155 gold dot data

[O4really]

I got some 155 gold dots to try out for my 40s&w, even found some load data for them on the speer website, which I thought would be the best source. I loaded up some work up rounds using power pistol powder, setup the chronograph, and then things got weird. The starting load gave me max load velocities at 8gr I was getting 1212fps.i thought it was a problem with my chronograph at first, but going through the work up I was getting 100fps higher than their load data. I started checking other sources and now I'm just a bit frustrated. Hornady matches up pretty well with my velocities and they do have a similar max charge at 8.9 for 1250fps, but then I see Lyman listing a max load below the start charge and velocity of either. I think the speer data is erroneous, just not sure if it's the charge or velocity they intended. Would think the hornady data would be the safe route If it weren't for the Lyman data looking so timid. With 40 being such a high pressure cartridge, and the data being so all over the place, what do you more experienced people do when you run into stuff like this?

 

[GooseGestapo]

What are you shooting them through?
What brass and primers are you using?

Speer used a 4”bbl S&W 4006 to generate their data. A 4-5/8” Glock or 5” barrel will run as much as 100fps faster. They also used CCI primers and Speer cases. Also, they tested at 1.12”oal. Seating deeper will raise pressures and velocities.

You need to provide more information...

Added, Lyman used a 155gr Winchester SilverTip, in a 4” Industry test barrel, which is at minimum specifications for .40.
Apples to Oranges... If your ejection and case head expansion is nominal, you’re ok...
The .40S&W isn’t as short and weak as you may have been led to believe.

 

[O4really]

4.4 inch barrel (P226), used once fired speer and few Winchester cases in the middle to compare, cci 500 primers, oal at 1.12 inches. Winchester brass had a little more spread, similar velocity at 8.5 grains, but didn't load enough to say anymore than they were similar. I loaded most of them at 9.0 because that was listed as closest to the velocity I was looking for, I only fired 1 of the 8.9, didn't shoot any of the 9.0 since it was above hornady max. I'm leaning towards just loading them around 8.2 since it's just above the target velocity i was going for, just wondered how more experienced people handle conflicting data like that. Before I got a chronograph, I wouldn't have even known there was something strange happening, probably would've shot the 9.0 rounds and ran with it

 

[GooseGestapo]

Doesn’t sound like you’re going to break anything.

And BTW, welcome to the zoo!