Shotgun Sight Installation Advice Wanted

rc · June 15, 2017, 01:10 AM

Hi, I purchased a shortened shotgun barrel without a rib from ebay that had a boogerd hacksaw job. Barrel is about 20" so length is fine. I have squared the muzzle with my 5" disk sander and now I need to install a bead. I've picked up a centering V shaped jig at harbor freight for my drill press and ordered a Mossberg plain barrel front sight and 5-40 tap + majic tap fluid. I'm going to build a jig to hold everything steady in the drill press and got an automatic center punch to help keep the drill from walking around when I start drilling metal. The one thing I haven't lined up yet is the drill bit. What size hole should I make when my drill press is set up? Should I do this in two step or just drill the correct diameter hole the first time? I'd like to keep the bead as square to the action as possible so the gun points right. Hope to get some experienced advice. Good news is if I booger the job the first time I can still cut back a bit and retry. I do hope to do it right the first time.

ShootistPRS · June 15, 2017, 07:34 PM

A #38 number drill will give you a 75% thread so that is the drill to use. The nearest fractional drill is 7/64 but it only provides a 50% thread.
Are you planning on drilling through the barrel and then filing the screw flush on the inside of the barrel? You may find that you need to raise the bead to get the proper fit to align with your target. We had to put the bead on a 3/8" ramp to get my brothers shotgun to line up with the point of impact. His was cut to 18-1/8" and I rolled a full plus choke on it for him. It shoots well for him now.

T. O'Heir · June 17, 2017, 12:14 PM

"...drilling through the barrel..." Hard not to with most shogun barrels. Thin, so they are. Fortunately most beads' thread shanks are just the right length. A #38 drill is the right drill size for a 5-40 tap.
http://www.lincolnmachine.com/tap_drill_chart.html

rc · June 18, 2017, 12:18 AM

I appreciate the correct drill # for correct thread engagement. I will see if I can find the right one locally since I didn't order it from midway. I will drill through and file down the inside with my dremel. How do you roll a choke? I would love to taper it down a bit from cylinder. Also, is there a standard 12 guage ramp? Not pointing correctly is a bit of a concern. Right now I can't even see the barrel with a good cheek weld.

ShootistPRS · June 18, 2017, 12:46 PM

rc,
I made a four roller clamp that was a bit like a pipe cutter without the cutter wheel. I rolled it and let it slide toward the front of the muzzle as I tightened it down. It went pretty quick but it did manage to break the small ball bearings I used. If I was going to make another one I think I would use bushings instead of bearings. I used a tapered shaft marked with tape to gage the amount of taper compared to another gun with a full choke. I stopped the process when it was a tad tighter than the full choke. Then we patterned the shotgun and adjusted the crown to shoot where my brother wanted it.

The ramp I used was an old ramp sight from a Thomson Contender. I had to match the fit to the barrel diameter and made a new bead with threads that were just long enough to not protrude into the bore. I know that "clip on" sights are made for shotguns and it would be a simple matter to use that with a locating hole and a screw to hold it in place. There are also extended beads that sit higher than the flush beads.

rc · June 19, 2017, 11:01 PM

Thank you for your help. I am hoping the Mossberg plain barrel bead will be high enough for my Remington barrel without a ramp and it also has wrench flats to tighten it. I'm not sure of the difference between Mossberg and Remington receiver height. I went to sears today but no luck finding a #38 drill bit and I would have to special order a 12 pack. Will try another hardware store tomorrow.

ShootistPRS · June 20, 2017, 09:40 AM

rc,
You can get a whole set of number drills from Harbor Freight. If you don't use them a lot they will be fine. I have three different sets from different manufacturers but then I use numbered bits a lot.

rc · June 22, 2017, 05:00 PM

I ordered 2 for about $5. The better the drill cuts the less it will try and walk.

June 15, 2017, 01:10 AM	#1
rc Senior Member Join Date: April 28, 2001 Location: CA Posts: 1,759	Shotgun Sight Installation Advice Wanted Hi, I purchased a shortened shotgun barrel without a rib from ebay that had a boogerd hacksaw job. Barrel is about 20" so length is fine. I have squared the muzzle with my 5" disk sander and now I need to install a bead. I've picked up a centering V shaped jig at harbor freight for my drill press and ordered a Mossberg plain barrel front sight and 5-40 tap + majic tap fluid. I'm going to build a jig to hold everything steady in the drill press and got an automatic center punch to help keep the drill from walking around when I start drilling metal. The one thing I haven't lined up yet is the drill bit. What size hole should I make when my drill press is set up? Should I do this in two step or just drill the correct diameter hole the first time? I'd like to keep the bead as square to the action as possible so the gun points right. Hope to get some experienced advice. Good news is if I booger the job the first time I can still cut back a bit and retry. I do hope to do it right the first time.

June 18, 2017, 12:18 AM	#4
rc Senior Member Join Date: April 28, 2001 Location: CA Posts: 1,759	Thank you. I appreciate the correct drill # for correct thread engagement. I will see if I can find the right one locally since I didn't order it from midway. I will drill through and file down the inside with my dremel. How do you roll a choke? I would love to taper it down a bit from cylinder. Also, is there a standard 12 guage ramp? Not pointing correctly is a bit of a concern. Right now I can't even see the barrel with a good cheek weld.

June 19, 2017, 11:01 PM	#6
rc Senior Member Join Date: April 28, 2001 Location: CA Posts: 1,759	good information! Thank you for your help. I am hoping the Mossberg plain barrel bead will be high enough for my Remington barrel without a ramp and it also has wrench flats to tighten it. I'm not sure of the difference between Mossberg and Remington receiver height. I went to sears today but no luck finding a #38 drill bit and I would have to special order a 12 pack. Will try another hardware store tomorrow.

June 22, 2017, 05:00 PM	#8
rc Senior Member Join Date: April 28, 2001 Location: CA Posts: 1,759	I wanted cobalt I ordered 2 for about $5. The better the drill cuts the less it will try and walk.

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June 15, 2017, 07:34 PM	#2
ShootistPRS Senior Member Join Date: January 3, 2017 Posts: 1,583	A #38 number drill will give you a 75% thread so that is the drill to use. The nearest fractional drill is 7/64 but it only provides a 50% thread. Are you planning on drilling through the barrel and then filing the screw flush on the inside of the barrel? You may find that you need to raise the bead to get the proper fit to align with your target. We had to put the bead on a 3/8" ramp to get my brothers shotgun to line up with the point of impact. His was cut to 18-1/8" and I rolled a full plus choke on it for him. It shoots well for him now.

June 17, 2017, 12:14 PM	#3
T. O'Heir Senior Member Join Date: February 13, 2002 Location: Canada Posts: 12,453	"...drilling through the barrel..." Hard not to with most shogun barrels. Thin, so they are. Fortunately most beads' thread shanks are just the right length. A #38 drill is the right drill size for a 5-40 tap. http://www.lincolnmachine.com/tap_drill_chart.html __________________ Spelling and grammar count!

June 18, 2017, 12:46 PM	#5
ShootistPRS Senior Member Join Date: January 3, 2017 Posts: 1,583	rc, I made a four roller clamp that was a bit like a pipe cutter without the cutter wheel. I rolled it and let it slide toward the front of the muzzle as I tightened it down. It went pretty quick but it did manage to break the small ball bearings I used. If I was going to make another one I think I would use bushings instead of bearings. I used a tapered shaft marked with tape to gage the amount of taper compared to another gun with a full choke. I stopped the process when it was a tad tighter than the full choke. Then we patterned the shotgun and adjusted the crown to shoot where my brother wanted it. The ramp I used was an old ramp sight from a Thomson Contender. I had to match the fit to the barrel diameter and made a new bead with threads that were just long enough to not protrude into the bore. I know that "clip on" sights are made for shotguns and it would be a simple matter to use that with a locating hole and a screw to hold it in place. There are also extended beads that sit higher than the flush beads.

June 20, 2017, 09:40 AM	#7
ShootistPRS Senior Member Join Date: January 3, 2017 Posts: 1,583	rc, You can get a whole set of number drills from Harbor Freight. If you don't use them a lot they will be fine. I have three different sets from different manufacturers but then I use numbered bits a lot.