Here's a technique I developed to smooth out the actions of my shotguns.
It is a self-taught process and one that I've never seen or read anywhere else.
Since my new Grizzly need a little work I thought I'd document and share it with others.
Objective:
To use the shank of a High Speed Steel (HSS) drill bit to manually de-burr sharp factory machined/stamped edges and to smooth out the action using a metal working technique called burnishing.
Advantages:
It is simple.
Requires minimal tools.
Takes 15-20 minutes.
Metal displacement technique rather than metal removal technique.
Provides uniform, self-limiting chamfer to sharp metal edges.
Performed by inexperienced person with little to no metal working skills.
Eliminates scratching/gouging/rounding edges.
Minimizes uneven chamfer width.
Minimal disruption to existing finish.
Works equally well on corners as well as straight sections.
Can be used on stamped or machined parts with no change in techique or force.
Allows for access to internal parts that might not be accessible using other techniques.
Background:
Technique was developed after reveiwing manufacturing process to construct typical shotgun. Most parts are either machined or stamped.Both processes result in a raised edge of material due to shearing of metal by cutting/stamping tool.
Gritty feeling is from these high spots rubbing against other high spots. When two high spots meet each other under high loading they have a tendency to "stick" before finally micro shearing material. By removing these high spots and lower the loading on the "rubbing" parts one can achieve a smoother operation.
Equipment
1. A high speed steel drill bit (the dull black ones you can get at any hardware store).
I used a 11/32" diameter one since smaller sizes require you to push harder and over time your fingers fatique faster. Larger drill sizes are more cumbersome and spread the load over a greater tangent surface. The depth of the "deburred" edge is smaller. Also, it is more difficult to get into smaller rounded corners with a larger diameter drill.
This is not a precise requirement so dig around for something near this size.
2. Paper towel or cotton cleaning cloth.
3. Degreaser
4. Gun oil.
Firearm Prep:
After ensuring firearm is unloaded disassemble firearm. Remove barrel, magazine follower, spring, and retainer. Trigger assembly can be removed if you want.
General Technique:
Note - Technique will result in VERY small shavings. These slivers are painfull if they embed themselves into your skin and are just about impossible to remove due to their size. Keep the areas you are working on well lubed with gun oil so that the shavings are trapped in the oil. You can wipe the oil off when you are finished and the shavings will stick to the removed oil via capilliary action. THIS KEEPS THE SHAVINGS FROM FALLING INTO THE ACTION THEREBY PREVENTING THEM FROM RE-APPEARING AT THE MOST INOPPORTUNE TIME.
1. You will be using the shank of the drill bit only (part that is chucked into the drill press spindle). At no time should the fluted cutting edges of the drill bit come in contact with the firearm. Wrap some masking tape around the flutes if you are worried.
2. Initial burnishing is done by holding the drill bit at a 45 degree angle to the edge you wish to chamfer. Start with light pressure and make several passes. You just want to knock off the high points on the edges at this time. Too much pressure and you will create "Divots" along the edges that are more difficult to remove. You will know when to increase pressure as the bit no longer "skips" along the edge but is drawn evenly along the entire length.
Start with the corners and then do the long edges as the corners are more difficult to get to.As you work the metal a microedge will develop that you will have to remove. Using a cotton cloth or paper towel to wipe area. Micro edges will catch small "tuffs" of material - showing you where you need to stopp the area. THESE MICRO EDGES ARE SHARP. USE YOUR THUMB TO FEEL FOR INITIAL SHARP EDGES. ONCE YOU START BURNISHING AN AREA USE THE TOWEL/CLOTH TO "CATCH" THE LOCATION OF THE MICRO EDGES.
3. The micro edges need to be "Stropped" or sheared off. This can be done by changing the angle of the drill bit to 5 degrees and repeating burnishing action. Laying it almost parallel to the receiver you are trying to remove the metal that was displaced to both sides of the chamfer.
Specific Techniques:
Reciever - Loading Port and Magazine area.
Figure 1 Shows me working on the loading gate. You can see the brigher (newly chamfered) edge above the drill and the duller (sharp machined edge) below. Note 45 degree angle of drill relative to edge. Work the area just inside the front leading edge where you load the shells.
Receiver - Ejection Port
The top edge needs to be worked on more than the other edges due to the fact this edge "breaks" into the interior of the reciever. The acute angle requires greater force to get a uniform chamfer that matches the other edges.I'd start here and then proceed with the other edges. Reducing pressure on drill bit to match chamfer width.
Figure 1A shows me working on this top edge. Notice how I am holding the drill bit. I'm using a "overhead knife stab" grip to allow me to apply the necessary force to "roll" this edge.
Figure 2 the results of working on the bottom edge of the ejection port. I've made my first light passes and you can see I've also just started burnishing the bottom corner.
Figure 3 Shows me working on the inside edge of the ejection port using the barrel opening in the receiver.
Reciever - Interior
I use a new technique here for edges that I have difficulty getting to. I call it pencil eraser and it works exactly as it is named. I grab the end of the drill and wipe across the edge like I would trying to erase the pencil marks from a sheet of paper.
Figure 4 Illustrates the Pencil Eraser Technique on the shell latch. Notice how I am depressing the latch so I can gain access to the edge.
Figure 5 shows the same techique
Figure 6 Shows the process almost complete. Note I have to even up a couple of the areas. Also, the chamfer won't be as wide due to the fact one cannot exert enough pressure using this technique to displace as much metal. However, as your fingers won't be brushing up against this edge it is not as critical.
Figure 7 Shows the other internal rail being worked on using identical eraser technique.
Magazine Tube End
Figures 8 -10 Show the de-burring of the magazine threaded end. Note the draw-filing technique I am using for the top of the tube. This is used to knock the edges off the displaced metal resulting from burnishing the interior/exterior of the tube.
Receiver - Barrel opening.
Figure 11 shows me knocking off the edges of the reciever where it accepts the barrel.
Fore end Rails
..........To be continued............. Got to go take more pictures.
It is a self-taught process and one that I've never seen or read anywhere else.
Since my new Grizzly need a little work I thought I'd document and share it with others.
Objective:
To use the shank of a High Speed Steel (HSS) drill bit to manually de-burr sharp factory machined/stamped edges and to smooth out the action using a metal working technique called burnishing.
Advantages:
It is simple.
Requires minimal tools.
Takes 15-20 minutes.
Metal displacement technique rather than metal removal technique.
Provides uniform, self-limiting chamfer to sharp metal edges.
Performed by inexperienced person with little to no metal working skills.
Eliminates scratching/gouging/rounding edges.
Minimizes uneven chamfer width.
Minimal disruption to existing finish.
Works equally well on corners as well as straight sections.
Can be used on stamped or machined parts with no change in techique or force.
Allows for access to internal parts that might not be accessible using other techniques.
Background:
Technique was developed after reveiwing manufacturing process to construct typical shotgun. Most parts are either machined or stamped.Both processes result in a raised edge of material due to shearing of metal by cutting/stamping tool.
Gritty feeling is from these high spots rubbing against other high spots. When two high spots meet each other under high loading they have a tendency to "stick" before finally micro shearing material. By removing these high spots and lower the loading on the "rubbing" parts one can achieve a smoother operation.
Equipment
1. A high speed steel drill bit (the dull black ones you can get at any hardware store).
I used a 11/32" diameter one since smaller sizes require you to push harder and over time your fingers fatique faster. Larger drill sizes are more cumbersome and spread the load over a greater tangent surface. The depth of the "deburred" edge is smaller. Also, it is more difficult to get into smaller rounded corners with a larger diameter drill.
This is not a precise requirement so dig around for something near this size.
2. Paper towel or cotton cleaning cloth.
3. Degreaser
4. Gun oil.
Firearm Prep:
After ensuring firearm is unloaded disassemble firearm. Remove barrel, magazine follower, spring, and retainer. Trigger assembly can be removed if you want.
General Technique:
Note - Technique will result in VERY small shavings. These slivers are painfull if they embed themselves into your skin and are just about impossible to remove due to their size. Keep the areas you are working on well lubed with gun oil so that the shavings are trapped in the oil. You can wipe the oil off when you are finished and the shavings will stick to the removed oil via capilliary action. THIS KEEPS THE SHAVINGS FROM FALLING INTO THE ACTION THEREBY PREVENTING THEM FROM RE-APPEARING AT THE MOST INOPPORTUNE TIME.
1. You will be using the shank of the drill bit only (part that is chucked into the drill press spindle). At no time should the fluted cutting edges of the drill bit come in contact with the firearm. Wrap some masking tape around the flutes if you are worried.
2. Initial burnishing is done by holding the drill bit at a 45 degree angle to the edge you wish to chamfer. Start with light pressure and make several passes. You just want to knock off the high points on the edges at this time. Too much pressure and you will create "Divots" along the edges that are more difficult to remove. You will know when to increase pressure as the bit no longer "skips" along the edge but is drawn evenly along the entire length.
Start with the corners and then do the long edges as the corners are more difficult to get to.As you work the metal a microedge will develop that you will have to remove. Using a cotton cloth or paper towel to wipe area. Micro edges will catch small "tuffs" of material - showing you where you need to stopp the area. THESE MICRO EDGES ARE SHARP. USE YOUR THUMB TO FEEL FOR INITIAL SHARP EDGES. ONCE YOU START BURNISHING AN AREA USE THE TOWEL/CLOTH TO "CATCH" THE LOCATION OF THE MICRO EDGES.
3. The micro edges need to be "Stropped" or sheared off. This can be done by changing the angle of the drill bit to 5 degrees and repeating burnishing action. Laying it almost parallel to the receiver you are trying to remove the metal that was displaced to both sides of the chamfer.
Specific Techniques:
Reciever - Loading Port and Magazine area.
Figure 1 Shows me working on the loading gate. You can see the brigher (newly chamfered) edge above the drill and the duller (sharp machined edge) below. Note 45 degree angle of drill relative to edge. Work the area just inside the front leading edge where you load the shells.
Receiver - Ejection Port
The top edge needs to be worked on more than the other edges due to the fact this edge "breaks" into the interior of the reciever. The acute angle requires greater force to get a uniform chamfer that matches the other edges.I'd start here and then proceed with the other edges. Reducing pressure on drill bit to match chamfer width.
Figure 1A shows me working on this top edge. Notice how I am holding the drill bit. I'm using a "overhead knife stab" grip to allow me to apply the necessary force to "roll" this edge.
Figure 2 the results of working on the bottom edge of the ejection port. I've made my first light passes and you can see I've also just started burnishing the bottom corner.
Figure 3 Shows me working on the inside edge of the ejection port using the barrel opening in the receiver.
Reciever - Interior
I use a new technique here for edges that I have difficulty getting to. I call it pencil eraser and it works exactly as it is named. I grab the end of the drill and wipe across the edge like I would trying to erase the pencil marks from a sheet of paper.
Figure 4 Illustrates the Pencil Eraser Technique on the shell latch. Notice how I am depressing the latch so I can gain access to the edge.
Figure 5 shows the same techique
Figure 6 Shows the process almost complete. Note I have to even up a couple of the areas. Also, the chamfer won't be as wide due to the fact one cannot exert enough pressure using this technique to displace as much metal. However, as your fingers won't be brushing up against this edge it is not as critical.
Figure 7 Shows the other internal rail being worked on using identical eraser technique.
Magazine Tube End
Figures 8 -10 Show the de-burring of the magazine threaded end. Note the draw-filing technique I am using for the top of the tube. This is used to knock the edges off the displaced metal resulting from burnishing the interior/exterior of the tube.
Receiver - Barrel opening.
Figure 11 shows me knocking off the edges of the reciever where it accepts the barrel.
Fore end Rails
..........To be continued............. Got to go take more pictures.
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