Is Hodgdon load data really conservative?

[notthattomsimonson]

I'm a relatively new hand loader and just looking for perspective from people who have been doing this longer.

I want to load 162 gr ELD-Ms with H4381SC for my 280AI. Not looking for advice on the choice of components - I'm trying a variety of powder/bullet combinations; this is just one I have the components for and want to try out.

Hornady load data runs from 51.7 grains (2500 fps) to 59.3 grains (2800 fps)
Hodgdon data runs from 53.0 grains (2662 fps, 54200 psi) to 56.4 grains (2788 fps, 61400 psi)

Hornady uses Hornady cases and Winchester LR primer
Hodgdon uses Nosler brass and Winchester LR primer

I'm using Peterson brass and Federal 210 match primers.

I understand that case capacity affects pressure. Is the difference in case capacity between Nosler and Hornady brass enough to explain a 3 grain difference in max load? Or did Hodgdon leave a grain or so on the table to stay well below the 65000 psi saami max?

Before anyone loses their mind, I should say that I'm going to start light and work my way up, watching for pressure signs; not trying to squeeze every fps out of this. I was just struck by the difference. Saw a similar thing with H4350 and 150gr bullets - hodgdon had lighter max loads than other sources.

 

[jfk69]

In my own personal experience, on my rifles in my conditions (did I get all the CYA legalize out of the way?), I’ve always found Hodgdon leaves some performance on the table. You pursuing that is at your own risk (their lawyers). FWIW.

 

[yak]

Yup, in my experience they have a bit of safety factor in the top end. Probably a little dependent on differences in components too.

Hogdon Max: 6.8W, 175gr bullet, H4831, 54gr@2736fps
My Load: 6.8W, 175gr bullet, H4831SC, 58gr@2835fps

 

[TaperPin]

That’s a normal question to ponder when figuring out reloading.

Every component will be made with a tolerance (acceptable error). Bullets aren’t exactly on weight or diameter, brass within a box will vary a little in weight and hardness, primers are sometimes slightly off size and different brands produce different velocities, different lots of the same powder can vary 100 fps or more and powder physical volume between lots has been said to vary by as much as 10%. As you’ve noticed, some loads stop slightly shy of max pressure. Different manuals will limit what they print for other undisclosed reasons - so every load will be somewhat short of other manuals. Once in a while a hot load would get published and in newer manuals it would be reduced a little.

With pressure barrels or electronic pressure measuring equipment so common today it seems antiquated, but old manuals didn’t always use pressure barrels and relied instead on measuring case head expansion.

 

[solarshooter]

I try to aggregate a variety of sources and find a common load, maybe towards the upper end of the range, that is deemed safe. Then I do a pressure test from there for my gun and specific components. This doesn't always yield perfect results and sometimes I end up too hot or being surprised later as conditions change. More and more I'm taking my foot off the gas in favor of consistent performance in a wide variety of conditions. Also because I've realized that last 50fps really doesn't make any meaningful difference in hit rates or lethality.

 

[Skerhunter]

I’ve used Hodgon data and not hit pressure at MAX for some loads and others I get there within 1-2 grains of max.

The loads that have been close to max the velocity has acceptable, so no reason to push my luck!

 

[Pescetism]

It depends more on cartridge/bullet/powder/gun combination rather than Hodgdon vs _______ data. I've found noticeable pressure 1% - 5% below listed max with CFE223 in 223/308 (AR*) and Superformance in 22-250. IMO that's not overly conservative. But I don't have experience with larger cartridges using Hodgdon powders.

 

[AZ_Hunter]

It all depends.

 

[Castle Rock]

Yes

 

[sdupontjr]

Same bullet but in my 7 mag. I found that with H1000 and the 162 eldm's, I was 3g over book max and still didn't have any pressure signs. They were running about 3050 fps so I just stopped. Plenty fast enough for what I wanted to do.

 

[Sinistram]

I try to aggregate a variety of sources and find a common load, maybe towards the upper end of the range, that is deemed safe. Then I do a pressure test from there for my gun and specific components. This doesn't always yield perfect results and sometimes I end up too hot or being surprised later as conditions change. More and more I'm taking my foot off the gas in favor of consistent performance in a wide variety of conditions. Also because I've realized that last 50fps really doesn't make any meaningful difference in hit rates or lethality.

This. I almost never use a single source of load data (unless that's all that exists), rather taking the min and max from as many sources as I have, tossing the highest high and lowest low and averaging the rest. This gives me a broader acceptable range for a given combination. You still have to work up carefully, but it helps narrow things down.

 

[prm]

Some yes, some no. When they develop load data they take into account the variability they see in testing. If they see relatively “large” swings in pressure the advertised max load is going to be lower to allow safety room for the higher swings. And sometimes the barrels, powder lot, bullets, etc. are just a little different leading to different results. I now believe they are merely erring to the safe side of the main variables (as they should) rather than broadly lowering max loads for no real reason.

In regards to modern loads being lawyered down, I compared a very old Speer manual to a current one and found they can be different, some higher and some lower, but there was no across the board lowering of max loads.

 

[seand]

I'm a relatively new hand loader and just looking for perspective from people who have been doing this longer.

I want to load 162 gr ELD-Ms with H4381SC for my 280AI. Not looking for advice on the choice of components - I'm trying a variety of powder/bullet combinations; this is just one I have the components for and want to try out.

Hornady load data runs from 51.7 grains (2500 fps) to 59.3 grains (2800 fps)
Hodgdon data runs from 53.0 grains (2662 fps, 54200 psi) to 56.4 grains (2788 fps, 61400 psi)

Hornady uses Hornady cases and Winchester LR primer
Hodgdon uses Nosler brass and Winchester LR primer

I'm using Peterson brass and Federal 210 match primers.

I understand that case capacity affects pressure. Is the difference in case capacity between Nosler and Hornady brass enough to explain a 3 grain difference in max load? Or did Hodgdon leave a grain or so on the table to stay well below the 65000 psi saami max?

Before anyone loses their mind, I should say that I'm going to start light and work my way up, watching for pressure signs; not trying to squeeze every fps out of this. I was just struck by the difference. Saw a similar thing with H4350 and 150gr bullets - hodgdon had lighter max loads than other sources.

Published load data is reference data. Your rifle is different. Hornady and Hodgson’s rifles&components are different.

I would look at the load data as pretty compatible. The max velocity is only 12fps different. 2800 is approx max.

 

[Harvey_NW]

I want to load 162 gr ELD-Ms with H4381SC for my 280AI.

Hornady load data runs from 51.7 grains (2500 fps) to 59.3 grains (2800 fps)
Hodgdon data runs from 53.0 grains (2662 fps, 54200 psi) to 56.4 grains (2788 fps, 61400 psi)

I loaded that exact combo in my 280AI and I swear Hodgdon changed their initial load data, because I was a fairly inexperienced reloader at the time and didn't like to go much over book max. My initial test was up to 58.8gr and IIRC that was max book, or .4 over. I settled on 58.4gr and never had issues. Later on I checked and noticed it was the max you listed, and I was confused because I was diligent about my work up being my first custom rifle.

FWIW, in many other chamberings I've found Hodgdon max data to be inline with starting to show pressure signs in Tikka actions with loads seated ~.040" off the lands. The 280AI was the exception.

 

[wind gypsy]

Brass capacity, lot of powder, barrel bore spec, primer, lot of bullets, chamber variance, etc all contribute to variance in data. Ive seen data from basically every source that doesn't align with what ive seen. Best one can do is understand the factors that contribute to pressure and watch for pressure signs, velocity, and go from there.

 

[elephantrider]

I understand that case capacity affects pressure. Is the difference in case capacity between Nosler and Hornady brass enough to explain a 3 grain difference in max load? Or did Hodgdon leave a grain or so on the table to stay well below the 65000 psi saami max?

Before anyone loses their mind, I should say that I'm going to start light and work my way up, watching for pressure signs; not trying to squeeze every fps out of this. I was just struck by the difference. Saw a similar thing with H4350 and 150gr bullets - hodgdon had lighter max loads than other sources.

Re: Hornady vs. Hodgdon load data. Hodgdon data always seems more on the 'safe' side of things based on charge weights and MVs, but then again they give the pressure data for each 'max' load, and it could be brass/component/test barrel variations as other pointed out. It's really hard to say without actually testing.

As for working up your own loads and watching for 'pressure signs.' Go watch the Ultimate Reloader YT video on loading .308 Win to .300 WM. They get the loads to well over 'safe max' before there are noticeable pressure signs on the brass and primer. The take away is that 'safe' loads have a pretty good safety margin built in, and with good brass, like the Alpha Munitions, that they used you are mostly just shortening brass life. Now I am not one to push past published data, but it is something to keep in mind.

 

[seand]

More common than not, your rifle isn’t going to hit the same velocity as the “book” load with listed charge weight.

Your rifle with Hodgdon max charge weight and your rifle with Hornady max charge weight, we know they differ, is your rifle going to run the same max velocity with both? Of course not?

Velocity is the best indicator of pressure handloaders have, not perfect, but will get you way closer than guessing pressure based on powder weight.