Home Forums Hunting & Shooting Gunsmithing Bad bedding job - what are the symptoms???

OK, picked up a new M70 Extreme Weather 300WSM earlier this year. I pulled the action out of the stock, or maybe I should say I spent 5min getting the action out of the stock - recoil lug is bedded all the way around - no gap on bottom, sides or front as I personally would normally do. Putting the action back in the stock takes a little bit as well to get everything perfectly lined up.

Anyway, to my question, what do you think the symptoms of this would be when shooting? Stringing, scattering, etc.?

I know the recommendations I always read, and what I do myself, are to tape the sides, bottom and fromt of the lug to ensure only contact at the rear of the lug. But I can't recall reading the reason, consequences, etc.

Thoughts? Thanks!!!

Adding clearance to lugs etc., usually only aids in the ease of disassembly or assembly. Actions which are "glued" in such as you describe don't, as a rule, cause problems unless it's done carelessly. What causes problems is If the action was not level when it was bedded, or, if there is uneven pressure on the barrel. These will cause problems.

All of the new FN M-70's I've seen have been bedded as described; they are also now using something that resembles Steel-Bed as the compound.

IMO, a big improvement over the old rubbery, theromplastic crap that USRAC was using, assuming, as Malm says, it's done correctly & straight.

MM

Like Malm says.. I don't leave gaps.. IMHO that defeats the purpose of bedding. When the rifle is bedded tightly and well, the accuracy at that point, for good or bad, can be attributed to the barrel, not the bedding..

Thanks Gentlemen! As I was thinking through it, I couldn't think of any reason it should be a problem (other than the action getting "locked" into the stock), hence my post.

I went ahead and dug it all out last night. Have some fresh Marinetex to re-bed it. I usually use 2 layers of masking tape on the sides, bottom and front of the recoil lug - may just use one this time - should be plenty to ensure it doesn't get locked in. Also, the was only a very, very small amount of bedding material at the tang and both pillar holes were full of it. There was also only about 1/2" of the barrel shank bedded - I prefer to bed the entire chamber portion of the bbl myself.

Plan on doing this tonight, so we'll see if there is any change in accuracy on Sat am.

Edit - Oh yeah, did I mention I don't like the trigger . . .

Bad bedding job - what are the symptoms???

As to consistent accuracy, same symptoms as no bedding job when you have a poor inlet/barreled action fit that is uneven causing stress when torqued. Just because a pour of bedding material is made to fill gaps around the recoil lug mortise, does not guarantee that the remainder of the stock inlet is even and on the same plane. In addition, if any pours are done without attention to detail, you may even mechanically lock the entire barreled action within the stock which may result in damage when the parts are disassembled.

I�ve yet to see any of the factory Winchesters with enough bedding material to mechanically lock the action requiring any excessive techniques for stock removal. I normally use the lap technique where the rifle lays upside down across your lap. You grasp the forend with your weak hand and slightly raise the barrel off your leg. You then lightly rap the barrel underside in front of the forend with a leather mallet. Any properly bedded action will pop loose with no damage.

Being you have it apart, removing the bedding material and re-bedding the action using your preferred technique and your preferred bedding material is not a bad idea. This will guarantee that you have a solid and neutral bedding that eliminates any binding. I do favor marine-tex gray as I�ve used it along with good technique to bed Winchesters up to a 416 Rem Mag in factory synthetic stocks shooting full house loads. The 416 Rem, modeled after Phil Shoemakers personal light rifle, only weighs 8 pounds 5 ounces and the bedding material has held up solid with hard use for several years. For best balance and minimal weight, the barrel contact pad at the receiver only needs to extend beyond the balance point of the assembled barreled action less stock. I use the knife edge technique to determine this balance point. As example, my last rifle balanced on a knife edge at 1.25" so I poured for a 1.5" contact pad.

Like any bedding job, when you break the rifle down for yearly LTIs, you can skim bed if needed to tighten things up.

I love a good Winchester, Good Luck!

I've noticed the "new" Winchesters seem to come directly off the CNC mill, basically they have a lot of sharp edges on them. Probably the reason you had a sticky one. I think thats the reason the whole masking tape thing got started. If the bedding is so tight as to cause scraping of the bedding compound that little bit of material is going to cause "rocking" in the stock.

An easy way to check your bedding is to get your rifle steady in a vice or rifle cradle and put an indicator out on barrel by the tip of the forearm. alternate tightening and loosening the guard screws, .003" of movement is my pass/fail.

two other tips:

on m-70's look for scraping around the trigger hanger

drill out the guard screw holes so the the guard screws don't touch.

Dale

OK, I rebedded the stock Thursday night. Everything went well. I chickened out and used two layers of masking tape on the bottom, sides and front of the recoil lug - glad I did 'cause it's still a very tight fit.

Not real fond of the tang area on these stocks - there is a large gap from where the rear action screw goes into the action and the stock - the action sits on the stock behind the action screw on the rearmost, thinner part of the tang. I built this area up with bedding material, but still . . .

I wrapped several layers around the barrel, but couldn't get it quite centered due to bbl inletting of stock not being perfectly centered. It has a gap at least two business cards thick all around up to the bedding at the chamber (went about 2" past the action with the bedding). Can't squeeze the barrel-stock together, and the gap is the same when the barrel is hot.

I used long, headless screws to guide the action - wrapped them with masking tape as well until they were a fairly tight fit through the stock. It took a couple of wraps of tape, so should be plenty of gap between the screws and screw holes.

Back to the range yesterday morning - no better than previously fired groups. All groups are 2-4X as wide as they are tall. For instance, one group was 0.5" vertical with a 1.7" horizontal spread. Shots are not "stringing" in order, but very random. Thinking it's gotta be the scope or mounts. It's not a proven load, but the results have been seen with every group shot out of this rifle (~20 different loads). Shot my 7mm Rem Mag along with this rifle a couple of weekends back - ~1-1.5" at 200yds with the 7RM, 3-6" with this one, so don't think it's me, wind, etc.

Details - M70 Extreme Weather 300WSM, Talley Ltwt extra lows, VX3 3.5-10X40 (new when mounted). Loads - 180gr Accubonds, 180gr Partitions, 150gr Hornady SP's, 168gr TTSX w/ Re17 (I know, try a different powder, but I'm having a hard time believing powder would cause what I'm seeing).

Any other thoughts guys?

When floating a bbl, what should the minimum gap be?

Thanks for the help so far!

A barrel should float enough to pass the "smack" test. If you "smack" the tip of the forearm in any direction with the palm of your hand and can hear or feel the barrel making contact with the stock, keep cutting. Keep in mind, barrels get hot and they move. You need to provide sufficient clearance to prevent contact when they move. If not, then you run the risk of a contact related flyer. Check the crown while you are at it. keep it clean of any build up so it doesn't interfere with the natural path the gas takes as the bullet clears. An off axis gas slap will cause fliers.

If it's a scoped unit and one has a boresighter try this exercise. Intall the boresighter and not the precise coordinates of the crosshairs. Without removing the bore sighter, carefull loosen the action screws and note the cross hair coordinates. If the cross hairs have moved at all, the barrel or action are being stressed.

I don't have a boresighter, but have thought about buying one.

I was thinking that I could also check the crosshair coordinates between shots to see if scope internals were moving between shots. Are they precise enough for this?

I have "fixed" a few winchesters that would not shoot buy floatiing the magazine box. Basically, the magazine box was pushing up on the center of the action, negating the "stress free" bedding job.

Also, the tightening of the center screw on the winchester and Ruger can bend the action in the middle. Just leaving the center screw figernail tight can relieve some stress on the action.

The trick of floating the magazine box has fixed many Winchesters, Rugers, and Remingtons. You should be able to drop the floor plate and wiggle the magazine box up and down with finger pressure, if you can not, the magazine box is pushing up on the center of the action.

The FN Winchesters are single piece bottom metal with only two screws. So the center screw can't be the issue.

I've also heard of this magazine box issue before. Anyone have any idea if this is an issue with a one piece bottom metal Winchester?

Thanks

Tom

I have shot a few groups through the rifle with no mag box/follower in place - no difference.

As Tom mentioned, the new FN M70's have a one piece bottom metal and no center screw. The front and rear action screws were torqued to ~50inlbs, now they are at 65inlbs.

Also, I removed the Talley Ltwts (someone mentioned the front screw in the front ring is sometimes too long and bottoms out on the barrel threads). It didn't appear to be the case on mine, but I ground off a small amount just in case. Reinstalled the Talleys, torqued to the recommended 30inlbs for the base screws and 20inlbs for the ring halves, with a new scope.

Will head back to the range this weekend for additional testing with some of the same loads previously shot to see if there is any improvement.

Thanks for the help guys!

The bore sighter should be an extremely sensitive indicator, since it's located out at the end of ones barrel. A thousandths of inch at the receiver gets multipled several times when it's extended to the end of a barrel.

Other than the screws or pillars, there should be no contact between the mag box and receiver on the various Mausers either. Working on a 96 Swede stock right now that might be a hair shallow on depth. Might have to shave a little off the mag box to eliminate contact.

Put your hand around the barrel and the tip of the forearm and with your other hand loosen and tighten the action screws one at a time and sometimes you can feel movement between the barrel and stock if there is stress in your bedding job,another way involves a dial indicator and is more precise at detecting stress,hope this helps!

OK, I think I may have figured this out . . .

Changed the scopes, and while doing it, removed the Talleys to check the length of the forward-most screw - someone in the reloading forum mentioned having a few bottom out on the barrel threads prior to really tightening down the mount. I couldn't tell that this was the case, but I ground a little off the crew just in case. Reinstalled the Talleys with proper torque, then install a different scope.

Back to the range this morning with some of the last loads that I shot - exactly the same results, less than 1/2" vertical but 1-2" horizontal. Absolutely NO wind this morning, paid careful attention to my bench technique, etc.

Got to looking at the crown. These things now have a recessed crown and everything looks good at first glance - no dings, etc. BUT . . . looking very closely at it, where the edge of the bore/rifling is broke at a 45 degree angle, it is apparent that right side of the barrel is "broke" much more than the left side (when looking at the muzzle). If you took two circles, one slightly larger than the other, and perfectly centered the small one in side the larger one, this is what it should look like. Now move the larger circle to the right about 1/32-1/16", still centered vertically, this is what mine looks like.

Would this explain why ALL of my groups have a much larger horizontal spread than vertical (2-4X as much)?

Thanks!!!

I don't know if you have lapped your talley ringmounts, but those things are NOT necessarily straight. I had a set that took quite a bit of lapping to get them on the same axis -- there was a vertical discrepancy. If yours are like that, they could be stressing the scope.

You might also want to try a different scope, once you've checked the rings

Texram,
I, like you, prefer to leave a space on the sides, bottom and front of any Win. Mod-70..otherwise you can get binding in the action, but the final score will be in the shooting and so you should try it before releaving it. On a Mauser I inlet them tight all the way around the lug, then releave the front of the lug only after the glass has cured, just to make disasembly easier..It is very easy to chip glass going in or out if they are too tight..

If I am going to bed a M-70 tight then it will be a perminent glue job to the wood or composite stock.

It does not matter if you have 2-pc or 1-pc bottom metal, you need to have enough free-play in the magazine box or it will act like a fulcrum and bind your action which can easily cause erratic groups. Most specify between .020" - .040" clearance for proper mag box fit. This is an important detail in a good inletting and bedding job.

When you bed the rifle, bed both the top as well as the bottom. Assemble the rifle less spring and follower and check for clearance prior to torquing the action screws. If you have proper up and down movement of the mag box, begin to torque the action while keeping a check on mag box clearance. If the mag box binds, take it apart and use a belt sander on the bottom face of the mag box until you get the proper amount of clearance. Your goal is for .020" - .040" clearance so that the barreled action will be stress free within the bedding.

Good Luck!