USP, USP Compact, P2000, P2000SK Mag-Spring Chart

[KurtP2k]

ill take ur word for it! hopefully they loosen up a little, so far no luck.

[randomHKlover1223]

thanks again for taking the time to post all the info

[hfd]

thanks for this , any info like this is useful...

[KurtP2k]

Ok, ill admit i was wrong. Ive been working the springs and they are getting easier to manage and feed the pistol well...

What should I do with the p2ksk mags I have? maybe the glock +10?

[peter2772000]

I recently traded one of my P-99's for an HK USP in .45 and I have a problem trying to get the 10th (and last) round into either of my mags. Simply put, there is no way on gods green earth that a 10th round will fit in there. When I asked the previous owner about it, he stated that he had replaced the mag springs in both mags with Wolff +10%. He also told me to break them in. Break them in? Jesus, the only thing breaking is my fingers, and that's just to get the 9th round in. I'd gladly swap anyone for the OEM springs so that I can get a full 10 rounds into the mags. Or is it simply that the USP mag only holds 9 rounds?
As well, what's with the need for extra-tensioned mag springs? Is this an issue with otherwise box-stock USP's?

[orfeo]

. . . is it simply that the USP mag only holds 9 rounds?
As well, what's with the need for extra-tensioned mag springs? Is this an issue with otherwise box-stock USP's?

If it's a fullsize USP 45, it gets either a 10-round mag or a 12-round mag. . . so I think your (2) mags are 10-rounders (no such thing as a 9-rounder for that gun). Some USPs benefit from the +10% extra spring power. . . it solves feeding issues in the ones that seem to need it. Some brand-new USPs (mine included) came with mag-springs that are only barely strong enough, and end up with FTFs and failures to lock the slide back on an empty mag.

The extra-powered mag-springs give an extra measure of lifespan and reliability over the stock ones. Most USPs do fine with the OEM springs though. Personally, I prefer the Wolff +10% mag-springs, but they sure can be stiff knucklebusters when they are new! :)

[peter2772000]

As terrible as it may sound, I'm glad that I'm not the only one having issues loading the 10th round. I tried again this weekend with both mags, it just ain't happenin'! So I left one mag loaded with 9 rounds and hopefully the spring will collapse a bit.
I can't believe I wrote/did that. Always been paranoid about leaving a mag loaded for any length of time for the eact reason stated above, yet here I am, doing exactly that in order to achieve exactly that....

Thanks for the reply(s) guys!

[AlphaWintermute]

No, the springs really have nothing to do with mag capacity. The two round block is in the floor plate and there is no good way to convert a 10 round mag to full cap. They were designed that way to be in line with ATFE laws that were in affect during the AWB. You need entirely new magazines if you want full caps. If making a full cap were as easy as replacing the springs or a simple floor plate swap the ATFE would never have approved the magazines for sale.

I'm not going to do this but thought it might be handy to know if the zombies ever come.

Could you in theory alter the floor plate, via filing/saw, to allow for a higher capacity? I know this would be totally illegal, but if the feds are fighting off the zombies I don't think they would mind! =P

In the event that you could do this, would you need a new mag spring? One would think so.

I'm double majoring in physics and engineering and I just can't help but to think of these things.

[AlphaWintermute]

Could you in theory alter the floor plate, via filing/saw, to allow for a higher capacity?

I just took the time to look and answered my own question.

No. You would have to make a mold out of the current floor plate, and base insert, possibly the follower as well ( don't want to destroy the ones ya got!). Modify your newly cast molds and make molds based off them and cast new pieces. Might as well just buy them from your local post-apocalypse traveling merchant for all the trouble.

You could feasibly do it though. You would just be reinventing the things. I'm going to look into the laws regarding this and see if I could possibly make a 30 rounder for a .40. I can't seem to find these anywhere, but I see them for the 9mm and 45 all over.

I don't know any zombies willing to test their might against 30 rounds of .40 S&W. =P

[BigD]

Curious about Jet funnel mags as well. Any updates on which spring?