Some new stuff

A new twist to the extension.. made from T-6 and a prototype slide instrument at the rear of the tube..not in focus,  designed by Al Marvel..very ingenious. Hope to finish it up soon..

like it!

I assume it's Aluminum 6061 since T6 is a temper designation and used on many Aluminum alloys.

Well, to elaborate a little further.. and in relation to the link some one posted regarding Dr Wong's article on a smaller objective, it is a coincidence that we have been testing different eye piece configurations..We started with a super long extension to combat the Perry wind and rain, and noticed it made a difference in the centering of the dot.. Now we are testing different diameter objectives, and different lengths... It is showing promise..These came from tubing, and is much smaller than an Ultra Dot 1 inch tube.. but I will be machining the next group from solid bar for  better flexibility with  the various test diameters..There's a lot to work out with desired angles, length straight sections, and diameters, etc.. Fun work though..

Fantastic work as always Jerry!  I'm looking forward to more on the slide instrument too...

Some new bar stock.. for a smaller objective with a filter in set.. Stay tuned..

The beginning...

Jerry,

Maybe it should be polished a bit??  Seriously, how do you find time for the number of projects you are involved in?

And thanks for your postings and all the pics.

Ron Habegger

Jerry Keefer has always been one to share and has been an ambassador to the sport of Bullseye.  I had joined the Bullseye list back in 2004 and read many names of those who posted.  The big news at that time was Jerry Keefer had been selected into the American Pistolsmiths Guild. 

During the Bullseye picnic at my first Camp Perry in 2004, a gentleman came up to me (I was a relative newbie) and introduced himself, none other than Jerry.  In my mind, I thought a nobody like me was talking to a celebrity, wow.

That year, Jerry donated his customed built 1911 for the top new shooter to Camp Perry. I have a picture of me holding that pistol, but that was as close as I ever got to that gun. As many had said, expect to drop a hundred points to your average when you come to Perry.  Sad, but true.  :-)

The next year during the BE picnic, Jerry had a drawing for a S&W model 14 revolver for those who didn't own a revolver for the distinguished revlover match.  Great trigger with a nice finger grooved grip.

Jerry would come to Camp Perry, not to compete, but to help service pistols which he built.  I recalled a line of shooters who brought their Keefer 1911 pistols which Jerry happily cleaned.  I was in awed when Jerry partially dismantled a 1911 in about 30 seconds.

Just wanted to share a bit of the past. 

Norman

And he loves to tease us with all this cool stuff we can never buy!   I'm waiting on the Keefer store to open....

DavidR wrote:And he loves to tease us with all this cool stuff we can never buy!   I'm waiting on the Keefer store to open....

Oh, the "Neiman Marcus" of gun parts...

Thank you Dr. Wong.. Here is the finished prototype..
I am going to call it the Dr. Wong Objective  Aperture...
We tested the first one this week.. The aperture on it is .750
She felt it is a definite asset.. but wanted filter capability for Perry. This one is .500 aperture with interchangeable filter discs. The insert is  an  Ultra Dot beauty ring that secures the filter disc.
I have found that an rubber "O" ring prevents the two shoulders from vibrating together tightly,  making it hard to remove the extensions/filters.
You will likely see this on the line..

That one looks like a 1 inch ultradot ring as the filter holder. Is the half inch coned or stepped on the inside?

jmdavis wrote:That one looks like a 1 inch ultradot ring as the filter holder. Is the half inch coned or stepped on the inside?

Yes it is coned in the rear leaving about 3/4 in at the front..

If you need a guinea pig I will buy one?

I have been working with one of these units for about a week. I have tested it indoors and out at both 50 yards and 25 yards. I have tried it on both the front and the back of an Ultradot Matchdot. Mine is a 3/4 inch aperture. 

It works to help keep things centered. I like 1 inch dots and this extension is even better. It gives me the option of using the match dot without all of the extra image area that quite frankly distracts me. 

The one that I have is coned on the inside and goes from the 30mm lens size (or tube size actually) to a 3/4 inch aperture. It screws into the existing thread on the front and rear of the Matchdot. 

Mounted to the front, it effectively performs as a blinder and makes the 30mm tube seem like a 25mm or smaller ultradot. I like this because at 25 yards, the image area is my target and just a bit more. At 50 yards the 3/4 inch has maybe 1 to 1.5 feet surrounding the target. I have seen a few points coming from it with the Ultradot. 

Mounted to the rear of the tube the 3/4 inch extension seems to me to perform in a manner similar to Dr. Wong's centering device. It doesn't have the non-glare properties, per se. But it will with some duracoat or alumi-hyde in the future. Mounted to the rear I find that it works better than the lobster band in the article below, or my first version which was a silver paint pen around the edge of the Ultradot 2inch extension. What you have is the aluminum extension acting like an aperature to create circle in circle in circle, with a dot in the center (in a manner similar to match rifle sights).  

http://www.starreloaders.com/edhall/nwongmain/enhancer.html

Being lazy I didn't want to make that entire extension with a reduced diameter to produce the "Wong" effect. It was easier to make a washer like insert and hold it in place with the filter disk on the Ultradot. I would think that anyone interested can make one from paper to test the application. However I did set-up my lathe to cut .75mm thread and made an extension tube for my 9000SC plus a short extension to act as a Ghost Ring from Acrylic. The bright red color shows up well. Acrylic being very light added almost nothing to the weight and is not noticeable. Currently I have the Sightron on my MatchGun2. I made a similar objective side extension for it plus a similar Red ring but the threads on the ocular side are very short, so far it lasted two 900s and seems to be surviving but time will tell. I do want to make longer extension to combat the rain at Perry that can easily be screwed on when needed. Last year I couldn't see a thing thru my micro. Guy I scored (won police class) used semi clear plastic cups that were split, bottoms removed, wrapped around the UltraDot tube and held in place with rubber bands. Adam did well with the 9000SC that had the rain guard extension tubes. The Sightron having a wide grove on the ocular side might provide a way to attach a long rain guard extension.
 The extension tube for the objective side in the photo is 1.5" long not including the threaded section. My 9000SC objective side measures 1.501" (slightly bigger than 38mm) The Acrylic material was 1.5" round bar  but measures 1.546". Again being lazy I didn't turn the OD to match the tube but may in the future or make a another longer version. I also have some Red translucent Acrylic I might try on the ocular side.

OK  A days worth of shooting reveals some areas of issue.. Groups were very good.. She complained that there needs to be a defined inner edge to easily enable seeing the inner circle to accurately orient the dot..Not an impossible problem at long line, but a real challenge in RF..
That was corrected by  machining .. Then various filter shades are necessary.. That has been addressed with blue, amber, green and gray.  It's apparent that a larger aperture is more desirable at short line..  The extensions were lightened / contoured to address weight and to be as compact as possible. The short line is exactly one oz. and the other is 1.3 oz.. Not bad for the strength and durability of T-6/6061.. plus it's not on the slide to interfere with function.

Jerry,
Any chance of posting a sketch or drawing with dimensions?
Thanks by the way for all the valuable info you so freely post.
Dave

OK Here's a  real quicky.
Crude, and not to scale nor an example of my drafting skills..
The critical dimensions are the threaded sections.. Metric 0.60 The major and minor diameters are very close..The Aimpoint Comps and others are different, most of which are 0.75mm..and the major/minor must be calculated.   I have found that many of the Ultra Dot extension items are not quite the same... The anodizing is probably the culprit. Thread depth is rather consistent at .014  I am lucky, in that,  my lathe cuts metric merely by shifting the levers..no convoluted gear swaps..
The other dimensions are really up to the users wants, needs, and imagination..

A note..
In the future..
I am quickly running out of  Ultra Dot rings/extensions/filters.
When that occurs, I will probably revert  back to  good old UNF threads..

Jerry,
Thanks for the quick reply and again thank you for sharing your insights with us all.
Dave