sizing for revolver?

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  • Last Post 11 July 2013
wazza2222 posted this 19 April 2011

Hi all

Here we go... I am pretty new to casting and my experience with revolvers extends to creating 265gr hollow base slugs for my Webley .455 I don't size these as the cylinder does the job for me and the skirt then flares to catch the rifling in the barrel.

I am now onto my second project which is 160gr rn slugs out of a Colt Police Positive in 38S&W calibre. Having slugged the barrel (.335!!!) I am sizing my cast boolits to .355 in a Lyman 450. My question is: Should I be sizing at all or is the cylinder supposed to be doing this for me like the Webley does?

Cheers

Wazza

P.S. the sized boolits drop into the cylinder but stop on the driving bands as I believe they should?

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RicinYakima posted this 19 April 2011

If it were I, I would size the bullet to just be a push fit in the cylinder throat. This has worked the best for me in making accurate loads.

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wazza2222 posted this 19 April 2011

Thanks mate,

I think thats what is happening here if i read you right... my boolits stop with the ogive showing out of the cylinders front face but firmly caught by the driving bands at the rear.

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RicinYakima posted this 19 April 2011

That should be just right. Ric

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Ed Harris posted this 20 April 2011

Most cast bullets designed for the .38 Special will work just fine in the .38 S&W if cast soft, 8-10 BHN and loaded as-cast and unsized at .359-.360 when tumble-lubed with Lee Liquid Alox. My favorite in these is the Saeco #348 double-end, bevel-based wadcutter, seated out and crimped in in the lube groove, rather than in a crimping groove, with 2.7-2.8 grs. of Bullseye, gives normal .38 wadcutter ballistics.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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wazza2222 posted this 20 April 2011

Thanks Ed, from .360 down to .335 seems a big squeeze to me! are you sure this will be okay? As for mold, I am using a Lee design and the Lyman book, the Lee instructions and the Lyman cast bullet handbook both state a maximun of 2.2 gr of Bullseye.

Waz

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docbob posted this 20 April 2011

wazza, Are You sure the bore is .335” that seems very small to me! I'd sure bet it's closer to .358 or somewhere around there. Good luck on your project.

Doc

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wazza2222 posted this 20 April 2011

Yeah, it is small isnt it? I slugged the barrel and mic'ed it so Im happy that its correct...

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curator posted this 05 June 2011

S&W revolvers have odd number land/grooves making measuring difficult with an ordinary micrometer. I suspect you are reading from groove to land not groove to groove. Try spinning the slug while liightly tightening the mictometer or wrapping the slug with thin shim material, measureing, then subtracting twice the shim thickness to get a true reading.

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CB posted this 13 June 2011

I used to have a Webley 38 200, and it was a bird of a different caliber.

Jerry

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bsdger45 posted this 14 June 2011

wazza2222 wrote: Yeah, it is small isnt it? I slugged the barrel and mic'ed it so Im happy that its correct... Is it not possible that you missed one full turn of the micrometer?

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Ed Harris posted this 15 June 2011

If your Colt has a 5-groove barrel, as most do, the odd number of lands and grooves results in a false measurement if you are using a standard thimble micrometer because the faces will be aligned land to groove, rather than groove to groove.  If you can find a V anvil micrometer designed for measuring 5-fluted reamers, you are more likely to find the groove diameter of your barrel is .353-.355.  With soft alloy a push fit with light resistance through the cylinder throats is correct, probably .360.

73 de KE4SKY In Home Mix We Trust From the Home of Ed's Red in "Almost Heaven" West Virginia

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olesmokey posted this 11 July 2013

I use a digital caliper and watch the dimension rise as I roll the slug gently between the jaws. I think I get a pretty good reading that way.

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badgeredd posted this 11 July 2013

My Police Positive Special in 38 S&W has a barrel diameter of .355 but the cylinder is at .360. I size my bullets at .361 with a very soft alloy...8-10 bhn. Until I sized them at .361 I had a little leading. Also found the soft bullets work far better than a harder alloy like AC COWW. I've tried several bullet designs but the best accuracy is from heavy (190-200) round nose bullets similar in shape to the original lead bullets that were loaded in the 38 S&W.

Edd

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Pigslayer posted this 11 July 2013

Size to the cylinder throats my friend!

If someone else had of done to me what I did to myself . . . I'd have killed him. Humility is an asset. Heh - heh.

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