Sizing...Newbie question

[SteveS]

I have an Ruger Security-Six that I've had for twenty-five years. Back in the day, I shot some cast bullets with mixed results. Now I'm getting back into it and trying to do a better job.

I've slugged all the chambers and they seem to be between .358 and .359 measured with an RCBS dial caliper.

From everything I've read, I'm looking to size my boolits to .360. Is that correct?

I'm not even sure my molds will cast a boolit that large but I at least want to know what I'm shootin' for. ;)

Thanks

[375RUGER]

Size so that the boolit passes through the throat of the chamber with a small amount of resistance. .359 will probably be fine for you. If you slug the barrel you may want to size according to those results. I suspect that you will be fine at .358 or .359.
How consistent are you with the pressure you put on the jaws of the caliper when measuring? Inconsistent pressure when measuring can give varied readings. You should be aware. Micrometers are more consistent when measuring boolits.

[Ed_Shot]

I have a 6" Security Six that I bought new in 1978. It's had nothing but cast boolits for 34 years and is a joy to shoot. I size to .358 .... don't believe I ever attempted to slug the barrel. I do have to use thumb pressure to push sized boolits thru the forcing cones. Never had a leading issue with it.

I recommend you start with boolits sized to .358.

[Whitespider]

With revolvers, I've never found any accuracy or lead-fouling advantage to sizing over cylinder throat diameter... in fact, accuracy seems fall-off just a bit (maybe??) when sizing over throat diameter. My SOP is to slug the barrel first, measure the slug (just for record) and see if it will freely pass through cylinder mouths. If it does, I know I'm good on barrel dimension relative to cylinder mouths... actual groove diameter means nothing after that. If it's a 5-grove barrel, like S&W, I don't even bother measuring the slug 'cause it near impossible to get an exact reading... instead, I slug all the cylinder throats and then see it the barrel slug will freely pass through the smallest. Finally, I size right at cylinder throat diameter (or as close as I can reasonably get).

Measure a few of your sized boolits... the number stamped on the sizing die ain't always what the boolit ends up being.

[SteveS]

Thanks guys.

My skill with a dial caliper might be a little weak but each slug measured a little over .358 and a little under .359 every time I measured.

I have a .358 sizing die so I'll try that first or, depending on how the boolits cast, not size at all.

I'll be casting over the weekend so I'll see how it goes.

Thanks again.

[stu1ritter]

For sizing a revolver cylinder a dial caliper really isn't accurate enough. It is best to use pin gauges. If you just want to check a .38, you can buy .358, .359 and .360 for about $2.83 each on Amazon at http://tinyurl.com/o3rgto7.
That will take a few seconds to load as it lists about 1700 of them. These are extremely accurate gauges and easy to use as go-no go. Those three sizes should cover you although I did end up with a Smith model 37 that I bought new in 1978 and have been shooting ever since with .355 throats. Now that I know, I will probably get it reamed to .358.
Stu

[Petrol & Powder]

I'm not a casting expert by any means but I have managed to learn a thing or two about reloading. If you have an unmolested Security-Six, chances are fairly good that the throats are no larger than .358". Using calipers to measure a slug could easily result in an error of .001". If you really want to know the diameter, pin gauges are a good method.
However, If a .358" bullet can be pushed through the absolutely clean throats with just a little resistance, that's where I'd start.

BTW - that Security-Six is an excellent gun and often under-rated! Good luck.

[tazman]

With revolvers, I've never found any accuracy or lead-fouling advantage to sizing over cylinder throat diameter... in fact, accuracy seems fall-off just a bit (maybe??) when sizing over throat diameter. My SOP is to slug the barrel first, measure the slug (just for record) and see if it will freely pass through cylinder mouths. If it does, I know I'm good on barrel dimension relative to cylinder mouths... actual groove diameter means nothing after that. If it's a 5-grove barrel, like S&W, I don't even bother measuring the slug 'cause it near impossible to get an exact reading... instead, I slug all the cylinder throats and then see it the barrel slug will freely pass through the smallest. Finally, I size right at cylinder throat diameter (or as close as I can reasonably get).

Measure a few of your sized boolits... the number stamped on the sizing die ain't always what the boolit ends up being.

Spider is absolutely correct. He condensed the contents of the revolver accuracy sticky into a few concise sentences. I use that method for my own revolvers and it works.
The full text of the sticky is here
http://castboolits.gunloads.com/showthread.php?21598-A-beginner-s-guide-to-revolver-accuracy

[Whitespider]

My skill with a dial caliper might be a little weak...

A caliper is the wrong tool for this task. At best, it's an "in-the-ballpark" tool when measuring to the third decimal place (.001), but with a little practice and a decent micrometer it's easy to accurately measure to the forth (.0001). A decent micrometer can be had for just a bit more than the price of a pound of powder or a brick of primers these days... and a "better" one for something 'round $50.00 (you can spend more if'n ya' choose to).

You wouldn't use a chainsaw to cut lumber building a house, and ya' wouldn't use a circular saw to fell a tree... the proper tool for the task at hand always results in a much higher-quality finished project..

[mdi]

If the cylinder throats measure .359", size the bullets to .359" (easy to "hone" a Lee die out .001"). For your own information, slug the barrel and make sure the cylinder throats are larger than the groove diameter.

[Buck Neck It]

Thanks, Tazman, I missed that sticky.
I am working on the same project, a 1976 ruger security six. First scrub the lead out from yesterday's test, then buy a .358 sizer.

[MtGun44]

+1 on caliper not up to the accy needed for this work.

YOu need a micrometer that reads to .0001". Enco Tools online usually has their
Fowler mics on sale for well under $40, it is a good brand. Or a used Mitotoyo or
Starrett or Brown and Sharpe on eBay can be a bargain if it is not abused.

Caliper accy is +/-0.001 - you need to be absolutely certain of .001 and better to
be reading to .0001" with a quality mic.

Bill

[SteveS]

OK, a micrometer it will be. I'll probably get a set of those pins too.

I really like this gun. When I first got into reloading I, unfortunately, wore it out with thousands of of rounds of ridiculous loads but Ruger was kind enough to rebuild it for me and this time I want to be a little more responsible with it. I've fired very few rounds since it was rebuilt.

I'll read that sticky. I appreciate you posting it.

[Buck Neck It]

Steve, what did Ruger do to your gun when they rebuilt it? I am curious about what is involved.

My SS has 2 tight throats in the cylinder. The slug from the other 4 measure .3584.

[SteveS]

I don't have the actual receipt but they replaced the barrel, reamed the chambers and replaced the cylinder pin. They also repaired or replaced a couple of parts in the trigger group. They reblued the gun and replaced one of the grip panels.

All for no charge.

[Buck Neck It]

No charge? Wow.

What was wrong with the barrel? What were you shooting in it?

[Petrol & Powder]

All that factory work for free - That would keep me in the Ruger camp, of course I'm pretty much there already.

Before you start cutting, reaming, honing or doing anything drastic; I would clean the cylinder real well and see if you can push .358 bullets through the throats with a little finger pressure. Use a fresh bullet to check each throat. That is not exactly a pin gauge or a micrometer but it is cheap and easy.

If you have a new barrel and they reamed the cylinder, you might get real lucky and find you have a .357 barrel and .358 throats. (I suspect you do considering all the work they did) I suppose it's possible Ruger reamed the throats to .359" but I think it's more likely your measurement is off just a little.

You've got a good gun, maybe better than new. Good luck.

[SteveS]

What was wrong with the barrel?

There was a noticeable bulge just ahead of the frame and the forcing cone was beyond repair.

This was almost thirty years ago and I was not cautious in my reloading to say the least. I've learned a lot since those days. I don't really remember if I even fired the gun once I got it back but if I did it was only a very few rounds. It's pretty much a new gun, at least to me. That's why I want to be careful this time.

I'm not in any rush. I'll cast some boolits next week, get the micrometer, maybe order a new sizing die if I need one and get back into shooting it. I want this gun to last me the rest of my days.

[dondiego]

I have a Security Six made in 1976 and it is a great firearm. I rate it right up there with my Python, Mod. 27, and Mod. 19.