Same Zero for 25 and 50

First topic message reminder :

I mount my scopes so that they are 2" above bore on the .22 and near mid range trajectory on what ever I've loaded in .45. Doing that I eliminate the need for sight adjustment between 25 and 50 yards.
 I don't think I ever gone to a match that someone hasn't complained about forgetting to make a sight adjustment. Being the 2" is mid range for standard velocity .22 I have no adjustment
 I one time was talking with Fred Kart at Perry and he told me that the additional black 8 ring on the 50 yard target was to compensate for the trajectory using a 6 o clock sight hold. At the time he was selling 1X scopes so we determined if mounted with the center 2" above the bore no sight change will be needed. I did and tested it, found it worked as thought.

Frank, You may have noticed that I deleted that part before you posted. That is because I remembered what you just said. I knew it, just disremembered. I get my ballistics from handloader.com and was using a 230gr FMJ doing 900 fps. I finally punched in the right numbers and we are talking identical numbers. Like you say it makes no difference where the sights are it just has to hit the same spot. I can't shoot 6:00 hold in timed or rapid. My sights just keep coming back up to center hold.

Len

Froneck wrote:
I doubt very much that a scope can be mounted 1" above bore without special machining!

Since there seems to be some doubt,  this quick illustration is to prove, I do not, did not and have no reason to embellish my posts..The gauge block placed at the bore C/L and  supporting the straight edge is exactly one  inch..  That Model 52 is very close to one inch center to center..The 45 is machined and mounted exactly the same way. The Pardini is, slightly higher by approx 5/32in.

But, but, but Jerry that sure looks like special machining to me. Almost makes me drool looking at that mount.

Len ( the envious shooter)

They sure look nice in person too.

As was said looks like special machining to me too.  But I'm wondering if that is a 1" tube, if so that's 1/2" to C/L If it's 30mm then it's 15mm (.591) dam near 19/32 to C/L.
 The 45 barrel is dam near 1/2" so using the barrel as a reference it seem like the scope is more that 2x the barrel. It also looks bigger than the gauge block but that can be an illusion.
 My 45 has the top of the slide dam near 1/2" above the bore center line and scaling your photo yours seems to be dam near 1/2" too.
The top of the straight edge or scale seems to be below the center of the scope yet it's on the top of the 1" gauge block located below the scale or straight edge.
 The scope is well above the slide, looks like 1/4" but hard to determine however it a lot greater than 0
 For your scope to be 1" above center line of the bore at best the bottom of the scope tube will have to be sitting on the slide if it were 1" tube! Yours is well above the slide!
 Either what you showing in the photo is an illusion or your proving you mount is higher than 1"

Seems to me that there is special machining involved to mount it 2 inches above the bore.

Cripes Froneck! Don't you ever give up?

If the man says it's a 1" block holding the scale on centerline of the scope, then it is what it is.

Give it a rest, it's getting tiresome...

Jim Chapman
Hell, Michigan

I just measured my Aimpoint Micro height; center of barrel to center of scope. Using my advanced engineering mathematical skills and Mitutoyo dial caliper I come up with 1.4000000"       :p)
I have a super thin Weaver base attached to rear of slide. The only way to get lower on slide mount would be to use KC Crawford ' s machine cut on slide. 
Jon

Perspective/camera angle, if you look at the leading edge of the straight edge it is much higher than the back edge at the front of the scope. If the camera would have been placed level with the straight edge it would be almost dead center with the scope.

All that aside if Jerry says it's 1" that's what it is.

- Dave

If you have a tablet, or way of expanding the photo, the "1" (inch mark) is legible on the gauge block. I was hoping it would be clearer,  as I anticipated a challenge... The mounting height is not exactly one inch, but it  is close enough to insure that it is possible.  That gun, as many may recall, is the prototype fast twist 52 I have been working on. The slide has been altered in height and weight.  I can still gain some additional drop. When the gun is rebuilt after this season, I will take advantage of the extra distance. The Micro is constructed in  a way that allows one to be very flexible with mounting. Frame mounts are much more flexible and lend themselves to being mounted lower than a slide mount.  
Here is the basic slide mount.. No rings..much to be gained just by eliminating the rings.

Basic Hammerli mount

Hammerlis and 1911

Roughed out slide mount base for Micro. The internal dimensions are critical.. The bolt c/ls and the recoil lug must be dead  on. The sides are milled at 20 degree angle.

Pocket milled into an Al Marvel Rib.. By making the pocket a light press in fit, the pocket acts as a recoil lug.

Installed ready to go

On the gun

One thing I want to clear up.. I post to share, compare, and talk bullseye shooting. If some one can gain from what you see.. That's good for the game. My reputation is on the line as a Guild member, I will not lie, fabricate or embellish, as has been suggested.. There are other pictures and statements in this thread that speak volumes...

I don't doubt camera angle may distort the image, As I mentioned it may be an illusion! Further more I did not dispute weather Jerry could mount a scope 1" above barrel on a 1911! What I did say was that it could not be done without special machining to which there seem to be a lot of it in the photo!
 Here is a measurement of the bushing hole in a Caspian 1911 slide showing the measurement taken with a Brown & Sharpe inside Micrometer. dam near .702 and the measurement from the edged of the hole to the top if the slide with a Starrett pin micrometer, really close to .142. Therefore height of the slide over bore if bushing and barrel OD were concentric with the bore will be 1/2 X .702 = .351 + .142 = .493 as I mentioned before being dam close to 1/2" (.500). Now if the scope ring diameter that Jerry makes is 1.000 outside diameter then that will add another .500, so now the scope minimum height will be .993! That's only .007 less than the 1" claimed! I don't care what camera angle you happen to use and how you look at it that scope ring height is quiet a bit higher than 2 1/3 hairs! (.007). I do not know what the Diameter of that ring is but measuring an Ultradot Micro it's 1.107 and my Precision Arms Micro (looks quite a bit like the Aimpoint) is 1.102. Both have a base mounted to the bottom yet even if they were removed the base attachment area will add at least .030. So adding the numbers the minimum center height to mount any one of these two scopes is 1.073 and that is without any attachment  that is needed similar to the device Jerry made to attach the Aimpoint. It might be argued that the barrel angle was taken in account but using the Tangent of 1 degree (.0175) X 2.000" = .035. Therefore subtracting the .035 will require the mounting device be .042" thick with out any clearance for movement of the slide. I also might add that due to the slide moving back straight and not at the barrel angle then the barrel incline has nothing to do with the required height when the scope is mounted forward of the trigger since the front portion of the slide will be under the scope. As Jerry now stated as I was writing this the height the scope mounted is not 1"!! The numbers prove it couldn't be and to possibly mount it 1" the slide height over center bore will have to be reduced. Getting back to my original statement that it could not be done without special machining and since We were discussing 45 1911 ballistics I neglected to mention 1911! Yet in most cases using standard items it will all most impossible to lower the height to 1" Naturally with machining any stock gun can be altered to what ever dimension desired. I don't question that especially since I have do it!
 GETTING Back to the topic. I do not see any reason to lower the sights for ballistic purposes. Not being a doctor I will not attempt to comment on weather it is better to have the sights lower for a more stable hold. If anyone is willing to simply draw the ballistics arc and look at sight placement the higher the sight the less adjustment needed.Being that the gun has to be in the same exact location in respect to the center of the target the sights are nothing more than a reference device so as to place that gun in the proper position. Keep in mnid that as the range decreases the angle of incline the gun is held lowers, The lowering of the incline changes the ballistics and the arc is slightly different if the center of the bull is the exact same height as it is at both ranges.
 I use the mid range as a starting point. As the gun is lowered the amount of bullet drop increases. When sighted for 50 yards the bullet is rising at 25 yards and soon falls to the center of the bull at 50 yet the peak of the arc moves rearward too until the gun is completely level then the peak will be at the muzzle.
 I therefore see no reason to lower the sights from a ballistic viewpoint. As to moving the red dot forward to minimize parallax it seems that Parallax decreases the closer I have my eye to the scope and as I get closer to the scope the field of view increases too and the dot is easier to find. But my testing was arms length, 1/2 arms length and few inches from scope looking at a target 50 yards away.
 The photos posted are really nice work! I never doubted that. However what is the exact outside diameter of the rings you make? What is the total height of the center-line of the scope to the center-line of the barrel bore of the 1911 you just posted? What about the pervious post, what is that center height??

Frank, does it really matter what exact dimensions are? The photos show very low mounting, which is how Jerry does it, and you advocate a higher mounting, the subject is zero changes with different setups. Of what ive seen here, I have no doubt jerry could mount a scope pretty much anywhere he wanted and at almost any height, So rather than debate a few thousands of disagreement, please give us what makes either style better or worse for accuracy or zero changes.Also please keep things friendly and cordial as the only thing any of us are interested in is learning new things.

Froneck
That is a one inch block..It's a frame mount..!!!!! Sorry that screws your brain up..  I am  a very  poor photographer, so my ability to alter an image is zero..
I post to show shooters other options, many and most of which are outside the box. I have explained my position to you for the last time, and since you have challenged my integrity, this is the very last communication you and I will ever have.

Jerry, You said your scope mount wasn't  1" in your post a few ago, I was simply wondering what it was. Your nice rings made for the scope, I simply asked what the OD was. In addition You have a nice 1911 posted with a combination scope mount, I'm simply wondering how high it is?
 Getting back to the topic, If some of you would like more information and will want to talk to the AMU they welcome questions at their website. I can find it for those of you that can't. Ask and I'll post it here.

Frank the dot jerry uses is the aimpoint micro, with his added sun shades, if im correct the micros are 30mm lens size.

Oh Ok Dave I gave mine to my other son, thought it was 30mm.
 Back to the topic at hand. Simplest way to check the 0 adjustment idea is to simply draw it out. Knowing that the trajectory will change as the gun is lowed to center bull at 25 yards is to simply accept it is there. Anything higher than mid-range will not work because the bullet will never cross the line of sight twice once above what ever peak height is and will be well above what anyone would like anyway. I can assure everyone that the sight height of the scope on my AW is 2" and that I have 0 sight change shooting it off the bench as described. If measurement photos are desired ask and I will make them. I will point out that I don't care for the height, it will not fit in my gun box with the heel I made. I may trim one or both. However as per shooting it, I like it. Remember the group has a 5/8" vertical spread so actual exact center of the target impact is not known. So I think I'll shorten the height 1/4". Then do more testing.
 I did some shooting this weekend the 45 in the photos also did well with some older Red Box Federal I had. Sighted in at 50 yards I shot some nice groups Timed fire at 25 yards. Quite a few 99 targets with good X counts but couldn't put 2 together so I won't mention the other targets. Group was good but the 8 ring was hungry and snatched too many of my shots!
 This may not be for everyone, I like it because it's something I don't have to remember to do. I did used nail polish with a pin and put dots on my sight adjustment, red for 50 and green for 25 yards. Good when I remembered to do it. Also did the dual loading, most accurate for 50 yards and reduced powder to shoot 25 yards without sight change. Hate to say how many times I did it the other way around! Then there was the time my gun box rolled over and the rounds were mixed so I colored the primers with magic marker. Until I got the Dillon 650. My 550 was "borrowed" by my son so it's gone! 650 is not an easy press to make changes on so I load them all the same! OK so I'm lazy! I know that!  lazy guy looks for a way to get the same results with out doing anything! Now I can complain more about my score on the way back to the bench and not worry about making a sight change! Besides there are a lot of good excuses as to why my score is lousy!

My Aw93 and my 208s both use a 1'' ud that is mounted lower than 2'' and neither needs adjustment from 25 to 50 with SV ammo and many of my friends find their 22 guns are the same.
So the real question here would be about the 45 or even the 32,38 or 9mm if someone has info on those.

As I mentioned many guns have the sight mounted near 1.5" above the bore. That's only .5 difference and if adjusted to split that it means the only vertical difference is .250. Because the incline is lessened at 25 it reduces the difference so it may be .187 (well withing anyone's hold) and why I intend to lower my scope.
 The photo shows Adams gun with brass as reference. When measured it's dam near 1.750. I get good results with it but use the load that gives me the tightest group. I got some 185 gr. Zero JHP bullets and some N310 powder. When I get my press changed over I can let everyone know how well the 1.750 height worked.
 

Hello Froneck,

Is that the bushing lug I see poking through the side of the slide?

Jim

Yes it's the lug! When Adam was young I removed as much weight as possible. Slide was cut to the bottom of the serrations located at the rear. Was good until I put the bushing in! Machining pushed the metal in the grove and when I put the bushing in I had a bump. Lug does not stick out and is slightly below the surface. That scope mount looks large and heavy too but in most places it's very thin. Only place it's not hollow is where the screws attach it to the slide under the scope rings. If I were to make a photo of the bottom near the firing pin it will look like Swiss cheese! Adam shot that gun from 10 years old to 19. He like it so much he didn't want changes made. I offered to put another slide on it but he didn't want it changed! Turned out to be a real tack driver! Only changes ever made on the gun is the scope and the trigger/sear. Because he didn't want it changed is why I have 2 frames and 3 slides. Maybe I'll get another frame from  Caspian at Perry.

OldMaster65 wrote:Frank, You may have noticed that I deleted that part before you posted. That is because I remembered what you just said. I knew it, just disremembered. I get my ballistics from handloader.com and was using a 230gr FMJ doing 900 fps. I finally punched in the right numbers and we are talking identical numbers. Like you say it makes no difference where the sights are it just has to hit the same spot. I can't shoot 6:00 hold in timed or rapid. My sights just keep coming back up to center hold.

Len

What I was meaning is that the gun has to be in the same spot in relation to the target. If I had a super ideal rest and could remove and replace the gun without changing any settings and there was no movement it would hit in the same place every time. The scope or sights then offer a means to return to that position. The shooter can choose any reference. If at the time the gun was shooting center bull in the target at 50 yards and adjusted the sights to hit the top of the post holding the target. When removed and sights were on the top of the right post the gun will be aligned to hit center bull. Like you I can't easily change. I attended a coaching clinic at Perry. Wanted to learn anything I could to help my son. Lots of talk about sub 6 hold. I borrowed a 45 ball gun I made for my brother-in-law. Best shooting ball gun I ever made. (thew it together in a rush, he had to sight it at the match) Only problem was his sight picture was different than mine. I had to aim at the bottom of about the 7 ring at 50 to Hit center bull. Shot my best ball slow fire ever! when back at the 25 I tried sub 6 hold, shot an X when I did but before the string was over I was shooting 6 o'clock hold. Had a nice group in the 8 ring! I didn't want to adjust his sights since he was shooting next relay!
 So what I meant is that no matter where you like the sight to be it's OK as long as you keep doing it the same way.
 The issue here is that the trajectory will remain the same if everything else stays the same. The bullets will all follow the same path to the target within the group size. The sights are a straight line and the path crosses the sight line twice. The ideal sight location is when the crossing is at center bull for both 25 and 50 yards. Therefore no sight change. What ever I say works for my gun does not matter! What matters is you must find that location for your gun. Kinda hard to do for a ball gun due to the rules at least the old rules. But if you want to do it on the Wadd gun then determining the height required to have the line of sight cross the bullet path center bull at both 25 and 50 yards is something you might want to do if your lazy like me!