Loading manual data differing

[Calvin45]

Bingo. That's ten different bullets.

An my moneys on the gmx pressuring out before any of the others. Same thing with nosler's e tip.

 

[Doom2]

I'll add this, comparing really old manuals (60s to early 80's at least) to new data is foolish because in those days the bullet manufacturers didn't necesserily pressure test their loads they used the same methods we use today to determine a safe load.

As for the OP's question it is likely though not necessarily a fact that the difference is due to the bullet addition.

 

[osok-1k]

I think that cases are one major factor in pressure variables. I've been using Petersen SRP cases for my 6.5 Creed and pressures went way up as compared to Hornady brass. A load that was fine in the Hornady case locked up my bolt in a Petersen case. Bought some Alpha SRP brass and weighed it against the Petersen SRP which was substantially heavier, hence less capacity, something is thicker. I measured case thickness at the neck and both were the same so it has to be somewhere else in the case. Haven't done water weight yet but the empty case is certainly heavier.

I have a Speer manual I bought in the mid seventies, obviously powders have changed in 50 years but I like to look back at it to see how much lawyer influence has occurred. It's a lot.

 

[chav0_12]

I think that cases are one major factor in pressure variables. I've been using Petersen SRP cases for my 6.5 Creed and pressures went way up as compared to Hornady brass. A load that was fine in the Hornady case locked up my bolt in a Petersen case. Bought some Alpha SRP brass and weighed it against the Petersen SRP which was substantially heavier, hence less capacity, something is thicker. I measured case thickness at the neck and both were the same so it has to be somewhere else in the case. Haven't done water weight yet but the empty case is certainly heavier.

I have a Speer manual I bought in the mid seventies, obviously powders have changed in 50 years but I like to look back at it to see how much lawyer influence has occurred. It's a lot.

That's why all of those "premium" brass manufacturers say to reduce loads by 10% because they know their cases are thicker. This goes for Alpha, Peterson, ADG, Lapua, I'm sure others too. It's always wise to reduce a load when switching a component.

 

[kwcreager]

So I'm loading for my tikka 300 wsm. I'm using 178 ELDx and H4350. Well at the bench tonight I looked at 2 different Hornady manuals to see what primer they recommend in their tests. While looking I referenced load data for 178-180 grain bullets. 10th edition list max at 63.4 H4350 and the 9th edition lists 65.2. Just wondering if any of you guys ever notice data changes over time with companies. I've often wondered why that is. I'm assuming lawyers have something to do with it and maybe marketing.
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I guess thats another reason I just use the manuals as a starting point, also check forums like these and see what people are actually doing, then start lower and move towards the max and see what I get in my rifle.... I've seen significant difference between rifles.

 

[Calvin45]

That's why all of those "premium" brass manufacturers say to reduce loads by 10% because they know their cases are thicker. This goes for Alpha, Peterson, ADG, Lapua, I'm sure others too. It's always wise to reduce a load when switching a component.

There's some non premiums that are real thick too. Federal comes to mind. I always reduce loads if they're on the warm side in Winchester brass if I'm gonna load with federal. It has notably less internal capacity AND it's less tough as well. Worst of both worlds!!!!! . Federal is some seriously soft brass in my experience, maybe they compensate for that by making it thicker?

OLD Winchester brass is still one of my faves. Best bang for your buck. But again, has to be older stuff, not their new "neck split special" production

 

[chav0_12]

OLD Winchester brass is still one of my faves. Best bang for your buck. But again, has to be older stuff, not their new "neck split special" production

Yeah, idk how many cases of Winchester I've thrown out in a brand new bag because of a ton of reasons.

 

[Calvin45]

Yeah, idk how many cases of Winchester I've thrown out in a brand new bag because of a ton of reasons.

But the stuff I have for my 300 win, 243 win, 270 win, and .30-30 win from pre-2000 years is awesome!

 

[memtb]

When I was developing a load (around 1987) for my old .375 H&H using Hornady 270 grain SP's….. I had some (quite) old Hornady data using WW 760 powder that was a full 4 grains less than the old Hornady data.

Increasing my loads 1/2 grain every 5 shots, the groups shrank with each increase! By the time I reached the listed Hornady maximum with 35 rounds already fired that evening, with the sun on the horizon …..my first 4 rounds went just under 1/2". The 5th shot, like all of the 5th shots before it, was about an inch out of the group.

I blame losing the 5th shot on hurrying and not allowing time for sufficient barrel cooling. It certainly couldn't have been the shooter! memtb


Oh……no indications of high pressures at that load! Another …..
I stopped there, I suspected it wasn't gonna get any better!

 

[memtb]

A good Chrono and meticulous observation while working up charges is the only way I know to find the right load combination

So……. you're saying that my tried and (occasionally) proven SWAG system doesn't work effectively? Now I'm in a serious quandary! memtb

 

[lancetkenyon]

Lawyer loads...

 

[memtb]

Lawyer loads...

That has been my belief for a very long time! Lawyers and litigation can mess up a ! memtb

 

[victor3ranger]

That's exactly what I feel like it is but didn't want to come right out and say it

 

[memtb]

That's exactly what I feel like it is but didn't want to come right out and say it

I used a "secret code"……I didn't come right out and say it! memtb