8 round kit for P220 Mags

deanf · July 14, 1999, 11:56 PM

I have heard mention of a retrofit kit for factory 7 round Sig P220 .45 ACP mags that will make them 8 round mags. New follower, and maybe a new spring. No mention of them at Sig website, and my dealer didn't know anything about them. Apperently they are a Sig product.

Does anyone know if they're available retail?

**4V50 Gary** · July 14, 1999, 11:58 PM

You can buy them direct from Sig. The only thing different between the standard 7 rounder and the 8 rounder is the follower. Same spring, same floorplate, same magazine tube, same assembly and disassembly technique. Sig takes Visa if you drop them a line.

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Vigilantibus et non dormientibus jura subveniunt

deanf · July 19, 1999, 06:59 PM

So, is the 8 round follower just a shorter version of the 7 round follower?

It would appear possible to cut down the 7 round follower so that it can travel further towards the floorplate, thus allowing 8 rounds. The portion to be cut would be the long side that travels down the spine of the mag as the rounds are loaded. Test fitting with 8 rounds with the spring out and the florrplate off indicates exactly 1/8th inch should be removed.

Would someone out there mind comparing the 7 and 8 round followers to see what the difference is?

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“The whole of the Bill (of Rights) is a declaration of the right of the people at large or considered as individuals. ... It establishes some rights of the individual as unalienable and which consequently, no majority has a right to deprive them of.” -Alexander Addison, 1789

[This message has been edited by deanf (edited July 19, 1999).]

[This message has been edited by deanf (edited July 19, 1999).]

**4V50 Gary** · July 19, 1999, 11:39 PM

It's more than a matter of shortening the tail end of the seven round follower. The front end of the eight round follower is shaped such that it mates flush against the inside body of the magazine tube. Think of it as two half domes pressed against one another. It was done this way to give the nose of the follower more bearing surface against the magazine tube and prevents it from nose diving down when loading.

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Vigilantibus et non dormientibus jura subveniunt

Robert Foote · July 23, 1999, 11:25 AM

I have the conversion parts for 8 rd but never bothered putting them in. I know what the guns will do with std. mags and don't think the possible tradeoff in reliability would be worth it. Since I am principally a revolver person anything more than 6 rounds is high capacity for me.

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Cheapo · July 23, 1999, 02:11 PM

I've shortened a few magazine followers in my time, and must advise you to remember that you must take off a bit more than what is needed to squeeze the next round in.

There must also be enough room for the bottom of the slide to press the top round down into the "before popping up to get stripped by the slide" position.

M14s and M1As with USGI magazines, for example, are strictly 20-round propositions, not 20+1. A fully loaded mag won't fit under the closed bolt.

Technically, you should also have a bit more wiggle room so if the full mag is pressed upward inside the mag well, there will not be enough drag from the top round to make the slide short-cycle. So, measure room for the last round, room for the closed slide/bolt to depress the round in the mag, a little more room for where the floorplate tops out in the mag well, plus about 1/16-inch to be safe.

Ram-Line's super high-caps got that way by using a flat ribbon spring attached to the top of the mag next to the feed lips. Loading the mag unrolled the coiled ribbon like a party whistle unrolls its paper tube (whaddaya call those things?). That design eliminated the need to include room for the compressed spring under the follower.

deanf · July 23, 1999, 03:56 PM

Thanks for the advice. I don't know if I'm prepared to go sawing on my relatively new P220, even on parts as simple (or so I thought) as a mag follower, so the discussion is academic.

I have one of those Ram-Lines with the ribbon spring in 9mm. It's a few years old and has never skipped a beat.

jimmy · July 26, 1999, 09:34 AM

FWIW, I have two SIG .45 P220s (one with "European" mag release and one with "American"). Both came from the factory with 7-round magazines. I considered increasing their capacity to 8 rounds, but, in the end, decided not to do so.

[This message has been edited by jimmy (edited July 26, 1999).]

July 14, 1999, 11:56 PM	#1
deanf Senior Member Join Date: June 5, 1999 Location: N47º 12’ x W122º 10' Posts: 1,599	I have heard mention of a retrofit kit for factory 7 round Sig P220 .45 ACP mags that will make them 8 round mags. New follower, and maybe a new spring. No mention of them at Sig website, and my dealer didn't know anything about them. Apperently they are a Sig product. Does anyone know if they're available retail?

July 14, 1999, 11:58 PM	#2
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,833	You can buy them direct from Sig. The only thing different between the standard 7 rounder and the 8 rounder is the follower. Same spring, same floorplate, same magazine tube, same assembly and disassembly technique. Sig takes Visa if you drop them a line. ------------------ Vigilantibus et non dormientibus jura subveniunt

July 19, 1999, 06:59 PM	#3
deanf Senior Member Join Date: June 5, 1999 Location: N47º 12’ x W122º 10' Posts: 1,599	So, is the 8 round follower just a shorter version of the 7 round follower? It would appear possible to cut down the 7 round follower so that it can travel further towards the floorplate, thus allowing 8 rounds. The portion to be cut would be the long side that travels down the spine of the mag as the rounds are loaded. Test fitting with 8 rounds with the spring out and the florrplate off indicates exactly 1/8th inch should be removed. Would someone out there mind comparing the 7 and 8 round followers to see what the difference is? ------------------ “The whole of the Bill (of Rights) is a declaration of the right of the people at large or considered as individuals. ... It establishes some rights of the individual as unalienable and which consequently, no majority has a right to deprive them of.” -Alexander Addison, 1789 [This message has been edited by deanf (edited July 19, 1999).] [This message has been edited by deanf (edited July 19, 1999).]

July 19, 1999, 11:39 PM	#4
4V50 Gary Staff Join Date: November 2, 1998 Location: Colorado Posts: 21,833	It's more than a matter of shortening the tail end of the seven round follower. The front end of the eight round follower is shaped such that it mates flush against the inside body of the magazine tube. Think of it as two half domes pressed against one another. It was done this way to give the nose of the follower more bearing surface against the magazine tube and prevents it from nose diving down when loading. ------------------ Vigilantibus et non dormientibus jura subveniunt

July 23, 1999, 11:25 AM	#5
Robert Foote Senior Member Join Date: December 31, 1998 Posts: 623	I have the conversion parts for 8 rd but never bothered putting them in. I know what the guns will do with std. mags and don't think the possible tradeoff in reliability would be worth it. Since I am principally a revolver person anything more than 6 rounds is high capacity for me. ------------------

July 23, 1999, 02:11 PM	#6
Cheapo Senior Member Join Date: November 19, 1998 Posts: 986	I've shortened a few magazine followers in my time, and must advise you to remember that you must take off a bit more than what is needed to squeeze the next round in. There must also be enough room for the bottom of the slide to press the top round down into the "before popping up to get stripped by the slide" position. M14s and M1As with USGI magazines, for example, are strictly 20-round propositions, not 20+1. A fully loaded mag won't fit under the closed bolt. Technically, you should also have a bit more wiggle room so if the full mag is pressed upward inside the mag well, there will not be enough drag from the top round to make the slide short-cycle. So, measure room for the last round, room for the closed slide/bolt to depress the round in the mag, a little more room for where the floorplate tops out in the mag well, plus about 1/16-inch to be safe. Ram-Line's super high-caps got that way by using a flat ribbon spring attached to the top of the mag next to the feed lips. Loading the mag unrolled the coiled ribbon like a party whistle unrolls its paper tube (whaddaya call those things?). That design eliminated the need to include room for the compressed spring under the follower.

July 23, 1999, 03:56 PM	#7
deanf Senior Member Join Date: June 5, 1999 Location: N47º 12’ x W122º 10' Posts: 1,599	Thanks for the advice. I don't know if I'm prepared to go sawing on my relatively new P220, even on parts as simple (or so I thought) as a mag follower, so the discussion is academic. I have one of those Ram-Lines with the ribbon spring in 9mm. It's a few years old and has never skipped a beat.

July 26, 1999, 09:34 AM	#8
jimmy Senior Member Join Date: January 29, 1999 Location: Texas Posts: 1,796	FWIW, I have two SIG .45 P220s (one with "European" mag release and one with "American"). Both came from the factory with 7-round magazines. I considered increasing their capacity to 8 rounds, but, in the end, decided not to do so. [This message has been edited by jimmy (edited July 26, 1999).]