Dedicated PC molds

[338RemUltraMag]

This PC is quickly gaining in popularity, and after playing with it I can see why! I plan to cut dedicated PC molds that drop UNDERSIZE these will also be flat sided. My question is just how undersized should they be?

Should it be .002? This is my thinking but I am super new to the PC operation.

To start we will use molds that are already available, this will allow a GB to run with as little as 5 people. But I need some feedback from you PC enthusiasts.

Joshua

[Beagle333]

Speaking only for me... if I had one that was cut undersized, I'd probably drop it too small most of the time. I often have trouble getting my Lyman 358xxx's to actually drop a bunch of em in a row at .358 because it isn't all the time that I got the alloy perfect and the mold/melt temp balanced just right. :oops:

[338RemUltraMag]

If it was a PC only mold then you add the PC which would bump it back to desired diameter right? Or would you prefer a regular diameter bullet with smooth sides.

[Beagle333]

If it was a PC only mold then you add the PC which would bump it back to desired diameter right?

Yes. That is correct..... if it drops exactly.
Powdercoating (the way I do it) usually adds .002 to the diameter.
But if I wanted a finished boolit at .358 and I bought a .356 mold, and the weather was colder, or I wasn't paying attention to my cadence the whole time, or if I'm using range scrap of unknown alloy... I could be dropping .355 a lot of the time.... and I'd end up small after coating. Even when I use the custom molds (most of which are .360 molds), and I coat and end up with .362 boolits, this stuff is so slick that it slips right through the sizer so easily that I have to check to make sure I screwed the right one in the press, even when sizing down from .362 to .358 :-D

Now... I have not used a grooveless boolit, so I don't know if they would size that easily or not, you'd have to wait for a couple of the guys who are shooting those to weigh in on how a solid boolit affects sizing. :coffeecom

[popper]

Can't size UP. Regular size with precautions of the NOSE size. SWC no problem but RN or TC I'd drop the diam. of the nose ~0.003 like a just barely SWC. Same for a bore rider where you don't size the bore riding portion.

[doctorggg]

Can't size UP. Regular size with precautions of the NOSE size. SWC no problem but RN or TC I'd drop the diam. of the nose ~0.003 like a just barely SWC. Same for a bore rider where you don't size the bore riding portion.

I agree with popper.

[338RemUltraMag]

Ok, thanks for the insight, I have a few cherries and people have been asking for pc molds but I was not sure how to move forward on that.

So it is best to start with the diameter you DESIRE then PC then size again to desired diameter.

[Beagle333]

IMHO, yes. 8-)

[Bullshop Junior]

That seems like the reasonable answer to me. If be happy to test any molds you make free of charge.

[alfloyd]

I agree with popper, also.
The only mold I would like is a bore rider for 30 cal. with a smaller nose section (0.002 to 0.003 inch.).
I would use it in my 308, 30-06 30-30 and 300 blackout.

Lafaun

[Super Sneaky Steve]

Can't size UP. Regular size with precautions of the NOSE size. SWC no problem but RN or TC I'd drop the diam. of the nose ~0.003 like a just barely SWC. Same for a bore rider where you don't size the bore riding portion.

Today I tested some TC .45 Auto rounds that had the PC treatment. I did have quite a few failtures to feed. The pan lubed bullets always shot fine. You may be on to something there.

[popper]

Alfloyd going to use the 31-165c in 308 & 30/30, when I get it.

[totalloser]

A dedicated PC mold will be HP if under .40 cal. Just too hard to balance them otherwise. Straight sides and .001" undersize from cast final ideal, no more. This will give a PC .001" over in theory, but even ES PC is NOT consistent enough to count on that thickness IMO. They *should* be sized to eliminate these irregularities, and also to catch casting goofs (fatties) which can be sneaky. Besides, it takes virtually *no* time to size in a Lee sizer. I'd be tempted to have them drop *at* size so that they will still work for those that like .001" bigger- like 9mm's that like .358" in cast.

I haven't found what I want on the market, but once my foundry refractory (weeks of foot tapping) dries so I can fire it that will be a different story. Last doodad to machine my own cherries is sitting down at the PO right now, found the packing slip on my way home tonight. :D

From a manufacturer point of view, I'd want to make *sure* that they wind up oversize and require sizing. Otherwise the risk is there that someone gets an iffy coat that doesn't bond and leading buildup from shooting these leads to an overpressure gunmetal face painting. If the customer *has* to size the boolit, they are much more likely to spot a problem. I routinely catch irregularities that get tossed in the remelt bin that were impossible to spot before sizing.

[donhuff]

My vote is for a standard size like non PC bullets. I also vote for a reduced dia. on a bore riding nose section that does not get resized.

Also to consider. How about a slight bevel base to reduce the fillet that is made on the base, when PCing. My bevel base bullets do not suffer from this problem.

They are not any harder to size, than a regular bullet with grooves is. But I do give them a light spraying with silicone to make it easier. I do that with all my cast bullets too.
97657
97658

[popper]

Got the mould USPS today. Was going to do brakes but I think I'll cast & coat a bunch tomorrow. Gonna be cold & rainy anyway, wife's out of town skiing. I'll actually get something done.
Edit: Couldn't wait. DTPC with HF red for the 30/30 & compare with my normal.

[338RemUltraMag]

Well guys, if you have a dedicated design that you would like let me know so we can work up a drawing!

[Maximumbob54]

I would only try one if it dropped normal size and during sizing I would make sure I'm evening out any thicker coating. I like the idea but the only reason I can see for this is if they dropped from the mold like magic. That would speed up production for more shooting pleasure later... Likey.

[popper]

slight bevel base to reduce the fillet that is made on the base, when PCing
Maybe a thin short shank like a GC design? 45 deg. to the band? No washers needed?

[donhuff]

The little fillet gets sized down and is not a problem on the side of the bullet. But then it tend to make "wings"(?) off the base, with one side always longer than the other. The bevel base designs I have do not do any of this as the powder kinda blends away on the bevel section. I usually set the bullets on screen wire over wire cloth, and do not have this problem cause the majority of the powder can fall through the holes in the wire, and I can reuse it. That's with 35 and up pistol bullets. But 30 rifle bullets dont want to stand up well on the screen, and I have to use alum foil.

[garym1a2]

How about the old 45 acp, 200 gr swc design with the lube groove removed.

Well guys, if you have a dedicated design that you would like let me know so we can work up a drawing!

[Bullshop Junior]

How about the old 45 acp, 200 gr swc design with the lube groove removed.

I'd go for a RF design. 230gn

[popper]

Results for the A31165C. Shot in 30/30 & 308 with 16 gr of 2400 (~1600 fps?), HF red ( came out almost like ESPC) D-T PC'd, NO GC, my rifle alloy. Not a particularly good shooting day but groups much better than A31165B, same load in 30/30 ('B' was terrible!). Back is tired from leaning over the bench to shoot. Now if I can get the AR to cycle @ 17 gr?
98045
98046
100 yds.
Shot off bipod & rear bag. Usually do a lot better with the full load 308 A31165B (1 1/2 MOA). I made the L.G real small & moved toward the nose, no C.G., drops 166gr. I'll load & GC some full power to compare.
edit:
98361 Add a target @ 50, from 30/30. LvrE is really slow fine grain powder (like 335) to prevent base damage. PB just doesn't cut it. A31165B is better. Did same test with 2400, not even worth posting. Evidence enough for me that the longer rear band, minimal L.G. & GC shank definitely improve performance. Gets me to wondering is a short shank on pistol might make better bases and drop easily. Most of the vertical stringing in the second pic is me breathing. Saw that the weight I strapped over the H.G has slipped to the G.B but mostly my lousy shooting that day.

[Maximumbob54]

Come to think of it if a slick sided 9mm mold that dropped 135gr bullets were to come up for sale I would be all over that. The more cavities the better. Maybe a round nose or a round nose flat point or even a TC.

[Oreo]

338RemUltraMag,
There is no one-size-fits-all caliber reduction for powder coat molds. There are different needs for different cartridges based on the various gun manufacturers' tolerances. However, here's an example that may help.

44mag is actually a .429" bore. Normal cast boolits would drop between .430" and .432". But some guns need a .434" boolit so the trend in semi-custom mold making has been to cut cavities larger. Lyman and Lee aren't doing it so there's a market niche being filled by the cutom shops. .432" molds are being cut closer to .433" or optionally .435", and so for all calibers. Now, consider a proper powder coat mold for a gun that really only needs .429", .433" is doable but excessive. The mold should drop .431", powder coat brings boolits up to .433", and then they get sized down to .430".

The point is, the molds still need to cast over-size but not as much. You'd also do well see if a particular cartridge / boolit benefits from having a larger size available as an option. This is common in 44mag as I described above. Also common with 9mm/357mag/38sp molds.

I also concur with the other gentleman's suggestion that the unsized nose portion of the boolit needs to be designed to account for the added thickness of the powder coat.

[VHoward]

I would go for a 230 grain round nose .451 size as cast 4 to 6 cavity mold.

[popper]

molds still need to cast over-size but not as much
One of the reasons I left the groove in the 30 cal mould. A place for the Pb to go when sizing. It drops 0.312. Groove is like 0.02 wide & 0.010 deep. Still see it after coating & sizing ( 0.311 & 0.310). Slugged it @ 0.309 & 0.304 as measure with calipers.

[Boogieman]

How about the old 45 acp, 200 gr swc design with the lube groove removed.
I removed the grooves & bevel base from a Lee 200gr.SWC (H&G clone) PC'ed them with HF red DT'ed. They came put at 218gr. grouped 1.5" at 50ft. 2 hand standing , about the best this gun does.(1991A1 Colt)

[popper]

So far testing with the 31165B & C shows progress. Same design but groove is moved up (tiny) & nose a tad smaller on C. Shooting @ 100 get <2 MOA on a windy day with 'C' 16,17 & 18 gr. 2400 NO GC. B (no GC) does ~ the same @ 50 with slower powder, a little better @ 100 with CG, hotter load - 2400+ fps. Didn't Chrony the B this time but should be 1800? Somebody with QL could estimate (308 win). My idea of a good strong rear band & 'heeled' (GC shank) base is apparently valid. I do need to verify with 4895 stick powder (base peening?). I did a 9mm 126 gr with thinner groove but probably should have just eliminated it. It does have a BB and is very accurate (same as jacketed but I only shoot 25 yds or less). If I get around to playing more with pistol boolit design, I'd probably do the short shank 'heeled' thing, no groove and stepped nose (SWC style) to eliminate chambering problems. Actually, the C that I was shooting were culls with not quite perfect bases that I was going to shoot in the 30/30. Also going to try it in a 300BO next month. Nose profile is the same as a Rem 220 BO jacketed so it should fit with the drive band at the bottom of the neck ( GC in the shoulder). Now to find some powder between 2400 & 335.