RCBS 45-270 SAA: Weight?

[mehavey]

I recently picked up an RCBS 45-270 SAA mould for my (3rd) Ruger 45 Colt in their New Vaquero.
Having several other RCBS moulds, RCBS name-designations were usually right on in terms of weight
(within the expected range difference of alloys).

This one was no different -- right at 266 grains using true Lyman#2 (90/5/5), and I'm adjusting my
QuickLoad record to modify a Lyman 255 Keith to that of the RCBS: 266gr & 0.711" length.

But......

Everywhere I look on the internet postings I see people saying the 45-270 actually casts
quite heavy (285gr+). Although I can adjust for the different specific gravities between pure
Lead and that of #2 alloy (11.35 vs 10.92), that still doesn't even come close to accounting
for the supposed difference. (In fact were I to take that 266gr actual #2bullet and cast
w/ pure lead, it would only come up to 276gr)

#2 = 266
1/20 Lead ~ 271.7
1/16 Lead ~ 270.4 (supposedly the RCBS Std for weight)
Pure Lead ~ 276.6

Am I missing something, or has the mould design changed over the years?

[Tatume]

My RCBS 45-270 SAA mold casts very close to 270 grain bullets of wheel weight metal. I think Brian Pearce started the rumor about the mold casting heavy, and everybody just believes it and repeats it. I'm with you, the mold casts what it says it will cast.

I've also found the front driving band to be too tall to fit most of my guns. Loaded ammo will not chamber unless the bullet is sized to enter the chamber throats.

I'm not very impressed with Dave Scovill's design.

Take care, Tom

[mehavey]

Chamber throats...They cast out at .455 w/ #2, but not-to-worry. I've sized to .452** and reamed out the last two Ruger cylinders to 0.4525". ;)
(about a half-hour job and very precise using Manson's reamer available from Brownells)

** Shooting this evening will tell me whether 0.003" is too much to size down

[detox]

Using 20/1 alloy my RCBS 45-270 SAA .454 diameter weighs 282.4 grains. I purchased mould new in 1995 from Midway.

.45 calibers are such lead hogs. I would much rather cast for .357

[donnie45]

My mold is a Mihec. It casts at roughly 285grs for the solid, 275 for the small hollow point and 270 for the penta hollow point. Maybe the folks reporting 285grs have a non-RCBS mold. All the above weights are with ww +2% tin.

[762 shooter]

As above.

285 for Mihec WW + 2% tin.

762

[mehavey]

Well, troops, definitely 266gr for the RCBS version of the 45-270, using #2. :lovebooli

Tatume: You are correct, the bullet's front cleaning band -- even sized 0.452" -- is a press-fit snug into the (New) Vaquero cylinder throat. Were the cylinder not reamed to 0.4525' I have little doubt that they'd not fit at all.

They do fit with no interference in the longer 5½" New Blackhawk -- but that's also reamed to 0.4525"

They also fit my old `73 3-Screw, even with factory cylinder throats... but that one came as-is at 0.452+" for some reason.

When did Ruger start reaming throats at only 0.450" ? (and why?)

[LAH]

285-288 for Mihec using WW or range lead.

275 for the NEI using 92/6/2.

I don't have the RCBS mould, they are 2 cavity.

[waco]

I just weighed five of mine and they are all 275 give or take 1/2 a grain. 86145