.357 or .358 diameter?

[Roland Thunder]

I am going to start reloading for the revolver I just bought a few weeks ago. I have been reloading 9mm and 45acp for pistols but this will be my first go round with .38 spl. I want to reload wadcutters and several people have suggested Missouri bullets for wadcutters. They have some double ended wadcutters (lead) for both .357 diameter and .358 diameter. My revolver is a Ruger Security Six (6" barrell). So, I don't know if I need .357 or .358 diameter.

I called Ruger and they were no help at all. The basically told me they don't advise using reloaded ammo. I asked them what size barrel it had and the rep said "I don't know"

[3kgt2nv]

try 357 first. or slug the barrel to see which you need

[chris in va]

Agree, slug the barrel first.

I will say though, my CZ 9mm works best with a 358, so I imagine you'd want at least that much with the 38 as it's supposed to be larger to begin with

[Roland Thunder]

Originally Posted by 3kgt2nv

try 357 first. or slug the barrel to see which you need

How do you slug the barrel.

Maybe somebody with a Security Six will respond and I won't have to

[Hal]

Slug you bore and chambers.

Use a fishing weight - which is usually pure lead.
Pick one that's close to the same diameter but a little larger.
Drive it through the bore using a wood block as a mallet and a dowel rod.

Measure the diameter of the fishing weight between the high spots the rifling leaves on it. That's the diameter of the grooves in the barrel.

Next, take 6 more fishing weights and drive one through each chamber.
Make sure you support the cylinder so you don't spring the crane.
You can just open it and place it on the edge of a table.

Measure the diameter of the weights for each chamber.

For lead slugs, you generally want to stay @ .001 over bore size.
If you bore slugs @ .357, then use .358 bullets.

Most .357's out there are going to slug out @ .357", so you're pretty safe to go w/.358 and not go to the trouble of slugging the bore.
It's still a good thing to know though in case you have accuracy or excessive leading @ some point.

[jal5]

Hal has it right. I would add, to grease up that lead that you will be driving through the bore- makes it easier. You will probably need .358 but slugging the bore will get you the exact dimension.

[m&p45acp10+1]

If you sluag the bore, and chambers make sure you run an oiled cleaning patch down the bore, and through the cylinder chambers before slugging.

[SL1]

I have a Ruger Security Six and a Ruger GP-100 and have slugged both. Both OF MINE have .357" barrels, but the Security Six has 0.358" cylinder throats while the GP-100 has 0.357" cylinder throats.

I suspect that your Security Six will also have .358" throats. Seeing if a .358" lead bullet will pass through the throats in your cylinder will tell you if you can use them. If not, you could "save" the bullets by buying one of Lee's cheap bullet sizing dies and size them down to 0.357". That may actually be cheaper than buying a Lewis Lead Remover to get the lead out of your bore if you get leading from shooting undersized lead bullets.

SL1

[wncchester]

No one knows within a thou of what bore diameter you have and it's easy enough to correct for without slugging anyway, just use .358 bullets; if you have that size all will be well. But, if your bore is smaller all will still be well, the bullet will be precisely the "right" size when it has traveled its own length anyway. Slugging a revolver is not as easy to accomplish as it may seem (without bore damage) and it can be difficult to measure the slug within a thou without a high grade micrometer as well.

Heavy charges will allow for lead bullets to be slightly undersized because accelleration WILL force them to slug up (obturate) to bore size when fired. But, light charges won't force obtruation so we have to make sure the bullets completely seal the bore before they start or leading will be awful.

As a side issue, you need not be concerned about the safety of using a larger than bore size bullet. Even the hardest lead bullets will easily swage down the small amount needed. Not only will they size down easily your wad cutter powder charges will be so light there's no way the pressure would become excessive.

[jepp2]

I'm not saying not to slug your barrel/cylinders, but just pay attention to the details on the Missouri bullet website: they specifically say the .357 diameter bullets are for match barrels.

I would go with the .358 diameter without even know the results of your slugging.

[zxcvbob]

Buy the .358's and be happy.

[dwhite]

I have a 6" Security-Six and have been running their .38 Match and .357 Action bullets for some time. They all function fine and produce pretty good accuracy.

All the Best,
D. White

[mikld]

I consider barrel slugging and cylinder throat measuring a part of shooting lead bullets. To turn it around, why would you not want to know your gun? Do you know what size tires your pick-up wears? I know what size the cylinder throats measure on 4, .44 Magnums, 2, .38 Specials, and 1, .357 Magnum. Almost the other firearms I own have had their barrels slugged (except my .22 rimfires), just for my own information, besides, it's really easy. A major plus, besides accuracy, is I rarely have to clean any lead outta my barrels. It's easy to do and I enjoy working on mt guns. http://www.lasc.us/Brennan_2-1_Measu...Dimensions.htm good info for measuring our gun...

Or, you could be like my wife when I asked her where the starter is on her new Acura; "In the hole in the side of the steering column, silly!"

[TXGunNut]

I'd go with the .358 but slugging is never a bad idea. I prefer buckshot or cast round balls over fishing weights. A simple whack with a hammer on an anvil should make a good slug from a .36 ball, maybe even a 00B pellet.

[darkroommike]

If you use a fishing weight make sure you buy lead weights, starting to see more and more zinc weights around here. Test 'em with your thumb nail, lead is softer.

[Roland Thunder]

Originally Posted by darkroommike

If you use a fishing weight make sure you buy lead weights, starting to see more and more zinc weights around here. Test 'em with your thumb nail, lead is softer.

I must have some zinc ones, they wouldn't go in. I'll have to find another source of lead in order to swag

[hk33ka1]

.358" !!!

You can't use a lead boolit that's too big! (or it just won't chamber) .358" is the normal size for lead in a .357 or .38spl. Too small and it may lead the barrel and or not shoot as well. A thousandth or more over the actuall barrel groove diameter is standard for using cast lead bullets. A .308 would get a .309 or .310" etc. Slugging your bore/throat/cone lets you know for sure what your gun is then you go from there.

[Roland Thunder]

Originally Posted by Hal

Slug you bore and chambers.

Use a fishing weight - which is usually pure lead.

I don't think my weights are lead, they won't go in. I lubed them with One Shot to no avail. Any suggestions what else I could use?

[bossman]

.358 for lead
.357 for jacketed

Works for me.

[Hammerhead]

You can safely use .358" or .357" lead bullets in the .38 spl.
If you get leading with the cast bullets try some swaged bullets like Hornady or Speer bullets. I get less leading with them at .38 spl velocities.

[zxcvbob]

I don't think my weights are lead, they won't go in. I lubed them with One Shot to no avail. Any suggestions what else I could use?

.358 is the right size. .357 might also be the right size. So use the .358's. Slugging the barrel and the chamber throats is what you do to diagnose a problem. You don't have a problem yet. You're borrowing trouble from tomorrow that may never happen.