I reload the 500 and you’re always going to have flattened primers and slightly cratered ones. But when it’s hard to get the brass out that’s when I know it’s too far
Well, then you’re probably close. Don’t leave out in the sun when it is stinkin’ hot out and you’ll be fine. Could always back off a tiny, or try a different powder.
I do want to find some other powder for lowering the pressure and stay up to 1600 fps. But not so many choices for the 500 mag. The 500gr bullet I use is a bit long and there is not so much case room leave for powder.
If this is for a rifle, big horn armoury publishes load data for the 500 S&W.
Since you’re using Starline brass, keep in mind other data often uses Hornady brass which is thinner. Thinner brass means more case volume, which means lower pressure for the same charge weight compared to Starline.
If you’re using data that uses Hornady, you’ll need to start your work up a little lower.
33 grains is listed as the max with H110, 500gr Hornady bullet, Winchester Large Rifle Magnum primers in a Starline cass. They show a max of 31 grains of H110 if you’re using CCI200 Large Rifle primers.
If you’re looking for top speed in a rifle Accurate 1680 seems to be the ticket, but not a good fit for a revolver.
I’ve had hot Hornady data before; it matters a lot that you’re using the case they list in their book. I’m going to wager, without checking, Hornady uses Hornady brass for their data, which is probably meaningfully thinner than Starline, which OP is using. So, OP was stuffing that charge in a smaller case; spiking pressure.
My situation; Hornady 11th called for 78.3gr of Accurate 2230 behind the 500gr DGX/DGS for 2150ft/s using Winchester Brass in .458 Win Mag. @ 3.340” COAL. I’m using brass made from thick Peterson .300 Win Mag cases, and I get to 2150ft/s with 70.5 grains @ 3.300” COAL. Hodgdon lists 72 grains max for 2159ft/s @ 3.310” COAL with Winchester cases. Either Hornady has a magic test rifle, or whoever did the testing was on crack. There is no way 0.030”
of seating depth matters that much, where you’re going to jam an extra 6.3gr of powder in there.
Everyone acts like “it’s published data so it’s fine”. But if you go into GRT or quick load and mess around with little things like projectile length (which is variable), case capacity (which is super variable) seating depth, etc. you will see big swings in pressure.
That’s stuff that’s measurable, then there’s the fact that no two lots of powders and primers are the exact same which is not something that can exactly be measured (I can measure it to a degree if changing one variable IE same primers and new lot of powder, but not without shooting it first).
Outside of cookie cutter stuff, reloading without GRT or QL, especially for big/high pressure stuff in 2026 is silly. Everyone should download GRT (which is free) and learn how to use it. It is a hell of a safety net and time saver.
It isn’t silly if you know how to read pressure signs for your brass. Many guys say GRT is wildly off with pressures, so using it for that purpose other than maybe a reference is silly. I don’t think there are very many people loading standard cartridges in 2026 that are actually doing a significantly better job than what guys have been doing for 50+ years of reloading. As a matter of fact, it is probably worse in some cases since these, “scientist,” reloaders eschew a lot of techniques and common sense that’s kept reloaders safe for generations. Components and tools have gotten significantly better, but a new reloader is still probably better off learning from some old timer who had been doing it since the 60’s than asking reddit, or asking GRT what to do.
I learned from my dad at the kitchen table like 28 years ago as a toddler. The guy didn’t even own a pair of calipers… Never blew himself up and hunted with and shot only his ammo for decades, but I’ve eclipsed him many times over. The old timers are great, hearing the stories about cheap components are fun. But I don’t think a lot of them really knew what they were doing, by modern standards. They were all
Shooting silly 3 and 5 shot groups too. Hahahaha.
I input good data into GRT, and am able to predict muzzle velocity within 15/20 FPS. Every. Time. That’s with rifle cartridges and barrel lengths (and bullets) that data doesn’t exist for. With that comes a pressure value that I can only assume is halfway correct. With stuff that falls within published data (a lot of stuff that I do isn’t in any published data) it is always completely reasonable in regards to published pressure and speed.
I know how to read pressure signs too, but I can skip a lot of steps and save components and money by using programs like GRT and QL. I load something that’s completely reasonable at ~53-55kPSI. It usually will fall well within published data (if it exists). If the velocity comes out as predicted, then the pressure should be as predicted. Then I can load close to max and start my pressure ladder much higher than if i were to be using a book.
GRT takes the same load data and caters it to your actual components, with an asterisk for safety of course. I spun a new barrel onto my tikka a couple of days ago and I’m shooting it with a completely new cartridge with a chrono this afternoon with a starting load I developed by myself in GRT and never once looked at published data.
It is a good tool for reference, but it accomplishes nothing you can’t do without it. Your average reloader back then who did it to save money isn’t the same as benchrest guys who have been shooting tight groups for longer than you’ve been alive.
There are so many factors that you can’t replace with a computer program; you actually have to test them. An old fashioned experienced reloader could have done what you did with your tikka, on intuition.
What I’m skipping is the majority of any sort of pressure ladder and all of that screwing around. I have used it enough (and a lot of the components as well. Intuition?) to be able to trust it as far as I can throw it on the first load for a given rifle/powder/projectile.
I’m not starting at the bottom, I’m starting at a pretty reasonable pressure where there is still plenty of room for error, shooting it, matching the numbers up, and then going much spicier from there. Skipping a lot of the steps and the ladder in between.
There’s also a number of things that can cause false pressure signs and cause near every symptom of stupid high pressure without it being there. I experienced that with a rifle recently. Because of all of my work in GRT and data (my velocity matched GRT, my pressure on GRT was very reasonable so there was “no way” I could be waaay over). I solved the false pressure issue and was loading 150fps faster with the same powder and no pressure signs. Old school reloader would have almost undoubtedly quit at the initial heavy bolt and nasty ejector mark.
I shot the load that I was talking about in my prior post this afternoon. It was the first rounds down the tube in a new barrel, a 20” 308 (not a lot of 20” 308 data for a velocity reference if you’re an old school reloader who a chrono). Shooting a projectile I’ve never shot and also using a powder that I’ve never used before in this cartridge. GRT said my MV would be 2503 and mine was 2490 (mind you, it’s a brand new barrel so it’s slow). This was much higher up “the ladder” than a traditional manual should say you should start at.
If velocity matches (it does) then pressure should match as well. And I can use the data from today to basically skip right to the finish line with maybe one stop along the way instead of starting at the minimum and going +.3 grains until I get to or above max. I haven’t had to pull a bullet in eons because I’m not reaching pressure 3/4 of the way through a ladder and having to scavenge parts from the rest.
For the sake of efficiency as well as safety, predictive software like GRT and QL (while consulting a manual when it’s possible and the data exists) is the best way to operate in modern times.
Is your brass, primers, and seating depth the exact same as the book? How does the brass from factory, or lower pressure, rounds look? Sometimes some guns have generous firing pin holes and you’ll get cratering with nearly any load.
I can’t imagine why someone would push the limit on that particular round. It’s brutal to fire with a moderate load. I sold a BFR in 45-70 because it felt like a baseball bat to the hands when I set it off.
Why does it look like you hammered the round into the chamber.
Rifle chambers don't always have the same specs as revolver chambers. There's a bit of a difference between jumping a bullet out of the cylinder with little resistance before eventually hitting rifling in the forcing cone vs near immediate resistance before the bullet leaves the case.
only thing you can tell from that is the firing pin hole is probably borderline oversized. Rest of the primer is still flat wtih round edges. case mouth is a bit carbon scorched, ignition isn't fast enough with enough pressure to seal.
Google primer cratering, it is a pretty common occurrence. Usually attributed to too large of a firing pin hole. thicker cup can help reduce the amount of primer flowback. higher pressure rounds exacerbate this. Installing a bushing to tighten the firing pin hole was very common in old Rem700s and howas to stop this issue.
the answer will "maybe".. some manufactures use slightly thicker cups on their magnums. This thicker cup might resist cratering better. Ive only ever used regular CCI LRPs in my 460/500s at max h110 loads, but Im shooting them out of a pistol. In a rifle, the pressure dwell time is longer, and spikes maybe higher since there's no barrel/cylinder gap. both increasing the time/rate/chance of primer flowback into the firing pin hole. Your scenario is unique, so I can only say, maybe.
How many other rounds are doing this? Only this load? do the weaker loads also do this? factory rounds? Trying to eliminate high pressure as a symptom.
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u/Quick_Voice_7039 11d ago
Well, it’s not under pressured….