Load Development Interpretation

[QuietTexan]

On the subject of brass...lets say after I nail down the charge weight and seating depth and come up with an accurate load that I am happy with based on new brass dimensions, would you do a normal FL resize for this load or would you just FL resize with a shoulder bump of .002"-.003"?

My plan was just to FL resize with a shoulder bump of .002"-.003".

Sizing brass is a whole nuther ballgame. I'm in the camp of I try to size as little as possible, so I don't actually try to size brass at all until it won't chamber anymore. I very rarely ever use a standard FL die to completely resize a case.

I find a load that works in new brass so I'm not wasting time shooting out barrel life for no gain, but then I'll rework the load again once the brass is stabilized. This really depends on round counts and brass counts also - my comp 6.5 Creed has multiple sets of 50-200 case lots in rotation because that barrel is going to last 2000+ rounds hopefully and I shoot it a lot, made sense to have a good load to form the cases with. My 300 RUM has one set of 50 cases, a lot fewer to shoot through because there's a lot less barrel life to risk wasting and honestly I should be able to make those 50 cases last the life of the barrel because I'm not trying to overpressure the cases.

Generally speaking I do this process:

Shoot new brass
Rechamber, if it rechambers-
Size the neck to hold a bullet

Shoot fired brass
Rechamber, if it rechambers-
Size the neck to hold a bullet

Do that until the brass doesn't rechamber, then I
Set the sizing die to bump as little as possible until it does chamber
Bump and size the neck to hold a bullet

Shoot fired and sized brass
Mess with everything ad naseaum until the brass, barrel, or I give up

I've used stardard FL dies, bump dies, neck dies, bushing dies, collet dies, you name it I've used it to size the neck back down to hold the bullet until the cases are fully grown. You can use pretty much any die, just leave it backed off enough to not touch the shoulders until the case doesn't chamber anymore. You only need about half the neck resized to hold a bullet well enough during this process (or in general, but length of neck sized is another long conversation)

Good watch on case sizing:

Jstanton - A "normal FL resize IS a .002 bump. No reason to ever do more unless the round won't chamber due to die not matching chamber well enough. Only then do you have to keep bumping back until brass will chamber - or try a different die.

I get what you're saying, but what I took "normal FL resize" to mean in this context was follow the instructions on an FL die and set it to minimum resize a case. I agree with you about that being excessive, but I think his question was about trying to size the brass down as close to the virgin state as possible to allow him to duplicate the virgin load going forward.

The difference between a bump die and an FL die is the amount of body sizing that goes on. You can set an FL die to get minimal shoulder movement, but you can't get body sizing from a bump die like a Forster.

Received this from Forster tech support when inquiring about die dimensions:

The bushing bump die sizes the neck and bumps the shoulder, it does not touch the body of your case

Different dies do different things, that's why there are so many to choose from.

 

[Willys]

Pretty sure he doesn't have a bump die, but good point I had forgotten he could have two ways to get the .002 bump.

 

[jstanton]

@QuietTexan you are correct, by "normal FL size" I was referring to following the normal setup procedure the die manufacturer recommends. This method I know gives me a .007" shoulder bump. For getting a specific shoulder bump, I have used Eric Cortina's method for setting a standard FL die to get your desired shoulder bump. Basically I set the die up as per the instructions, sized one piece of fired brass, measured with headspace gauge, compared to measurement from a fired piece of brass, and take the difference between the two. Next measure the bottom of the die to the bottom of the lock ring and then adjust for the difference to achieve desired shoulder bump.

This method worked pretty well for my 7mm Rem Mag. I am using a standard set of Hornady Custom Grade dies by the way. I was really just curious what other people are doing with their brass if they find a successful load with virgin brass.

 

[QuietTexan]

Sounds like you're on a good track When I find a good virgin brass load I tend to feel sad that I didn't buy more brass, but then I'm happy again when I get a good load on the fired brass.

 

[Justice1327]

On the subject of brass...lets say after I nail down the charge weight and seating depth and come up with an accurate load that I am happy with based on new brass dimensions, would you do a normal FL resize for this load or would you just FL resize with a shoulder bump of .002"-.003"?

My plan was just to FL resize with a shoulder bump of .002"-.003".

IMO your finished accurate load is with 3x fired brass...not new brass