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reloading 300 wsmDiscussion regarding the reloading of ammunition and tuning of loads for accuracy
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Vince Site Admin
Joined: May 25, 2005 Posts: 15718 Location: Brisbane AUSTRALIA
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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Wed Oct 07, 2015 5:57 pm Post subject: Re: reloading 300 wsm |
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bdriller wrote: |
I need to buy me a concentricity gauge |
bdriller, a concentricity gauge will tell you that you have a problem but doesn't fix it. The Hornady's tool can help correct some but it still doesn't solve your problem - your dies. I had a thread of my fight with concentricity but can't find it right now.
_________________ "To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt
"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein |
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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Wed Oct 07, 2015 6:04 pm Post subject: Re: reloading 300 wsm |
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Here is the second one
www.huntingnut.com/ind...pic&t=9459
Still looking for the first.
_________________ "To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt
"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein |
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slimjim Super Member
Joined: May 16, 2009 Posts: 8314 Location: Fort Worth TX
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Posted: Wed Oct 07, 2015 6:08 pm Post subject: Re: reloading 300 wsm |
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Here is the original topic where I got new expensive reloading equipment and my loads went from a 0.5 MOA to crap. Turned out to be concentricity.
www.huntingnut.com/ind...pic&t=9417
_________________ "To anger a conservative, lie to him. To anger a liberal, tell him the truth." - Theodore Roosevelt
"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein |
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SingleShotLover Super Member
Joined: Dec 26, 2007 Posts: 1005 Location: Illinois
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Posted: Thu Oct 08, 2015 5:10 am Post subject: Re: reloading 300 wsm |
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Everyone has his or her own ideas when it comes to sizing a fired case. Some neck-size only while others insist that full-length sizing is necessary. There are positives and negatives to both opinions. Neck sizing allows the rest of the case to retain the coveted snug fit in the chamber that helps ensure perfect alignment. The two major drawbacks to this method are the likelihood that cases sized in this manner will probably not fit well in another firearm and, because of the mechanics of the sizing process, case shoulders will creep forward ever so slightly with each sizing requiring a full-length size to bump them back and allow them to chamber at some point. It is hard to argue the fact, however, that neck sizing does seem to promote more accurate ammunition in many cases. Of course the neck has to be sized enough to securely hold the bullet, but just how much of the neck needs to be sized is a subject of controversy. Most accounts seem to agree that there should be at least one caliber length of the neck sized (and a corresponding amount of bullet body seated) for a secure grip. This of course would translate as a minimum of .224” for the various “.22” calibers, .308 for the various “.30” calibers and so forth.
Few rifles shoot their absolute best with full-length sizing, but many do surprisingly well with “partial” sizing. This method requires adjusting the die to size the neck of a fired case fully but only lightly bump the shoulder. Rather than moving the shoulder back to factory “spec”, this allows the completed cartridge’s shoulder to remain at a length that firmly contacts the shoulder area of the chamber from which it was fired and creates positive headspace. This also slightly sizes the body of the case for ease of chambering but not so much that it is a sloppy fit. Using this method prevents the shoulder from growing to the point of difficult chambering after a few loadings.
Regardless of the method you choose, quality dies and setting them up correctly is of great importance. Remember that the coarse nature of the die body threads makes precision difficult. The best way to take the slop out of those threads before tightening the locking ring down is to make sure that the die is aligned with the press ram. With no case in the shell-holder, place enough washers (I keep a handful of thin "fender" washers handy) on the shell-holder to come into firm contact with the adjusted die base when the press ram is fully extended. This pressure helps align the die squarely with the shell-holder. Holding this pressure firmly on the die, tighten the die's locking ring. (Do the same thing to your seating die for better bullet seating alignment.)
Primers also create a conflict. Benchrest primers run anywhere from a few dollars more to three times as much as standard primers. Many shooters aren’t too happy about those kinds of prices but figure that since they are factory “best” their consistency is better. Since in theory this should translate to better groups due to more consistent ignition, many bite the bullet (all puns intended) and pay the tariff. The surprising part is that many times side-by-side comparisons have shown some of those expensive benchrest primers to have a larger deviation in performance than those considered to be standard. Bottom line is that you need to do your research and not get hung up on preconceptions.
Bullet choice usually isn’t as much of a hassle. Everyone has his or her individual favorite brand and/or style. While all manufacturers keep tight quality control on their general offerings, thankfully each also offers at least a few versions that they consider to be “match” quality. In these cases the manufacturers do indeed hold their products to higher standards of quality control. Most of these bullets are fully capable of shooting far better than either the typical rifle or rifleman (or woman) can really appreciate. For others who have an inflated opinion of either their rifles or themselves as shooters (perhaps with reason), there are the makers who specialize in truly match grade performance. Berger in particular specializes in phenomenally accurate bullets…assuming a quality rifle through which to fire them.
The last component we need to address is the powder. With the vast number of powders available to the loader, what do we want to look for when pursuing that perfect group? First let’s consider case capacity. It is generally a good rule of thumb that the best powder for a given cartridge should occupy at least 80% of the case with appropriate loads. This makes sense since a powder that occupies that much space will present a more uniform burning surface to the primer flame than one taking up less space that might end up distributed along the bottom side of the case. Powders that both achieve the desired velocity range and fill the case are usually the best place to start when building accuracy loads but are no guarantee that they are the best choice. Where the quest usually breaks down is in the fact that many loaders insist on settling on a powder that encompasses the largest range of rifles in their possession. The thought that this is a compromise at best seldom deters these people and top-notch accuracy usually suffers pretty much across the board. Finding the perfect balance of brass, primer, bullet and powder for a particular rifle necessitates experimentation with various powders to find the one that performs the best in a specific caliber; let alone rifle. This experimentation is critical since during the process of firing any individual shot, the conditions and environment over which we have any semblance of control stops at the end of the barrel. Our goal is to provide that perfect balance to ensure that everything is as close to ideal as possible within that short 20 to 26” distance to give the bullet a chance at accuracy. Once it leaves that barrel all bets are off and conditions far outside our control take charge.
Bullet seating is a critical part of the overall picture. A person can do everything else perfectly and totally ruin the effort by improper seating of the bullet. Some dies come with seating stems that are crooked or out of alignment. Dies such as this will defeat your best efforts to seat bullets straight. Even those whose stems are straight may have enough “wobble” to cause error. If you think your stems are straight but still get non-concentric seating you might try leaving the stem-nut loose to allow the stem to follow the bullet rather than forcing it to one side or another. Even custom “benchrest” dies can exhibit run-out and some of the least expensive dies may load the straightest ammo. Only testing can tell. In general, seating dies that support the bullet all the way into the case will load straighter ammunition. It also helps to seat bullets about half way then rotate the case 180 degrees and finish the seating process. This lessens the likelihood that the bullet is started wrong and stays wrong all the way through seating. Crimping is seldom needed (or desired) with single-shot or even most bolt guns unless for the really heavy recoiling rounds.
Bullet concentricity, or “run-out”, can be measured with a wide variety of relatively inexpensive devices called comparators. An easy on the pocket quick check is to roll the loaded cartridges across a table while watching the bullet. If a discernible amount of wobble is seen the run-out is definitely excessive. Using the various gauges will give you precise measurements but can’t solve the problem for you. The most you can do with grossly out of line cartridges is to break them down and start over. Obviously less is better and those with .002” or less run-out are best used for varminting and target.
Cartridge overall length (OAL), or seating depth, is a subject guaranteed to start a big argument…or a small war. Everyone has his or her own theory concerning that “perfect” OAL, generally thought to be around .03” off of the lands. The problem is that everyone is wrong. Let me explain: We all know (or should know) that each rifle is an individual. What works for one (powder/primer/brass/bullet combination) is quite likely not to work for its identical mate coming off the manufacturing line immediately after. Such being the case, what makes any of us think that any one OAL is right for all rifles? Seating depth is just one more factor that requires trial and error to find that sweet spot that makes our individual rifle sing a pretty tune.
Finding that perfect length can become confusing but there are a few factors that we can look at that might simplify things a bit. The newer homogeneous (constructed of a single material; copper alloy most commonly) bullets are lighter than lead-core bullets of the same length. As a result, a 55-grain lead-core bullet is shorter than the same weight bullet of copper alloy. A quirk of these copper bullets is that they very seldom like being seated close to the rifling. In fact, most manufacturers will suggest seating them to allow for a fairly generous running start. This must be taken into deliberations when considering one of these new bullets for your rifle. Remember that longer bullets will require a faster barrel twist rate. It would be silly to try to use one of these longer bullets in a barrel whose twist rate was marginal for the same weight lead-core bullet. Accuracy is pretty well assured to go downhill fast.
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