Why the differences in load book data?

[sar4937]

I have been reading through the specs in the Hornaday 7th Ed, and the Speers #14 regarding 45acp 230g FMJ RN. For the same basic bullet, but differing brands Hornaday says 5.7gr W231 = 800fps and is maximum load, but Speers says 6.2gr W231 = 858fps and is maximum load. I'm using Ranier Ballistics, but can not get any load data from them nor are they listed in any tables. So I assumed to just use the Hornaday data for a similar style and weight bullet, and for now always go with the lesser load until I'm more experienced. I have made a bulk Hornaday purchase through the range I belong to, but I still buy bargains when I find them. How should I handle bullets that are not in tables? Comparing manufacturer's does this mean a Speer 230g TMJ RN is made better in that it can be loaded hotter?

 

[sar4937]

I have been reading through the specs in the Hornaday 7th Ed, and the Speers #14 regarding 45acp 230g FMJ RN. For the same basic bullet, but differing brands Hornaday says 5.7gr W231 = 800fps and is maximum load, but Speers says 6.2gr W231 = 858fps and is maximum load. I'm using Ranier Ballistics, but can not get any load data from them nor are they listed in any tables. So I assumed to just use the Hornaday data for a similar style and weight bullet, and for now always go with the lesser load until I'm more experienced. I have made a bulk Hornaday purchase through the range I belong to, but I still buy bargains when I find them. How should I handle bullets that are not in tables? Comparing manufacturer's does this mean a Speer 230g TMJ RN is made better in that it can be loaded hotter?

 

[WR Moore]

There's several factors at play-checking threads you could have picked up on this.

1. Everyone is using different test weapons. This affects pressures developed by any load.

2. Different bullet manufacturers use different jacket material, core material, bullet bearning length, diameters and other variables. The differences may or may not be significant. This also may change pressures and load data.

This is why the loading manuals insist that you start at the starting loads and work your way up until you achieve acceptable functioning-without exceeding their recommended maximum charges. There is load data marked to be used exactly as published. Obey these warnings.

 

[sar4937]

I understand how the barrel length effects fps, but why would one company vary the maximum charge by .5g, I thought this had more to do with safe pressures, and not overdriving the bullet design. When using a bullet that data does not exist on, should I always load on the light side? The Speer book lists the test gun used, Hornaday does not.

 

[canoe on the yukon]

WR Moore gave an excellent and complete answer.Test guns will have slightly different chambers,etc.....Like he said,start low and work up.

 

[Paul5388]

It isn't a matter of over driving the bullet. It's because their design either causes more pressure than another manufacturer's bullets or less pressure, i.e. the Remington Golden Saber is a very low drag bore riding design that produces more velocity and less pressure, because it doesn't have as much resistance/drag/friction as other bullets.

 

[OKFC05]

DO NOT use jacketed bullet load data for plated bullets, like Ranier. They are softer and will be overpressure.
"We, at Rainier Ballistics, recommend using lead bullet load data when loading our bullets."
http://www.rainierballistics.com/mainframe.htm

Start with load data for plain lead bullets. I find that Ranier and Berry take a little more powder than a lead bullet to achieve the same velocity, but nowhere near as much as a FMJ.

As I said in another thread, you can either
1. chrono your load in your gun and know what you have, or
2. Guess.

 

[sar4937]

So to be clear, if I buy a chrono and achieve the fps I was attempting I have found the coorect powder charge for that bullet? The Rainier's that I have loaded fall within the lead bullet range. The Oregon Trail Lasercasts and Berry's have no recommendations that I can find, although I load for target shooting so the loads are on the light side. Finally, on a bullet such as the Remington Golden Saber, is that listed in the data book or would you get that info from Remington? What do I use the ballistic coeficiant number to figure?

 

[OKFC05]

Berry's have no recommendations that I can find

" How do I load Berry's Preferred Plated Bullets?
Plated bullets occupy a position between cast bullets and jacketed bullets. They are soft lead, but have a hard outer shell on them. When loading plated bullets we have found best results using low- to mid-range jacketed data in the load manual. You must use data for a bullet that has the same weight and profile as the one you are loading. Do not exceed mid-range loads. Do not use magnum loads."
http://www.berrysmfg.com/faq.aspx?q=9&c=1

My experience with Berry is that they take slightly more powder than Ranier to achieve the same velocity: a bit more than lead, but nowhere near the high range of JHP bullet loads.

"How fast can I shoot these bullets?
Velocities depend on the caliber, but as a rule of thumb, we recommend you don't shoot our plated bullets over 1200 feet-per-second. Our 44's actually shoot best around 1150 fps. 45's are generally good at 850-900 fps."
http://www.berrysmfg.com/faq.aspx?q=10&c=1
I hope this helps.

 

[WR Moore]

Ballistic coefficients are used to calculate velocity loss and trajectories. Don't worry about them. The only folks who generally bother with such stuff are long range rifle competitors (600-1000 yards) and they generally let the bullet makers run the calculations for them.