Bearing surface comparison

[chet]

occasionally a new bullet will be introduced in an uncommon weight. Of course reloaders always need an excuse to buy a new manual, but this is not always practical. And the new data may not be the best anyway....

for example: the 110 grain Nosler AccuBond in .257
It is safe to use the 115 grain BT data, but I like to get as much as I possibly can out of a cartridge.

In my opinion, the bearing surface of a bullet has alot to do with pressures, as well as weight. So my question to you all is this:
Which is more crucial in effecting pressure? weight or bearing surface?

also, if someone happens to own the following three bullets:
100 grain BT
110 grain AB
115 grain BT
could you please measure the bearing surface for us to get an idea of which BT is most like the AB. Obviously the 115 is closer in weight, but the different internals may just put that 110AB a closer relative to the 100BT???????

 

[Ol` Joe]

You are assuming the jacket and core hardness are the same in all three bullets, right?
How about bullet geometery, are they the same shape?
Is the bullet seated as deep in each case?
How far from the leade is each ogive if they are seated so?
Personally I`d call Nosler or E-Mail them and use whatever data they give. Trying to guess at how far you can go or purposely hot rod is never a good idea when reloading......JMO

 

[chet]

my point exactly!
I tested some bullets from a friend once, the box was old, but still sealed.
I liked the bullets, so I bought some more. TOO much pressure!
Identical brand, identical weight....... a slight shape change that took place over the years turned a safe load into a hot load!

 

[Nosler4]

Design changes can definately be a factor in your loads. Also, humidity, temperature, case volume and primer type can change the performance of a load significantly. I don't have load data off-hand for the 110 gr. AccuBond but you can call our technical support department directly at 1-800-285-3701 ext. 1046.

If they don't have specific loads for you, they're going to tell you to use the load data for the 115 gr. Ballistic tip, starting with the minimum load and working your way up (of course, always checking for signs of excessive pressure)

There are so many factors to consider when looking at pressure that there is no practical way to calculate that information for everybody's rifle.

FYI: The AccuBond bullets will be listed in the #6 reloading manual which will be out early next year.