Stock spring vs. Heavier G20/mid power...

alank2 · 07-19-2012, 18:52

Hi Everyone,

I picked up a 20SF and I'm going to start loading for it. Probably going to run 200gr @ 1050 fps or so. Would you guys recommend running this with the stock spring or a heavier spring?

Thanks,

Alan

nickE10mm · 07-19-2012, 19:01

At that level, I'd honestly leave the stick spring in it! Good luck!

jimsmith1941 · 07-20-2012, 04:17

Quote:

Originally Posted by nickE10mm

At that level, I'd honestly leave the stick spring in it! Good luck!

That is what I use in my G-20 with loads on that level. Agree w/ nickE

alank2 · 07-20-2012, 12:34

Hi,

What do you guys recommend for power to do a 200gr XTP @ 1050fps? I was looking at aa#7 or longshot... Goal being highest consistency, low temp sensitivity, lower felt recoil, quieter, less flash...

Thanks,

Alan

nickE10mm · 07-20-2012, 12:47

Quote:

Originally Posted by alank2

Hi,

What do you guys recommend for power to do a 200gr XTP @ 1050fps? I was looking at aa#7 or longshot... Goal being highest consistency, low temp sensitivity, lower felt recoil, quieter, less flash...

Thanks,

Alan

You can get a 200gr XTP up to 1050 with quite a few powders. Longshot, AA7, AA9, Power Pistol, and Blue Dot being the ones that come to mind. Accurate powders meter the best of the group and have the lowest flash, if that matters to you.

Any Cal. · 07-20-2012, 14:04

With your objectives, you can probably scratch Longshot off the list. You might give #7 a shot, but I don't know much about it. 7625 works well for lead 200s with very light recoil, but it may be too fast for the XTPs.

TDC20 · 07-20-2012, 18:07

Quote:

Originally Posted by alank2

Hi,

What do you guys recommend for power to do a 200gr XTP @ 1050fps? I was looking at aa#7 or longshot... Goal being highest consistency, low temp sensitivity, lower felt recoil, quieter, less flash...

Thanks,

Alan

For that I would go with AA#9.

nickE10mm · 07-20-2012, 18:10

Quote:

Originally Posted by TDC20

For that I would go with AA#9.

Now that I think about it, considering loudness and temp sensitivity, I believe you are 100% right.

AA9

alank2 · 07-20-2012, 19:48

Hi,

You guys think AA#9 over AA#7? I once tried N105 a long time ago and didn't care at all for trying to compress it (it wanted to mash the bullet!) Does anyone know around what charge weight AA#9 will be 100% case fill with a XTP 200gr @ 1.250?

Thanks for the help!!

Alan

nickE10mm · 07-20-2012, 20:33

Quote:

Originally Posted by alank2

Hi,

You guys think AA#9 over AA#7? I once tried N105 a long time ago and didn't care at all for trying to compress it (it wanted to mash the bullet!) Does anyone know around what charge weight AA#9 will be 100% case fill with a XTP 200gr @ 1.250?

Thanks for the help!!

Alan

Not sure on the case fill but AA9 was suggested simply because you will have room to grow with that 200gr pill ... AA7 is a "bit" fast for super heavy 200gr loads, although it should make your 1050fps requirement easily.

They are both fantastic powders.... AA9 is probably more efficient for 180-230gr bullets because its quite a bit slower. Still, both will get you what you need.

alank2 · 07-20-2012, 20:41

Hi,

Thanks nickE10mm!

Alan

alank2 · 07-21-2012, 19:18

Hi Guys,

Well I loaded up some:

200gr XTP, AA#7, 9.4gr, Starline Brass, CCI 300, 1.250"
and
180gr GDHP, Blue Dot, 10.3gr, Starline Brass, CCI 300, 1.250"

That AA#7 is the thinnest powder I've seen. I usually use VV which is a bit bigger. I noticed the AA#7 was getting between the powder measure (small bar) and the faux bar on top of it and making the measure a little herky jerky.

I'll try to get these shot and chrono'd to see how they do.

Thanks,

Alan

alank2 · 07-22-2012, 19:39

Hi,

Well, here are the results of my two loads. I was feeling pretty good until I tried to resize the cases - 18 of the 20 cases had expanded so much that resizing them left them with a sharp edge where the resizing die stops.

What I find odd is that these two loads should have both been mid level with lower pressures.

.400 Hornady XTP 200gr, Accurate #7 9.4gr, 10mm Starline Nickel New, LP CCI 300, 1.250: 1030 fps avg, sd 7,es 25, n=10

.400 Speer GDHP 180gr, Alliant Blue Dot 10.3gr, 10mm Starline Nickel New, LP CCI 300, 1.250: 1133 fps avg, sd 28, es 91, n=10

QuickLoad shows the first one at 29.8K psi and the second one at 26.3K psi. I guess I didn't expect so much case expansion/balooning with this pressure...

I'm getting some extractor gouge as well. Stock barrel and stock RSA.

Temp was 100 deg F, but the ammo was not likely at that temp, perhaps 90 deg F.

Thanks,

Alan

Any Cal. · 07-22-2012, 20:38

Well it looks like you are almost where you wanted to be. Don't worry about the case expansion, that is normal in a generous chamber. The case has to expand to touch the chamber walls, even at lower pressure. The only real downside is that it is hard on brass to size it way down then blow it way back out. The nickel (Remington brand) doesn't last very long for me anyway, so it may not matter much.

Any Cal. · 07-22-2012, 21:36

I am assuming that when you say a sharp edge, you just mean a visiblie line where the die stopped sizing. If it is something different than that, then there may be other issues.

orangeride · 07-23-2012, 12:06

All my 10mm loads get run the the lee buldge buster when I'm done. After several firings in the stock barrel the brass will really start to get wonked out and cause feeding issues. A normal sizing die will not size down low enough to get the buldge out.