Working up a load

[TRIGGER]

Have read when working up a load start small and work up to pressure. What am I looking for? I have watched videos of pressure signs on primers but what else can I look for? Where is the sweet spot? I know it will be different on each barrel but what's the general guideline? Seems like 1 thing I learn about reloading I realize there are 5 more I need to learn.

 

[Rubberduck270]

Depending on the rifle, you can look for the bolt face to start leaving marks (mainly the ejector hole). Hard bolt lift is another sign that you're over pressure.

As far as finding the sweet spot goes, if you start low and work up (without adjusting the scope) you'll generally see when the velocity levels out within a particular range of powder weight (similar to a ladder test) or you'll start to see pressure signs. Once you halfway settle on a powder charge you can go back and fiddle with seating depth to squeeze the last bit of accuracy out of the load.

For a hunting rifle, I've pretty much settled on the "kiss, find pressure and rock-on" method. Seat the bullet a few thou off the lands, work up till I find max pressure (or a really good level velocity range) and go hunt. IF that doesn't shoot I'll fiddle with seating depth (bumping it in a few thou at a time).

It really depends on what you consider "good enough" for a load.

 

[infoman jr.]

I was expecting a thread on chinese food.

 

[Hunter 257W]

The hard ones to load for are the cartridges that operate at pressures so low that primers never flatten. With those, I just go conservative and never go above the manual recommended charges.

For cartridges that do operate in the approximately 60,000psi range, look for primers to have a mushroom cross-section when you punch them out. If they are doing that, you need to back off a bit. Also as Rubberduck said, if you start seeing the ejector hole imprinted on case heads, you need to back off on the powder until that stops happening. I was getting that at the "book" Max charge of IMR 7828 in my 257 Weatherby with 100 grain bullets so had to back off 1 grain. I can use the recommended Max load with 120 grain bullets.

 

[DaveB]

Typical, but not always, you can run your fingernail across the primer and feel a ridge around where the firing pin hit the primer.

Next, the primer is FLAT. I get this all the time on maxloads. It says back off your charge weight.

Next, the base of the brass is scratched. This is because the brass tried to meld with the bolt. I get this on some loads slightly over book max.

Next, the bolt will lift and extract but you can tell the bolt is binding-it is stiff to operate. You are overpressure. If you have fired this load before, what did you do different? I had this on my 22-250 when I used a Ballistic tip OAL for a Partition bullet. I ejected the round and left the bullet stuck in the barrel.

Next, the bolt won't move backwards and extract. This is where you can break things. Let rifle cool down. You are overpressure. Do not fire any more loads that match the one that is stuck untill you examine what has occurred.

Measure the length of a similar load. You over-length? That is, when you chambered the round did you have to crank the bolt to get it closed? if this happens never ever fire the round, your bullet may be/is in the lands and you can go overpressure (unless you are suppose to be in the lands)
so just extract the cartridge.

Pull the bullet from any similar load and re-weigh the powder after setting your scale to zero. Is this an electric scale or a beam? Doubler check with beam if you have one.

Look at your powder. You load the wrong powder? If you did, you made a mistake in that you did not check your book load against what was on your bench.

Free the bolt/cartridge and take a hard look at the brass and then render that brass unusable.