Differences in Reloading Manuals always amazes me

Not all 180gr bullets are the same. Some have a hard shell while others are soft, same goes for the core too. All impacts the charge.

Use the Speer data.

Maybe because Speer tested a 180 Gold-Dot Plated bullet in a 4006 S&W pistol.

And Lyman tested a Sierra Jacketed bullet in a pressure test Universal Receiver.

Reloading data: It's all in the details.

rc

Gold dots are jacketed:

http://www.speer-ammo.com/products/gold_dot_const.aspx

Uni-Cor technology bonds an incredibly uniform jacket to the core—one molecule at a time.

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Besides, then the data would be the other way around, with the jacketed bullet getting the heavier charge over the plated bullet

Uni-Cor technology bonds an incredibly uniform jacket to the core—one molecule at a time.

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= plated.

No, they are not jacketed.

bonds an incredibly uniform jacket to the core—one molecule at a time.

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That right there defines electroplating.

rc

You have to remember that, a lot of the listed loads are a bit calmer, than say, factory loads. I think they are sometimes lower as the company doesn't want the liability of having such powerful loads they end up ruining some guns!

As RC stated, each bullet/powder manufacturer uses different testing barrels/methods to determine minimum and maximum charges.

And Gold Dots, though the plating is much thicker than a standard plated bullet, is by all deffinition a plated bullet. A plated bullet that, depending on it's intended loading purpose, will handle full house magnum charges just fine. But as I stated, depending on it's intended loading purpose, Speer has clearly identified some of the Gold Dots as not being recomended for high velocity short barreled guns. For my .357 magnum applications I always look at the Speer part # to be sure it is one that's OK for full house magnum loads, rather than lower velocity 38 spcl or low velocity magnum loading, which is also consistent with the notations in my reloading books.They state that bullet deformation is possible, and personal experience in this area has proven to be true.

Something anyone can do at home is, use a fine hack saw blade and cut a 125 gr. or 158 gr. Gold Dot in half, then do the same thing to the 110 gr. and you'll see why not all Gold Dots are created equal.

The newer Speer data is a good amount higher also for the 380 auto. Then again they list pressures up to 20k, where most others stop at <15k or so.

They have to test things differently and use different components. If all the reloading manuals were the same, you wouldn't need but one and they would lose all that money every time they wrote a new one.

In reality it isn't all that much to taking load data for one bullet and work it into a different bullet. It's all about the bearing surface. The point of the bullet that never touches anything in the bbl has no affect as far as powder or primer.

They have to test things differently and use different components. If all the reloading manuals were the same, you wouldn't need but one and they would lose all that money every time they wrote a new one.

In reality it isn't all that much to taking load data for one bullet and work it into a different bullet. It's all about the bearing surface. The point of the bullet that never touches anything in the bbl has no affect as far as powder or primer.

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Not entirely true. You have OAL constraints due to the magazine, feeding, and occaisonally how the chamber is throated.

"Differences in Reloading Manuals always amazes me "

Yeah. It's enough to make a guy think reloading is more of an art than an engineered science, ain't it?

"Differences in Reloading Manuals always amazes me "

Yeah. It's enough to make a guy think reloading is more of an art than an engineered science, ain't it?

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Ding, ding, ding! Give the man a cigar!

+1 to Gold Dot being "thick plated" - http://www.speer-ammo.com/products/gold_dot_const.aspx



As to variations in load data, you need to look at all the testing variables used to measure chamber pressures for the published load data. When I saw start/max charge discrepancies that were significant between powder manufacturer and Lyman #49 load data, I looked closer to the details.

Lyman #49 on page 362 lists the 4" Universal Receiver's groove diameter as .401" instead of the typical .400" for .400" diameter jacketed 40S&W bullets and the load data for W231 shows higher powder charges than Hodgdon load data (probably due to more high pressure gas leakage around the bullet). BTW, Speer TMJ bullet used is a plated bullet.

Lyman #49 load data - 4" barrel, 1:16 twist, Winchester SP primer:
165 gr Speer TMJ W231 OAL 1.120" Start 5.2 gr (937 fps) - Max 5.8 gr (1050 fps )

Hodgdon load data - 4" barrel, 1:16 twist, Winchester SP primer:
165 gr Sierra JHP W231 OAL 1.125" Start 4.8 gr (946 fps ) - Max 5.3 gr (1001 fps)

Add to this different bullet type, pistol barrel lengths, groove diamter, leade length, rifling type, recoil spring rate, primer and OAL used ... you may deviate from published velocities/pressures quite a bit. Hence, I tend to lean to the side of safety and not try to push my luck too much. YMMV

I'm glad the manuals are all different -- it gives a reloader a reason to think through what he's doing instead of just adhering to a standard recipe without really understanding what all the factors mean and how they interact.

Choosing a standard low-end recipe and just following it is safe, and it's how everyone should start and learn, but it's through the rational application of sound principles and reasoned experimentation that reloading truly satisfies.

Quickload is your best friend for reloading data

Not entirely true. You have OAL constraints due to the magazine, feeding, and occaisonally how the chamber is throated

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But this has nothing to do with which primer or powder or powder charge weight.

As I stated, the part of the bullet that touches nothing has no effect on the powder or primer choice.

But this has nothing to do with which primer or powder or powder charge weight.

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How deep you seat the bullet can affect pressure. Sometimes OAL is stated as Minimum OAL. A different bullet nose may require deeper seating thus reducing internal capacity and affecting pressures.

The newer the manual increases the number of Lawyers that get involved.

I'll try this once more:
Two bullets with exactly the same bearing surface and base construction loaded to the same depth will have the same operating pressure no matter what the nose shape is.

If it don't touch anything it can't have an effect on pressure.

That's nice, but you don't have the luxury of doing that in an autoloader pistol (which most 40 S&Ws are).