Hunting Gun Sighted In!!

[Doc Will]

I went to the range and spent all day last Sunday working on getting my hunting gun ready for the season. T/C Renegade stock, 32 inch Green Mountain 1 inch across the flats drop in barrel in 54 cal. 1-72 twist. I put a set of T/C's low light sights. Looks like the Tru-Glo sights, rear sight has 2 green dots and front is a red dot. These should work well for those late in the evening shots. I was not interested in sighting it in at first, just wanted to work on getting a good tight group with different powder loads. Started with 75 grains of 2F and worked my way up in 5 grain increments, was shooting at the 50 yard mark off of a rest. The slow twist barrel finally settled in at 100 grains of 2F with a .018 ticking patch lubed with Lehigh Lube. I was shocked to find with 100 grains of powder the round ball did not drop between 50 to 75 yards. I was able to keep the same sight picture out to the 75 yard mark. Where I hunt 75 yards would be the longest shot I would have to make.
Has anyone else noticed that with a slow twist barrel and a fairly large powder charge the rounball drop is not significant at that range? :: I did not move out to the 100 yard mark, but curiousity has got to me. I will try it next time I go to the range. even though I will not hunt at that range, I just need to see! :hmm:
Doc Will
Keep Yer Powder Dry :thumbsup:

 

[madstone]

I think it has something to do with 50 and 75 yards being the 2nd and third time the ball passed your line of sight? A quick peep at a trajectory chart will predict where you will be at 100, but it certainly will be low? I know "nothing" but hit upon using shot charges tied up in "baggies" conrners and using low powder charges. All 120 odd #6's would go through one hole! I made some enemies at Turkey shoots this way! :results:

 

[Stumpkiller]

Couple of things at work here. As healing scope shooters, most of us are used to a lone-of-sight being 1-1/2" +/- over the bore. With iron sights, that is half that distance, or even less. This gives you less rise in a round balls' early trajectory.

Your observation that the ball "did not drop between 50 and 75 yards" probablty indicates that with your sight setting the ball's apogee is at 62 yards, meaning it will hit highest "on the paper" at that range. The ball is dropping from the line of the bore as soon as it leaves the barrel (if you beamed a lazer out the barrel the ball would never rise above that line once it was fired). It crosses the line of sight once going up, and again coming down.

I like 2" high at 50 yards, which puts me on at 25 and on again at about 85, and just one or two inches low at 100 yards (at which point the balls are striking an inch high to four inches low in any given "group").

 

[GobblerKnob]

Excellent explanation Stumpy. :RO: It surprises me that many shooters think the ball/bullet actually rises when it leaves the barrel. Very good illustration using the laser beam. :thumbsup:
Rick

 

[Claude Mathis]

I think it has something to do with 50 and 75 yards being the 2nd and third time the ball passed your line of sight?

It's my understanding that the projectile will only pass your line of sight TWICE. Once, shortly after leaving the barrel, and again on it's way back down to Earth.

If a rifle is sighted in at 100 yards, the first time the projectile crosses the line of sight is about 15 (+-) yards. The second time is at 100 yards.

 

[madstone]

You are certainly correct about passing line of sight only twice! With iron sight less than an inch from ctr of bore the ball "rises" into the line of sight close to the shooter and then "peaks" somewhere before falling into the LOS the 2nd time. With a zero at 50 and 75 yds? It is probably still slightly high at 50 and slightly low at 75 is you measured precisely. :sorry:

 

[cayugad]

Doc..

I put a 1:70 twist Green Mountain Barrel in .58 caliber on my Renegade. It tuned in at 100 grains of Goex FFg and a .018 patch and ball. I noticed the same thing shooting. I was dead on at 25 yards, and the difference of where it was hitting out to 75 yards would not make a difference in a hunting aiming situation since I always try to shoot dead center of the pie plate as I call it. A little high, a little low will not make a difference when that big ball smashes through there.

I stuck a big bulls eye out on the range(5 inch bull) and aiming dead center of the bull was still in the black from 25 yards out to 100 yards. Whether this big bore just floats out there better then the smaller ones, I have no idea. Maybe I was just lucky. But I am ready for hunting season. I did not put fiber optics on the GMB. I figured to give the stock sights a chance since the rifle shoots so good.