So this little guy followed me home today. I needed a companion for the P220. I've been eyeballing one of these 610's for a while now as a hunting gun.

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I'm glad that the members here had the opportunity to buy these GoldDots. Probably the last time you'll see that kind of pricing in quantity for this bullet. I just received my last order before they sold out and I'm well stocked for defensive billets for years. Those numbers look pretty good. I don't think you'll really need to push the GoldDot very hard. I have mine traveling close to 1250 FPS but looking to back down to right around 1200 FPS. I have some of the 200 gr NOE bullets on order. I will be looking to push those as close to 1300 as I can safely using longshot as I have 9 pounds of it.

It's very interesting to see how different guns produce vastly different results. I'm sitting at 8.8 grains of longshot at 1.245 to fit and feed in the Sig P220 with the 200 grain Golddots. No signs of excessive pressure. For any other gun I'd back off to 8.2. At 8.8 I'm getting 1247 average FPS with an ES of 25 FPS and an SD of 11 using a LabRadar for a chronograph. I could probably back off to 8.7 grains and still get a solid 1200 FPS. Assuming your barrel length on both guns is 5" I'm curious as to whether your bore diameter is contributing to the difference or that different chronographs give vastly different readings

I'm loving my Legion. Soft shooting with the hot loads unlike the Glock 20/29 and RIA 1911 that I had.

Barrel length is 5.0 inches. Powder is Longshot.

So a few weeks ago I destroyed the sky screens on my CED millennium chronograph for the second time. Soooo I bought a LabRadar. Tested it out today on a few guns as well as the new Sig P220 to work out some 10mm loads. Loving the new Chronograph

Attached is a screen shot of my load spreadsheet. All loads worked up in the Sig P220

Here's a summary of the loads so far
135 gr Nosler @1684 FPS  850 FtLbs
180 gr XTP @1342 FPS
200 gr XTP @1166 FPS
200gr Gold Dot @1158 FPS

Brass looked great on all the loads and I think I have room to push both 200 gr loads a little harder to get a solid 1200FPS.
This P220 shoots a lot softer than I remember the Glock 20 shooting with similar loads.

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Bore diameter on the Sig P220 is .399 measured with a ball micrometer. Also the barrel length you have listed is 4.3", should be 5.0"

A few more pics

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The bullets showed up faster than I thought. They look good. They don't look like pulled bullets but more like new old stock. I weighed a few from the bag with weights varying from 199.7gr to 201.1gr
Can't wait to load up some these over Longshot and see how they do.

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Thanks Ken,
I put some on order. Who knows when I will get them but when I do I'll post some pictures. I've been out of the 10mm game for a few years. Dove back in with a P220 Legion and reworking loads in the gun.

Just wanted to post this here. If anyone is looking for 200gr Gold dots for reloading, Rocky Mountain Reloading has them. They say they are brand new blemished but from the photos probably just the older style bullet they are trying to move.
https://www.rmrbullets.com/shop/bullets/pistol/40-10mm/40-180-gr-speer-gold-dot-hollow-point-bullets-pulled/