Why over 300 gr

[JED]

A lot I read talks about projectile weights of over 300 gr. Why?
Does the lighter projectiles work just as well? Does it have something to do with ballistics? I am thinking the lighter projectile would shoot flatter. Is that true?

 

[rangerod]

The lighter bullet shoots flatter but only to a point. Down range the heavier bullet will retain its velocity better. The lighter bullet will loose velocity quicker. Also I find larger bullets to be more accurate at the greater range. Also some guns just seem to shoot bigger bullets more accurately. For hunting I think it depends on how far you intend to shoot. If staying within 100yrds the smaller bullet would be fine. Longer distance the bigger bullets. These are just my opinions someone else might disagree.

 

[ENCORE50A]

The lighter bullet shoots flatter but only to a point. Down range the heavier bullet will retain its velocity better. The lighter bullet will loose velocity quicker. Also I find larger bullets to be more accurate at the greater range. Also some guns just seem to shoot bigger bullets more accurately. For hunting I think it depends on how far you intend to shoot. If staying within 100yrds the smaller bullet would be fine. Longer distance the bigger bullets. These are just my opinions someone else might disagree.

Don't forget bullet energy, where light bullets lose energy much faster and heavier bullets retain sufficient energy much further.

 

[willie14228]

Think of it this way,,,, which would you rather be hit with a ping pong ball moving at say 30 MPH or a baseball at 20 MPH ( I know a huge exaggeration )
Not to say me and the guy chunkin those objects at me will not be haveing a very serious discussion after the fact I personally would much rather get smacked with a ping pong ball.


the fact is its all about balance.
A heavier round will take more powder and most likely not travel as far or fast but will hit harder and expend more energy into the target as long as it's within its effective envelope.
We are shooting very close to the magic line of speed of sound. The modern smokeless rifles have gone far enough past the point that impact is still above the line most of the time, where as Black Powder still is close enough that many times the round has fallen below that line, that transition point plays havoc on a bullets flight pattern think of it like a boat on its plain skimming across the water, that slows to the point it drops off plain, when it does water rushes in from behind and skews it sideways.
that same effect happens to bullet when it drops below the speed of sound. Lighter rounds many times will start to tumble losing more speed and accuracy where a heavier bullet because of mass will be less effected.
The flip side is a heavy round takes more time to get to the target and can be effected by cross winds.
the key is staying inside each rounds power envelope.

 

[alaska viking]

Uhmmm, I don't think the speed of sound really plays into ballistics, be it energy, or trajectory.

 

[BuckDoeHunter]

Uhmmm, I don't think the speed of sound really plays into ballistics, be it energy, or trajectory.

From some of the research I have done, it does. Bullet design seems to play a part in whether the bullet with stay stable enough when transitioning thru the SOS.

 

[ENCORE50A]

Uhmmm, I don't think the speed of sound really plays into ballistics, be it energy, or trajectory.

From some of the research I have done, it does. Bullet design seems to play a part in whether the bullet with stay stable enough when transitioning thru the SOS.

I agree. The bullets design and rotation play a big role.

To solve the problem, shoot the bullet really really fast........ :wink:

 

[rangerod]

Some bullets seem to shoot better the faster you shoot them. Barnes 290 grn Tez.

 

[willie14228]

I don't make claims that I understand all of how this works by no means so please don't think I am nor that my statements or terminology will be be completely accurate but yes the bullets transitioning to or from the speed of sound does play an part on its flight stability.
all a bullet is in essence is an circular airfoil designed to fly through the air at maximum stability, minimum drag and maximum K.E on impact.
In that same manner the very same issues that early jet aircraft attempted to break the sound barrier and became unstable due to the configuration of its flight surfaces the same holds true for the bullet. Even more so because muzzleloaders shoot so close to that line the bullet needs to be able to do all of this both above and below the speed of sound. By the same token an aircraft designed to fly faster than sound has a much higher stall speed (flaps and other devices allows them to fly slower)than one that has an airfoil that stays below it. A bullet has no way to Change its airfoil it's fixed so it has to be "flown" within that airfoils stability envolope.
check out all the new high powered air rifles that kill big game, deer and just about any game a muzzleloader does. What will amaze you is that they shoot as close to but below the speed of sound as possible to insure accuracy.
this is one of the reasons why many of the 44 and 45 caliber pistol ammo works well in muzzleloaders the flight surface, center of gravity and mass is balanced for speeds close to that of a muzzleloader.
Around 1500 to 1800 fps, is is able to hold its stability at speeds as low as 900 fps.
just like a boat speeding across the water the wave front moves back as the boat moves faster and back forward as it slows.
Understand that scientists has used water as an easy medium to study the way air flows around an object, its a way of scaling the effect so it can be studied easier.
I have to admit that I am getting over my head here but I think the key to muzzloader success is finding the bullet that shoots best with your gun balanced with what you need that bullet to do.
Why does a 300 grain maxiball work so well because it can fly below the speed of sound limiting the effects of turbulent air with enough mass to impact an object with killing force.
But the flipside you zero that 300 grain at say 100 yards but the animal is only say 50 yards depending on the amount of powder your shooting of course, your zero can now be as much as a foot or more high on the target. (Learnt this lesson the hard way shot over a good 12 point buck back exact same situation this season)

I would stress one word of caution
I don't know the numbers but when you shoot higher grain weight bullets you increase the internal pressure in the barrel. So a very very rough example a 177 grain round ball with 80 grains powder will produce 19000 psi pressure a 300 grain bullet will produce 38000 psi with the same 80 grains of powder. Again I don't know the numbers but the ratio is close so be careful. And hang on to your hat because it makes that gentle giant kick like a MULE!

 

[ENCORE50A]

...................Why does a 300 grain maxiball work so well because it can fly below the speed of sound limiting the effects of turbulent air with enough mass to impact an object with killing force.
But the flipside you zero that 300 grain at say 100 yards but the animal is only say 50 yards depending on the amount of powder your shooting of course, your zero can now be as much as a foot or more high on the target. (Learnt this lesson the hard way shot over a good 12 point buck back exact same situation this season)

I would stress one word of caution
I don't know the numbers but when you shoot higher grain weight bullets you increase the internal pressure in the barrel. So a very very rough example a 177 grain round ball with 80 grains powder will produce 19000 psi pressure a 300 grain bullet will produce 38000 psi with the same 80 grains of powder. Again I don't know the numbers but the ratio is close so be careful. And hang on to your hat because it makes that gentle giant kick like a MULE!

Shooting a 300gr bullet zeroed at 100yds and being a foot or more high at 50yds? Dang, a pitcher can throw a rock about that fast/flat (joking). You're talking about a charge of only 600fps or less. :huh?:

Now there's a few on this site that are knowledgeable about pressures but, I think 38,000 may be a little high using just 80grs.

Most modern in-line bullets are more capable and with the charges that most use today, remain above the speed of sound (1,126ft/s) out to most shooters maximum shooting distances. A bullet with a BC of .210, fired at 1,500fps, doesn't drop below the speed of sound until approximately 175yds.

My 300gr crosses back at around 475yds. :wink:

 

[BuckDoeHunter]

The one pressure trace I could find with a 300gr bullet and 121 grains of BH209 by volume (85 grains weighed), was 26,146psi.

This was shot out of a 45 cal barrel sabotless. I'm trying to remember if this same load shot with a sabot out of a 50 cal would yield less pressure?



475 yards :yeah: My 250grainer is around 445yds

 

[willie14228]

My sidelock pretty much has fits when I load more than 80 grains and as stated I don't know the numbers I was talkin about ratios and the fact that higher grain bullets increases muzzle pressure not so much the exact numbers themselves.
unfortunately because there are so many in line shooters M.L bullets are mostly designed for them. My maximum grain load for my Sidelock is 110 grains and I feel that's pushing it.
A TC Maxi 300 grain groups for my Kentucky at about 1.5 inches with 80 grains any higher and my groups open up.
I haven't been able to test any in my Deer Hunter because the only source is gander mountain and they dont keep their stock up.
but ya your right for some reason i was locked into a mini or maxiball and not just any 300 grain bullet.

 

[JStanley]

Having done a little (over 1500 hrs) of flying for Uncle Sam off of big gray boats, I can say with certainty that willie14228 and buckdoehunter is making a true statement regarding the speed of sound and it's effect on objects in flight. Anything moving through a fluid (including air) pushes that substance out of the way at the same speed it is traveling. Think of passing a semi and feeling the push to the side when you get beside the cab. When an object approaches the speed of sound, the shock wave can no longer get out of the way fast enough. The more quickly and cleanly it exceeds the sound barrier the less turbulence it feels. For a bullet this happens immediately upon exiting the barrel and is why when you hear someone shoot a high powered rifle from far away, you often hear both the report of the rifle and the sonic boom of the bullet. The lower frequency of the boom gets attenuated or slowed down faster than the high freq report and so they arrive at your ear a bit separated. Back to the supersonic object. Immediately after going super sonic the shock wave slams shut like a door behind it (sonic boom) and when slowing down through SS the shock wave catches up and bumps it in the tail. This is only part of the benefit that high speed boat tail bullets have. The taper at the rear softens the SS bump at really long distances to keep it a bit more stable, although it also helps a lot in other ways for high powered rounds. Is this important to us who shoot MZ? Probably not as much as to the HP shooters. Our bullets just aren't as slick as theirs aerodynamically speaking and so the upset at the SS transition probably is much smaller for us. Besides, by the time our bullets slow back down through SOS, they are usually either already through our target or past it. My ballistic calculator (Ballistic) on my iPad/phone actually provides a line across the table for the SOS transition for long rang shooters to consider. I don't worry about much with my MZ's.

Be blessed.

 

[alaska viking]

Thank you for the detailed description!