why you work up loads-- Data may not match

[swampratt]

Too many variables have changed

Ok so the Lyman 49th in the 45 Colt section they used a Blackhawk with 7.5" barrel and Winchester cases and Winchester primers.

Load from book -200gr bullet cast from lead. 6.1gr Red Dot =923fps, 6.9gr= 975fps.
My load 7.5" Blackhawk 200gr cast lead. 6.5gr Red Dot = 727fps.

I used Remington cases and CCI primers.. and my alloy and bullet profile is different as is the lube.

Then another load with 231 powder.
Book used 8.3gr with their 200gr bullet= 1020fps
I used 10.8gr and was rewarded with .. 1093fps.

Another variable that changed is that my bullets were seated .032" farther out.


Of course anyone who has loaded enough years knows this above information is old news.

I just want to bring to the attention of new reloaders that if you change 1 variable you can change the outcome.

Have fun and go make some empty brass.

 

[Okie4570]

I've got a couple of first edition manuals who's max load is couple grains higher than the current edition. Things do change I guess.

 

[swampratt]

The Rugers can take a hotter load than some other guns and maybe the old manuals were catering to the stout Rugers.
No kidding things change all the time.

And if you really try to narrow down what will change velocity from your load to the book load there would be a long list of things.
Lets see if I can name them all. If i leave something out then post what you think will change.
Assuming the only things that are the same is bullet weight and the Type of gun used.

1: the brass brand you choose
2: the ID and OD of the brass before loading.
3: Springback of brass.
4: Volume of brass.
5: Primer hole size.
6: The amount of crimp.
7: surface texture of case ID. (will that make a difference)
8: primer used.
9: powder lot numbers.
10: Bullet lube.
11: bullet alloy.
12: OAL of loader round.
13: Chamber size in gun.
14: Barrel inside diameter.
15: Barrel finish on the inside.(slick or rough)
16: Bullet lot numbers Sometimes there is a major change in the shape of the bullet. (Yes I found this out)



feel free to add to this mess.

 

[magna19]

You forgot probably the biggest affect on velocity. Temparature

 

[swampratt]

No kidding and that also plays with group size, sometimes to an extreme level.

 

[NikatKimber]

I actually have two different manuals, where the max load given in one manual is below the STARTING load of the other.

 

[swampratt]

WOW! That will make you scratch your head.
I am always playing with stuff that isn't in the book.
Right now I am playing with red dot in 30-06. It is below "The Load"

read here.
http://members.shaw.ca/cronhelm/TheLoad.html

 

[Jcann]

I haven't used a manual in years. I look on line for a start load and then work up until pressure signs dictate to reduce. No two firearms shoot the same load equally. That's why we're hand loaders and not just re loaders.

 

[tubesthatglow]

I use as many sources as possible to develop a consensus. I use LoadData.com which has an enormous database.

Roger H

 

[Okie4570]

I haven't used a manual in years. I look on line for a start load and then work up until pressure signs dictate to reduce. No two firearms shoot the same load equally. That's why we're hand loaders and not just re loaders.

Same here, most of what I reload for now isn't in a lot of the older manuals. I've only come across a couple of questionable loads in as many years on the web.