Rifle Bedding, Part 2: the BAD.
I almost labeled this section the ugly but that is not really what this is. An ugly bedding job can be functional, so it is not really bad except that it is unacceptable, especially from a âprofessionalâ. A stock that doesnât fit your metal is ugly but, worse, it is bad. A rifle will never shoot to its full potential if the stock to metal fit is not perfectly stress free.Â
Never assume even the best stocks, whether factory supplied or aftermarket, are actually ready to go drop-in inlets no matter how they are marketed. With the exception of V-block chassis like the Manners Mini-Chassis (which I think is the catâs meow but even then I have had to have them fixed a little) I will bed everything to ensure it has a good fit. Now I have to qualify that statement because even as a little boy doing something just because I was told to was never a good enough reason. What we are looking for here is, âWhere is the stress in this system?â Without the answer to that question your bedding will never be as good as it should be because it will either not be properly centered, bedding will not be even and uniform, or you will induce stress into your bedding because you failed to eliminate it when you started jamming epoxy in the stock and bolted it down.
When you first buy a rifle the first thing you should be doing (new or used) is disassembling it, cleaning it, properly reassembling it, then testing function. Honestly, if you bought it at a store you should have identified a lot of this before purchase. If you bought it online you should be giving it a once over before filling out your 4473 and taking it home. If there is any bind you will feel it. If there is uneven or off-center inlet you will usually see it (barrel channel is most common). Sometimes an inlet is so crooked it shouldnât be fixed, the stock should be returned but sometimes you can work around minor errors. If the inlet is off you will often have a hard time getting action screws into the  action threads easily without finagling. You will also have to finagle the action into alignment if the in-letting is too large which is just as bad (unless you have ordered over-sized inlet for the purpose of epoxy bedding) as too tight in regard to performance potential. When you take it apart and when you put it together you are getting your first snapshot of how well the stock fits your barreled action.
Leveling the stock is like leveling sights and is where I start for general snapshot:
Level shows McMillan installed pillars are not straight and is the reason assembly was difficult:
I say I want the snap shot because it helps me figure out where to go next. I will usually deal with a barrel channel first because I am either going to free-float it or I am going to full-length bed it. Either way, I am taking material out of it. I am taking material out in either case (and from around the action when I get there) for the sake of uniformity and to relieve any torque the forearm may impart on the action by means of contact with the barrel. Free-floating it up front allows me a more honest assessment of how the action fits the stock in-letting.
I generally do this with emery cloth if the barrel channel is pretty close to where it needs to be. If there is a lot of work to be done I will use a cutting tool made for barrel channels (that you use like a plane), next clean it up with scrapers, then go to emery cloth. If I am working with a gun that already has a finish on it I tape the barrel with at least two layers of masking tape to prevent damage to the metal finish. As I remove material, I may add layers of tape to increase the diameter of the barrel channel until I have the amount of clearance I want. Â When using the emery cloth you must be careful to pull straight up and down and not at an angle or you will round off the top of your forearm inlet. I keep snugging up the action until it is sitting tight in the stock and the barrel has the desired clearance.
Some guys donât like big gaps but I want enough to ensure there will be absolutely no contact with the barrel during normal use. I put that number at .050-.060âł ,as a minimum, and more is not wrong if you have enough forearm to support it and donât mind the way it looks. Tom Manners of Mannersâ Composite Stocks shoots for .100âł of clearance and on a beefy stock I think that is pretty ideal. I have never had an issue with a Mannersâ barrel channel hitting the barrel no matter what I was shooting off of from bipod, to rested over logs and rocks, to steel or concrete barricades. Either way, that dollar bill you have seen guys slide between their barrel and stock to test float does not mean jack. It is nowhere near enough float regardless if you intend to leave it full-floated or full-length bed it.
Once I am certain that my barrel is not in contact with my forearm and that I have no other glaring issues, I will wrap the barrel with tape at the shank and the tip of the forearm to center it in the barrel channel. I coat the action with in-let black (a transfer ink) and bolt the gun into the stock and tighten it down. If your stock is dark, use in-let gold (or bright lipstick just donât get caught). When I remove the action screws and pop the action out of the stock it leaves a black footprint in the stock in-letting where there is actually stock to action contact.
McMillan KS stock with in-let black showing actual contact with action:
Often you will see that there is very little, and uneven contact, as seen in the McMillan stock above. I then remove those black spots just like a stock maker would with a wood stock blank. I re-apply the in-let black and bolt the gun together again then repeat until I have even contact. Why go to the trouble you may ask? I want my bedding material to have an even thickness all the way around and that cannot happen if you have high spots in the substrate you wish to apply bedding compound to. If you allow the fit to remain unchanged you will induce stress when you bolt that stock on. Itâs like trying to make a flat table with warped lumber; it might look flat and straight but there is a slight bow that is fighting to return to its original shape.
Stock with evenly floated barrel, action substrate fitted, and ready for epoxy:
Some folks have peddled bedding blocks as the solution to all bedding issues. Other people have bought that story and perpetuated that fallacy. I recently bought a left-hand Remington 700 Varmint as a donor to build my dad a Smokeless Muzzle-Loader. The 700 Varmint (and its long action brother, the Sendero) came from the factory with H-S precision stocks which have a molded in aluminum bedding block. The issue with the type of hemispherical bedding block used by H-S Precision and Bell & Carlson is they are surfaced (vice V-block which suck the action down into a wedge) but do not provide full contact. I am not saying that the blocks are not accurately made, just that they do not adequately fit the actions (the notable exception being the KMW IMB that uses a hemispherical interference fit).
The problem is that a lot of factory actions are slightly warped from heat treat processes. Polishing/finishing compounds the problem. Newer actions are often tumble polished and come out more even. Older actions were hand polished on a wheel/belt which left them a little more inconsistent in surface dimension (one reason the rear bridge often needs bedded in regard to a scope base). As a result, action to bedding block contact is severely compromised.
If you look at the H-S Precision bedding block below you will see there are exactly five points of contact where the inlet ink transferred: front receiver ring either side of the action screw (1&2), left side between mag well and trigger well (3), at the tang on the right sight, top by trigger well (4), and the left side of the tang where the guy who painted the stock ran a heavy coat of paint over the tang portion of the block (5).
It is also clear that contact is uneven and disproportionate from side to side if you look below at the close up of the front receiver ring. The left side makes contact for half and inch and the right side makes contact at single, small point. The recoil lug well also shows that the lug makes about 50% contact which means that either the receiver face or block is out of square.
A quick glance at the barrel channel showed that the barrel was not centered. Since the bedding block is molded into the stock you cannot really realign the bedding. I know I said you want more clearance than a dollar bill but if a dollar will not pass the channel then you most certainly need to remove material. I could not get a slip of paper to go past the tip of the forearm. A quick wrap of the barrel in tape and a five-minute job with emery cloth cleaned up the barrel channel enough to allow me to evaluate the factory barrel (had to decide if I was selling it or keeping it for a trainer action) but does not have a full .010âł float. I will fix that when I get the muzzle-loader barrel installed however, floating the factory barrel took groups from a little over three inches to half that with cheap plinking ammo.
This small sample demonstrates that even expensive stocks with good reputations (justifiably earned) are not perfect drop-in replacements that will be trouble free. You cannot expect what you do not inspect and you cannot inspect what you do not know to look for. These are some common areas that are problematic and things you should inspect on every rifle you purchase or build. Next time we will look at how proper bedding jobs fix these issues.