Two and a half foot drop at 100 yards?

[bear3855]

Howdy folks. I am relatively new to the world of muzzleloading (or to rifles at least) and I'm looking to gain a better understanding of bullet drop when it comes to my rifle.

I took my Hatfield .45 out today for the third time. The first, I shot at 25 yards - she was printing maybe a tad low at that distance but was otherwise dead-on. The second time, I shot it at 50 yards. There was a pretty big drop at this point, probably averaging about 8 inches, but again the ball was falling reliably in the same spot every time, at least when user error didn't budge it a little bit. Today, I tried the 100 target. Note that I've used the same charge of 60 grains of 3F Goex for all of these shots, aside from the first few where I was working up my load and settled on this. At first, I was having a difficult time even telling where the bullets were hitting, but after a while I realized I was getting a drop of about 30 inches or so at the worst, maybe more like 18 at best. I ended up with I think three shots on paper, out of the nearly 20 I fired! I could account for 12 or 13 of them, some of them were absent altogether.

I mentioned this to my dad, who used to shoot his flinter in local competitions fairly successfully, and he wasn't overly surprised about the drop. But it makes me wonder, why? It seems to me that the same charge of powder I use in my 45-70 that pushes a much heavier bullet with practically no drop at that range should be keeping the comparatively tiny patched round ball in the air longer than that. Obviously the ballistics are drastically different, the twist of the rifling is different, the way the PRB engages the rifling is different, etc. Of course there are many reasons this could be the case, but I'd like to understand exactly why such a drop is to be expected (if it is to be expected), and if possible, how to bring it back up a little. I'm no stranger to Kentucky windage, but two and a half feet seems awfully hard to compensate for. Maybe the only answer is practice - in which case practice I shall. Figured it was worth picking the brains of some folks more knowledgeable than myself though.

 

[Phil Coffins]

That does sound odd. Making some estimate, with a .440” ball and a “WAG” velocity of 1600 fps the compute says if you were dead on at 25 yards then the 50 yard hit should be - .2” and 100 yards would six inches low going 907.4 fps. So how much is your tad low in inches?

 

[SDSmlf]

Depending on your muzzle velocity, may make sense. You are already ‘a tad low’ at 25 yards. If you were dead on at 25 yards, with a MV of 1500fps, with a .440” roundball, you would likely be a 11” or 12” low at 100 yards. Get a load worked out that gives you a group, then worry about the sights.

 

[oldwood]

My competition load for out to 100 yds. was 60 GR. FFFG. , .440 ball w/. compression miked .012 patching material lubed w/ spit substitute. Rifling twist was 1 turn in 60". 75 yds and beyond the .45 is wind sensitive. Beware. Luck to ya.......oldwood

 

[bang]

Sounds like you are shooting either way to level to some down to start with.
All the 45s I've had shot best with 70-80 grains for distance.
You'll have to shorten the front sight or get taller rear sight. To be accurate at distance it will need to hit high at 25, 50 and 75.
Muzzleloaders trajectory is almost like a mortar.

 

[Britsmoothy]

Has somebody bent the barrel

 

[jackpine54]

Back when I had a .45 I always figured 3.5" high at 50 would put my round ball about on at 100 yards. That was 85gr fffg. No 2 guns will shoot the same.
I'd work up your most accurate load, then adjust your sights to get your point of impact to match point of aim with that load, at your desired range.

 

[Phil Coffins]

Using a different zero with the same ballistics gives much more useful line. The .440” ball has a BC of .052 and if the sights are 1” from center of the bore then hitting 2” high at 25 will hit 3.7” high at 50 and 1.9” low at 100 yards. you can’t start low and expect it to come up.

 

[Bigpete]

Raise your rear sight and get it on at 50m and see how much it drops then. Seems to me you just have it sighted in too low. Bet your 45/70 shoots extremely low at 100 with an 8" low 50 sight in too

 

[biliff]

The ball will cross the line of sight at two points. As it exits the barrel it is below the line of sight. At around 12 yds from the muzzle the ball should cross the line of sight where it will be above the line of sight until it reaches your sight in range when it again crosses the line of sight. From that point on the ball is below the line of sight. It sounds like your ball never crosses the line of sight at all. Fire a group at 12 yds or so and see what the point of impact is. At the very least, raise the point of impact so it hits 1/2" or so high at 25 yds which should get you on paper at 100.

As to why a RB drops so much, it's because the ballistics coefficient sucks. It may be moving faster at the muzzle than a 45-70 but it slows much more rapidly.

 

[Rudyard]

I would venture to say the longer heavier conical has more ballistic co efficiency viz dosn't run out of steam like the corispondingly little round ball is wont to do .If shooting at 1'000 yards the bullet is about 24 foot in the air mid range . no ball would reach with any hope of doing any good. Same cal differerent principal .
Rudyard .
PS I see Biliff has said the same thing

 

[hanshi]

Yes, that's waaay more drop than normal. With 60 grains you should be getting velocity in the 1600 to 1700 fps range. At 25 yds you should be at least poa with every shot. I sight my .45s & .50 to be one to two inches high (notice how specific I am ) at 50 yards. This puts the ball 4" to 6" low at 100 yards. File that front sight down slowly just a couple of file strokes at a time and shoot a group before filing again.

 

[Dude]

There are all sorts of different answers here, a lot having to do with the sights. It doesn't sound like the OP has a problem with sights - it's the amount of drop. From what I'm hearing, 6" drop at 100 yards is normal for a .45 patched round ball?

If that's the case, then something is really wrong if he's got a two, to two and a half foot drop. That's what needs to be addressed, not his sights.

 

[Old Hawkeye]

Whatever your POI is off at 25 yards, it will be 4 times that at 100 yards. So if a "Tad" low is 2 inches at 25 yards, it will be 8 inches lower at 100 yards before you even account for bullet drop. If you can't even account for 12 or 13 shots how can you even tell what you are doing? Get it shooting small groups at 25 yards, then adjust your sights for 50, 75, & then 100 & see what happens.

 

[Britsmoothy]

How does this rifle feel under recoil? Is it letting you know something just happened or is it like shooting 22?

 

[Dude]

If the gun is held level, say it's at five feet, pointed at a target five feet high, what's the normal drop at 100 yards? Six to eight inches? Not trying to be a smart a$$, just want to know. Forget what the sights say - just looking through the barrel at the bulls eye, how much drop can be expected?

 

[dave951]

He needs to revisit his sights. If he's dead on at 25, there are 2 possibilities. First, if he's on at 25 then should be on again at about 70 as the bullet trajectory arches. Second if he's shooting flat, then the bullet is headed pretty much down as the trajectory is lowered. Think of it this way, if a bullet impacts zero at 100, then it's high for part of that distance and will have a "peak" at about 50. However if he's on at 25 depending on the sights, the bullet is doing nothing but dropping.

 

[Dude]

I just don't get it. If he'd dead-on at 25, and normal drop is 6-8" at 100, how could bad sights have anything to do with an 18" to 30" drop? That's three to five times more drop than normal. Shouldn't he be hitting 8" low at the worst?

Why would this be considered a sight problem rather than low muzzle velocity?

Of course sights could be adjusted to match POI at that distance, but isn't the real issue excessive drop?

 

[gerryherd]

Weird numbers. If you’ve sighted in for a center hold at 25 yards, I’d expect you to be hitting 6 to 8 inches below point of aim at 100yds. Chronograph a few shots so you have an idea what MV you’re getting. Take somebody with you and let them try a few shots on the off chance it’s a technique issue. You ought to be getting 1500-1700 fps with a 60-70 gr charge. Try to lay hands on an old Lyman BP handbook or other such book that explains drop and bullet path and has trajectory tables. Good luck.

 

[Brokenbear]

RPM'S are low so gravity has more time to work
Ball /bore dimensions should be re-examined ..patch thickness as well as material construction should also be challenged ..as well the patch lube effectiveness
The engine's not going to run right unless the combustion chamber is sealed ..nor will it be an accurate engine (reliable)
Bear