Substituting Bullets With Other's Load Data

[sandspider500]

Here's a 45 colt load fired from a 20" rossi 92 barrel. The bullet used was cast from zinc using a lee 452 230 tc mold. The load used was extrapolated from Lehigh defense data. The bullet weighed 144gr. Seating depth was adjusted for the load.

Description: lee 230tc zinc
Notes 1:
Notes 2:
Distance to Chrono (FT): 0.00
Ballistic Coefficient: 1.000
Bullet Weight (gr): 0.000
Altitude (FT): 0.0
Temp: 82 °F
BP: 1011.00 inHG
Shots
# FPS FT-LBS PF
4 2364 0.00 0.00
3 2330 0.00 0.00
2 ERROR 3
1 2348 0.00 0.00
Average: 2347.33
StdDev: 17.01
Min: 2330
Max: 2364
Spread: 34
True MV: 2347.33
Shots/sec: 0.07
Group Size (IN): 0.00

 

[sandspider500]

Lyman 357 magnum data. One bullet is 40gr heavier, so it should get less velocity at the same pressure.

Hmm...these loads look very similar, anyone like to take a guess why?


Here's a clue.....

 

[Hvymax]

On the left is a 45 colt case, it measures 1.278, on the right is a 9.3x74r case that has been fire formed and then loaded and shot with a 451 345gr ssk in a 45/410 shot chamber. This load was extrapolated from 45/90 and 458 win mag data and it does not exceed the limit of my firearm.
It measures 2.840 and is still short in the 3" chamber. The colt case is 2"+ shorter. That's a big jump, in a hole that is larger than the bullet.




Both 220gr bullets from Lehigh are soft enough to take the rifling. By the time it hits the forcing cone the pressure is way down. In this particular case, the brinell hardness has no effect on the MAP of the load. Fast pistol powder is used, there is no secondary pressure spike bigger than the initial one that launched the bullet in the first place.

When dealing with handgun cartridges, the biggest factor that effects pressure is the seating depth. All copper bullets are substantially longer than an equal weight jacketed or lead counterpart. When dealing with an oal that is limited by a magazine or cylinder.

From left to right
263gr 45, 296gr 45, 185gr 45 Barnes xpb, 115gr 355 Barnes xpb, Lyman 358156, mp 360-640 hp 145gr, mp 357 130gr rn.

The copper bullets are much longer than a cast or jacketed bullet. The 185gr Barnes bullet is longer (.727) than a 300gr bullet (.712). The 115gr Barnes bullet is longer than a 163gr bullet of similar diameter.

So it would be foolish to use load data for a 115gr jacketed bullet(which is much shorter!!!) for a Barnes bullet loaded to the same length, as the Barnes would take up much more case capacity. If loaded to the same seating depth the Barnes would be too long to fit the magazine. If a Blackhawk 9mm cylinder were used, then no problem.

Powder selection can play a part as well. A denser powder takes up less space allowing for deeper seating depths. A very lightly compacted load is ideal for consistency and accuracy. So I will frequently deep seat a bullet so it lightly rests on the powder.

 

[Hvymax]

The ssk load fired from a 45/410 19.5" barrel.

Those would be perfect for a Judge/Governor!!!

 

[Hvymax]

Lyman 357 magnum data. One bullet is 40gr heavier, so it should get less velocity at the same pressure.

Hmm...these loads look very similar, anyone like to take a guess why?


Here's a clue.....

In this case I would look at the H110 along with the few that are used in both. The biggest variable between these projectiles is that the FTX has a much heavier jacket to hold up to rifle velocities and the JHP has a thinner jacket and a soft lead core and would fly apart on impact at rifle velocities.
When I started loading for 350 Legend and 450 Bushmaster I used standard 9mm & 45acp bullets for a lot of my initial loads because I had them laying around. Regular JHP's would pretty much disintegrate in the first jug with the base making it to the second. FTX's would mushroom nicely and end up in the 4th jug.

 

[sandspider500]

Those would be perfect for a Judge/Governor!!!

That would be fun.