Quote from: TightLines on November 09 2015 10:34:03 AM MST
Thanks everyone for the input.

G20 Gen 4 finally made it in and I was able to test some loads at 9.3 and 10.5 gr of Blue Dot at 1.255 OAL.  Everything functioned well.

Did get some case bulging on new Starline brass out to .433 - .434 on the 10.5 gr loads.  These were not smiles but bulges that seem to resize fine through the Lee resizer die (no bulge buster, etc.). 

Thoughts on reloading these, especially to another 10.5gr load?

That's a modest-heavy load. I routinely load and shoot 180 gr. XTP and heavier BD loads at 1.260" in the OEM barrel. No problems after a few thousand rounds and several years, with R-P and Starline brass.

9.3 gr. is in the range of full .40SW. 10.4-10.6 gr. is strong, but not "heavy".

Quote from: TightLines on November 09 2015 10:34:03 AM MST
Did get some case bulging on new Starline brass out to .433 - .434 on the 10.5 gr loads.  These were not smiles but bulges that seem to resize fine through the Lee resizer die (no bulge buster, etc.). 
Thoughts on reloading these, especially to another 10.5gr load?

My set load for a progressive press is 10.4 Blue Dot ( so really 10.3-10.5 ) with 180 heads and starline set at 1.250+/- ... some cases going on 6+ times reloaded with normal lee resize die.
I don't see a problem reloading them.

IIRR, the max book for BD is 11 grs with 180 , so there is some room

Thanks for the input guys.

My manuals also direct me to 11.0 gr as a max load with a 180 gr bullet.

Just wanted to get some feedback on reloading the slightly bulged cases from the OEM barrel.

Will continue with my plan to proceed cautiously.

Alliant's current maximum listing is 10.2 gr, but they list very few bullets, and relatively low pressure. They're previous max was 11 gr, and they listed a lot of bullets. The change occurred around the same time they pulled all .41Mag and some .357Mag loads, so it may have been a formula change. I've been using it for over 30 years with very little variation in all that time. It was the absolute best for .41M and short barrels, but I quit using that load after the warning. Something bad must have happened, to someone.

I've found 11 gr. will bulge just about any brand of brass in the Glock barrel. Almost none of them "bad", and only the weakest of brass may smile (don't try to fix smiles - scrap them). I've not seen any case head or primer pocket expansion on any of them. I do consider this a safe load, even in the D.E. If your sizing die irons them out and they chamber fine, don't sweat it.

The change in Blue Dot data was due to temperature sensitivity of the powder.  As I recall they found that rounds left in a hot car and then immediately fired were spiking in pressure, so they backed off the max values to compensate.

These are fringe cases, but the load data is meant to be "universal" so they have to allow for fringe cases.

That's inline with the response I got from Hercules/Alliant, at the time. However, it didn't add up. Only 125 gr. JHP .357M and all .41M were removed from the tables and warned against loading. None of the others changed. Ironically, in my experience, BD seems to be the most temperature-stable power I've used. Significant temperature-pressure correlations should show in chronograph and performance tests, but they didn't, and don't.  More recently, Alliant reduced the max load of several high pressure loads, pistol and rifle. SAAMI pressure specs have also been reduced for many cartridges, including many magnums and high pressure autos. These were not done by SAAMI, in itself, but the manufacturers. SAAMI doesn't specify pressures. They only certify stated pressures. I suspect you're right, though. In that, it's the "universal" intent that is the root cause. The "lawyer generation" may also have had an impact, methinks.

Yep Corporate Lawyers and Lawsuits drove the changes more than any other factors.  In recent test of 44 magnums using my 16.2 grain load of Blue Dot showed the velocity virtually identical between my older load of Hercules Blue Dot were shown as 1360 fps adv. from my 30 year old RCBS 240 grain cast Silhouette gas checked and Newer Alliant Blue Dot was 1370 fps adv..   

The cast HP is the Lyman Devastator 260 gr and the other is the RCBS 240 gr Silhouette


240 gr RCBS Silhouette GC 0.430"
16.2 grains Blue Dot
CCI 350 primer
COAL seated in cannelure 1.654"
Velocity 1360 fps 8 3/8" BBL
Energy 1006 ft/lb

BTW the HP also shows the same velocities...

260 gr Lyman Devastator HPGC 0.431"
16.2 grains Blue Dot
CCI 350 primer
COAL seated in cannelure 1.692"
Velocity 1370 fps 8 3/8" BBL
Energy 1083 ft/lb


Yes, I loaded many 357's including 125's using Hercules Blue Dot back in the day from manuals of that time period.  There is one load that I do with a RCBS 180 grain Silhouette gas checked where I load it as follows;



Caliber – 357 Magnum
Powder-Blue Dot 11.0grs
Case – Mixed
Primer – CCI  500
RCBS 180gr Gas Check Silhouette
COL – 1.660"   Sized .358"
Velocity 1320 feet/per sec

Some of my now empty jugs of the wonderful Blue Stuff!

Yep.

I've burned through a bunch of those old cans. I'd like to find some with that price tag, now!

No kidding.  Powder is $25-$30/lb in my area these days.