how does a gun react to different projectile weights?

[Fixmy59bug]

I am new to reloading and just bought my first press (Lee Anniversary Single Stage on sale from Midway) and am looking at projectiles and I am seeing many different weights.

But how does the gun react to the different weights?

I understand that a heavier projectile will have more momentum behind it (it won't be slowed down as fast as a lighter projectile).

But does a heavier projectile cause more or less recoil and/or wear?

I would think a heavier projectile would have a slightly lower POI compared to a lighter bullet, is that correct?

What scenarios exist where a heavier projectile would be better, and what scenarios would you prefer a lighter projectile?

Thanks to all who offer help to a first time reloader.

[sofbak]

Rule of thumb that I have learned here is: to lessen recoil, go to a heavier bullet and a faster burning powder. worked for me.

Heavier bullets usually have a lower muzzle velocity in the "safe load range", so indeed the POI will be slightly lower, as it takes just a miniscule larger time to travel to the target. Thus a very slightly lower impact point since it has more time to fall toward the ground during flight. In most cases a difference so small that it will be hard to detect.

Heavier bullets only have more momentum (and kinetic energy) if the velocity is the same as the lighter bullet.

[Chief-7700]

Remember it takes more powder to move a light bullet. I can't tell the difference between a 155 grain LSWC and a 230 grain FMJ in .45ACP

[BLR81]

Choose you projectile based on the barrel and purpose. If your just punching paper, you can get away with a lighter bullet than if your trying to take down an elk or knock over a 50lb silhouette target.

Your twist rate of the barrel will determine the limits of the speed and weight of your projectile. Plan purpose first than choose gun, bullet and powder.

[sargenv]

Um.. the quote about more powder to move a light bullet is sort of silly...

It's not that it takes more powder to move the light bullet, it's more along the lines of "With a light bullet, pressure doesn't build up as fast as with a heavy bullet and you can use more powder to gain more velocity at the same pressure level.". If firing a single charge weight that is safe for the heavy bullet, you can likely fire a lighter bullet at the same charge weight and you will gain velocity (less resistance) and have lower pressure doing so.

I can certainly tell the difference between a 155 LSWC and a 230 FMJ loaded with the same amount of powder.. It becomes muddy when you load the 230 to max pressure and the 155 to max pressure.. the velocity of the 155 will "feel" the same since it is producing a similar amount of kinetic energy and using more powder to do so. The 155 at higher velocity will shoot "flatter" and will generally print lower on the paper than the slower moving 230 (which spends a little more time in the barrel). This shows itself to be more evident at farther distances.. say 25 yards and farther out.

[Ritchie8719]

Remember it takes more powder to move a light bullet

Isaac Newton, take the back seat and pay attention!

[kentactic]

A heavier slower bullet could potentially have a higher POI then a faster lighter bullet. It all depends where the barrel is pointed when the bullets exits. The vibrations from the explosion make the barrel vibrate. To try and type this all on my phone would suck. But deffinatly a faster burning powder and a heavier bullet will yield more recoil then a lighter bullet and a slower burning powder. Also primers come in different rates aswell and can have a big affect on velocity, accuracy and recoil.

[donnrcp]

Welcome to reloading! Safer than crack. Makes it easy for loved ones to pick out presents for you. My wife got me a Dillon 550 last year . A few years before that, the Sierra Ballistics. Here's a link to an online ballistics program: http://www.realguns.com/calc/exteriorballistics. Be safe.

[kentactic]

Much more precise and you can calculate all sorts of crap to confuse you some more.

http://www.jbmballistics.com/ballistics/calculators/calculators.shtml

[uhlan1]

What scenarios exist where a heavier projectile would be better


For me, shooting steel in 9mm.

[Fixmy59bug]

What scenarios exist where a heavier projectile would be better


For me, shooting steel in 9mm.

Mind telling a newbie why that is?

[Germz]

I am new to reloading and just bought my first press (Lee Anniversary Single Stage on sale from Midway) and am looking at projectiles and I am seeing many different weights.

But how does the gun react to the different weights?

I understand that a heavier projectile will have more momentum behind it (it won't be slowed down as fast as a lighter projectile).

But does a heavier projectile cause more or less recoil and/or wear?

I would think a heavier projectile would have a slightly lower POI compared to a lighter bullet, is that correct?

What scenarios exist where a heavier projectile would be better, and what scenarios would you prefer a lighter projectile?

Thanks to all who offer help to a first time reloader.

When stopping power is your goal.

[Bastard]

most of the time the bullet weight all depends on barrel twist rate, what the gun likes, how much you are willing to spend, what you can find in stock.... there are many different reasons to go heavy over light or vice versa

the easy way to figure out what your gun likes is to get a bunch of factory ammo all different weights and test... but then again that applied back when you could get a bunch a a fair price.

Mind telling a newbie why that is?

example with steel you would get a better report, or more oomph to knock over a plate.


as far a felt recoil goes... I feel that the lighter bullets tend to be more snappier, simply because they are usually pushed faster.... but that is all going to depend on caliber and what they are being shot out of.

POI might be said to be lower than with a heavier bullet.... but I have always looked at it as usually higher with a light bullet.




***and I think that your '59 bug is broken, but no worries, I will reluctantly take it off your hands... don't want you to get stuck with it now

[Fjold]

Man, there is a whole lot of stupid in some of the posts above! You people don't even know what type of firearm the OP is talking about.

OP,

In the front of every reloading manual there is a large section on internal and external ballistics and terminal performance. Try the Hornady reloading manual it has excellent information in it.

Read this before you touch any of your reloading equipment. After you get done reading it, read it again.

Are you reloading for a rifle or pistol?
What is the intended use for the gun?
What distances will you be shooting at?


Recoil is generated by the mass of projectile exiting the bore and it's velocity, the mass of the projectile includes the weight of the bullet and the amount of the burning gases and unburnt powder exiting the bore.

Felt recoil is the combination of the above recoil plus how the weight of the gun being shot, how the gun fits you and your shooting technique.



As far as point of impact variations with projectile weight goes, it depends on the range being shot, whether it's a rifle or a handgun being shot, the individual barrel's characteristics and reaction to different bullets, the difference in weight of the bullets as well as the difference in velocities of the different bullets.

[bruceflinch]

^ Nicely said Frank.

Isaac Newton, take the back seat and pay attention!

103 posts of stupidity. Do you ever have anything to really contribute? I haven't seen it yet.