Interchangability of published load data
Let me start out by saying that I'm a fairly conservative reloader- I always start with a reduced charge and work up, and I only have one load that exceeds published max, by .5 gr.
Here's the situation: I've been wanting to work up a load from my 300 H&H using 165 gr. interbonds, but Hornady's load data is significantly lighter anyone elses for comparable weight bullets. For example, their max load with H4350 is 5% less than the starting load in the Nosler manual. With IMR 4350 Hornady's max load is the same as Nosler's starting point. Obviously published velocities are way lower also. Are Hornady's bullets really that different, or are they just very conservative.
How far out on a limb am I going if I use Nosler data with Hornady bullet?
Use the Hornady data. It was compiled with their bullets. You are working up anyway, so what does it matter? Your rifle will tell you when.
19 July 2004, 08:28
Savage99belaw,
It's good to be cautious. While rifles etc vary there is not complete agreement on what every pressure sign means.
I have many loading books, have most loads memorized and use formulas once in a while also. The thing to do is to get more information.
If you take Sam's comments and think about them or Hagle's writings long before that each rifle is an individual you can think of the reciprical that the Hornady data may have been with a test rig that showed higher pressure than average.
I look at the Sierra #5 and Nosler #5 the most. I was looking for data on the 264 WM with a 120 gr bullet and found that the data is quite old. So I am working up a load with RL 22. I am no pioneer with hot loads. Maybe that's why I am still enjoying it after 51 years.
19 July 2004, 09:42
stubblejumperThe thing to remember is that most published load data is based on a single gun with a single lot# of each powder and brass.Due to variances in barrels,chambers and lot#s of powder and brass, the maximum safe loads for guns in the same chambering can vary a great deal.For this reason,loading manuals should be used as starting points but I wouldn't put too much faith in the maximum loads or in published velocities.
19 July 2004, 10:05
dentonHornady bullets have a shape that is different from Speer, Nosler, and Sierra. It is more nearly conical in front.
I have one '06 where I have to use a .100" shorter COL with Hornady than with Speer. That's a respectable difference in powder capacity.
Partitions are a more rigid bullet, and harder to engrave. Their tech support tells me that you will usually get slightly higher pressures and velocities with Partitions than you will with other bullets, all other factors equal.
So reloading data is only approximately interchangeable.
You also have to bear in mind that the measurement systems at these various companies are not as precise as you might suppose. If you pull 20 identical cartridges from a lot, and have a tech test 10 of them, and then hand him the other 10 to test, the copper crusher system will not reliably repeat to within 1,000 PSI. And that's just one tech, on one day, at one lab. Put in two different techs at different labs, and it's inevitably worse than that.
Just slowly work up, the rifle will let you know when you are getting close. Once again tho, sometimes 200 fps does not make any real world difference if your game is taken within 250 yds, and is not a varmint size critter.
Too many people don't pay enough attention to a trajectory chart. They need to look at that more and analyse their needs and then go look at load data to see if it is accomplishable.
Just the way a wise person taught me.
Cheers and Good shooting
seafire
19 July 2004, 10:41
fredj338Loading manuals are a guide. Unless you are using monosolids like Barnes, there isn't that much diff. between bullets of the same weight. Before someone flames me, if the bearing surfaces are of sim. length & mat'ls. are sim. you will get sim. results. Just start a couple grains lower when substituting a new bullet, & work up.. You'll find you can probably get your HIB to sim. vel. as the NP.
As an example, I have loaded my .280 w/ 160gr SPeer, 160gr NP & 160gr NAB w/ the same powder charge; 57.5gr IMR7828. Vel. runs 2805fps, 2895fps & 2888fps. As you can see, vel. are close, but the NP is a bit harder due to the solid partition & the NAB has a bit longer bearing surface. To get all 3 to the same vel. I drop the NAB & NP loads by 1/2gr.