rimfire ammo , 22 lr

[Lynn Brase]

I got a second case of standard velocity ammo of an imported brand. I had no problem with the first case that I got a few years ago. The new case is working ok in my bolt guns, a 54 ms and a 54 sporter. I did notice the rounds chambered a bit harder than the older batch. The new batch would not work in my two semi-auto hand guns. The slides would not close on next round. The old case worked just fine in both guns. Anybody had this kind of problem with ammo made in south America? At first I thought it was the lube, but after more inspection I am not sure??

 

[Lumpy’s guns]

Probably head space difference

 

[Lynn Brase]

the rounds push into the chamber quite stiff, only the 54 MS is pushing into the rifling but the sporter is pushing in like it is going into the rifling but it is not.??

 

[Lynn Brase]

The rims are not extra thick. they measure the same as the old case.

 

[doclu60]

My guess, different lot number causing issues. Sometime a go I was running CCI SV in my target pistol. Bought some more, different lot number, and had tons of fail to feed and some fail to eject. Compared the new lot to the old lot and the new lot had thick, excessive bullet lube. Shot some of the old lot again, pistol ran flawless, as it always did before the lot change.

Depending on how good your "South American" ammo MFG's QC is, there could be many different issues between lots, and with the long period of time between your first purchase and the new one, most likely even more.

Scott

 

[DShortt]

Use a micrometer to check the diameter of the brass cases.

Without being able to handle it myself, I'd say the cases are slightly larger in diameter than what you had before. I've run into this myself with a tight-spec chamber diameter.

You could also check to make sure your chamber walls are spotless. Might be some sort of fouling present that's just enough to cause problems.