Nosler and Sierra loading manuals

[wvcountryboy]

I was wondering if anyone knew how far off the riflings nosler and sierra seat their bullets in their manuals. They tell the barrel, the length, the twist the velocity, and the most accurate powder tested but they dont tell one of the more important things. If they seat their bullets .050 off the lands and call it a max load and i seat mine .002 I will be over pressure.

Also, I was wondering the severe difference in max load from nosler to sierra manual. For example: I shoot a 338 ultra mag. I realize the match king and partition are totally different bullets but max load was something like 4 grains difference with most powders. I dont have the manuals handy to check but thats just off the top of my head. In my rum, the nosler loads are ok, the sierra is about 2 grains hot. If I shoot the max load from sierra I will have loose primers in 2 shots and bad tattoos on the first. I am shooting 100-125 fps faster than their max velocity with 2 less grains but i am using a 30 inch barrel.

Sorry for the jumping around but back to the seating depth, I made a dummy to have my reamer made for my ultra mag. I had what I thought would be a short throat so I could shoot small bullets. I use a 700 action with a davidson ramp but the other day i was curious to how much room I would have in the magazine of a magnum action..... it wont fit. I looked at the saami coal in the book and it is way shorter than mine.I am figuring my round wouldnt chamber in a factory cut chamber but does anyone know if they are possibly like a weatherby and have .250 free bore? That would explain why I cant shoot max loads.

Thanks for your input in advance.

Jeff

 

[portx5]

Hi Jeff,
I use the Quickload software from Necos. What I really like about the program is that you can put in a lot of parameters that fit your specifications to your gun. It has really took a lot of the guess work out of it for me. All you have to do is design your load using the components you want to use. They have a big library on bullets and powder. You can also adjust the barrel length and all of that kind of stuff. It gives you the estimated pressure. But like using regular manuals I've found it best to still work up to it. As far as the second question sorry I can't help on that.

 

[Kevin Thomas]

Jeff,

There really is no attempt to seat the bullets a specific amount off the lands in most cases when developing a manual. There's so many variables in play for most that this simply isn't practical with most cartridges. There are a few exceptions (the 80 grain SMK in the 223 Rem comes to mind) where the seating is somehow central to the OAL. In those cases, the manual should mention specifically what chamber was used, and some indication of where the ogive was in relation to the lands. Again, in the 80 SMK/223 combination, the chamber was a 5.56mm NATO chamber, which gave an OAL of 2.550"; since most competitive shooters use a Wylde chamber, that bullet will actually engage the rifling at about 2.440", or thereabouts. So there's major differences out there, and a decision has to be made about which one gets used. There's not enough space, time or money to do all the possible variations, and this isn't done in any manual.

A reloading manual is simply a report which states, "We tried this combination of components, and these are the results we obtained. Your mileage may vary." The variation between manuals is simply a very clear demonstration that all those little variables in play can, and do, create some major differences in the final results. That alone, is a worthwhile reason to have a wide variety of manuals on hand, and to update them as new ones come out. Powders change, bullet designs change, throating dimensions in factory rifles change, new components are introduced, to say nothing of new cartridges. Keeping a good variety of manuals at hand is one way to keep pace with some of these changes.

When you set out to load your own, you're doing exactly that; loading your own. If you follow the loads in the manual exactly, you're still not using the "same" components as the manual. It's a different lot of powder, different lot of primers, differen't lot of cases and a different lot of bullets, even if your load is the "same" one listed in the manual. These are the differences we deal with when loading our own. Not to discourage you here, just to let you know where the differences are coming from. Virtually every manual out there cautions you to start with a reduced load an work up to the listed max. It's good advice, and they put it there for a reason.

Anyway, I hope this clears up some of your concerns, or at least sheds some light on how manuals get developed.

 

[Boss Hoss]

Thank You Kevin for that answer! For those of you who do not know Kevin is the one person here who can speak with authority on that subject....

Many folks do not realize the blood, sweat and tears it takes to put out a manual!!!!

 

[Kevin Thomas]

Mostly sweat. The tears usually came when the boss shows up and says "good news guys, we're gonna start on a new edition!"

 

[B23]

Hey Kevin I was told once that often they use a C.O.A.L. that they know will feed thru everyones magazine. Is that true?

 

[Kevin Thomas]

Yes, it is. Magazine length was always a consideration that went into setting an OAL, unless it's a situation like the 80 gr SMK, where it was intended to be used as a single shot. That was one of those situations where the rules of HP competition (requirement that all rounds be single loaded for the 600 yard stage) made developing a bullet that wouldn't fit within the industry OAL standard a worthwhile proposition. Other than that, the magazine length is a factor not only in manual data, but the bullet's design process as well.

 

[wvcountryboy]

Thanks for the info. I do use the loading manual only for a starting point, I was just wondering why the manuals dont say. When I start with a new load i start usually with the medium load in the manual and start at .005 off the riflings. Sometimes I move in sometimes I move out. For instance, I have never been able to get a speer to shoot good unless its .030-.040 off the riflings. Its just something I pay a lot of attention to and now I know why the manuals dont.