.001 or .002 over slugged diameter?

[mvintx]

I just started casting for my Gold Cup. The bore slugs right at .451” so I ordered a NOE 452 sizer. The boolit is a powder coated 200 SWC (50/50 COWW/PB) and comes out of the sizer at .453+. Loaded with 4.0 grains Bullseye it is an accurate and pleasant load to shoot but I’m getting some lead streaks after just 30 rounds fired. I use the same process for all my PC…a PID-controlled bake at 400 for 25 minutes then ice-water quenched. There is no leading from my 9 or 10mm cast loads so I believe my PC process to be sound.

Question; can a bullet .002” over bore diameter defeat the ability of PC to protect the bore from leading as opposed to one that is sized .001” over? Or do I have a different problem here?

[onelight]

Have you tried any sized back to .452 after powder coating ?

[cupajoe]

Size between throat entrance diameter and groove diameter.

[GARD72977]

I shoot a lot of PC in rifle .002 and .003 over

Try using softer alloy

[GregLaROCHE]

You should have bought some additional sizing inserts for your NOE sizer. The benefit of it, is you can have a variety of sizes inexpensively. I’d get at least one size above and one below, besides the main size. Sometimes boolits don’t come out the exact size of the sizer in my experience.

[M.A.D]

I find all guns different... My 357 like the coated bullets at .357, My 38 Super likes .3563, My other 38 super likes .3560. Id ne concerned that your bullets are dropping out of the sizer 0.001 plus over the size of your sizer

[GregLaROCHE]

I find all guns different... My 357 like the coated bullets at .357, My 38 Super likes .3563, My other 38 super likes .3560. Id ne concerned that your bullets are dropping out of the sizer 0.001 plus over the size of your sizer

I haven’t really checked this closely, but I get the feeling that PCed semi hard boolits end up a little larger than the sizer, especially if I size down more than two thousandths. Maybe there is a spring back effect. As I said, I haven’t really looked into this. I’m not into spitting cards these days. If it went through the sizer, I’m confident it will go through the barrel.

[ioon44]

I just started casting for my Gold Cup. The bore slugs right at .451” so I ordered a NOE 452 sizer. The boolit is a powder coated 200 SWC (50/50 COWW/PB) and comes out of the sizer at .453+. Loaded with 4.0 grains Bullseye it is an accurate and pleasant load to shoot but I’m getting some lead streaks after just 30 rounds fired. I use the same process for all my PC…a PID-controlled bake at 400 for 25 minutes then ice-water quenched. There is no leading from my 9 or 10mm cast loads so I believe my PC process to be sound.

Question; can a bullet .002” over bore diameter defeat the ability of PC to protect the bore from leading as opposed to one that is sized .001” over? Or do I have a different problem here?

"PC…a PID-controlled bake at 400 for 25 minutes then ice-water quenched" this could part of your problem, try letting your bullets air cool and see if it helps. Bullets don't need to be that hard, I shoot Hi-Tek coated coww at around 10BHN with out any leading.

[mvintx]

The 452 sizer is the only one I have. I assumed it would be of the correct diameter and have spoken with a nice fellow at NOE. He said I could send it back along with a couple of my sized and unsized boolits for their examination.

After PC and before sizing they measure .456+. I wonder if the sizing operation could squeezing the PC down so much that it's not thick enough to protect the bore?

LaRoche - you could have something there about springback to a larger diameter. I'll have to try some air-cooled boolits to test your theory or maybe push a piece of pure lead through and see what happens.

ioon44 - I will certainly give that a try.

[RickinTN]

Or, run through the sizer before PC, and then again after. Also, as mentioned, let the bullets air cool. 45 ACP doesn't need a hard bullet.
Rick

[Valley-Shooter]

The 452 sizer is the only one I have. I assumed it would be of the correct diameter and have spoken with a nice fellow at NOE. He said I could send it back along with a couple of my sized and unsized boolits for their examination.

After PC and before sizing they measure .456+. I wonder if the sizing operation could squeezing the PC down so much that it's not thick enough to protect the bore?

LaRoche - you could have something there about springback to a larger diameter. I'll have to try some air-cooled boolits to test your theory or maybe push a piece of pure lead through and see what happens.

ioon44 - I will certainly give that a try.

456 sounds really big for any mould designed for the 45 acp. All mine cast .451 - .452.
Try to get that 456 down. What mould are you using?
Size before PC if you have to.

Sent from my Pixel 4 XL using Tapatalk

[jsizemore]

It's easy to do a pound cast of your forward edge of your chamber, throat , leade and barrel groove. If your sized bullet isn't at least as big as your throat, all the PC in the world isn't going to protect it from leading. You can try the softer alloy/pressure timing with the right powder thing, but it takes more work to find than making the bullet fit the throat.

I've got a couple barrels that have too small a chamber at the mouth and too big a throat to work any other way then time the powder to obturate the bullet base to fit the throat. Once it's figured it's easy to repeat. Bullseye is the right end of the powder pressure curve as long as the bullet is soft enough. I'm using Red Dot/Promo with the same alloy as you but air cooled. Bullseye does the same thing. Promo is about as cheap as it comes.

[Burnt Fingers]

I've shot powder coated pure lead through a 1911. No need or reason to have anything harder than say 10 BHN for a 45 ACP.

[GregLaROCHE]

I wasn’t wanting to imply that the NOE insert was not the right size, just that strange things can happen and we are talking about small differences. Part of what I think I have observed, may be to the amount of PC on my boolits. I probably don’t shake as much powder off as I should. Maybe it’s the excess PC that is causing spring back.

[JonB_in_Glencoe]

You should try your alloy without the water quenching and without PC...lube them.

[mvintx]

456 sounds really big for any mould designed for the 45 acp. All mine cast .451 - .452.
Try to get that 456 down. What mould are you using?
Size before PC if you have to.

Sent from my Pixel 4 XL using Tapatalk

It's a SAECO H&G 68. I don't remember the dropped size but it measures .4565 or better after PCing.

jsizemore, I'll try the pound cast of the throat. A visual inspection doesn't show much of a leade.

[mvintx]

OK, I understand now that water quenching is not required. The .45 is a new animal for me...never shot one, much less reloaded for one. Seemed a shame to let it sit in the safe and never see daylight when it was a favorite of the good friend who bequeathed it to me. If all the above recommendations don't pan out, I may look for a mold that drops a smaller boolit.

[megasupermagnum]

You either...

A: have an undersized bullet; pull a loaded one to see if brass is sizing them down

B: poorly applied powdercoat.

Simple as that. Different alloy won't fix this.

[white eagle]

your gun will tell you what it likes
use the over bore size as a guide, it may be your gun will like
boolits sized to the bore dia.or even something different

[mvintx]

You either...

A: have an undersized bullet; pull a loaded one to see if brass is sizing them down

B: poorly applied powdercoat.

Simple as that. Different alloy won't fix this.

I checked for the bullet being undersized during seating/crimping. I crimp the case mouth to .472". Bullet diameter is .453" plus .020" for the case walls. The extra thou' is to help feeding.

The powdercoat passes the smash test. I don't know how else to evaluate it except for recovering a fired round. I might have to do the water-filled trashcan recovery technique...that would tell me. But I hate to waste 30 or so gallons of water too.