Has anyone tried using the same bullet but 75% of regulated propellant to see how it groups?

I think Cal has done the 75% bullet weight as well as the 75% charge with the standard bullet weight. Not sure what his findings were though.

Hi guys:
I've been doing this for some time. On average the groups are not quite as good as the standard method but it is acceptable for plinking and informal shooting. The nice thing about the reduction in powder and keeping the bullet weight the same is the use of cast bullets is easier as there is less fouling in the bore due to the lower velocity.
Cal

Thanks. This could be the answer Norsk is looking for.

Will th 75% rule work for 45-70 as well? I know it is not a true big bore safari round but it is what I have. I have sighted my 45-70 Baikal for 405 grain bullets so if I am understanding the 75% rule I should get a close group using a 305 grain bullet. Or am I daft?

quote:

Originally posted by zgunbear:
Will th 75% rule work for 45-70 as well? I know it is not a true big bore safari round but it is what I have. I have sighted my 45-70 Baikal for 405 grain bullets so if I am understanding the 75% rule I should get a close group using a 305 grain bullet. Or am I daft?

You correctly interpret the 75% Rule, use the powder load for the 405's.

However, I wonder if the 45/70 has enough recoil with the light bullet to make the rule work.

Only one way to tell!

Last question should I use filler since the 300 is shorter than the 405? Did more research last night and the same charge is listed for the 300 grain with no filler.
So I guess I answered my own question

After zgunbear's last question is answered, I've got another question to throw into the mix, if everyone doesn't mind.

If you reduce the powder charge by too much, are you looking at a potentially dangerous pressure spike, assuming same weight projo as recommended for the standard load? At what point does that become an issue?

Can that be a reason for sticking to the original 75% formula? It's something I've been wondering (and no, I'm not a hand-loader, so I understand it may not mean anything).

Shack,

I know there are powders which become dangerous when density is too low, and there are powders where dropping the charge is no issue. As far as which powders for which cartridges, I have always relied on the powder manufacturer's guidelines.

JPK

quote:

Originally posted by Shack:
After zgunbear's last question is answered, I've got another question to throw into the mix, if everyone doesn't mind.

If you reduce the powder charge by too much, are you looking at a potentially dangerous pressure spike, assuming same weight projo as recommended for the standard load? At what point does that become an issue?

Can that be a reason for sticking to the original 75% formula? It's something I've been wondering (and no, I'm not a hand-loader, so I understand it may not mean anything).

I have been reducing powder charges for 20-25 years and never a problem. However, I always put a filler in the case to keep the powder next to the primer for good ignition. I still do this with my big doubles when I go to the range and folks want to shoot them. I give them the reduced charge as many can't handle the recoil.
Cal

quote:

Originally posted by Shack:
After zgunbear's last question is answered, I've got another question to throw into the mix, if everyone doesn't mind.

If you reduce the powder charge by too much, are you looking at a potentially dangerous pressure spike, assuming same weight projo as recommended for the standard load? At what point does that become an issue?

Can that be a reason for sticking to the original 75% formula? It's something I've been wondering (and no, I'm not a hand-loader, so I understand it may not mean anything).

Yes to the bold above!

quote:

By Cal:
I have been reducing powder charges for 20-25 years and never a problem. However, I always put a filler in the case to keep the powder next to the primer for good ignition. I still do this with my big doubles when I go to the range and folks want to shoot them. I give them the reduced charge as many can't handle the recoil.
Cal

However, Cal is right! The danger of a flash-over causing a spike is headed off by the proper use of filler. The key word here is "PROPER". Very light charges in a large case without filler or the wrong kind of filler is not the best idea anyone ever had.

I have seen mentioned here on AR and many other place the use of Crème of wheat as filler. That is a mistake if used behind a bullet. Cream of wheat over a light load of very fast powder, with no bullet is used to fire-form cases to a chamber. That should tell you that if the cream of wheat develops a lot of pressure without a bullet, it may go through the roof,latterly, if a bullet is seated over it. The filler would be far better when using Dacron fiber as filler with filler slightly compressed by the seating of the bullet to hold the powder against the primer flash-hole.

The use the way Cal does it is fine, but some may misunderstand how he does it. The best policy is to just use the full charge with a lighter 75% bullet. I have pulled the solids from factory 470NE ammo and replaced the bullets with the handgun bullets for the 480 Ruger handguns. Works like a charm and reduces the felt recoil considerably.

Just one man's opinion, and worth just what the reader paid for it!

quote:

I have pulled the solids from factory 470NE ammo and replaced the bullets with the handgun bullets for the 480 Ruger handguns.

When fire forming with hand guns it's typical to use a lighter powder charge instead of changing the bullet.

One example might be working up a load for an Auto Mag pistol, the .41 JMP caliber to be exact. You start out low and gradually work up to a charge that will cycle the gun. The bullet in 41 magnum is supposed to be .410 bore diameter. The fire form load is actually more than 75%. Filler though is not done. You just go on and use the same bullet as with the full load.

All of which made me think about trying to do a reduced 450/400 NE load using one of those .41 Magnum handgun bullets. Meaning, the original version of the 75% rule. But, I don't know of any bullets of the right weight for that. They'd be much lighter than 75%, like 210 gr and so forth. That's more like 50%.

Anyway, not much point in downloading the 450/400. The recoil's not that big a deal to start with. And it would totally screw up your scope settings, going back and forth between loads. That alone would discourage it.

Shack:
For the .450-400 at 75%, use Hornady 300 grain bullets for the .405 Winchester. I've been doing this for nearly 20 years. They work fine.
Cal

quote:

by MacD37:
I have pulled the solids from factory 470NE ammo and replaced the bullets with the handgun bullets for the 480 Ruger handguns.

quote:

When fire forming with hand guns it's typical to use a lighter powder charge instead of changing the bullet.

For fire forming there is no need to waste bullets at all! A small amount of powder with cream of wheat and a thin wad,on top, hold the pistol barrel up and fire. The case will be fireformed. This can also be fireformed in a fixture that uses a sizing die. However,the 75% rule has nothing to do with fireforming!

quote:

One example might be working up a load for an Auto Mag pistol, the .41 JMP caliber to be exact. You start out low and gradually work up to a charge that will cycle the gun. The bullet in 41 magnum is supposed to be .410 bore diameter. The fire form load is actually more than 75%. Filler though is not done. You just go on and use the same bullet as with the full load.

There is also no need when fireforming to cycle the handgun either, as above the cases are fireformed, so they can then be loaded with your full load to shoot.

The 75% rule has nothing to do with pistols anyway. The rule is for light regulating loads for double rifles.

quote:

All of which made me think about trying to do a reduced 450/400 NE load using one of those .41 Magnum handgun bullets. Meaning, the original version of the 75% rule. But, I don't know of any bullets of the right weight for that. They'd be much lighter than 75%, like 210 gr and so forth. That's more like 50%.

Anyway, not much point in downloading the 450/400. The recoil's not that big a deal to start with. And it would totally screw up your scope settings, going back and forth between loads. That alone would discourage it.

For the 450-400 cheap bullets from Hawk for the 405 Win for practice, and stump shooting, because as you say, there is no need to reduce the recoil of a 450-400NE double.
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I am currently using 300 grain Hawks in my 450/400 3 inch. I am usin the same powder charge, Norma 203B with soft foam filler that I use for my 400 grain bullets. Accuracy is as good as the 400 grain loads.
I'm a believer. Thanks to Tony Black for coming up with the idea.

Mac, my reference into handguns was a poor analogy. What I was doing there was a one time only fire form to furnish a case to a reamer maker. The bullet you intend to be shooting was supposed to be used for that. There's a standard fire form charge for that too, which just happens to be roughly 75%. I would never be loading a batch of fire formed cases as they now have factory Auto Mag cases. There was however a time when you had to cut down 30-06 brass and roll your own.

So you're absolutely right, the 75% rule has nothing to do with handguns that I know of either.

Anyway, for the same reason I imagine few opportunities would arise to do fire forming for the 450/400.

So what is your favorite "standard" 450/400 charge and bullet? Would you duplicate Hornady's factory load? Let's say, you wanted to use it for deer stateside.

Update:
The 75% rule works for 45-70 as well. 300 grain bullets shot same point of impact as 405 grain. Now just have to get more bullets to load and shot it more.