Picking the correct sight combination

[dlbarr]

I have an H&R Buffalo Classic in 45/70 - just rec'd it back from the factory fitting it. I have pretty much decided, unless someone can convince me differently, that I'm going to buy the Williams FP receiver sight to attach to the rear of the barrel. What I am having a challenge figuring out is what should the height be on the front sight - I want a globe sight, like the Lyman 17 series.
 
 The center of the aperture (at its lowest adjustment) is .325" above the plane of the barrel in the rear. The difference in diameter between rear & front of the barrel = .310". So, dividing that in half = .155" which means that the center of the rear sight aperture is .470" (.325+.155) above the plane of the barrel where the front sight will rest.
 
 So...ideally, should the front sight height be as close as possible to the exact measurement of the rear sight (.470)? And since it will likely be impossible to match this exactly, is it better to have a shorter or higher front sight given that the rear sight is measured at its lowest setting? Also, the fact that this is a 45/70 with its unique trajectory characteristics, how does that figure into these calculations?

I should probably add that my main interest is hunting and informal shooting. I can be convinced to start in some friendly competition at my local range, but shooting beyond 200 yds is probably not going to be much of an interest to me.
 
 Thanks a bunch for any help.

[quickdtoo]

The .494" Lyman 17A sight would be the appropriate front sight for the Williams FP sight, the .404" would be best if you wanted maximize range, 405gr @1500fps hit 1½" high at 100yds using the .404" with the FP. 

Tim

[Buster95]

I have purchased a Williams FP and a Skinner rear sight for my Buffalo Classic but I'm not yet decided which one I will mount on the rifle, does the .494" Lyman 17A is correct with the Skinner or do I need a .404" ?

[quickdtoo]

Dunno, never used a Skinner, that would be a question to ask Andy by email to their site or post in the Skinner Sight forum here, seems to me one of the first Skinner sights was on a BC. 

Tim

http://www.skinnersights.com/

[dlbarr]

i considered the skinner sight and spoke with the owner about this very topic. from my discussion with him, I got the idea that the .584 Lyman 17 sight was the correct choice....but I got confused after that. So don't go by my last statement. Oh - he did tell me that the skinner sits .400" above the barrel plane at the rear. 

That's why I posted the question here...I wasn't sure. Hope somebody will answer your question.

[dlbarr]

Thanks quickdtoo. You sound pretty confident about that. I like that. 

[dlbarr]

quickdtoo, after review I think I'd like to question your answer...not trying to be smart here. I looked at the 17A in .494" height, That height is measured from the BOTTOM of the dovetail. The dovetail itself is .105" deep which means that the sight in question actually sits .389" above the barrel plane in the front.

So...how does that change your recommendation? Do I presume the .584" is the correct choice?

[quickdtoo]

The .494" sight is the standard BC front sight, the .584" usually comes on it in error and is too high, there are dozens of previous discussions on this over the last 8yrs or so, the .584" is the correct sight for the discontinued 38-55 Target model. I have the .404" front sight on my 45-120 BC with a Williams FP-TK rear sight, that's what I've used for most of my shooting with it. Bernie(dodd3 used the same sight combination on his 45-70 BC(see Long Range Sights in the FAQs), but he shoots 600-800meters with his, so the .404" makes sense for him, for under 200yds, the .494" will work fine. The .584" would work too, but the FP sight would have to be set considerably higher to begin with to work right.

Tim

[dlbarr]

OK, thanks. I will go with the .494" you suggest as nothing beats experience. I found this calculator at Brownell's which I thought was pretty slick:

http://www.brownells.com/.aspx/lid=13186/GunTechdetail/Sight_Height_Calculator#.ULacbIbJewJ

Based on my barrel & sight data, it pointed to w/i .001" to the .584 height (.479 above the barrel). But probably why the .494 is a better sight on the BC is because of the trajectory of 45/70 round (?) Is my thinking sound on this?...just curious

Thx again

[quickdtoo]

The Brownell's sight height calculator(and a couple more IIRC) has been in the FAQs for a looooong time. 

The .494" sight is best because it requires minimal elevation range of travel use of the rear sight to be zeroed, it also keeps the rear sight low for a good cheek weld on the BC stock which has a lot of drop to it.   

Tim