A question about Glock 21 SF's

[mississaugagunnut]

Hello,
I was at the range today with my new Glock 21 SF. With a fully loaded 10rd factory magazine the slide is very difficult to pull to the rear and it seems to struggle stripping the first round off the magazine. If the magazine is not fully loaded there is no problem.
Could the recoil spring be weak? Is this normal?
I am using factory loads.
The pistol is lightly lubed with oil and all parts seem to be in working order.


Thanks

 

[bollox]

Just the drag of the cartridge against the slide, Glock mag springs are really stiff at the last round. It will loosen with cycling of the mag spring.