School me on LFN nose-length differences

[outdoorfan]

For the .45 Colt and 280-300-ish weight plain-based running around 1100 fps. What would be the preference between the .4 and .45 nose? Ruger Blackhawk.

[stubshaft]

I shoot the 300gr LFN out of my NMBH and FA83 454. The nose measures .45".

[bobke]

http://www.montanabulletworks.com/pistol_bullets.html

pretty good reference on nose length for a variety of bullets. meplat diameter not shown, but lbt site should get you there.

[outdoorfan]

Thanks, gentlemen.

To simplify, I'm wonding what the preference between a .4 nose and a .45 nose would be in the above-mentioned weight range as it relates to stability and accuracy? Maximum range that I would potentially be shooting this boolit at would be 150 yards.

I'm guess the shorter nose would be the better choice, so I'm looking for confirmation along that line.

[outdoorfan]

I shoot the 300gr LFN out of my NMBH and FA83 454. The nose measures .45".

Is that gc or pb, and what velocities do you shoot it at?

[anachronism]

Thanks, gentlemen.

To simplify, I'm wonding what the preference between a .4 nose and a .45 nose would be in the above-mentioned weight range as it relates to stability and accuracy? Maximum range that I would potentially be shooting this boolit at would be 150 yards.

I'm guess the shorter nose would be the better choice, so I'm looking for confirmation along that line.

I may be missing your point, but these dimensions are for bullet nose length, and are most commonly matched to revolver cylinder length. For example, I cast a 300 gr WFN for my Super Redhawk. The nose length of my mould is .4, I specified this length to hedge my bets, because I plan on getting a short barreled revolver for a belt gun. S&W 629 max out around .4 on the nose length, where my Super Red maxes out at .5. I did not want a $100.00 mould that would only fit one revolver. My next planned mould will be a LFN with a .5 nose for (hopefully) long range shooting. As far as bullet balance goes, the longer nose bullets put more of the bullet weight forward of the case. This decreases the length of the bullet that remains in the case for a given weight. This makes the volume of powder space in the case larger, allowing more powder to be used, with careful experimentation. This translates into higher bullet velocity, because the std 44 mag case "thinks" it's a larger case than it is, because the bullet doesn't take as much case room. There are limits to what you can accomplish, but it does allow higher velocities with heavier bullets. This is why LBT claims higher velocities, with higher bullets. Clear as mud?

[outdoorfan]

Thanks for the explanation. Yes, I do understand how having more lead outside of the case means higher velocity potential. I don't think that's my goal because I'm not looking to hot rod these. However, it will mean that I can make my goal velocity of around 1100 with less pressure. My guess is that having more nose on the boolit means it'll need to be driven faster for optimal stabilization. But, I'm not sure.

MTB's lists most of their .45's lfns with a .375-.4 nose.

[anachronism]

Only experimentation & load development will tell. Some guns rewrite the rule books to suit themselves.

[stubshaft]

Is that gc or pb, and what velocities do you shoot it at?


Gas Checked version. Out of the 454 I get 1759 fps chronographed ahead of 33.5gr WW296. I have taken it up to 36.5 but don't see a real need to push it that hard. In 41 tries it has never need more than 1 shot to drop game.

I don't load it up too hot in the LC but usually push it out at 1050fps. I prefer the longer nose version as it has a better BC. I have toyed with it on the silly wett range (casull) and get < 5" @ 200yds with iron sights.

[44man]

Yes, there are pressure changes but the difference in velocity is so small it is a waste of time.
Accuracy can be equal with either boolit and that is what you should look for. At the most, 1/2 gr powder difference between boolits is all you will find, maybe less. Each is capable of under 1" at 50 yards and that is much better then a 75 fps velocity increase.
A deer hit with either will never laugh at you for not shooting faster.
Drop at long range is so close, you waste time and energy again.
If you want a .454, buy one. Results over the .45 is only good for long range steel or larger animals.
The quest to push a boolit faster is really silly with the .45 because it is good enough as is.

[outdoorfan]

Okay, after thinking about this some more I realize I think I've had it all wrong as to what the longer vs shorter nose means. A longer nose doesn't necessarily mean more unsupported weight up front because as long as the ogive remains the same there would simply be more bearing surface ahead of the crimp groove as opposed to the bearing surface in the case.

If that's the case then a longer nose would have its benefits in being able to reach out and engage the forcing cone sooner to keep alignment secure. I then suppose the only way to know which design would shoot better than another would indeed be to simply try both and see.

[Changeling]

For the .45 Colt and 280-300-ish weight plain-based running around 1100 fps. What would be the preference between the .4 and .45 nose? Ruger Blackhawk.

To answer your question as written consider this. The difference in nose length if it will fit your revolver is the time/length to the forcing cone/rifling of the barrel. Different revolvers have different linear nose measurements that they can accept. In short the closer/longer to the end of the cylinder the better. This is normally known as the "nose to meplat length".
A preferred way to measure "exactly" what your revolver will accept is to take a fired case and reload it without the bullet or powder, I mean right down to crimping it correctly. Do these things exactly as I have said.
Then take a gauge and measure from the case mouth to the surface of the cylinder (fake cartridge loaded), this will be your absolute max distance from crimp groove to meplat.
Check by loading a dummy case to these measurements, leaving your self about 25 thousandths for anomalies such as bad casting, advise, and assure cylinder rotation without catching on the bullet.
The longer the nose, " crimp groove to meplat" will in cases need more velocity to stabilize itself correctly. This is something that will take some shooting of your loads (on paper) for you to discern accuracy with your particular firearm.

PS. Also pay close attention to everything "44MAN" has to say, he knows where accuracy comes from and how to attain it.