Load data diferences

[Big JD-From the hills]

Ok this is taken from the lee hodgdon powder manual:

here is the data on the hodgdon site:

http://www.hodgdon.com/data/rifle/303brit.php

Wich do I folow?

 

[ricciardelli]

The Yellow Brick Road...

right to stevespages...

 

[6gm6]

I have the same book and use the h 380 loads for 8mm and 6.5x55.

Hodgdon Streamlined their load data two years ago (they did the same with IMR powders). I was wondering if the data I was using was now "unsafe" since they no longer listed them. So I emailed them, they wrote that the loads were not "unsafe" but were streamlining the data to list the "best powder for the job" for velocity or accuracy.

 

[Boomer]

Use the manuals or on line data to find a starting load which should be about 10% below the maximum load listed. Make up a few rounds of each load, and increase loads in increments of 1 grain (in medium and large cartridges). When you start to see pressure signs stop! A better way is to use a chronograph and stop when you reach the maximum book velocity - this will be the maximum safe pressure. If you can use a chronograph, you might see that the increases in velocity plateau just before the maximum load is reached. I usually stay on the low side of this plateau. When I'm working on load development, I generally weigh my bullets and cases so that I can properly interpret changes in velocity from load to load. This practice allows me to make up a single round for each load. Once a safe working load for your rifle is determined, weighing components is of limited value.

 

[Big JD-From the hills]

Yeah, but Im saying that the website says max 42 grains of h335 with a 150grain hornday, wile this printed data says 48 grain. Thats a 6 grain diference!

 

[PerversPépère]

Fact

Yeah, but Im saying that the website says max 42 grains of h335 with a 150grain hornday, wile this printed data says 48 grain. Thats a 6 grain diference!

In doubt, always err on the side of the lowest load unless you're using small slow powder charges in large cases, which is a whole different matter.
PP.

 

[gushulak]

I always work up loads and err on the side of the lowest published load I can find as well. There is a lot of confusing data out there, the best is to always err on the side of the lowest published load, just to be safe.

 

[Fall Guy]

Here is a quote from Hodgdon Data Homepage for Rifle:

NEVER Exceed the Loads Listed in This Publication.

This tells me that the internet data supercedes the print data. Follow the internet.

 

[Boomer]

Given the bore and head space variances observed in Lee Enfield rifles between various numbers and marks - to say nothing of the variances found between individual rifles within each number and mark I would certainly start with the lower pressure data with an unknown rifle. This is another reason I like to get data from a number of different sources before I begin loading for an unknown rifle.

This is not an uncommon situation. The Hornady 6th edition has 300 gr H-4350 data for the .375 Ultra which is a full 5 grains below the same data from other sources. The point is to develop safe reloading habits, and if you come across data that does not make sense, it can be checked against other data, and against the data you have developed for that rifle. I don't know if you caught it or not, but for each powder listed in your scanned data, there is 2 grs difference between the 150 and 180 grain data - yet there is a difference of 7 grains for the H-335 data despite the 150 gr loads being close to the other powders listed. This in itself would make me suspicious of all the data published for that cartridge from that source.