My M&P22 will run 100% on Mini-Mags or Remington Golden, even though I don't normally use the Golden, as it's filthy and produces large group sizes. Today, I tried some Federal Champion 36gr HP in it. Got a lot of short cycling of the slide. It would come back, eject the empty case, but not go far enough back to allow a new round from the magazine to pop up and chamber it. It's because they are weaker than the other brands and you can even hear the difference, as they sound weaker. Also, when they eject, they only kick out about a foot or less from the gun, whereas the others kick out about five feet. Since this allows the slide to fall on an empty chamber and you don't know it till you pull the trigger, you are dry firing the gun, which S&W tells you not to do in their manual, as it can ruin the gun. I had this exact same problem with a Walther P-22. The M&P22 is made by them, so I guess that explains it. European ammo tends to run hotter than US ammo, so maybe that's why this happens.
I'll going to pay more and stay with the Mini-Mags. They group the best, burn the cleanest and go bang every time. BTW: The 36gr HP groups better than the 40gr solids.

I get similar results with my SR22P, but the GB is still pretty accurate out of it. Not as accurate as most CCI flavors, but a lot less expensive.

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M&PC FS BG Shield+ 642 686+

I reworded my original post to make it more clear. The slide goes back far enough to eject the empty case, but not far enough to pick up a new round.

You've stumbled upon the dirty little secret of firearms chambered for .22lr. .22lr firearms can be ammo sensitive, even within the same make and model. It's the nature of firearms chambered for .22lr.

That being said, my M&P 22 cycles any .22lr ammo I put through it from left over ammo from 1971 to FC bulk ammo. The only thing I ever did to mine was to thoroughly clean out the viscous preservative lube from the pistol, then lube with a little dab of copper/graphite lube on the frame rails.

Do you notice any unusual witness marks on the slide and frame surfaces where they interface? Are there any rough spots on the face of the hammer on your pistol? This can cause just enough dragging to cause a short skide cycle.

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-John

Federal Champions didn't work well in my M&P 22 - in fact, I got FTEs on EVERY magazine load. It wasn't pretty. If you can actually find CCIs without paying double the price for them, by all means go for it. I haven't been able to find a place that has CCIs in stock yet. GunBroker has them, but again, you are paying nearly double the cost in my cases, especially when you factor in shipping.

Sadly, the supply of reasonably priced CCI Minimags has all but dried up for the time being.

That said, having cleaned and then greased the rails of my M&P 22, I must say that I am impressed with its ability to feed and cycle weak .22lr ammo.

If I can find some Federal Champions I'll give them a try and see how they do. I will note that last week it fired 200 Federal 335rnd bulk 37gr CP HP's flawlessly. It also shoots Remington 37 gr bulk Golden Bullets and Stingers quite well.

It doesn't happen on every shot with Federal Champions, averages between one in 5 or 10, randomly. You can actually feel the lighter recoil and hear the lower decibel level with them, as compared to other ammo. As mentioned above, the empty cases only kick out a foot or less, as compared to other ammo, which kicks out about five feet.
The gun is cleaned, and rails smooth and lubed. I'm an amateur gunsmith and very meticulous with them.
It appears to be a stronger recoil spring on any 22's from Walther. My daughter and I have P-22's and they have the exact same problem.

Federal used to sell a .22 RF round made just for auto pistols...Auto Match or some such name. I got a 550 round box of it at Walmart some time ago, and have used it in my S&W 2213 auto pistol, bolt action rifles and revolvers with no problems at all. It's solid, not plated and very uniform...I'll try to find the right name...

OK, it's still around and called Automatch...

http://www.midwayusa.com/product/953...ead-round-nose

I like it a lot...never had a problem with it at all, very accurate, too.


mark

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Liberals made the USA

Thanks for the information. I ordered several boxes of the stuff, but was able to cancel it.

I've have GREAT luck with the Remington Golden as well.

I shot a ton of the Federal Champion 36gr hollow point out of the wifes M&P 22 with no problem. Might be gun or Lot# specific.

So far her M&P has cycled everything thrown at it like a champ.