BACO's mould designations

[TexasMac]

I believe I understand some of the obvious bullet mould designation suffixes that BACO uses. Examples of moulds listed are: CX (Creedmoor), PX (Postell), MX (Money Bullet), etc. What I’m not clear on is the final numerical character meaning. For example, listed are Creedmoor bullet moulds with suffixes C1, C2, C3, C4 etc., and Money Bullet moulds with M1, M2, M3, etc. Since the complete mould designation includes the expected bullet diameter & weight, what does the last character signify?

Wayne

[Michael Rix]

If I remember correctly;
The number indicates how many full diameter driving bands vs the reduced driving bands. M1 would have all full diameter bands

[TexasMac]

Mike,

Thanks for the very helpful hint. I just checked a bunch of BACO moulds. With a couple of exceptions it seems the numerical suffix indicates:
X1 - No bands reduced
X2 - Tapered 1st band
X3 - 1st band reduced
X4 - 1st two bands reduced
X5 - 1st three bands reduced

When BACO decided to list the bullet I designed (410410M3) for the Browning BPCR I wondered about the M3 suffix. But with the 1st driving band reduced it correctly falls in the designations above.

I did find one exception. The 409400M4 is described as the Jim Kidwell designed bullet with the 1st three driving bands reduced, which would normally have a M5 suffix. The "Kidwell" bullet must be special. It does seem to work especially well in my Shiloh .40-65; thumb seating into a fireformed case without any resizing.

Wayne

[Michael Johnson]

TexasMac what is the as cast nose diameter of your bullet 409400M4 as they come out of the mould? I have a Highwall 40-65 with a .399 bore. I have been looking for a mould to get a little more powder capacity.

[TexasMac]

TexasMac what is the as cast nose diameter of your bullet 409400M4 as they come out of the mould? I have a Highwall 40-65 with a .399 bore. I have been looking for a mould to get a little more powder capacity.

Mike,

Using 16:1 alloy the nose measures approximately 0.3995" & 0.4000" using 20:1 alloy.

Wayne

[Yankee Bill]

TexasMac,

I thought that higher tin content yields a larger diameter.

[TexasMac]

TexasMac,
I thought that higher tin content yields a larger diameter.

Yankee Bill,

You are correct. The correct answer is:

Using 20:1 alloy the nose measures approximately 0.3995" & 0.4000" using 16:1 alloy.

Given the same mould, generally the harder the alloy or bullet the larger the diameter. Thanks for catching my error.

Wayne

[Clarence]

Michael,

Jim will cut the bullet diameter to your specs. I had him do mine to 0.408", vs. 0.409". I expect he would cut the nose slightly smaller if desired.

Like TexasMac said, this bullet shoots very well in the Shiloh chamber.

I seat mine to 3.170" OAL, with a 0.060" poly wad and enough Swiss 1-1/2 to give me 0.160-0.170" compression. Either unsized or sized cases with a 0.408" expander plug (for ~0.001" neck tension) work equally well for me. I can feel the reduced band engraving for close to 1/8", with the final 0.030" or so seating as I close the block. Wiping with 1:10 NAPA cutting oil, I leave patches just wet enough that one can see a bit of liquid in the bottom of the chamber; chamber mopped. This generally is sufficient to manage fouling. I don't clean during the day, so run 2 patches just before I begin the next relay. On a very dry, hot day, I either leave a bit more liquid on the patches or run an extra patch if I feel a rough spot in the forward 6" of the barrel.

I have an extremely scientific way of controlling the patch wetness. I put enough patches for a relay, with extras, into a sandwich baggie, pour in the wiping fluid, then squeeze the patches between my palms and pour the excess liquid back into the bottle. After a couple of matches, it's second nature to get the right wetness. I guess I could get even more scientific and weigh wet and dry patches to determine how much liquid per patch I would need, but that seems like a futile exercise.

Clarence

[TexasMac]

Clarence,

What alloy are you using with your 409400M4? With 16:1 my bullets start to engrave (contact the leade) at 3.125" OAL. So I've been loading to 3.110" which results in a lube groove just in front of the case lip to minimize the possibility of lead collecting in the 45 degree transition step. BTW, that's using 60gr of Swiss 1.5 with a .060" vegi wad, resulting in about 0.070" of compression. By adding another 3 or 4 grs, I could load them to 3.170" OAL & use the breechblock to seat them hard into the leade, which would result in a driving band in front of the case lip.

I made a chamber cast & reported the details here some time ago. The chamber is exactly 2.1" long, which is what my fireformed cases are trimmed to. The 45 degree transition step is only about 0.013" long, so it's most likely too short to collect enough lead to worry about. Just thinking out loud.

Wayne

[Clarence]

Wayne,

I use 1:16 alloy. My testing showed better accuracy with it than 1:20, so was likely getting more slumping with the softer alloy.

My tests also showed that accuracy improved as I seated the bullet further into the lands. This was particularly true with unsized cases. I believe that allowing bullet jump with finger-seating gives less consistent ignition.

I'm probably engraving for at least 0.050-0.060", although I've not measured it exactly. Because of the smaller bands, it's not difficult to push the cartridge into the chamber to the point that the block can do the last 0.020-0.030". No problems with this method when wiping; I don't own a seater.

Clarence

[kenny s]

HI Clarence.
when are you going to give classes? you're advice has proven correct for me at least.
Thanks for sharing the knowledge.

Sharps shooting 101. yup..you'd make a great prof!
Ken

[gunlaker]

One thing to be aware of, at least for the .45 cal molds. The noses are not all the same. My 458535M has a .452" nose while the 459535M has a .449" nose, so there is more going on than just the driving band changes based on the "M" number. Also some are standard groove dimensions and some are "mini".

Another interesting thing is that my new 459540M3 has only one reduced driving band, and even though it's heavier than the 535gr mold, the weight increase appears to be entirely in the nose as the length is the same as my 535gr mold.

Chris.

[gunlaker]

One thing to be aware of, at least for the .45 cal molds. The noses are not all the same. My 458535M has a .452" nose while the 459535M has a .449" nose, so there is more going on than just the driving band changes based on the "M" number.

Chris.

Oops... I typed that in backwards The 459535M has a 0.452" nose and the 458535M has a 0.449" nose.

They both shoot very well in the Shiloh chambers, but the 459535M sits deeper in the case because the ogive on the nose contacts the leade whereas the nose on the 458535M sits entirely in the bore.

Chris.