Differences in reloading manuals

[Horse96]

okay, I am learning to reload. I have built some accurate sub-moa rounds, but I am having a difficulty with the differences in maximum's between reloading manuals.

For example, in the Sierra loading manual, for 180 grain'ers I am given 59.3 grains of H4831sc as a max; but in the Speer reloading manual, for the same 180 grain bullet, I am looking at 62 grains of H4831sc. The difference is 4.5%. How significant is that difference

How does that make sense?!

[sns2]

Originally Posted by Horse96

okay, I am learning to reload. I have built some accurate sub-moa rounds, but I am having a difficulty with the differences in maximum's between reloading manuals.

For example, in the Sierra loading manual, for 180 grain'ers I am given 59.3 grains of H4831sc as a max; but in the Speer reloading manual, for the same 180 grain bullet, I am looking at 62 grains of H4831sc. The difference is 4.5%. How significant is that difference

How does that make sense?!

It's not significant, as long as you are starting with a light load and incrementally working your way up, carefully watching for any of the pressure signs your manual speaks of, as you go. Let your gun speak to you, instead of a manual.

[Hogie135]

I'm finding the same issue reloading for my 165 gr Nosler ballistic tips. Nosler has a max of 50 gr and Lymans says 52.

[Horse96]

also, not to mention, when I compared my handload group against a factory group of hornady 180 grain sst, I found the hornadys were grouping about one inch higher than my max speer loads...

[MattSako]

They use a different Test rifle. Correct me if im wrong but i do believe its a safe maximum load each manual list.... but your rifle can take more powder until you see pressure sign...

[elkhunter11]

There are very good reasons for differences in published maximum loads, even using the exact same bullet. Differences in barrel and chamber dimensions, differences from lot to lot of powders, and different volumes of cartridge cases, all effect the chamber pressure, and the resulting velocity. When you add in different bullet shapes and constructions, you add even more factors that effect chamber pressure. The simple fact is no manual can accurately predict which load will be the maximum safe load in your gun, and all loads listed in all manuals, may not even be safe in your gun.

[32-40win]

There are a lot of variables involved in the load testing, and they try to narrow it down to what is working consistently, and that is an accomplishment in itself.
Have to take it with a grain of salt to an extent, and read the whole thing, but, this sheds some light on it;

http://www.24hourcampfire.com/ubbthr...pics/1155572/1

[Bushrat]

If folks would actually read all the information in their manuals before they go to the load recipe pages they would know why load maximums are different for every rifle. The maximum each manual lists is the maximum load for the rifle they actually tested the loads in. Due to differences in chambers, throating, and barrel dimensions, bullet bearing surface lengths, hardness of bullet, differences in powder lots, one batch of the same powder can be hotter than the last batch, etc, etc, individual rifles can have very different pressure levels with the same load. Thats why they tell you to start low and work up looking for pressure signs in your rifle. Even rifles of the same make model and cartridge designation can react differently to the same load.

[Dick284]

Read, "why ballisticians get grey hair" it's in the Speer manual.

[bigshell]

Get yourself a chronograph and shoot at least five loads over it.If your average speed is significantly over what the book says for that charge wieght then back it down and try again.

[elkhunter11]

Get yourself a chronograph and shoot at least five loads over it.If your average speed is significantly over what the book says for that charge wieght then back it down and try again.

If the velocity is significantly over the velocity for the max load listed in most books,with that bullet/powder combination, you likely either didn't work up from a starting load, or you overlooked some pressure signs along the way. The people that usually end up with the most issues, are the people that start out with the maximum loads listed in the manuals.

[greylynx]

Originally Posted by elkhunter11

If the velocity is significantly over the velocity for the max load listed in most books,with that bullet/powder combination, you likely either didn't work up from a starting load, or you overlooked some pressure signs along the way. The people that usually end up with the most issues, are the people that start out with the maximum loads listed in the manuals.

x2

Could not have been said better.