to mag prime or not????

[Kato_Guy]

I have the lee book which I was going to go by for my 270wsm (130gr solid base boat tail). with h414 powder it says 57.0-61.0gr with a standard primer. In the hodgen powder book it says 130gr soft point 61.0gr max with a mag primer. In the lyman manual I have it says 60.0 gr max with a mag primer.

There is no specific load data for this bullet only other 130gr soft points, so do I load up to 60.0 only with the mag primer or can I load to 60 grains and slowly inch up to 61.0gr? could someone take a look at their manual and point me in the right direction??

if this is a little confusing let me know and I will explain it different. I might have rambled a little. sorry


thanks for your help!!
kyle

[Ifishsum]

Just a difference in load data between manufacturer's and testing platform. What I do is start at the starting load with whatever primer you decide on, then inch up until you find the most accurate group. I usually go 1/2 gr at a time. There's not necessarily a need to get to maximum, and you might reach pressure signs in your rifle before you get there. You're gonna get velocity out of a .270WSM anyway, so I'd look for the accuracy even if it is near the starting load.

I usually use magnum primers with ball powder like 414. Just stick with what you tested with, it could be unsafe if you are near a max load and then switch to different primers without working back up.

[Kato_Guy]

I was so frustrated last night working with this load!! My wonderful lee equipment! Love it so far but my auto prime doesn't work with mag primers. So I got out the ram primer that worked pretty swift though. and I dont know if I am a little picky of it everyone's does this but every charge is different. they are off a tenth or two!! I need a powder trickler I guess.

thanks for the info
kyle

[Unclenick]

Most ball powder will throw to about the accuracy you mention with standard measures, and with a benchrest measure you can stay within 0.1 grain. That said, keep in mind that about 0.2 grains of difference in water capacity of a case will have about the same effect as changing powder charge 0.1 grains. 70:30 cartridge brass is 8.5 times the density of water, so your brass weighs +/- 1.7 grains, it will have about the same effect as a varying the charge +/- 0.1 grains. You want to trim your cases (the factory often doesn't do a very consistent job) and cut the primer pocket bottoms to uniform depth and deburr the flashholes before weighing so you start with dimensionally similar brass, and the weight variation then reflects the water capacity more closely. If you want the case volume variation to be insignificant compared with the powder, you probably want to sort it tighter than I just mentioned. Say, +/- a grain. Half a grain if you are benchrest shooting.

After you've done all this stuff, the next trick is to find a load that is relatively insensitive to charge weight error in the first place. Take a look at Dan Newberry's Optimum Charge Weight site.

[T. O'Heir]

Load for the bullet weight. Who made it doesn't matter. Begin with the starting load and work up to the max.
A trickler used with your scale is the way to go. It does matter if the charge is different for each load. Not dangerous, just inconsistent.
I can't imagine why your auto-primer won't work with the magnum primers. The diameter is the same as a regular primer.

[Kato_Guy]

Just playing with my stuff and relized that there is a 2nd tray that is for the mag primers.

Sorry for ranting about the lee products not having the stuff I need !!

[brickeyee]

That does not make a lot of sense since there is NO difference between the dimensions of a magnum primer and a standard primer.
The change is in the priming composition.

[rfdillon]

Are you sure you don't mean there are two trays, one for small primers and one for large primers? Magnum primers are not larger dimensionally; small pistol or rifle magnum primers should be loaded with the small tray, and large pistol or rifle magnum primers should be loaded with the large tray.

[Shane Tuttle]

"Load for the bullet weight. Who made it doesn't matter."

TO'Heir,

I have to respectfully disagree with your statement. Even if the bullet weights are the same, the shape of the tails could be different. Therefore, it would change the burn characteristics of the powder due to differences of powder/empty space ratio.

Could you provide and explaination? I can see if you mean in the context that since you stated to begin with the starting load it wouldn't matter as far as overpressure. Is this what you mean?

[Kato_Guy]

My wsr primers and the WLRM primers need two separate trays. the large magnum primers are bigger than the wsr primers