Oversize boolits in hand loads

[jeff100]

I'm loading up some ammo for my Ruger BH .357 magnum revolver using Lee 358-158 cast boolits powder coated and sized to .3590" diameter (size after PC). I test fit my boolit to the cylinder chamber and it is an interference fit, does not drop through the cylinder opening. Cylinder opening (where the bullet exits) measures .3585. Bullet hardness is 16.6 brinell tested with my Lee hardness tester (divot = .056"). I know these boolits will swage down when fired and I want them slightly oversize for a good fit. I'm loading with Accurate #5 to create a 'target' load, max load being tested is 8.0 grains, .8 grain below the max load in the Accurate manual (8.8 gr).

My question is will this oversize condition cause chamber pressures to be unusually high? I don't believe this is a problem as long as the boolits are seated deep enough and the cartridge OAL doesn't jam the boolit in the cylinder, but I don't have a lot of experience with cast boolits & wanted to check with other experts for a second opinion BEFORE I load up this ammo.

Thanks all...JJ

[sqlbullet]

If the loaded round drops in and out of the chamber freely, and the load is otherwise safe, an oversize bullet will have no ill effect.

[USSR]

My question is will this oversize condition cause chamber pressures to be unusually high?

Nope. Shoot away.

Don

[fredj338]

Well it will raise pressures some, but if you are working the load up, no issues. I wouldn't take a max load & substitute an oversized bullet, just plug & play, that could cause issues.

[DougGuy]

It does raise pressures, but not astronomically unless A. the boolit is REALLY hard, 22-24 BHN or B. the throats are REALLY small.

[jeff100]

That's what I was looking for, thanks all.

JJ

[17nut]

I cast that bullet from 97/3 and push it to @1500fps from 6".
I dont size as loaded bullets will chamber.

[USSR]

The pressure difference from going to a lead bullet that is .001" larger than normal will be lost in all the other variables that are involved in your handloads. If that wasn't the case, my .455" bullets being .003" over normal for my .45 Colt would be off the chart, which it isn't.

Don

[lotech]

I spoke with a technician at Lyman about this very thing a number of years ago. He said the pressure difference using various diameters of cast bullets was minimal.

[mdi]

Your cylinder throat is .3585" and your bullets are .359". That's one half of one thousandths of an inch (.0005") or fifty, ten thousandths of an inch (.00050"). Not very much at all and there will be no problem swaging .0005" of bullet diameter. How did you measure the cylinder throats?...