Dennis & Brian\'s Build

I noticed in the above pictures that you don\'t have any jam nuts on your shaft ends. With my gun, the head space would change while firing it without the jam nuts tightened down good. This would add to any frustration that was already happening.
bruski

Great work and great write up. I really need to get working on mine again.

Hi All,

We are using nylok nuts at the barrel end on the main shaft. Not easy to see in the picture. Thanks for the reply and tip concerning a possible issue. Final assembly will be all nyloks when the gun is finished.
Brian

Here are some pictures of the changes we made to correct some of our problems.

As I said, we used Cutter\'s hammer design but failed to use shorter firing pin springs so we had way to much spring pressure when multiple hammers were being pulled back by the cocking ring. So we just turned the end of the hammer to match what it would be like using the screw design. This corrected that problem.

We were also having problems with the button head screw on the hammer tagging on the leading edge of the cocking ring in the decocked position. This seemed to be just way to critical of an adjustment so we milled a small ramp on the leading edge of the cocking ring as shown below.

We have also determined that the .020 protrusion length of the firing pins was not enough. We attempted to solve this by milling .004 off of the bolt face and resetting the head space but the firing pin was still to short. We remade one pin with .028 protrusion which works but comparing the impact of the firing pin to a commercially made gun shows that we are still light. More testing next week.

Did some more tweaking and finally seem to have it shooting reliably. We don\'t have the top cover or clip finished so we loaded bullets by hand in the barrels and it fires and ejects them all. We had a couple of misfires before we made the firing pins longer and it ejects the misfires as well. We are very pleased at this point. The plans leave a lot to be desired but with a good bit of head scratching and frustration it can be figured out. Oh yea, and with a lot of help from people on this forum. If we can get it to load as nice as it shoots I will be HAPPY!    :lol:    :twisted:

GREAT JOB GUYS !

Thanks, and thanks for all your help and all the great information you posted over the years.

Double thanks to Jerry and all that have helped ! We are not done yet , but getting close.  To all that have finished and are in progress, the good news is :
No need to sign up to LUMOSITY to strengthen our brains after figuring out these plans ! :mrgreen:

Brian

It’s time to make the top cover.  We purchsed some DOM tube to make the top cover. It looked good but when we cut it, it was out of round and twisted, so Brian was elated to be able to bore out yet another piece of round 1144 stock into tube. We cut it to length and silver soldered the side plates on before cutting it in half. We drilled and tapped the side plates to the cover to hold them in place doing soldering. The pieced twisted a little when heated so we had to take .010 cut to get the top of the side plates parallel. Hopefully we will remember to compensate for this when we make the baseplate for the stick magazine. We are not going to make the rotary mag.

Since we made the breech casing wall .187 instead of .063 we will have to take the gun apart yet one more time to turn the front .375 of the casing down to .063 for the top cover. When you make changes it always comes back to get you, kind of like Cutter’s “smidgens of doubt”.  Oh how I can relate to that.

Finally, let me mention that when you are surface grinding the firing pins you should remember to turn on the magnetic chuck before grinding or the results will not be good. I won’t elaborate, just trust me on this.    :oops:  :oops:  :oops:  :oops:  :oops:  :oops:

What length protrusion for the firing pins did you find works?

Hi,

We were about .035 past the bolt face. The the best way to determine length with all the variables involved is to have the firing pin length so it clears the bottom of port depth by about .003 to .005 thousands. Other wise when dry firing the pin hits were the bullet case rests and will damage that surface. We cut the pins a little to long and found out the hard way and worked backwards to establish the longest pin length with out hitting. Hope this helps you !  

Brian

Thanks for the response. I had the solder fail during test firing with a bolt made per the plans. It pushed the pin back about 3/8\" causing the hammer to stick out and jam the gun. After that I decided to start over on the bolts and make them one piece like Cutter\'s. I never liked the solder method to begin with I should of just made them one piece to start with. I\'m finally back to almost test firing again and all that I have left is the firing pins. This info will help a lot getting mine going.

Another thing we did was to depth mike all the barrels after porting to make sure the port depth was the same on ALL barrels. You can check firing pin stick out with bolt assembled and pushing firing pin forward with bolt held in v-block and use height gauge to check stick out from bolt face. ( bolt vertical on surface plate )
Since head space is \" zero \" you will get accurate results on assembly.

As we got down to the final few pieces I was feeling really good about our build. Man did that change.

The magazine base assembly or what I call the top cover was one squirrelly piece. As I said earlier, we

scrapped the tubing and turn our own cylinders from 1144sp. That even proved to twist and close up

when we cut the holes and did the soldering as shown below. The solder joints also popped from the

stress in the piece. I was sure they would have held as we used Brownells high force high temp silver

solder but they still broke loose. Brian decided to remake his from a single piece. He took a 5.25

diameter solid round bored and turned it as shown and then milled the side plates, the hole and slot.

Finally he bored the ID to size. This worked much better.

 

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Brian whipped out the elevating ball socket. We are doing the non oscillating version and he made it to

bolt on rather than more soldering. He used a boring head to turn the radius and then bored and milled

the pocket as shown. Since I wasn\'t there when he did it I assume he just whipped it out. It is always

easy when someone else does the work. i have to Thank Brian for doing an awful lot of work that I was

not party to.

 

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Next we made the stick magazine base plate.

 

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Finally we made the hinge and took everything apart to drill the rails and we were ready to go or so we thought.

 

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So now we put things together and everything goes south. The first thing that doesn\'t fit is the base plate does not go completely down because the barrel plate protrudes into the area where the base plate fits. I am thinking we did something wrong but after checking everything we look at the 3d drawing and it shows the barrel plate protruding into the opening in the top cover for the base plate. Below are to pictures showing the problem and a very small snippet of the 3d view. Since there is no way two pieces can occupy the same space we had to take the gun completely apart yet again and modify the hinge and casing to move the top cover back so the barrel plate was clear of the opening. ::: :oops: :cry: :cry:

 

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Since nothing every seems to fit when made to the plans we decided to make a short 3 inch test stick mag to see how things were going to work.

This is what I did to solve the ejection problem.
Putting the contact point at 48° , kicks out the misfires.
Empty casings usually just fall out. Also on the left edge
of the .281 channel,  a .02/.03 radius or chamfer.

And the beat goes on