Why so much difference in different manuals

[kup1236]

Easy on me, my first post.

I am back into reloading, being gone for 20 years

So I have a Ruger M77 Hawkeye .223
I buy Hornady 50gr V-max bullets, Winchester brass, Winchester small rifle primers and Winchester 748 powder, and a Hornady 7th edition manual.

Hornady manual states 24.5 grains to 28.3 grains of 748

I think I will be safe at start about 10% back from max and load. I pick 26.0 grains
Then I start reading my other manuals and there is quite a spread in min-max loads

1978 Speer manual #10 says 26.5 to 29.5 and use mag primer.

Sierra 2nd edition manuals says 26.5 to 28.3

Then I look at Hodgdon site and all they list is max loads for 748 at 26.0 grains

Soooooooo Whom do I believe??
Will I be OK with 26gr 748??
Also I seat bullets until the action closes easy and leaves no rifling marks on my bullets that have black marker on the bullets. My shells are longer that the book says for max length, but they fit in my mag, and don't mark my bullets.
My book says max lenght 2.200 C.O.L. and mine measure 2.270, but they fit.
Any comments??


PS I just purchased 55gr Nosler Ballistic-tip for future loads

 

[Ol` Joe]

Each book is useing different components for their loads. The bullet is the major factor, but the powder lot, primer type, case brand all change the load. I would try to stay with the data for the bullet you are planning on shooting.

OAL is a variable that you need to play with to find where your rifle prefers the bullet. I load to max lenght (SAAMI) and after establishing a max load shorten the OAL by 0.005" increments until the groups tell me I`ve hit the sweet spot. I record that lenght and use it.

BTW I use a stoney point tool, now by Hornady, to measure my OAL from cartridge base to bullet ogive. This is a much more reliable measurment, and with the tool is easy to apply to other bullet brands and styles.

 

[Ol` Joe]

Ooooops, I almost forgot. I`d check out the powder company web sites for modern data, or if possible get a few new books, and not rely too much on the old books. (I know I`ll get flamed big time for this :twisted: ) The various components in some cases have changed or new pressure testing with more accurate equipment has shown some of the old books are offering occasional loads on the hot side.

 

[YoteSmoker]

kup- If it makes you feel any better, I'm using 27.5 W748 with the 50s in my CZ with no pressure signs. Time will tell when the weather gets warm.

 

[Powerstroke]

Kup...
Welcome to the forum... there is a lot of good info here and a lot of experience !

748 is a great powder for the .223 as well as the rest of the components you listed. You certianly have the right idea by backing off 10% and working up from there.
As you've noticed, powder & reloading manuals have changed over the years as well as a company or two changing labeling.
You'll need to back the bullet out of the lands a tad... ..015" would be a good start....I also have the Hornady / Stoney Point Tool for checking.

As stated above, there is also a lot of good info on-line at the powder / bullet manufactures sites.

 

[hubcap]

I kinda like sticking with reloading books from the company that makes the bullet. For example the nosler manual number one lists their max loads nearly indentical as manual number five for the .270 and 30:06. Even though the components changed between the two additions the listed max loads for the same powders are very near the same. It,s just a little less confusing to load using data from the bullet maker thus avoiding such large differences often found in a different bullet brand manual. Just my opinion.

 

[BK]

I`d check out the powder company web sites for modern data, or if possible get a few new books, and not rely too much on the old books. (I know I`ll get flamed big time for this :twisted: )

I'm not about to flame you for this. In fact, that was my first thought. I have always been of the opinion that if a new manual comes out, the previous books are obsolete, and should be used for historical reference only.

 

[Richracer1]

I`d check out the powder company web sites for modern data, or if possible get a few new books, and not rely too much on the old books. (I know I`ll get flamed big time for this :twisted: )

I'm not about to flame you for this. In fact, that was my first thought. I have always been of the opinion that if a new manual comes out, the previous books are obsolete, and should be used for historical reference only.

+1. I think Nosler even states that.

 

[steve4102]

My book says max lenght 2.200 C.O.L. and mine measure 2.270, but they fit.
Any comments??

Here is what Accurate Powder says about OAL.

SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must
be seen as a guideline only.
The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.
This parameter is determined by various dimensions such as 1) magazine length (space), 2) freebore-lead dimensions of
the barrel, 3) ogive or profile of the projectile and 4) position of cannelure or crimp groove.

 

[Antelope_Sniper]

Well, as for you original question of 'who do I believe" I believe what I'm told by my chronograph, and my rifle. Everything else is a "guideline" to get me in the right area to begin experimenting unit I find the combination that gives me the accuracy and velocity I'm looking for in that particular rifle.
Lets face facts. How often do any of us use the EXACT same componets listed in the Manual? I'm sure we didn't all go out and buy new Nosler brass just because Nosler uses it for your favorite caliber in the new Manual.

Ultilmatly the Books are all just guides, and in the end you have to trust you chronograph, your rifle, and you own good judgement. I'm pretty content starting low, trading a few extra components for an extra margin of safety, and a little more chronograph data.

 

[Ridgerunner665]

Ultilmatly the Books are all just guides, and in the end you have to trust you chronograph, your rifle, and you own good judgement. I'm pretty content starting low, trading a few extra components for an extra margin of safety, and a little more chronograph data.

+1000...just don't shoot the chrono

 

[hubcap]

Antelope sniper is dead on. A chrony and a knowledge of pressure signs is exactly what I count on too. I,d rather buy some bullets than another reloading manual. :grin:

 

[kup1236]

Thanks for the help and information. I do have the newest manual from Hornady. What had me wondering is when I looked at
Hodgdon (I think they make the Winchester 748) and all it listed was 26gr max load.
I will cut back alittle more and try some.
Thanks again,
Kup1236