Sighting in for multiple loads

[williamc]

I'm nearly finished polishing up my new 16" .44 mag carbine (longer review to come).

I attached my Skinner barrel mount peep, and using the factory front sight I was hitting about 8.5" high at 35 yards. I know the sight works great with the factory front on my 20", so I took it home to compare. Lo and behold, the front sight is taller on my 20".

Fortunately, when I bought the rear peep I went ahead and bought the front sight to go with it. Doing the math, it looks like I'll need to get a front sight that is .082" taller than what's on there now to get my plinking loads on the X. The Skinner front is well over that, so I need to do some filing.

Here's the thing. I use 3 different loads through the 92:

Plinking (.44spl) - 200gr RNFP moving at 933fps (about 75% of my shooting, almost all at 25yds)
Moderate (.44spl) - 240gr Keith @ 1083fps (20%, my 50yd load)
"Meat hammer" (.44mag) - 265gr Hornady Interlock @ 1538fps (5% or less, up to 100 yds, seldom beyond)

All loads are chrono'd from my 20" rifle.

I'm trying to figure out how much to file. For general use, I'd prefer to have the rear sight all the way down. My thought is to file to make my plinking loads on target, since everything hotter will most likely be at much farther ranges where I'll need to come up anyway.

I plugged the loads into a ballistics calc (using 0" sight offset and sighting in at 0yds to get bullet drop), and here's what I get for drop at 25, 50, 75 and 100 yards:

Plinking: 1.44", 5.52", 12.38", 22.16"
Moderate: 1.09", 4.16", 9.31", 16.65"
Hunting: .58", 2.19", 4.95", 8.97"

So my thought is if I sight in for the plinking load at 25yds, the two hotter loads will be a little high at 25yds, but past that I'll have to come up anyway if I want to sight my rifle for hunting at say 75yds. I know that changing loads will change the POI, but I want to get the elevation in a place where I can sight it in.

Does this make sense? Am I completely missing something? This carbine is so versatile...a good problem to have.

I'm loving the trapper! As soon as I get her cleaned up, the 20" is going up for sale.

William

[Archer]

It all depends on what you want to do.
If you want to bust Necco wafers at 25 yards set the sights for that.
If you want to hit tennis balls at 100 yards then set it for that.

IF you get it figured so that you can make the adjustments for each load at each range that would be ideal but you probably need a range card taped to the stock.

It is pretty easy to file the sight but it is pretty hard to put metal back after the fact.

I'd honestly worry the least about the 25 yard range as all the loads are pretty tight there so unless you are trying to hit the same bullet hole you aren't likely to miss a goblin target at that range.
As you step out the differences get more pronounced. What if all the ammo you've got is your mild load and you need to hit at longer range with it?

I'm feeling the need to work up some more range cards...

[Archer]

I still haven't made the trapper plunge.
The 20" feels so handy to me every time I pick up the trapper it feels like a handgun with a stock on it.
If I were trying to drag it in and out of a vehicle I guess I might feel a little differently.

[williamc]

I guess what I'm trying to do is figure out how much to trim the front sight in order to give me as much flexibility as possible in the future.

I think I need to bring up the rear a bit to allow some downward adjustment in the future. What I wish I could find is a program showing elevation changes for multiple loads using the sights set for a single particular load. I think I can do the math and get that on my own.

I had originally bought the 20" model to be my "one lever gun to rule them all". Now I'm wanting something chambered in .45-70, so I'm making the switch to an "intermediate" carbine in .44 magnum (between my six gun and my future thumper). I agree, the 20" balances beautifully, but I think the handiness and portability of the trapper makes for a fun little gun, especially if you have a bigger brother to shoot long range with. Just my opinion.

William

[williamc]

Ok, I think I have it figured out.

To sight in with the plinking load, I have to bring the barrel up 5.5 MOA. If I do that, my simplified "range chart" looks like this:

Plinking= 0, -2.64, -8.06, -16.4
Moderate= 0.35, -0.16, -4.99, -10.89
Hunting= 0.86, 0.69, -0.63, -3.21

So in essence, if I zeroed at 25yds with the plinking load, I'd be zeroed at 50 with my moderate load and at 65 yards with the hunting load (with plenty of room to adjust up if I wanted to move the zero out). That sounds pretty good.

William