A word of CAUTION using loading data off of the powder cans....this happen

[acemisser]

This happen to me yesterday useing H380 power and 55 gr V max

Working up some news test loads for the 22-250 I load only 3
of each...Working my way up...My last 3 where the load off the
power can to see how it worked...

To make a long story short....blown primers and a stuck case..
Shot 2 of the 3 loaded..Now this is off the powder can..

Way to frackin hot.....So use with caution....ace

[Jamie]

Yes, that is why we start low and work up for each rifle and why the can usually states something about it. No two rifles are the same, what may be safe in one is not in the next one.

How much of a jump in powder do you do when working loads? .5 grain? 1.0 grains? To go from zero signs to blown primers is tough without other signs showing up first.

[BoilerUP]

Well, the powder can DOES say the listed loads are MAXIMUM...

Were you getting any pressure signs leading up to the max loads?

H380 is kinda temp sensitive too; if those loads were in direct sunlight it could contribute to blown primers & worse.

[acemisser]

I got like .5 at a time....There were no signs what so ever.Easy bolt-extraction,etc.....Just bang and there it was...
Just wanted to point this out to you guys....And your right the heat will cause this as well...I keep allammo in the shade or at least cover it up with a news paper if I have one handy..Sometime I read the paper while the barrel is cooling after 5 shots...works for me..

[nsaqam]

The cartridge sitting in a hot chamber for any length of time will raise pressures precipitously.

Half a grain from zero pressure signs to blown primers isn't the problem.

You don't usually see any pressure signs until a load is well over 70K anyway.

[tobnpr]

Exactly why I'm glad the temp insensitive powders work for us. Aside from the "too hot" risk, velocity/consistency does not vary with temps.

[fgw_in_fla]

In a 22-250, .5gr may be too much of a jump. The case is almost the same as my .243 & I jumped right over the sweet spot with .5gr. I move in .2gr. increments. I kinda sorta learned that the hard way, too.
I went thru 50 - 55gr Noslers trying to find the accuracy node / load. After I realised .5gr was too much, I found it with no problem at all. All that's left to do is laugh at my boo-boo and fine tune it.
Which, by the way, it's now shooting 5 rounds that can be covered with a dime..... I really like that caliber. High velocity, low recoil, incredible accuracy......sorry....... I didn't mean to mentally wander off on a rant.

Good luck, good shootin' & be safe!
Frank in Fla

[WuzYoungOnceToo]

How far below the max charge did you start, and how many .5 gr increases did you go through before you had problems?

[82boy]

The can also states "For those loads listed where a starting load is not shown, start 10% below the suggested maximum load and then approach maximums carefully, watching for any sign of pressure (difficult extraction, cratered and flattened or blown primers, and unusual recoil)."

[darkker]

Exactly why I'm glad the temp insensitive powders work for us. Aside from the "too hot" risk, velocity/consistency does not vary with temps.

If you are referencing Hodgy's "Extreme" line of powders, you are aware that those ARE NOT universal properties right?!!
Those are built for A specific application, only Hodgy doesn't tell you what that is; so it gets ASSumed that it is a universal property of the powder.

It WILL vary, just not as great as it's contemporaries... Or at least the powders tested against, one of which hasn't been available for MANY years.
Here is what they currently show for "testing" this theory:
http://www.hodgdon.com/smokeless/extreme/page2.php#top
Notice in the 22-250, that they can beat the closest competitor by a whopping 6 fps!!! That is a difference without a distinction. No primer is that consistent, and I am to believe that the powder can walk on water? Only if it's frozen..

[leo158]

380 is dangerous powder in my knowledge I got from watching a friend load up some. He loaded 38.9 gr for a 55 gr sierra bullet out of a 22-250 and it missed the cartridge u big time along with damaging his bolt ejector pin. It had so much pressure it bent the pin. I was there when he loaded a few rnds and went with him while he test fired them. I would not of believed it if I didnt see it all my self. My sierra book says 38 is max with 55 gr bullet. And 380 on the can says 41 gr I believe. I wont play with any powder unless it is extreme as does he now.