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sniper
02-22-2021, 05:09 PM
My revolver cylinder throats all measure.358 with a .358 zz Minus pin gauge, and my bore slugs at .0.3564. I don't cast any more. Problem is, any of the boolits @ BHN 12 I have ordered from places on line ALL measure smaller than the .358 I specify. :eek:

I understand this is not an uncommon problem. My quandary is: shall I order .359 diameter boolits and run them through my .358 sizer, which I know is accurate, Or just shoot what I can get when I order .358 boolits, and hope obturation will take up the slack? My goal is 900-1000 fps for lead, and not much higher for jacketed.

A related problem: my dial caliper is really old...more than a quarter century, and I suspect it may not be a as accurate as it once was. Is it better to stick with a dial caliper, or is there maybe an electronic caliper (not Harbor Freight?) that is very accurate, and not really expen$ive at the same time?
Suggestions, wise counsel and experiences are welcome! :cbpour:

Outpost75
02-22-2021, 05:23 PM
Check your micrometer against your .358zz- pin gage and tweak as necessary. If your 12 BHN bullets a half thousandth, 0.0005" smaller than the cylinder throats, that is perfect. At .38 Special +P velocity and pressure a 12 BHN bullet will slug up when loading powders similar to Bullseye, TiteGroup, 231, WST, 452AA, or Unique. Slower powders like Herco and AutoComp less so.

I would shoot the bullets you have and not worry about it.

Wayne Smith
02-24-2021, 09:24 AM
No caliper is as accurate as a micrometer - it has to do with the way they are made and the slack inherent in each. Get a micrometer and learn to use it. Otherwise listen to Outpost and shoot what you have.

44MAG#1
02-24-2021, 11:23 AM
One thing one needs to ask is this: Can I shoot well enough from field conditions, not from a sandbag bench rest under ideal conditions, to tell the difference in .357", 358" diameters?
I am not asking do you feel you can, or do you think you can, or do you hope you can. Being truthful with yourself, can you shoot well enough from field conditions that you CAN tell the difference?
Most cannot. Hope, feel or think has nothing to do with it.
Please dont get bent out of shape by what I say. I am just trying to get the "REALITY" thing to kick in.
Sometimes it is hard to accept reality.

stubshaft
02-24-2021, 03:01 PM
Someone gave me a box of 500, .357" bullets he bought for a 9mm. Since I do not own a 9mm, I put together a bunch of them to plink with. I shot them out of my S&W model 586 which I used to shoot PPC with and found virtually no difference in accuracy between .357" and .358" bullets.

gwpercle
02-24-2021, 07:46 PM
In all of my 38 special and 357 magnum revolvers ( two in each caliber) boolits sized .357" work just as well as those sized .358" .
I've sized them to both diameters and tested them side by side ... Accuracy was the same and no leading with Lithium-Beeswax lube .
I honestly wouldn't worry much about either size ... they will both do the job .
Shoot whatever size you can get your hands on !
Gary

DHDeal
02-25-2021, 12:47 AM
I'll say the same about calipers versus micrometers. The micrometer will be more exact and repeatable. I use Mitutoyo in both and trust both but I'll unbox the micrometer for all things I want to know what size something is. I still use the calipers a lot, just not checking checking bullet diameter. Take a look on Fleabay for either used or new calipers/micrometers. I've bought a few and all have been in great condition and not terribly expensive. Pick and choose what you want and you'll more than likely find a decent deal. I buy Mitutoyo electronic as it's what I prefer.

Your idea is not a bad one, buying a fat bullet and sizing it down, but it may not be necessary. Try those undersized .358" bullets and see how they do. You're dealing with a relatively soft alloy and you're also looking for a decent velocity/pressure level so I suspect you'll be fine. You can always try your idea if accuracy isn't what you expect.

sniper
05-03-2021, 11:30 AM
Thanks for all the input, and pardon my tardy response. Actually, accuracy is not my main goal, although it is nice. At my age, (82) keeping all rounds in an 8" bullseye at 25 yards is a good day!:D My wish is to eliminate leading, at least as much is possible, although my Lewis Lead Remover cleans it up in a trice.

JoeJames
05-03-2021, 11:38 AM
I do not size my boolits out of my double cavity Lee mold. It throws .358 148 grain wc's, and I tumble lube them with 50-50 LLA and mineral spirits. They shoot fairly well.

45DUDE
05-03-2021, 11:55 AM
I think you need to slow them down to about 800 to prevent lead in the barrel. I did some 148 dewcs yesterday at 1020 and they were all over the place and a little lead and keyholes in the target but had some more slowed down to test and they did fine with the same gun. I just wonted to see how fast I could push them for fun. The accuracy started going away after 920 fps with my boolits. All of my 38s-357s throats seem to be 357 and 358 lead seems to have the better groups. <I am about to catch you on age.>
.

mdi
05-03-2021, 11:59 AM
Have you tried any of the .358" bullets? Any leading? One thousandths of an inch isn't much for a lead bullet to obturate, even at 38 Special pressures. Try some, those .358" bullets may work perfectly in your gun.