Bullet profile and powder charges

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Jbird45

Jbird45

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I looked in the front of my Lyman 50th for an answer but it's possible I could have missed it. Anyway, here goes:

I have recently loaded some .45 Colt with 8.0 grains of unique. I am using a .452 LRNFP 250 grain cast bullet from SNS casting, starline brass and Winchester large pistol primers. The SNS cast bullets are pretty much all I have available locally without ordering from the internet

Lyman does not specifically call out the bullet I am using, but I matched mine similar to the picture. I noticed there is another 250 RNFP but it appears to have 2 lube grooves instead of one and has different powder loads for it. Does the elimination of a cannelure and 2 lube grooves make that big of a difference? I ask because they state with unique that 8.2 is a Max load and I am at 8.0. Being that close to Max and seeing the different data for same weights and general profiles is making me a little nervous. I don't want to assume anything and then pull the trigger on a hand grenade.

Basically I am asking am I ok to assume that my bullet, although not made in a Lyman mold, is safe to use with their data because it is similar? I didn't think lube grooves would affect powder charges.

These will be used in a .45 Colt Ruger new Vaquero.

Sorry if this is a stupid question or has been beaten to death, I tried searching the forum and didn't find much.

I know safety is my own responsibility and I, and only I, am responsible for my actions, but I would like to hear from more experienced reloaders than myself. I have had bad experiences in the past when I have made assumptions, and reloading is not the time for assuming.
 

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Pressure is a function of, roughly:
1st order: case volume and bullet weight
2nd order: lead vs jacketed
3rd order: bullet profile/driving band length

Within a couple or ten grains of projectile weight, you can substitute any other close cast bullet data, and work up. Profile of the cast bullet is such a small effect on pressure that it doesn't hardly matter.

Additionally, max loads with cast bullets are frequently (but not always) set by max useful velocity for the bullet lube, not a pressure limit. You can find lots of cases where a jacketed bullet has a much greater max charge than a cast bullet of the same weight. . .
 
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New Vaqueros will readily and happily handle Tier 2 Ruger Only loads. They will not sustain Tier 3 Ruger Only loads, meant for the large frame Blackhawk and original Vaquero, but the Tier 2 loads are no slouch.
 
edwardware said:
Pressure is a function of, roughly:
1st order: case volume and bullet weight
2nd order: lead vs jacketed
3rd order: bullet profile/driving band length

Within a couple or ten grains of projectile weight, you can substitute any other close cast bullet data, and work up. Profile of the cast bullet is such a small effect on pressure that it doesn't hardly matter.

Additionally, max loads with cast bullets are frequently (but not always) set by max useful velocity for the bullet lube, not a pressure limit. You can find lots of cases where a jacketed bullet has a much greater max charge than a cast bullet of the same weight. . .
Click to expand...

Thank you. This would make sense why the bullet with 2 lube grooves in the manual has a larger powder charge than the bullet with a single groove even though they are the same weight and profile. I suppose if a bullet has more lube it can be pushed a little harder without major leading problems. I hadn't looked at it this way. Thank you for the response!
 
Hodgdon has this listed under General Warnings, Rifle,Pistol pdf.

45 Colt: 45 Colt data is listed in two categories. The first is intended for original Colt revolvers
and their replicas. Max pressure, is 14,000 CUP. The second category is 45 Colt (Ruger
Blackhawk, Freedom Arms and Thompson/Center Contender/Encore handguns. Max pressure,
30,000 CUP. Do not use these data in any other make or model of firearm.
Click to expand...

The Ruger only loads are for the Blackhawk. I learned something today. Thank you .
 
243winxb said:
Hodgdon has this listed under General Warnings, Rifle,Pistol pdf.



The Ruger only loads are for the Blackhawk. I learned something today. Thank you .
Click to expand...

Thanks for your input! The Ruger loads can also be used in large frame early Vaqueros made before 2005. The difference between the 2 is fixed sights on the Vaquero and adjustable on the Blackhawk.

The Ruger new Vaquero is based on a smaller frame and cylinder than the larger calibers. The new vaquero is slightly beefier than an original colt but is smaller in size than the Blackhawk or original Vaquero built on the large Blackhawk frame.

I have read an article in a recent magazine suggesting that the new vaquero, while smaller than the Blackhawk or old Vaquero can withstand slightly higher pressure than the original Colt's, but not Blackhawk loads. In their data they have listed tier one original colt loads, tier 2 Ruger new Vaquero loads, and tier 3 Ruger/T/C loads.

I personally do not want to load over the original loads, as I do not see a reason to push my gun to it's limits, but there is data out there if someone wishes to do that
 
So one last question here. If the data in my book for the double lube groove 250 grain has a Max load of 9.0 grains, I should have no worries of over pressure with 8.0 grains in my single lube groove 250 grain correct? I did notice my bullet style has a slightly shorter OAL, so maybe the charges are different based on case volume?
 
LiveLife said:
.45 Colt 250 gr Lead OAL 1.55" Unique Max 8.0 gr (850 fps) 11,800 PS
Click to expand...
Maximum SAAMI PRESSURE is 14,000 PSI. So the 8grs of Unique is below that.

Pressure may go up, the deeper the bullet shank goes into the case, reducing volume. If you seated & crimping into this groove, pressure should be ok. 20200108_094011.jpg

The Ruger is not going to blow up with 8 grs. Imo. I would shoot them.
 
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243winxb said:
Maximum SAAMI PRESSURE is 14,000 PSI. So the 8grs of Unique is below that.

Pressure may go up, the deeper the bullet shank goes into the case, reducing volume. If you seated & crimping into this groove, pressure should be ok.View attachment 883050

The Ruger is not going to blow up with 8 grs. Imo. I would shoot them.
Click to expand...

Thank you! I appreciate the input.

I was at the store today and was able to glance at the Lee manual as well. There starting charge for a 250 grain lead bullet is 8.4 grains, so I feel better about it now.

I'm still new to the reloading world, so I tend to ask questions first, shoot later.

Thanks everyone!
 

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Jbird45 said:
I know safety is my own responsibility
Click to expand...

Not a stupid question at all!

Sounds like the 2nd bullet is longer & so more of it sticks out of the case.

I'm no expert, but I play one on thr :eek:
I would feel safe with your load.
That close to the "max" even if you're wrong isn't going to explode.
Constant use may loosen up your revolver some over time.
But Rugers are built like tanks, so I wouldn't worry

Just my 2¢ worth YMMV
 
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