner

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This is my M&P 340 with Altamont "Aged" bonded ivory grips & BK grip adapter. Loaded with Remington 125 gr JSP. Locked up after the third shot. I have heard about this being a problem only on the lighter PD, so I did not think it necessary to check for bullet jump after each individual shot. Now I know better...

My question is: What do I need to do now, to open the cylinder without damaging or scratching the gun?

You'll also notice in the pics, that the right side grip broke.

Any and all comments & suggestions are appreciated. Here are the pics.






 
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In your third picture, push that bullet back in. Lightly tap with a brass rod and gunsmith hammer if you need to, and only go just below flush.

The cylinder will open when that one bullet is pushed back in.
 
Waywatcher said:
Lightly tap with a brass rod and gunsmith hammer if you need to, and only go just below flush.
Click to expand...

I have neither of those tools. All of my tools are auto & light truck repair tools. Can I tape up a regular steel punch, and use a small hammer and safely do the same? Tape on the gun too, to protect the finish.

What are the dangers in this operation? Pretty sure the bullet can't go off. But can I damage the gun behind the cylinder?
 
307-Niner said:
I have neither of those tools. All of my tools are auto & light truck repair tools. Can I tape up a regular steel punch, and use a small hammer and safely do the same? Tape on the gun too, to protect the finish.

What are the dangers in this operation? Pretty sure the bullet can't go off. But can I damage the gun behind the cylinder?
Click to expand...

Unlikely to cause damage unless you miss with the hammer or rod. A .357 contains 35,000 psi.

Well, brass rod will be very easy to figure out. Either buy some from a home improvement type store, or buy a cheap cleaning kit and chop the ends off a cleaning rod. Just use the lightest, smallest hammer you have and use lots of light little taps. Don't use a punch.
 
Appreciate the help. I'll update this thread after I get the cylinder open.
 
Thank you Waywatcher!

I substituted the body of a plastic ink pen (Bic) for the brass punch. A little blue masking tape on the gun, including between the offending bullet & the frame, to protect from scratches or dings. And a couple hundred light taps with a tiny little framing hammer made for picture frames from an "As Seen On TV" Wally World kit. The cylinder is open, and no damage to the gun or me. :)

What should I do with these two "stretched" 357's?


 
Well done! :)

As for the ammo, I'd deposit those cartridges in a shooting range's squib/misfire bin. The rest of the ammo is probably fine for use in a big steel framed K or L frame.
 
I have a 4" 686.

I don't reload yet, don't own any of the tools yet. I do have plans for the future, but my current living arrangement leaves me with no space to set up a reloading bench.

But if I one of my friends or co-workers has a reloading press, would it be possible to press the bullets back in?

There are no formal shooting ranges near here. My shooting range is the great outdoors. :)
 
Any cost savings from re-seating the bullets is likely not worth it. Give 'em to a reloader, let them pull the bullets and use the components.

BTW, not sure on the limitations for appropriate ammo for that revolver, but if these are theoretically ok, the crimp is likely inadequate and you might want to check all the remaining ammo from that batch.
 
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Thanks for the post Doug.

These 5 bullets were the last of a box of 50. The rest have already been ran thru my 686. Of course, never a problem with them in the 686. I should probably just pull the bullets, dump the powder, and save the brass for someday. (I always save my brass). I was just wondering if it was even possible to press them back in.
 
307-niner,

Next time if this happens you don't have to resort to punches and hammers. Obviously not many realize that the cylinder on a S&W will turn backward! Simply pull the hammer back until the cylinder stop releases the cylinder, then, while holding the hammer back, turn the cylinder backward. Repeat as needed. Once the protruding bullet is below the level of the barrel the gun will open normally. The only time this won't work is if the bullet is far enough to interfere with the frame. then you may have to tap it back just far enough to clear the frame.

There appears to be NO residual crimp on those cartridges as there should be. Apparently they were not adequately crimped in the first place. Never shoot ammunition without a solid crimp in a revolver, particularly a Scandium frame .357! Don't assume that because it was "factory" that it's right.
 
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Glad to see you got your 340 functioning again. Pulling the hammer back to the just right position drops the cylinder stop down to allow cylinder rotation but that might be a little trickier in a dao that was jammed by the crimp jump.
 
Alk8944 said:
307-niner,

Next time if this happens you don't have to resort to punches and hammers. Obviously not many realize that the cylinder on a S&W will turn backward! Simply pull the hammer back until the cylinder stop releases the cylinder, then, while holding the hammer back, turn the cylinder backward. Repeat as needed. Once the protruding bullet is below the level of the barrel the gun will open normally. The only time this won't work is if the bullet is far enough to interfere with the frame. then you may have to tap it back just far enough to clear the frame.

There appears to be NO residual crimp on those cartridges as there should be. Apparently they were not adequately crimped in the first place. Never shoot ammunition without a solid crimp in a revolver, particularly a Scandium frame .357! Don't assume that because it was "factory" that it's right.
Click to expand...

You make a very good point about the crimp, and it's something that I had not ever thought about. These are Remington UMC, and I don't see any crimp at all on them.

But about pulling back the hammer, my 340 is hammerless. Also, one of the bullets jumped farther than the other, and had extended past the frame. Here's a zoomed pic.

 
A not uncommon query on this Forum concerns which factory .357 loads will not have this "bullet jump" problem in the super light Scandium guns, PD or M&P. This seems to vary by lot. I've read here that R-P Golden Sabre 125gr "medium" ammo works in the Scandiums, yet it has "pulled" in my original 360Sc.

I have the remains of an older box of W-W 145gr Mag Silvertip which will not pull, yet later lots will have this issue. Even some .38 loads will pull in the Scandiums, despite claims that they cannot. You must try each load: some will show jump after just one round.

BTW, I absolutely LOVE the above caution about pulling the trigger partially to free and rotate the cylinder by hand. Can be done carefully on an exposed hammer gun, but not safely on a concealed hammer 340. Some awfully savvy folks on this Forum!

Kaaskop49
Shield #5103
 
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