I found a Marlin 57M, metal action, a couple weeks ago. Took the action off, gave everything a good cleaning and did some shooting. I have 3 different types of ammo, one is 45 gr Win Dynapoint, the other 2 are 40 gr offerings from Win and Rem.

The 45 gr load will shoot 1/2" consistently @ 50 yds. Both 40 gr loads will not group, literally spraying all over the place, some even hitting the target sideways! I'm assuming the gun can not handle the higher velocity with the smaller bullets? I've heard that sometimes with this caliber you have to find which brand your gun prefers. This seems a lot more wtf than that, though.

Anyone else seen this? Guess I need to find another batch of 45 grain stuff.

Very common for both 22LR and 22 mag to be ammo picky. Also the marlins have the microgroove rifling which I have heard more than once can cause issues with certain bullets. In particular with lead bullets. Going to a oversized bullet solves the problem. Based on that here is my line of thinking. 22 mag is a .224 bullet. 22LR is .222. 40 grain bullets are fairly common in 22LR ammo. Don't know of any 45 grain 22LR. I am wondering as most of the time .002 does not make a difference if the 40 grain bullets are not actually 22LR bullets loaded in a 22 mag case and the 45 grain is of the .224 diameter. Again just thinking which can be dangerous at times for me. If it were me I would just say to hell with it and stock up the ammo that shoots.

The 40gr bullets loaded in 22Mag cases are NOT .219 diameter bullets designed for 22LR.

If you have a rifle that prefers the heavier bullets, you might try the Federal 50gr. They are loaded to about 1650fps and have proven very accurate in all of my 22mag rifles.

Best of luck!

In my marlin 22 mag the best shooting ammo is the 33 grn win supremes. Not only are they accurate, but they kill like a 22 centerfire up to 50-75 yds. Crows come apart when hit, coons,skunks and chucks just slump when hit. At 75 yds or so, big yotes make a short dash and drop. a 22 mag is a great farm/ranch gun.

I was hoping to find a light fast load for this gun too, but it appears it likes the heavier stuff. Thinking to use it for fox and lynx calling, need something besides my centerfires that are a bit hard on thin skinned critters. How do the 45 gr and up loads work for fox/ cats?

This is my first go round with the mag, trying to get a feel for what it will do.

Havwe you tried the Federal 30gr TNT hollow point?

I think you might have a crappy micro groove barrel that is pitted or over size. The dyna point ammo is a plated lead el cheapo bullet.

quote:

I've heard that sometimes with this caliber you have to find which brand your gun prefers.

That's been my experience....but not as dramatic as yours.....in my gun the CCI hollow points shoot the best.....others didn't compare at all.

Curious. I just recently came by a Marlin 57M and tried the 45 grain Dynapoints along side the regular 40 grain WW JHP. The groups with Dyanpoints were not too bad, about 1.25" at 50 yards, but the groups with the 40 grain WW JHP were half of that.

Try various weights and brands -- individual rimfires, especially the WMR's, are finicky and it is impossible to tell which ammunition will shoot best in a given gun. For example, the 50 grain Federals which did well for Drewhenry have never done well in any of my guns, which just goes to prove the point. On average, the WW 40 JHP has done better than CCI for me, while the more recent 33 grain hyper velocity rounds don't seem at all accurate in my WMR's (three of them).

But hey -- if the inexpensive Dynapoints do well for you, then you're in Fat City already and I wouldn't mess with anything else.