Home Forums Reloading Reloading Software H4831 vs. H4831sc?

My primers actually blew out, and left an extractor mark on the cases' base face. The brass bases of the two blown cartridges also would no longer fit into the reloading press's #3 base suggesting circumfrance expansion. Must have been well over 59,000 CUP!

Hmmm, loaded 1000s or Win primers and never had an issue.
I'd like to see the documentation from Winchester.

The load was 3 gr over Barnes max.
If you assume all 130 gr pills are the same, you best stick with factory ammo.

Are you sure that the rifle is not chambered for the 375 Weatherby?

The problem with LOTS of Winchester LR primers occurred a few years ago, and was well-documented. You could probably even find several threads on the Campfire about it--including the phone number Winchester provided so people could have their faulty primers replaced, or be reimbursed for them.

"The load was 3 gr over Barnes max." How do you come up with that? The load he used was 60 grains, and the maximum Barnes lists in their on-line loading data is 60.5. (These days on-line data is usually the latest ballistic-lab results from any company, because they can update it far easier than reprinting paper manuals.)

Might add that I have all the Barnes paper manuals as well, and looked up the .270 in the last one that listed data for the pre-TSX bullets, the Number 3, published in 2001. It lists 60.0 grains of H4831 as maximum for 130-grain bullets.

if you are blowing primers use Remington primers the metal is a little heavier

I too keep wondering where Armchair got his "57gr. max." information.

It's on the Barnes site for 4831. Probably because you can't get anymore in the case and seat a bullet.
Note that SC is higher as it's denser.
The 4831 load was faster in their test barrel.
Nothing you shoot will ever know the difference.
OP ignored the basic rule of start low and work up.

armchair,

You're FOS. I just looked, once again, at the Barnes website and the maximum load for the 130s is 60.5 grains of H4831.

Are you by chance looking at the 150-grain data? That does list 57.5 grains of H4831 as max. But GrouseChaser plainly stated that he's using 130s.

Or were you looking at the data for IMR4831--which is also NOT was what GC is using, and is considerably faster-burning than H4831. The max listed for IMR4831 is 57.0 grains with 130s.

You might want to go back to the original post and read it again, slower....

Every time I hear a person ask why their load seemed to be over pressured I start to ask specific questions because the answer is in the details.

I would need to know specific info to be able to come reasonably close to a good estimate of what is happening with your load, but without those specifics I can easily point to too many assumptions being made by the OP and most everyone else.

Ken Waters' book "Pet Loads" is pretty specific about what he did when he tested his .270 Win loads and if you take the time to actually read those specifics, then you will see that he used a longer cartridge overall length (COAL) and a longer trim to length (TTL) for his cartridges. He also used a different bullet. All of these things make for far less pressure than the load the OP describes. Waters also mentions that the differences in case volume caused a difference in pressure and velocity.

Additionally, developing a top end load in the middle of winter in Montana (and yes, I live in Montana too) and then testing the load in the summer will cause quite a difference in pressure and velocity. QuickLoad estimates somewhere around 6,000 PSI and 100 FPS more in the summer (30 degrees vs 90 degrees).

Then don't forget lot to lot variations in powder burn characteristics.

Personally, when I'm working with top end loads, I chronograph everything I do so that I can get some idea of the kind of pressure I'm getting. Chronographs are not perfect but way too many people claim that they aren't necessary, but I disagree completely and the OP's situation would be easier to troubleshoot with measured muzzle velocities. Barnes claims that their bullets were producing muzzle velocities of just over 3100 FPs in a 24 inch barrel, what was the OP getting? Those Barnes loads don't look right to me but if they are then with the information I can dig up they must be pushing the max SAAMI pressure pretty hard. Without knowing the OP's case volume and COAL numbers, and using Barnes COAL and TTL data, QuickLoad says that they are producing just over 69,000 PSI with a muzzle velocity of 3200 FPS. But that number assumes that the standard QuickLoad powder data is correct. It could be that Barnes was using a powder lot with a less energetic powder burn rate, in which case their numbers would be below the SAAMI max and safe to use. Or the OP's powder lot could be hotter than normal and simply too hot for the powder charge.

Regardless, yes, working up your load is the safest way to develop a new load, no matter how cold it is outside. If you don't want to follow safe reloading practices then you really shouldn't be surprised when things don't produce the results you expect. I've heard it said that reloading data is not predictive, it simply tells us what happened when they tested a load. In other words, reloading data is a guide, it doesn't guarantee the results that you will get, so it's up to the person reloading the ammo to verify that it is safe and works the way he intended. Making too many assumptions without verifying anything can bite us pretty badly.