Zeroing in a H&R Springfield trapdoor with Tang mounted rear sight

[Ashley D Austin]

I just obtained a (never been fired) H&R Springfield trapdoor Officer's carbine, .45-70, with a tang mounted rear sight and blade front sight. There are no markings on the rear sight.

There is no rear sight on the rifle barrel. Only the tang sight on the rear stock.

I could use some help here on developing a plan to zero it in.

I am going to start at my local club that has a 100 yd. range, but plan shoot 200 yards with it.

Edited September 21 by Ashley D Austin

[Texas Maverick]

You might want to check out Limb Saver recoil pads as well. I have mine on my 45-70 and it makes a world of difference for shooting more than a couple of rounds.

 

TM

[Hoss]

Rifle came with a barrel mounted sight. Someone must have removed it. 
 

the tang sight does not have any meaningful markings, as it all depends on the load you shoot thru it. On my rifle, I found the tang sight to be more decorative than useful. It’s just too “floppy” (not sure that’s the correct word) I only used the barrel sights. 
FWIW I won the Texas State Cody Dixon single shot title with my H&R trapdoor 3 yrs ago, shooting a 305 grn bullet with 14.2 Unique. They are nice guns, fun to shoot. Once you learn the rhythm they can be shot fairly quickly. 

[Reverend P. Babcock Chase]

Howdy Ashley,

 

I have no experience with the sight you have, but if you find that it is stable enough, here's a thought. I have heard that a 45/70 sighted in at 25 yds will be high at 50 and getting back down to close at 100. Of course your load will make a big difference. I believe that foregoing was for a standard 405 grain load. There is some real expertise available here from others. Let' see what they have to say.

 

Rev. Chase

[Cholla]

I have a rifle just like yours. I found the factory tang sight had a tendency to move side to side. If I remember correctly Lee Shaver makes a new staff that is much better. 
I also recommend going to a 292-grain bullet over 12 grains of Unique. I have shot 75 in one sitting with no issues with recoil pain. 
if you are interested in the sight, I can dig up the information. 

[Larsen E. Pettifogger, SASS #32933]

It depends on what you want to do with it.  If you only wanted to pop off a few shots at 25 yards you could probably get it do that.  But I notice that you want to be able to shoot at least 200 yards.  I had an officer's model and that rear sight is totally useless.  From your photo it looks like it is the one that you loosen the eye piece and the eye piece will move up/down and left/right.  It is completely non-repeatable and if you get it zeroed at any particular distance it is a matter of pure luck.  The sight is also set directly into the wood stock with just a couple of wood screws.  Not a very secure system expecially since the 45-70 can have quite a bit of recoil.  And, as previously noted, the sight is "floppy" and is going to fold with almost every shot.  If you want to do any serious shooting and actually reliably hit targets at 200 yards your best bet is to junk the sight is and buy one with vernier or click adjustments.  What a lot of people do is make a steel base that is three or four inches long and about 1/4" to 5/16" thick and inlet/glass bed that into the stock along with some decent screws.  The new base is drilled and tapped for metal screws and the new sight screwed to that.

[Ashley D Austin]

1 hour ago, Cholla said:

I have a rifle just like yours. I found the factory tang sight had a tendency to move side to side. If I remember correctly Lee Shaver makes a new staff that is much better. 
if you are interested in the sight, I can dig up the information. 

Yes, that would be very helpful. A

 

[Ashley D Austin]

3 hours ago, Reverend P. Babcock Chase said:

45/70 sighted in at 25 yds will be high at 50 and getting back down to close at 100. Of course your load will make a big difference. 

 

This makes sense taking trajectory into consideration. Thank you, A

 

[Cholla]

1 hour ago, Ashley D Austin said:

Yes, that would be very helpful. A

 

Here's his website. Call him and explain what you have. He will tell you what you need.

 

https://stores.leeshavergunsmithing.com/

[WOODFOX , sass#34179]

Get a laser bore sighter that will at least get you on paper

 

[Lucky R. K.]

Since you have no idea where the round is striking (high, low, left, right}, as others have said, shoot it on paper at 25 yards. You should see the impact and adjust. 

Lucky                                 

[Cholla]

Once you get shooting, make a log of the rear sight's height at the various ranges. Provided you use the same load, you can refer to the log when shooting at new matches.

 

My private range is mostly brush so seeing bullet strikes on the ground was impossible. I started out close to get on target, then started backing up and noting what I had to set the rear staff at. When I made the jump from 100 to 150 yards, I raised the rear staff what I thought should be enough and shot at the 2'x2' target. The target was big enough and my calculations close enough, I hit the target, then adjusted until I was hitting center. At 330 yards, I procured a massive piece of cardboard and made more calculations. I was able to get on the cardboard, then adjusted.

Edited September 21 by Cholla

[Texas Maverick]

Ck out Smith's sight. I had one on my Buffalo Classic and it is well made and mounts on the receiver and runs a couple hundred bucks.

 

https://www.smithenterprise.com/product/pn-8005/

 

TM

[Sedalia Dave]

Get a pair of 6" vernier calipers. With a little work you can find a place that will allow you to measure between the base and the movable part that contains the eyepiece that is repeatable. Once you have this, Start at 25 yards. Once you are on paper get the windage dialed in.  Don't worry so much about elevation. Concentrate on getting the windage dead on. Then use a diamond point scribe to make a witness mark that will allow you to repeatedly get the windage adjustment correct.  Practice moving the sight and resetting it so that the windage is dead on every time.  Now work on elevation, using the calipers to allow you to get the elevating setting correct every time. Once you can do this now move out to 50 yards and adjust the sight for a bullseye. Now you can work on setting the sight for further ranges. Make a dope card of the elevation settings.

[Cholla]

DOPE = Data Observed on Previous Engagement

[H. K. Uriah, SASS #74619]

17 hours ago, WOODFOX , sass#34179 said:

Get a laser bore sighter that will at least get you on paper

 

Let me echo this.   I have used this method on my M1s, and 1903 Springfields, with and without scopes.   Foe the iron sight, just adjust your sights to where the dot is.   Then using the same sight picture, see if you hits the bullseye.   Adjust accordingly.   For a scope, well, put the crosshairs on the dot, and then take it from there.

I have found that the best laser bore sights are the ones shaped like the cartridge that you chamber in the rifle.  

in fact...  https://www.bhphotovideo.com/c/product/1799929-REG/osprey_global_45_70_bs_45_70_red_laser_boresight.html

 

Edited September 22 by H. K. Uriah, SASS #74619

[Ashley D Austin]

I want to thank all of you for sharing your thoughts and information. I did purchase a laser and sighted to 25 yards then shot at a 2'x2' target at 100 yards and actually got on paper every time and hit the bulls eye 3 times. Beginners luck. You have provided enough info to keep me busy for the next two years. For now I am going to stay with the manufacturer's sights and just concentrate on learning to use long range sights and how to shoot long range with this rifle. I will keep a log so I learn as I go. When I feel ready to start competing I will most likely upgrade the rear sight. Hope I get to meet some of you out on the long range some day. Ashley

Edited October 10 by Ashley D Austin

[Griff]

The only thing I'd add to the above suggestions is to use a stable, adjustable front rest such as the Caldwell Rock Deluxe and a good rear bag.  Or a system that allows you to make sight adjustments with the rifle in position.  One that supports the rifle while you concentrate on breaking the shot.

 

Additionally, don't adjust sights after each shot... shoot at least three shots to form a group, then adjust for the group.  Rinse & repeat until sighted in.

Edited October 12 by Griff

[Cpt Dan Blodgett, SASS #75655]

Put a Lee Shaefer sight on mine.  He makes a quality sight just not expensive enough to have any snob appeal.

 

Edited October 13 by Cpt Dan Blodgett, SASS #75655

[Major Crimes]

I recently got this same rifle (2nd hand).

I used 300gr LFN with 12gr of TB and found at 50M that the rear sight aperture was not clearing the barrel fully (through the aperture it was a quarter barrel three quarters front sight) and was still shooting a bit high (aiming at bottom of black would hit around the 10 ring). It was also shooting to the left but I precision tapped (alright I hit it with a hammer until it moved) the front sight to fix that as my rear sight didn't appear to move left, or right?

 

It was similar with 500gr and 21.3 2205 and 405gr with 34gr 2207 (these are ADI powders but there are Hodgen near equivalents you can look up). It really liked the 500gr lead RN loads (about 1120fps) with two holes touching at 50M.

 

I have a couple of Lee Shavers sights so I might look into that, but I got this for a single shot comp where the targets are only 50m ish so don't need anything too accurate.

 

EDIT

I went back to check, and the rear sight does move left and right, sigh!

 

I will break out the hammer again and recenter the front sight.

 

Edited October 14 by Major Crimes

[watab kid]

On 9/22/2024 at 1:20 AM, H. K. Uriah, SASS #74619 said:

Let me echo this.   I have used this method on my M1s, and 1903 Springfields, with and without scopes.   Foe the iron sight, just adjust your sights to where the dot is.   Then using the same sight picture, see if you hits the bullseye.   Adjust accordingly.   For a scope, well, put the crosshairs on the dot, and then take it from there.

I have found that the best laser bore sights are the ones shaped like the cartridge that you chamber in the rifle.  

in fact...  https://www.bhphotovideo.com/c/product/1799929-REG/osprey_global_45_70_bs_45_70_red_laser_boresight.html

 

thanks i didnt have this and had wanted one for a while now , i just ordered one ,