Starting Point?

[Para-DocX]

Being new to reloading, I wonder if it is possible to derive some sense of how a load will perform (felt recoil, accuracy, etc.) based on the data found in resources like the Lee Manual. Is muzzle velocity the most significant factor or is it pressure that one should consider to anticipate the comparative performances of different recipes?

[revchuck]

This is a tough one to answer. There are a ton of variables that affect velocity and accuracy, and not all of them are connected to the load itself.

The factor that's most likely to be predictable will is velocity, but even that's kinda squooshy. Some manuals use pressure barrels to determine velocity; these tend to give higher velocities than actual firearms of the same barrel length due to the fact that pressure barrels are made to absolute minimum industry standards dimensionally, which tends to increase pressures, which in turn tend to increase velocities. OTOH, some manuals work up their loads in pressure barrels, and then chronograph them in regular guns, but there is so much variation among even identical guns that determining velocities from your gun is pretty much an educated guess.

Relative felt recoil can usually be estimated by looking at the powder charge - lighter charges give less recoil, even at the same velocity. This is due to different burning characteristics among powders and to the fact that the weight of the powder charge is part of what comes out of the barrel. Shooters in the "practical" sports tend to use faster powders which give the velocities they need at relatively low charge weights due to this; they also tend to burn more cleanly, which helps maintain reliable function.

Accuracy is something your gun determines for you. We talk of "letting the gun tell us what it likes"; this is not a phony Zen statement, but an acceptance of the fact that different guns have different preferences. There are some loads which usually work well in different guns, but you can't accept this blindly - you have to make sure your gun likes them too.

Pressure indirectly affects accuracy. Most powders have a range of pressures in which they work best, and the width of this range varies among powders. Staying within the range of charges in the manual usually keeps you out of trouble in this regard. Also, lead bullets require a certain level of pressure to shoot well, and this level depends on the alloy used; softer alloys (swaged bullets) work better with lower pressures, harder alloys (commercial cast bullets) work better with higher pressures.

The way most of us do it is to consult the manual, looking for loads which give about the velocities we want with the powders and bullets we have. We'll start a little below that level and load some ammo there, and at several increments above it (not exceeding the max charge), take them and the gun to the range and chronograph them. When we get the velocity we want, we'll shoot it for accuracy. If it meets our standards, most of us stop there, although some prefer to try other powders and bullets to squeeze just a little more accuracy out of the gun.

Bottom line: While checking out the manual gives a good and safe starting point, the only way to see how a given load performs out of your gun is to shoot it in your gun. If you're worried about velocity, the only way to determine the velocity of a load from your gun is to chronograph it from your gun.

[fenwick]

I wouldnt consider any load developement without

a chronograph. I have always found accuracy will

peak before max velocity.

[DougCarden]

IMHO....the best way to learn is to find someone you shoot with that is an experienced reloader, and they can literally show you ammo or load it to demonstrate slower powder vs. fast powder, etc.

Nothing wrong with the book, but read the books and find experienced people to learn from as well. Remember, some people will teach you what not to do more so than the other.....

Good luck on your journey,

DougC

[bgary]

I think, too, one of the subtexts to the question is "is there a science to reloading, so that you can predict what the effect will be when you change one of the variables?"

The answer is "no, not really". Reloading is a fascinating blend of science and voodoo. There are some things which are linear and predictable, but for every one of those there are five things that are... inscrutable.

Case in point: I loaded up a number of small test/chrono batches of ammo over the weekend. Same bullet, same case, same powder, same overall length, same everything *except* powder charge, and those were a linear range. (e.g., 4.0gr, 4.2gr, 4.4gr, 4.6gr, etc).

I would have *expected* to see a relatively linear range of velocities, and not too many other differences. What I got was that the first two batches had almost *identical* velocity averages, but wildly different spreads. The 3rd batch had slightly (like, 3%) higher velocity but *great* consistency. the 4th batch was as dirty as any load I have every fired, greasy black soot all over everything. And the 5th batch had a really unpleasant "recoil impulse" - snappy, harsh movement.

Could not have predicted any of those things by plugging numbers into a formula. You just gotta try 'em.

B

[vluc]

Add to all that our individual perceptions of how that load feels, and what is a nice snappy load for me might be a bear for you - and vice versa.