Reloading Data Differences....

[Dups]

So i'm reloading for my .280 remington... I've worked up to a maximum load of Reloader 19, (57 Grains) Remington LR primers, Remington Brass, and a 140 grain Nosler Ballistic Tip bullets, and the book says, 3156 fps... (maximum load)...

the alliant website shows a CCI primer, 59 grains of RL 19 powder on top of a 140 grain Speer SP, at 2962 fps...

What all can create this difference?

i'm assuming barrel length is #1, and then mabey the length/Sectional Density of the bullet, causing less or more friction inside the barrel.... am i Crazy or is this almost weird? the Max load in the nosler book is 57, and the STD load in the Alliant website is 2 grains over that??? almost sounds dangerous?

Dups

 

[Fleet]

Every chamber is different, that's why you always start low and work up.

 

[ranger335v]

"Every chamber is different, that's why you always start low and work up."

Correct. And "working up" means to stop if you encounter any excess pressure signs.

 

[Jasper1573]

When I started reloading last year, I had the same questions. I noted that the Sierra data for their bullets was much more conservative than that in the Lyman reloading manual, so I sent out a couple of emails. The best answer came from Sierra...yes, barrel length was one difference, but other factors including chamber differences, measuring equipment and methods, and so on produce all these differences.

It would probably help us all if there were one and only one industry-wide standard method and one standard piece of equipment to use for measuring ballistic data, but even then, there would be variations.

I have only loaded my .308 Win up to a max load one time, and will never do it again...the recoil increased about 50% because a great deal of the last grain or so of powder was being burned outside the end of the muzzle, and the additional velocity, which wasn't that much, wasn't worth the additional stomping I was receiving.

 

[918v]

Different brass, different internal capacity.

 

[Ol` Joe]

Different primer
Different brass
Different OAL
Different powder lot (powder burn rate has a +/- 5% industry tolerance)
Different bullet geometry
Different Bullet core
Different jacket thickness
Possible different core alloy
possible different jacket alloy
Different lab with different equipment and technicians
Different chamber

Mmmm, what was the question again........

 

[gamestalker]

RL19 is a slow burning powder in this application and should be worked with caution regarding how far down you start. But that of course doesn't suggest starting at the max listed data either. Seating depth is going to make some difference in both pressure and velocity. I like to work up to the max load with my bullets seated just off the lands .002" or as long as you can without olgive inconsistencies accidentally putting the bullet against the lands. Some bullets can have a pretty wide range of olgive location, especially those without bonded cores for some reaosn. My experience has been good with this method for accuracy, velocity, and pressures with worked up to max. loads. If you seat like this be careful not to touch the lands or pressures can jump up quite a bit.

 

[murf]

speed and pressure are the only constants. increase speed and you increase pressure. unless, of course, the load data uses a 22" barrel and you use a 36" barrel. or the data uses lead and you use copper. or ...

murf