flyfishdave
04-17-08, 21:37
Shortening the Benelli Tactical Stock a la Ned Christiansen
The Benelli M1 (or M2 or M3) is a nice shotgun, but I found that the stock was too long for comfort, especially when compared to my 870 that wears a shortened LOP Speedfeed stock. After some random searching of various forums, I learned that Ned Christiansen did a nice LOP reduction on the Benelli stocks, but given his busy schedule and various projects, only does this work in small batches on occasion. However, he was kind enough to share with me some suggestions and advice on how to do this modification, so I decided to try it myself.
Parts/Materials used:
Miter/chop saw
Jigsaw
Cordless power drill (drill press would be better)
Orbital sander (belt sander would be faster)
Ύ thick oak/birch/anything HARD
Brownells Acra-Quick Gel (Brownells 081-000-020)
Sims Limbsaver Grind to fit pad (Brownells 902-000-072)
Can of WD-40
Tee nuts/threaded inserts (part numbers to follow)
Socket head cap screws (part numbers to follow)
Roll pins (part numbers to follow)
1. First determine how much shortening you need on the stock. I decided to remove 1 3/8 inches. Based on my crude calculations, I think 1 5/8 is the maximum you can safely cut, when using a Ύ thick piece of filler; the internal shape of the stock changes radically as it gets to the portion where the sling plate feeds through the stock. Make sure you tape up the stock before cutting, and use whatever means necessary to secure the stock when making the cut. See photo A
Photo A: cutting the stock
http://images34.fotki.com/v1126/photos/1/1301170/6110738/20080406_LA5B5883-vi.jpg
-----------------------------------------------------------------------------------------------------------
2. Prepare the stock. I removed the internal raised ribs to facilitate fitting of the hardwood insert various carbide burs in an electric dental lab handpiece. I then took a round bur, and using the shank as a stop, made a half-round retention trough on the inside, to increase the epoxy bonding surface area. See photos B, C, D, E
Photo B: raised internal ribs of stock. Note this is photo of cut portion; I forgot to take photo of the ribs in the portion of the actual stock prior to removal.
http://images28.fotki.com/v1029/photos/1/1301170/6110738/20080409_LA5B5892-vi.jpg
Photo C: raised ribs, alternate view.
http://images22.fotki.com/v837/photos/1/1301170/6110738/20080409_LA5B5893-vi.jpg
Photo D: retention troughs created with round bur.
http://images22.fotki.com/v810/photos/1/1301170/6110738/20080409_LA5B5891-vi.jpg
Photo E: portion of raised rib remains, which acts as a vertical stop for the filler piece.
http://images27.fotki.com/v967/photos/1/1301170/6110738/20080406_LA5B5886-vi.jpg
-----------------------------------------------------------------------------------------------------------
3. Cut and fit the hardwood filler. Using the cut portion as a template, place on your slab of wood and mark accordingly. Using your favorite tool, cut out the filler carefully. Then, using whatever means necessary, start sanding/grinding the piece until it fits into the stock, flush and secure. This part took me about 45 minutes using a POS orbital sander. ***Ned has used G10 laminate on some of his previous projects, but advised against it due to cost, weight, and difficulty of preparation. Besides, grinding G10 and inhaling the glass particles would be equivalent to smoking a few packs of menthol cigarettes. See photo F
Photo F: hardwood filler piece cut and ready for sanding & fitting.
http://images24.fotki.com/v874/photos/1/1301170/6110738/20080406_LA5B5887-vi.jpg
-----------------------------------------------------------------------------------------------------------
PARTS IDENTIFICATION:
http://images24.fotki.com/v865/photos/1/1301170/6110738/20080409_LA5B5888-vi.jpg
(A) 18-8 Stainless steel knife-thread tee nut/insert. This is the insert I planned on using, but due to size constraints and pad screw placement, I could not use it for the project.
(B) McMaster-Carr #92105A670. Zinc-alloy tee nut, 10-32 interior thread, 33/64 long, 9/32 drill size.
(C) McMaster-Carr #92105A016. Zinc-alloy tee nut with flange, 10-32 interior thread, 33/64 long, 9/32 drill size.
(D) McMaster-Carr #92949A270. 18-8 stainless steel button head socket cap screw, 10-32 thread, 7/8 length, 5mm hex head.
(E) McMaster-Carr #98296A914. Steel roll pin, 3/16 diameter, 1 ½ long. Requires 4.8mm/0.189 diameter hole Use drill bit McMaster #2958A81, not shown.
(F) McMaster-Carr #98396A913. Steel roll pin, 3/16 diameter, 1 3/8 long. Requires 4.8mm/0.189 diameter hole Use drill bit McMaster #2958A81, not shown.
-----------------------------------------------------------------------------------------------------------
4. Filler preparation. With filler inserted into stock, mark the vertical centerline, and note the ANGLE and position of the stock retaining lock nut. When you drill the access hole for the lock nut, you will have to drill at an ANGLE so your socket will engage in a straight line. I made a 3/4 hole that fits my standard socket just fine just make sure you take your time, especially when using a cordless hand drill. See photos G, H.
5. Pad placement. Using the template supplied, place over stock/filler and mark appropriately on the wood piece. NOTE, you may want to bias the placement towards the top, as the stock, and filler are angled sharply on the bottom, which can make the placement of the threaded insert difficult, if not impossible. Also make sure you are not violating the minimum outline requirement of the pad the Sims pad has hollow sections you do not want to perforate. Again, drill slowly and carefully, going from your smallest bit to the size indicated for the insert. A drill press would be good here, ensuring a perfectly straight and perpendicular hole, but a cordless drill will work. See photos G, H.
6. Determine roll pin location. Find an area where two roll pins can be driven into the stock and filler, away from the tee nuts and stock lock nut access hole. For my application, I found two spots where a 1 3/8 and 1 ½ roll pin could be placed. Again, secure filler and stock, and drill carefully, the appropriate sized hole for your roll pin. I used 3/16 roll pins. See photos G, H.
7. Insert tee nuts. Lubricate well, and carefully screw in the inserts. I used an insert with a flange/stop for the upper hole, and a plain insert w/o flange on the lower, since there was no room for the flange. The photo shows some splitting, but since everything was going to get coated in epoxy, I didnt really care. See photos G, H.
Photo G: Prepared insert. Ύ hole drilled for access to stock nut. Roll pin holes seen on side. Arrow indicates where some wood blew out, as the tee nut placement was close to tapered edge. Upper portion has enough support and room for use of flanged tee nut.
http://images26.fotki.com/v957/photos/1/1301170/6110738/20080409_LA5B5889-vi.jpg
-----------------------------------------------------------------------------------------------------------
Photo H: Alternate view of hardwood insert, detailing tee nuts, roll pin holes and access hold for stock nut.
http://images35.fotki.com/v1162/photos/1/1301170/6110738/20080409_LA5B5890-vi.jpg
-----------------------------------------------------------------------------------------------------------
8. Glue and secure. Get the pins, punches and anything else ready. Apply the epoxy to both the stock and wood, insert, wipe off excess, and tap in roll pins. Set aside and let cure. See photo I.
Photo I: Hardwood insert glued and secured with 3/16 roll pins.
http://images36.fotki.com/v1157/photos/1/1301170/6110738/20080417_LA5B5899-vi.jpg
-----------------------------------------------------------------------------------------------------------
9. Pad grinding. Affix pad to stock, using appropriate driver. Hex heads sure beat the Phillips head commonly used to secure pads. I then used a carbide to get the plastic portion of the pad ground down to the last 1/16 of an inch, and then threw the pad in the freezer overnight. When hardened (will not be rock hard), I then went at it with the sander, using the 80-grit disc. As you grind, spray WD-40 liberally and often on the rubber, as this will facilitate a smooth removal. Make sure you tape up the stock.
10. You are now done. Note, I got lazy so I never did bother using anything other than the 80-grit disc, and it looks just fine to me. Maybe, Ill go back later with some finer grit discs.
FINISHED PRODUCT:
http://images34.fotki.com/v1144/photos/1/1301170/6110738/20080417_LA5B5897-vi.jpg
http://images27.fotki.com/v995/photos/1/1301170/6110738/20080417_LA5B5898-vi.jpg
-----------------------------------------------------------------------------------------------------------
***If youre feeling really lazy and dont feel like grinding down a recoil pad, the Sims/Remington R3 recoil pad for the 870
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=18136&title=LIMBSAVER?%20RECOIL%20PAD
will fit about 96% of the Benellis contour, provided you cut the correct length off the stock. However, given that the pad fitting is not too difficult, especially when compared to fitting the hardwood insert, just get the pad of your choice and grind away. Do not skip the WD-40. It makes grinding much easier and affords a smooth finish, even with 80-grit paper alone.
***I recommended a drill press in the beginning only to ensure straight perpendicular holes. A cordless drill is fine, but when starting with the skinny bits, there is a tendency for the bit to bend so use care when drilling. You can see where some of my holes got off-axis, but even so, this is not really a problem as long as you catch the mistake early, redirect, and drill with intent.
***the 33/64 long tee nuts were the longest available for this particular application. Nevertheless, with 7/8 long cap screws, there is more than enough engagement to secure the pad
***Please disregard this post if you have unusually long arm and have a tendency to drag your knuckles on the ground when you walk.
Again, I must extend my sincerest thanks to Ned Christiansen for giving me those few pointers that made this project possible. While my results may not be up to Neds standards, this is a nice DIY project that accomplishes the task at hand that most people should be able to undertake.
Dave.
The Benelli M1 (or M2 or M3) is a nice shotgun, but I found that the stock was too long for comfort, especially when compared to my 870 that wears a shortened LOP Speedfeed stock. After some random searching of various forums, I learned that Ned Christiansen did a nice LOP reduction on the Benelli stocks, but given his busy schedule and various projects, only does this work in small batches on occasion. However, he was kind enough to share with me some suggestions and advice on how to do this modification, so I decided to try it myself.
Parts/Materials used:
Miter/chop saw
Jigsaw
Cordless power drill (drill press would be better)
Orbital sander (belt sander would be faster)
Ύ thick oak/birch/anything HARD
Brownells Acra-Quick Gel (Brownells 081-000-020)
Sims Limbsaver Grind to fit pad (Brownells 902-000-072)
Can of WD-40
Tee nuts/threaded inserts (part numbers to follow)
Socket head cap screws (part numbers to follow)
Roll pins (part numbers to follow)
1. First determine how much shortening you need on the stock. I decided to remove 1 3/8 inches. Based on my crude calculations, I think 1 5/8 is the maximum you can safely cut, when using a Ύ thick piece of filler; the internal shape of the stock changes radically as it gets to the portion where the sling plate feeds through the stock. Make sure you tape up the stock before cutting, and use whatever means necessary to secure the stock when making the cut. See photo A
Photo A: cutting the stock
http://images34.fotki.com/v1126/photos/1/1301170/6110738/20080406_LA5B5883-vi.jpg
-----------------------------------------------------------------------------------------------------------
2. Prepare the stock. I removed the internal raised ribs to facilitate fitting of the hardwood insert various carbide burs in an electric dental lab handpiece. I then took a round bur, and using the shank as a stop, made a half-round retention trough on the inside, to increase the epoxy bonding surface area. See photos B, C, D, E
Photo B: raised internal ribs of stock. Note this is photo of cut portion; I forgot to take photo of the ribs in the portion of the actual stock prior to removal.
http://images28.fotki.com/v1029/photos/1/1301170/6110738/20080409_LA5B5892-vi.jpg
Photo C: raised ribs, alternate view.
http://images22.fotki.com/v837/photos/1/1301170/6110738/20080409_LA5B5893-vi.jpg
Photo D: retention troughs created with round bur.
http://images22.fotki.com/v810/photos/1/1301170/6110738/20080409_LA5B5891-vi.jpg
Photo E: portion of raised rib remains, which acts as a vertical stop for the filler piece.
http://images27.fotki.com/v967/photos/1/1301170/6110738/20080406_LA5B5886-vi.jpg
-----------------------------------------------------------------------------------------------------------
3. Cut and fit the hardwood filler. Using the cut portion as a template, place on your slab of wood and mark accordingly. Using your favorite tool, cut out the filler carefully. Then, using whatever means necessary, start sanding/grinding the piece until it fits into the stock, flush and secure. This part took me about 45 minutes using a POS orbital sander. ***Ned has used G10 laminate on some of his previous projects, but advised against it due to cost, weight, and difficulty of preparation. Besides, grinding G10 and inhaling the glass particles would be equivalent to smoking a few packs of menthol cigarettes. See photo F
Photo F: hardwood filler piece cut and ready for sanding & fitting.
http://images24.fotki.com/v874/photos/1/1301170/6110738/20080406_LA5B5887-vi.jpg
-----------------------------------------------------------------------------------------------------------
PARTS IDENTIFICATION:
http://images24.fotki.com/v865/photos/1/1301170/6110738/20080409_LA5B5888-vi.jpg
(A) 18-8 Stainless steel knife-thread tee nut/insert. This is the insert I planned on using, but due to size constraints and pad screw placement, I could not use it for the project.
(B) McMaster-Carr #92105A670. Zinc-alloy tee nut, 10-32 interior thread, 33/64 long, 9/32 drill size.
(C) McMaster-Carr #92105A016. Zinc-alloy tee nut with flange, 10-32 interior thread, 33/64 long, 9/32 drill size.
(D) McMaster-Carr #92949A270. 18-8 stainless steel button head socket cap screw, 10-32 thread, 7/8 length, 5mm hex head.
(E) McMaster-Carr #98296A914. Steel roll pin, 3/16 diameter, 1 ½ long. Requires 4.8mm/0.189 diameter hole Use drill bit McMaster #2958A81, not shown.
(F) McMaster-Carr #98396A913. Steel roll pin, 3/16 diameter, 1 3/8 long. Requires 4.8mm/0.189 diameter hole Use drill bit McMaster #2958A81, not shown.
-----------------------------------------------------------------------------------------------------------
4. Filler preparation. With filler inserted into stock, mark the vertical centerline, and note the ANGLE and position of the stock retaining lock nut. When you drill the access hole for the lock nut, you will have to drill at an ANGLE so your socket will engage in a straight line. I made a 3/4 hole that fits my standard socket just fine just make sure you take your time, especially when using a cordless hand drill. See photos G, H.
5. Pad placement. Using the template supplied, place over stock/filler and mark appropriately on the wood piece. NOTE, you may want to bias the placement towards the top, as the stock, and filler are angled sharply on the bottom, which can make the placement of the threaded insert difficult, if not impossible. Also make sure you are not violating the minimum outline requirement of the pad the Sims pad has hollow sections you do not want to perforate. Again, drill slowly and carefully, going from your smallest bit to the size indicated for the insert. A drill press would be good here, ensuring a perfectly straight and perpendicular hole, but a cordless drill will work. See photos G, H.
6. Determine roll pin location. Find an area where two roll pins can be driven into the stock and filler, away from the tee nuts and stock lock nut access hole. For my application, I found two spots where a 1 3/8 and 1 ½ roll pin could be placed. Again, secure filler and stock, and drill carefully, the appropriate sized hole for your roll pin. I used 3/16 roll pins. See photos G, H.
7. Insert tee nuts. Lubricate well, and carefully screw in the inserts. I used an insert with a flange/stop for the upper hole, and a plain insert w/o flange on the lower, since there was no room for the flange. The photo shows some splitting, but since everything was going to get coated in epoxy, I didnt really care. See photos G, H.
Photo G: Prepared insert. Ύ hole drilled for access to stock nut. Roll pin holes seen on side. Arrow indicates where some wood blew out, as the tee nut placement was close to tapered edge. Upper portion has enough support and room for use of flanged tee nut.
http://images26.fotki.com/v957/photos/1/1301170/6110738/20080409_LA5B5889-vi.jpg
-----------------------------------------------------------------------------------------------------------
Photo H: Alternate view of hardwood insert, detailing tee nuts, roll pin holes and access hold for stock nut.
http://images35.fotki.com/v1162/photos/1/1301170/6110738/20080409_LA5B5890-vi.jpg
-----------------------------------------------------------------------------------------------------------
8. Glue and secure. Get the pins, punches and anything else ready. Apply the epoxy to both the stock and wood, insert, wipe off excess, and tap in roll pins. Set aside and let cure. See photo I.
Photo I: Hardwood insert glued and secured with 3/16 roll pins.
http://images36.fotki.com/v1157/photos/1/1301170/6110738/20080417_LA5B5899-vi.jpg
-----------------------------------------------------------------------------------------------------------
9. Pad grinding. Affix pad to stock, using appropriate driver. Hex heads sure beat the Phillips head commonly used to secure pads. I then used a carbide to get the plastic portion of the pad ground down to the last 1/16 of an inch, and then threw the pad in the freezer overnight. When hardened (will not be rock hard), I then went at it with the sander, using the 80-grit disc. As you grind, spray WD-40 liberally and often on the rubber, as this will facilitate a smooth removal. Make sure you tape up the stock.
10. You are now done. Note, I got lazy so I never did bother using anything other than the 80-grit disc, and it looks just fine to me. Maybe, Ill go back later with some finer grit discs.
FINISHED PRODUCT:
http://images34.fotki.com/v1144/photos/1/1301170/6110738/20080417_LA5B5897-vi.jpg
http://images27.fotki.com/v995/photos/1/1301170/6110738/20080417_LA5B5898-vi.jpg
-----------------------------------------------------------------------------------------------------------
***If youre feeling really lazy and dont feel like grinding down a recoil pad, the Sims/Remington R3 recoil pad for the 870
http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=18136&title=LIMBSAVER?%20RECOIL%20PAD
will fit about 96% of the Benellis contour, provided you cut the correct length off the stock. However, given that the pad fitting is not too difficult, especially when compared to fitting the hardwood insert, just get the pad of your choice and grind away. Do not skip the WD-40. It makes grinding much easier and affords a smooth finish, even with 80-grit paper alone.
***I recommended a drill press in the beginning only to ensure straight perpendicular holes. A cordless drill is fine, but when starting with the skinny bits, there is a tendency for the bit to bend so use care when drilling. You can see where some of my holes got off-axis, but even so, this is not really a problem as long as you catch the mistake early, redirect, and drill with intent.
***the 33/64 long tee nuts were the longest available for this particular application. Nevertheless, with 7/8 long cap screws, there is more than enough engagement to secure the pad
***Please disregard this post if you have unusually long arm and have a tendency to drag your knuckles on the ground when you walk.
Again, I must extend my sincerest thanks to Ned Christiansen for giving me those few pointers that made this project possible. While my results may not be up to Neds standards, this is a nice DIY project that accomplishes the task at hand that most people should be able to undertake.
Dave.