I'll start it off with some basic tips...if you have additions, expansions, corrections, etc., just add them on and we'll incorporate them into the process by edit. Then we'll see if there's a place for it on the Board somewhere...This is a group effort, so don't be shy...besides, I'm hoping to learn more tips, too! We'll start with the most obvious and common and work our way into the more serious...
ACCURIZING TIPS FOR MILSURP RIFLES
Assuming we're starting off with a rifle with headspace checked, in good physical condition, no significant unrepaired stock cracks....
1. Check to see if you are using the correct ammunition. I know, it seems strange to think a mistake like that could be made, but....weirder things have happened. Folks have used wrong calibers, training ammo, etc. Keep your ammo at room temperature for 24 hours before shooting.
2. Check your action screws to make sure they are snug. No, you don't have to have them pry-bar tight; just snugged up. Make sure your band springs are ok-your bands aren't too tight- and your handguards are in place. (If they slide around, topsec recommends installing 2 #4 wood screws per band in the stock to keep them in place. Check your sights. Are they wiggling? They must be solid and firm. Don't assume - check. You may be surprised.
Fire for affect.
3. Check your rest. Make sure you're using sandbags. Firing from a "hard" rest can literally bounce your rifle in the air, changing every shot's point of impact. Make sure you are not using the barrel or the magazine as a point of contact with the rest. Use the stock.
Fire for effect.
4. Try different types of ammunition. Every rifle "likes" and "dislikes" certain surplus ammo and/or handloads. Try different powders, bullet weights, and charges. If subsequent shots are stringing or going wild, let the barrel cool between shots. Sometimes, barrel heating expands the barrel or stock, putting pressure on both, changing harmonics and destroying your rifle's grouping ability. A recent discovery is that milsurps seem to like those long, round-nose bullets...I would hazard a guess that they behave better because the bullet offers more bearing surface for the bore. This REALLY shows up when you have a less-than-good bore to work with.
Fire for effect.
5. Swallow your pride, before we get any further, and hand the rifle to the best shooter you know. See how they do. This isn't a knock on you as a shooter; some folks shoot better with certain rifles, poorer with others.
6. Let's look at that bore. Clean the bore first with soap and very hot water, using a slightly oversize brush; then with a cleaner containing ammonia or ammonia itself. If your lands and grooves are still not where you think they should be - distinct and sharp - build yourself a homemade "Foul-out" kit from 2 D batteries, a steel rod, wire, alligator clips and shrink-on tubing. Thanks to BurgieC, the link to the homemade foul-out kit is www.storm.ca/~debinn666/ht...ects9.html. I use industrial ammonia as a solution; others use different types of solutions or solvents. After an hour-long session, clean again with solvent, then back on the foul-out for another half-hour. Clean up and take a look. Don't be too discouraged by a bad-looking bore, or "sewer-pipe"; some of the best shooting rifles have bad-looking bores. The main thing is to get rid of the zinc and gilding-metal fouling that's left after all those FMJ surplus rounds.
Make sure your chamber and locking lug recesses are clean and dry.
Sometimes, bores are oversized. Slug your bore by driving a lead slug through, then use a micrometer to check. If your bore is indeed oversize, you may need a different caliber projectile...or may end up using cast bullets.
If you're plagued with inconsistent ignition, you may want to disassemble your bolt and really give it a thorough cleaning. If that doesn't help the problem, try a new mainspring. These can be had at Wolff gunsprings, (gunsprings.com.) For the 98, 98k or Turk Mauser, you want the 22# spring.
Fire for effect.
7. OK. Now we're getting serious. Disassemble the rifle. Look at the stock- for M-Ns, Mausers, etc., take a look at that recoil lug. Is it sharp and in place? It's not common, but sometimes that lug gets squashed rearward (picture dropping your rifle on its muzzle from on high). Look for evidence of shims- most likely, they will have left an imprint in the wood. Note: I just found a 1911 penny being used as a shim in a 1917 Eddystone! If shims are obviously missing, you may want to replace them. (Most folks use sheet brass or steel; some use aluminum can stock; knor recommends pipe strapping; topsec and Bimmer suggest gasket material; others use their imagination! I use heavy brass sheet stock.) Mosins sometimes have shims under the very rear of the tang as well as in front or in back of the recoil lug. M-1 carbines benefit from shimming the rear action lock-in. Topsec's tried and true techniques: With the barrelled action in the stock, put thumb pressure on the tang, watching the barrel. Now put pressure on the barrell, watching the tang. Either end rising may indicate a need to shim the other end. Sliding a dollar bill under the barrel can help you detect contact points on the stock- if the dollar won't slide, shim the barrell as indicated below, about 1" behind the very end of the stock. Now grab the bolt rail and try to move the stock forward/backward. Movement may indicate the need to shim in front or behind the recoil lug. Also, if the barrel is not correctly lined up in the barrel channel, a shim on the SIDE of the recoil lug may be in order.
If your stock checks out ok, you may not need to shim at all.
Next, look at the barrel channel. Is it obvious that the wood is in contact with either side of the barrel channel? Sometimes a shim won't be enough. Put the action in and take a look. If an area is rubbing, it may have to be shaved/reduced. Brownell's sells a dandy barrel channel tool- I've used mine for twenty-five years or so.
If you haven't found any evidence of barrel contact, try placing a brass or aluminum shim about 1" back from the foremost portion of the stock, directly in the middle under the barrel. The idea here is to place a constant and consistent up-pressure on the barrel. Winchester, Ruger, and many others routinely do this to their rifles. Topsec reports that there is an aftermarket gizmo that claims it can tune the barrel of a gun to any ammo, using adjustable screws to put this up-pressure on the end of the barrel!
Experiment with shims under the tang, in front of/in back of the recoil lug, at the bottom of the recoil lug recess. Yes, you're going to do a lot of disassembling/reassembling and shooting, bt the end result will be worth it.
Fire for effect. Keep track of what works!
8. OK, time for minor surgery...if needed, let's try a new crown. You can purchase tools from Brownells to recut and chamfer a brand-new crown; or, if you are incredibly "frugal" like me, chuck a brass round-head bolt in your drill. The head diameter must be larger than your bore. Cover the exposed crown and bolthead with valve grinding compound...and reapply as necessary as you push the head up against the crown. Do figure-eights to ensure each part of the crown will be identical. Be careful to clean up thoroughly when you're done.
This step should give you a new crown with the rifling leading right up to it. Often, overzealous cleaning from the muzzle with a steel rod without a muzzle guide will wear the crown along with a measure of the bore. Hopefully, you've solved that problem.
Fire for effect.
9. That crown didn't have good, sharp rifling leading all the way up to it? We may have to counterbore. CBing is drilling out the barrel to move the actual crown rearward, while leaving the outside of the barrel intact. This is best accomplished with a floor-mounted drill press. (Could someone suggest tooling and specs here? Thanks-)
Fire for effect.
10. You've done all of this- and still no improvement? There are some further steps you CAN take. Major surgery is one- a rebarrelling job. If you plan to acquire the correct tooling and do it yourself, please make sure you have headspacing procedures down COLD before you attempt it. Surplus barrels are available for most milsurps.
Trading stocks is also an option that I have seen work. Can't explain it, but....worth a try at this point.
Confession time- I once hooked up a very oversize brush on a steel rod (with Brasso as a cleaner) and connected to my drill. That bore positively shone afterward- and it DID improve the group sizes quite significantly. NOT for the faint of heart.
11. If you've done all of the above, and it still won't hit the broad side of a barn, don't fret. I've got one like that...a 91/30 that's very nice looking. It's going up on the wall in the den. Someday, I'll figure it out....till then, life is spicier with a little mystery!