Are there any magazine spring kits to increase round capacity of a P220 for 8 rnd magazines?

No. The only other option is the Sig factory 10rd extended mag. Other than Mecgar, all other aftermarket mags for Sig suck.

For a time an effort was made to increase the capacity of the original flush fit seven round 45 ACP P220 magazine to eight rounds by means of a modified follower. When those magazines were loaded with eight rounds, though, they were often unreliable.

I don’t know now where one would find the eight round follower or if it would fit and function in the current standard eight round P220 magazine, but something like that might make it possible to load the standard mag with nine rounds. Even if so, however, I wouldn’t bet the rent on its being reliable.

quote:

Originally posted by 45ProCarry:
Other than Mecgar, all other aftermarket mags for Sig suck.

As a counter-point, I've had very good luck with aftermarket magazines from ACT-Mag...to the point where I've used them as duty magazines. Mine were marked "Novak" who was importing them at the time. ACT-Mags are currently imported by Armscore

quote:

Originally posted by sigfreund:
For a time an effort was made to increase the capacity of the original flush fit seven round 45 ACP P220 magazine to eight rounds by means of a modified follower. When those magazines were loaded with eight rounds, though, they were often unreliable.

I don’t know now where one would find the eight round follower or if it would fit and function in the current standard eight round P220 magazine, but something like that might make it possible to load the standard mag with nine rounds. Even if so, however, I wouldn’t bet the rent on its being reliable.

The 8 round "followers" have never been inherently unreliable in my flat metal bottom P220 mags. What's been unreliable is that the 8th round compresses the HELL out of the mag spring in the original magazines (like completely flat), which aren't that great to begin with. A brand new mag spring loaded to 8 rounds in my mag ends up a significantly shorter after one full mag loading. I load my 8 round follower equipped mags to 7 rounds for long term storage and shooting and never have a problem. It's only when the 8th round is mashed in there (and you do need to MASH it in), especially after leaving it loaded with 8, it starts to have problems pushing the cartridge up fast enough since the spring is so fatigued. Often too, it'll be the top round causing problems, because it's so tight with 8 rounds.

There's just not enough room for the spring with the 8 round followers when fully loaded to 8 rounds. Yes it'll work fine for a little while, but the spring becomes so fatigue weak. Maybe if it used a spring like the one Magguts uses (the folded leaf one), but the stock coiled spring simply gets jammed to tight when loaded with 8. Downloaded to 7 and the 8 round follower works just as good as the 7 round follower in the original flat bottom mags..

I bought my P220 used at Cabelas over 10 years ago with the original stainless flush fit 8 round mag & have bought a factory sig 8 round & a 10 round mag.
Both the 8 round & 10 round mags have ridiculously stiff springs that are painful to load by hand & still takes effort with magula loader, especially the 10th round!
I have tried just leaving the mags loaded for however long between range visits.
Then I shuck out the defensive ammo for range ammo, shoot at range with no issues, then when home, disassemble mags along with the 220 to give good cleaning & rub down internals with a silicone cloth before reassembly & reload with defensive ammo for home protection.

I LOVE the trigger on this gun or I would have sold it & either bought a used 227 or a MKII /P226 as I really like a minimum of 10 rounds, (I hate the 10 round extended mag).
I would just miss my two-tone P220 with silver slide.
It matches my two-tone 365, like a big brother.

Thank you all for your responses.

quote:

Originally posted by 9mmepiphany:

quote:

Originally posted by 45ProCarry:
Other than Mecgar, all other aftermarket mags for Sig suck.

As a counter-point, I've had very good luck with aftermarket magazines from ACT-Mag...to the point where I've used them as duty magazines. Mine were marked "Novak" who was importing them at the time. ACT-Mags are currently imported by Armscore

I have a couple of the ACT-mags for the P220 and they are excellent. Never a malfunction.

I’m not aware of any method to increase the capacity of an 8 round P220 mag.

quote:

Originally posted by sigfreund:
For a time an effort was made to increase the capacity of the original flush fit seven round 45 ACP P220 magazine to eight rounds by means of a modified follower. When those magazines were loaded with eight rounds, though, they were often unreliable.

I don’t know now where one would find the eight round follower or if it would fit and function in the current standard eight round P220 magazine, but something like that might make it possible to load the standard mag with nine rounds. Even if so, however, I wouldn’t bet the rent on its being reliable.

I have had 6 of the eight round, flush fit magazines since they came out in the late 70s or early 80s. I added the SIG rubber base plates to them.

Mine have not been unreliable during the past 4 decades, but they required a different spring than the 7 round magazines. Just changing the follower would not do the job

The follower and spring were manufactured by Devel, yes the same guys that did the chopped down conversion to the Smith & Wesson models 39/59. They also made the conversion parts for the 1911 magazines to hold 1 more round. There were also model 39 conversions followers and springs and others I no longer remember

The follower/spring patents were purchased by Shooting Star/Chip McCormick. I do not recall the sequence of events back then, but I believe the followers are still in use in so many of the 1911 magazines today

Back then the follower and spring could be purchased fromD devel to tconvert your 7 round P220 magazines as well as all the 1911 magazines

Using the follower and spring conversion in a 8 round P220 magazines will not yield a 9 round mag.

So nobody makes one of those +1 mag baseplate things for the P220? Like the ones from HYVE etc.

I thought for sure that would be the solution to this query. But I guess they don't exist.