with Master Gunsmith and
AGI Instructor Ken Brooks
Gun Club of America members get special help from the AGI instructors as part of their membership, including the “Ask The Pros” forum on the members-only website. Here are just a couple of the thousands of great tips that have been answered by Ken Brooks.
Gene Shuey’s video on glass bedding was very good, but he did not explain the benefits of pressure bedding even though he mentioned he preferred it over other methods. Can anyone tell me what those benefits might be?
Also: I took in an old bolt action 20 ga. shotgun repeater that was in “well used” condition. It is a Sears Roebuck Ranger 141-7. I found that H&R had a similar model # 121, but there are not any parts available at Jack First or Numrich. The part I need is the carrier spoon. It looks like it is a part that acts as the secondary cartridge stop. If I knew what they looked like I could probably make one. Anyone got any info on this gun and or parts Answer:
I don’t know why Gene prefers that method. I prefer whatever works. Some barrels like pressure and some do not. I like fiberglass stocks for many reasons and you cannot pressure bed correctly with fiberglass or plastics, so if you have a gun with a small barrel dia and it likes pressure you would have to have a wood stock.
The easiest way to do this is, as Ken says, see how it shoots if you free float it. Then stick a couple of business cards between the forend tip and the barrel, trying the groups as you add each card. If this makes for better groups, turn the gun upside down and clamp it into a vise. Pull down on the end of the barrel with a trigger pull gauge and note the weight registered at the point that the card(s) pull out easily. Then, as I said in my 10/22 Tips and Tricks article in GunTech vol 5, “you can also color up some of the ACRAGLAS gel to match the stock and lay about a 2” band in the barrel channel from the fore end tip back. Use the gel so it doesn’t run out because we’re going to put the stock upside down (horizontal) in a vise and hang a 1 fi-2lb weight (in your case, whatever weight the trigger gauge showed) from the muzzle. I use a big crescent wrench with a shoestring through the handle hole (very hi-tech and scientific) and hang it over the muzzle. When the glass sets up, you will have an upward pressure at the fore end tip equal to the weight of the wrench (or other weight). Try the gun before you do this and only do it if it needs help.”
Rimfire Offset Firing Pin
I am working on a Cobra Derringer .22lr. The firing pins are long (.124 on top and .113 on the bottom, max and absolute protrusion) and have dinged both chambers. The firing pins are also offset (you can’t just chuck it up in a drill and put the hemisphere on it). I also do not have a four jaw lathe chuck to put it in either. Any ideas or simple fixtures that might work?
Vice and files and sand paper then buffer. Remember on a rimfire it doesn’t have to be hemispherical. Ken
Don’t fire rimfires if absolute protrusion exceeds .035”. Get a Menck rimfire chamber swage from Brownells to remove dings, or make your own. Jack
AR-15 Barrel Dimpling
I need to install a low profile gas block. It seems most come with set screws. Is there a standard depth the barrel should be drilled to? I assume the dimples should be ever so slightly larger than the set screw. Any tricks for lining up the gas port?
You will want the dimples in the barrel to be smaller than the screws so the tip of the screw will engage the dimple and keep the whole affair tight. If the dimples are oversized then the screws may not keep it tight. As far as indexing the hole, mark the top of the barrel where you will be able to see it with the gas block in position. Then line up the gas block as needed with your index mark. Ken
Make pencil line on barrel in-line with gas port. Index gas block with line. Point up screw that fits set screw holes. Screw in to mark center point of dimples. Use a sharp drill slightly larger in diameter than the screws. Only drill deep enough to make the dimple slightly smaller in diameter than the screws. The bevel on the screws will then center in the dimple. Jack