Bedding with a V-block

[Boozer]

Just received my magpul hunter 700 long action stock. I've decided that even though it has a V block, I'm going to go ahead an bed it. It may not do any better, but hell, it can't hurt! I've only bedded actions in wood stocks before, never plastic or with a bedding block, any pointers? In general I use the "stress free" method.

When doing the wood stocks, I typically dremel out a good amount of the material so that there is a decent thickness of epoxy all over. No thin spots, and the epoxy is in 100% contact with the action, no wood. I don't know how feasible or necessary this is with the aluminum bedding block. I would prefer to have 100% contact, meaning just knocking off the edges of the V block except for 2 areas right around the action bolts (would be similar to a pillar bed job). Pic of the bedding block is attached

Thoughts?

 

[J E Custom]

I also believe in bedding the stocks with chassis to avoid the chance of it not shooting the first time.
(Sometimes they will shoot good without bedding but you cant depend on it).

Most Chassis are not set up to bed and they do not have true pillars the way they are made. If you look at your stock you can see that the action screw hole does not contact the action because of the groove. (This is common with bedding block stocks) and a metal shim or a pillar should be added to support the action and give it metal to metal to metal contact for best results.

In many cases I just bed a washer or insert to this area or drill out the action screw hole and thread a pillar all the way through to eliminate any chance of compression of the bedding material in this area. (I like the action and floor metal setting on the pillar). When done this way I find that actions stay torqued correctly for ever.

Chassis systems give the stock a good foundation for bedding and if prepared properly makes for a very good bedding job.

Also most chassis are designed to have the recoil lug contact the chassis in back. I always remove some of the material with a mill or Dremel in the lug slot so that bedding can go between the lug and the chassis for best results.

Some don't believe in bedding chassis, but I do because it is just one less thing to worry about when load development starts.

J E CUSTOM

 

[Canadian Bushman]

+1 to what jerry said. Hard to argue with that man.

I could add a couple things.
Like JE i have had good luck using shims around to bolt holes to plant the action as well as position the barrel in the channel. With that particular stock you would need to c'sink the bolt holes in order to use shims.

Another thing ive always done with bedding blocks is dremel the high spots down, rough up the surface of everything else, and drill holes perpindicular to the surface about .2-.3 deep. When i apply the compound i use a tooth pick to get most of the air out of the drilled holes, and lug channel before i drop in the action in. This makes sure even if the compound doesnt adhere to the aluminum, it is mechanically locked into the stock and thick enough around the action that it doesnt chip.

 

[Boozer]

Good advice from both you guys. thanks so much.

I do like the idea of installing a shim under the bolts, but I'm not quite sure how I would accomplish it. I can drill it out, but with a drill bit on the press, but the area will have a beveled bottom, not flat. I don't have a mill, so I may have to get creative. may have to go the route of drilling it out deep enough to epoxy in short pillars.

Maybe I can get a flat bottomed router bit, and chuck that up in the drill press, then just go nice 'n' easy. That may be just enough to get er' done.

 

[Canadian Bushman]

Good advice from both you guys. thanks so much.

I do like the idea of installing a shim under the bolts, but I'm not quite sure how I would accomplish it. I can drill it out, but with a drill bit on the press, but the area will have a beveled bottom, not flat. I don't have a mill, so I may have to get creative. may have to go the route of drilling it out deep enough to epoxy in short pillars.

Maybe I can get a flat bottomed router bit, and chuck that up in the drill press, then just go nice 'n' easy. That may be just enough to get er' done.

An endmill would probably be your best bet. They are not perfectly flat on the bottom but with a hole going through the center, the angle will be minimal.

 

[bigngreen]

I would not worry about shimming up the screw holes, Kelbly's did some testing with bedding and they found in bench guns that having direct contact with pillars and action was slightly detrimental to accuracy, one of the best guys I know of at bedding and building record setting rifles will not bed them on the pillars but has an even thickness of epoxy over them, hunting rifles he will set them on the pillar.

 

[Canadian Bushman]

I would not worry about shimming up the screw holes, Kelbly's did some testing with bedding and they found in bench guns that having direct contact with pillars and action was slightly detrimental to accuracy, one of the best guys I know of at bedding and building record setting rifles will not bed them on the pillars but has an even thickness of epoxy over them, hunting rifles he will set them on the pillar.

Do you have any idea or understanding why that is?

 

[Boozer]

As I mentioned in my original post, I do like the idea of having the surface in contact with the action consistent (not part aluminum, part epoxy) it would seem to me that with temperature changes, and different rates of thermal expansion, that things would inevitably move around a little. if the material touching the action is consistent, the expansion/contraction would be more consistent. Just throwing this our there as a thought, makes sense in my head anyway...

 

[J E Custom]

Good advice from both you guys. thanks so much.

I do like the idea of installing a shim under the bolts, but I'm not quite sure how I would accomplish it. I can drill it out, but with a drill bit on the press, but the area will have a beveled bottom, not flat. I don't have a mill, so I may have to get creative. may have to go the route of drilling it out deep enough to epoxy in short pillars.

Maybe I can get a flat bottomed router bit, and chuck that up in the drill press, then just go nice 'n' easy. That may be just enough to get er' done.

I use a piloted drill bit for this. I can find/make a pilot that fits the screw hole and cut a nice flat bottom hole for the shim/washer to sit on. When I first started I bought several cheep drill bits the size I thought I would be using for the pillars and simply ground them down to a piloted point and then squared the part of the bit that would cut the flat bottom hole. It worked well and I used them for years before buying piloted bits.

Like these, Search results for: 'piloted drills'.

J E CUSTOM

 

[Winny94]

I also believe in bedding the stocks with chassis to avoid the chance of it not shooting the first time.
(Sometimes they will shoot good without bedding but you cant depend on it).

Most Chassis are not set up to bed and they do not have true pillars the way they are made. If you look at your stock you can see that the action screw hole does not contact the action because of the groove. (This is common with bedding block stocks) and a metal shim or a pillar should be added to support the action and give it metal to metal to metal contact for best results.

In many cases I just bed a washer or insert to this area or drill out the action screw hole and thread a pillar all the way through to eliminate any chance of compression of the bedding material in this area. (I like the action and floor metal setting on the pillar). When done this way I find that actions stay torqued correctly for ever.

Chassis systems give the stock a good foundation for bedding and if prepared properly makes for a very good bedding job.

Also most chassis are designed to have the recoil lug contact the chassis in back. I always remove some of the material with a mill or Dremel in the lug slot so that bedding can go between the lug and the chassis for best results.

Some don't believe in bedding chassis, but I do because it is just one less thing to worry about when load development starts.

J E CUSTOM

What is the reasoning with removing aluminum in the lug area? Your logic is saying bedding material is compressed by torquing the action screws to 65 in/lb so surely the bedding material in the lug is compressed during recoil, or am I misunderstanding something?

Unless there is some conflicting info out there, I would believe this is a moot point as devcon has a compression rating of 8,400 PSI - much more than the action screws can apply.

Do you happen to have a write up or video of the process you use for bedding? Ive been trying to follow your advice in both this thread and in the own I started about pillars contacting the action and there are just some gaps in the logic in my head and I think reading/watching a tutorial would fill them in for me.

 

[J E Custom]

What is the reasoning with removing aluminum in the lug area? Your logic is saying bedding material is compressed by torquing the action screws to 65 in/lb so surely the bedding material in the lug is compressed during recoil, or am I misunderstanding something?

Unless there is some conflicting info out there, I would believe this is a moot point as devcon has a compression rating of 8,400 PSI - much more than the action screws can apply.

Do you happen to have a write up or video of the process you use for bedding? Ive been trying to follow your advice in both this thread and in the own I started about pillars contacting the action and there are just some gaps in the logic in my head and I think reading/watching a tutorial would fill them in for me.

The reason for removing aluminum in the rear of the lug area is to get clearance for bedding material. Most bedding blocks are designed to have the lug in contact with the back of the lug area
and little if any compound can get behind the lug to give 100% contact helping the recoil lug avoid bending or at best flexing. also most of the time the slot is not located correctly in order to center the action screws in the pillars and if they contact the pillars anywhere but the ends, they become recoil lugs and really hurt the consistency.

On the compression rating, recoil is momentarily and should not compress and yield. but the action screws apply constant pressure and can give the bedding time to compress and yield changing/lowering the torque. also the reasoning behind the pillar bedding is to take this constant load and stabilize/eliminate any bedding being compressed leaving the bedding to hold the action in the same place each time it is fired. (A true stress free bedding is what we are looking for and with the pillars taking the torque this is the optimum condition for consistency). If pillars are not used, over time the bedding or the stock will yield to the constant torque.

Many bench rest shooters actually glue there action to the stock with bedding material and just
leave the action screws off. (Some install them with Loctite and just screw them in hand tight with no torque). Of Corse this is not practical for our type of hunting and with the big magnums so we try to get the same results by using pillars with our bedding system. Barrel blocks are another way to eliminate or minimize this problem but again it is not practical for a hunting rifle.

J E CUSTOM