200gr gold dots

[Jtigertic]

So I loaded some 200gr gold dots in new starline brass with CCI 300 and started at 8gr Longshot and loaded 8.2 and 8.4gr loads at 1.255 coal. I plan to take the he chrono out to the range and will report back on velocity and what the primers look like in my Springfield and RIA 1911's.

[Jtigertic]

[Jtigertic]

Here were my results
8.0gr Longshot coal 1.255 fps 1198,1198,1193
8.2gr fps 1213,1233,1212
8.4gr fps 1238 and seemed over pressure. Pics to follow.

[Jtigertic]

[Jtigertic]

Rounds were fired in a Springfield 1911 RO Elite 5' with a 20# recoil spring, Wilson recoil buffer, and flat bottom firing pin block from EGW.

[Muskrat]

Maybe it's the light, but the piece on the right doesn't look like it even has a firing pin indentation. That would be a sign of overpressure all-right.

Regardless, you're adding .4 grains of powder for only another 40 fps over the starting load, which doesn't seem like a real good trade to me at those pressures.

I'd be a lot more interested in seeing what 7.5~8.0 grains provided in the way of accuracy and velocity than shooting any more 8.4 grain loads. As dramatically as Gold Dots expand, more velocity isn't necessarily going to equal more lethality. It might be just the opposite, in fact.

[The_Shadow]

That happens when the case is still pushed against the breech face and the barrel drops out of battery and the case wipes against the breech face.  It can be when the pressure is up and the recoil system is being overridden thus early unlocking.

[Jtigertic]

So Shadow I am assuming that means the pressure overrode the spring and flat bottom fps?
Either way I am happy with almost 1200 fps and no over pressure with 8.0 grains of Longshot.

[Nemorivagus]

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

[Jtigertic]

I was using a Caldwell chronograph same as I use for my rifle loads it seems to be pretty accurate as I use the speeds to calibrate MOA at ranges out to 1k yards and it has served well. It was about 5 ft from the muzzle for these tests. I think the difference could be the barrel but probably more the design of the gun as Shadow pointed out the slide opening early causing the shearing of the primer flow. I think that brass and primer type plays a part also.

[Bimmer]

I think the difference could be the barrel...

This would be my guess, too...  Different barrels and guns (even with the same length barrel) can produce significantly different velocities with the same ammo.