3953 Mag problem

[RGK]

I need some help. I purchased used a 3953 with one mag. I can load 8 rounds in the mag and it inserts fine in the pistol. I bought a new 8 round, it is S&W brand, and it will not go all the way in to latch if loaded! It will empty. What gives? What am I doing wrong. Help.
Both old and new have red followers.

[demkofour]

Welcome to the SW Forum! It's my guess you are loading the mag into the 3953 with the pistol in battery (slide forward...) Since the mag is new and the spring is really not broken in, this would be a common occurrence, seen on many other pistol , models and calibers. Just try loading the mag into the pistol with the slide locked to the rear for the time being until the mag breaks in a bit.

[snw19_357]

+1 on what demkofour said, including the welcome

[RGK]

Thank you soooo much. You guys are really fast.
I will do that tonight.
Thanks again.

[handgunner356]

Remember that when the slide is forward you're holding the rounds down about another 1/8" or so in the tube. It's not unusual to have to load one round short on new mags till they get broken in a little. Always use a good slap to seat your mags.

[RGK]

The reason I felt this was different, I have added additional Mags to other pistols, and yes they were very tight. Some times it took a while to load the last round.
This new mag loaded right off to the full 8 rd., but would not lock in.
I like to load the mag, rack a round in chamber, remove mag, and top off mag and lock it back in for 8+1 Can't do that.
I will continue to load 8 rds in mag and insert mag with slide back. Slide forward to load top round in chamber and use it that way for a while to see if later I can add the 8 rd and insert the mag.
Thanks for all your help.I guess I am a little slow in understanding why.

[handgunner356]

One other thing you might check is that the spring is in the mag correctly. There was just a thread on someones 4500 mags that one of the springs was in wrong, could be binding up causing failure to have enough play to seat the mag.