Hogdon H414 overpressure...

[std7mag]

I'm reloading 7mm-08.
Using the Lee reloading information, along with references from Hogdon's manual.
139 gr. Hornady SST
Casings chamfered, deburred, trimmed. Primer pockets cleaned.
43.5 gr. of Hogdon H414
Bullet seated 0.010" off of the lands for my rifle.
I do collet sizing, not full length.

Getting hard extraction.
Flattened primers.
Casings shiny from being pressed into bolt head.

Obviously not reusing those casing again!!!
Pulling bullets out and dumping powder.
Checking weight.
43.5gr.

Any ideas???

Or rather does anybody want some H414? I'm planning on going back to Alliant Reloader 17.

I would like to know why such a low charge would over pressure!!!

Std7mag

[mouser868]

According to Hodgdon's website, your load is too light

[Brian Pfleuger]

Sounds more likely to me that your brass needs to be full length sized. How many times has it been fired with neck only sizing?

No reason not to use those cases again, unless they exhibit some unsafe condition, like incipient case head separation.

[std7mag]

Yes, I did indeed do a typo. Was supposed to be 43.5 gr. of powder.

Casings have been reloaded 3-4 times.
Factory ammo- first firing.
Reloaded-second firing.
Tumbled, trimmed, chamfer, deburred, brass brush run through necks, primer pockets cleaned, canned air(like for a computer) blown through.
Loaded-third firing.
Then reloaded with the H414.

All cases that showed overpressure signs were promptly put into my scrap metal bin!!

Got all the bullets pulled out now. Powder in separate container for proper disposal in a bon fire.
All primers out, and went through my routine, except for tumbling.

Cartridges were chambering fine, heck of a time extracting the last one.

[243winxb]

That powder needs a magnum primer if your not using one. Good neck tension is needed so that the bullet does not move when the primer first fires. The shank of the bullet needs to be at the neck/shoulder junction for good neck tension. A long COL when trying to get near the rifling is not good at times. Brass of a different brand may also make a difference, if yours is heavier then normal.

We tested loads at both maximum normal pressures and at the starting loads (some labs calculate start loads—we shot them). Standard primers caused no ignition issues at the max load but posted higher extreme variations in pressure and velocity in the lower pressure regimes of the start loads. In extreme cases, the start loads produced short delayed firings —probably in the range of 20 to 40 milliseconds but detectible to an experienced ballistician. Switching that propellant to a Magnum primer smoothed out the performance across the useful range of charge weights and completely eliminated the delays.

Read more: http://www.shootingtimes.com/2011/01...#ixzz32samWLkf

Link is one that Unclenick had posted before.

[mouser868]

Starting load according to the website is 45.5gr, you're still light

[CarJunkieLS1]

OP loads that are under the minimum charge can be just as dangerous as loads that are over maximum.

I had this issue with a .243 Win at the starting charge all the way to 2 gr over starting charge I had flattened primers, sticky bolt, and extractor markings. I am 1gr under max and all those issues disappeared.

Also as already stated according to Hodgdons website the minimum charge is 45.5 and maximum is 47.0 with the 139gr SST.

[schmellba99]

Under the min charge can give the powder too much air space to burn too fast, which can lead to bad things happening. It's not just overcharges that you need to look for - and that's why books have minimum charges defined.

H414 is a good powder, mildly fast burning for a rifle (IIRC). I use it in my .243 because it produces some amazing results for an off the shelf hunting gun with only a trigger job done to it. I never use magnum primers and haven't had any issues with igniting at all. Granted, in Texas we don't typically have the most extreme temp swings, especially on the low end of the thermometer. I never had problems in AZ in the summer either though.

I would suggest that before you abandon all hope, get your charge into the book specs and shoot a group or two to see what happens. It's really hard to rely on data that is outside of the accepted range to make a decision on, for me anyway.

[Woodyed]

I agree that you first should full length resize your cases. Next seat your bullets .010 to .015 off your lands. If your bullets are shoved into the lands this could result in your pressure problem.
I have used H414 in my 7mm-08's for over 25 years now and my charge of H414 has always been 48 grains with a 139 or 140 grain bullet. This formula has been deadly on deer in 22 and 24" barreled rifles. In my TC Encore pistols I switch to H335 powder. I might add that I always use standard LR primers also. So don't throw away that H414 powder, try some of the suggestions mentioned above and give H414 a second chance. I use H414 almost exclusively I my 243, 308, and 30-06 reloads and I swear by this powder.

[243winxb]

collet sizing

Lack of neck tension from the lee collet die, would be my guess, as being the main problem. The neck wall thickness may get thinner after a few loadings, requiring a small custom diameter mandrel .

[Brian Pfleuger]

Variations in neck thickness have no effect on the collet die. The neck is squeezed against the mandrel. The only way it could vary is if they weren't being sized enough to touch the mandrel.

[Woodyed]

It's been my experience that neck wall thickness increases with repeated firings, not get thinner. This is why they have inside neck reamers to use when wall thickness increases.