Great informative post ned, I also do same sizing with same press and dies however i also neck turn new Lapua brass just removing any high spots i then size with a .335 neck bushing down to 3/4 the overall length of neck which i belive helps case to centre when chambering, Do you find runnout reduces on subsequent reloads after fireforming first load also may i ask what your runout is with new brass regards, paul t.Loudcherokee - the limiting factors likely to be noticed immediately when shooting such a setup out to 1000 yd will be related to barrel length, chamber specs, and the rifling twist rate. You should be good to go with your 10-twist barrel, which will effectively stabilize most lead core bullets up to about 215 gr. The 24" barrel will be a limiting factor as you're not going to get the kind of velocities with that barrel length and the various weight bullets you might choose with good BCs that you would see out of a 28" to 30" inch barrel length. Nonetheless, it's what you have, so you'll need to work within that parameter. Finally, it will be important for you to determine how long the rifle is throated so you can decide what bullet weight you can effectively load. The shorter the throat, the shorter (lighter) the bullet needs to be in order to prevent the base of the bullet from being seated too far down into the case neck with a long (heavy) bullet, which occupies otherwise usable case volume, and causes higher pressure at a given velocity. Of course, if you're loading rounds to magazine length, that limitation, rather than the length of the throat, may be the more important factor in terms of realistic bullet selection [weight/length].
In general, the heavier the bullet, the longer it will be, and the higher the ballistic coefficient (BC) it will have. There are certainly exceptions to these generalizations, but they hold true for many bullets. Working under the assumption that the bullets you might choose from all have fairly similar stability (i.e. no major design issues that negatively affect performance), the higher BC bullets available within a given weight range will usually be your best choice to minimize wind deflection at 1000 yd. There are a couple different ways you can go with this. For example, a 155 gr .30 cal bullet will typically have a much lower BC than a 185 gr bullet. However, you can push the 155 gr bullet much faster out of a 24" barrel using a slightly faster powder, so the difference in wind deflection between the two bullets isn't as much as you might think. Nonetheless, when loaded to equal pressure, the heavier bullet with the higher BC will almost always show less wind deflection. In other words, it is not typically possible to push the lighter lower BC bullet fast enough at safe operating pressures to overcome its BC deficit as compared to the heavier/slower/higher BC bullet. The one exception to that generalization is Berger's 168 Hybrid. It has such a high BC for its weight that you actually can push it fast enough to overcome the BC deficit it has with the next higher weight class of bullets like the 185 Juggernaut. I'd suggest choosing the bullets you intend to use very carefully with this information in mind. The 175 Matchking may not your best option. It is a much older design with mediocre BC, and there are better options available in that weight range, such as the 175 TMK you mentioned, and Berger's 168 Hybrid, 175 OTM, or 185 Juggernaut, if you can load a bullet that heavy/long. Along the same line, the 195 TMK might be worth a look if you're not loading to mag length and the rifle is chambered with a sufficiently long throat to seat them optimally. Choosing the best bullet for your setup and desired use is a very important factor in getting the best performance.
The next suggestion I would make is with regard to your interest in turning necks. Unless you have a very good reason to do that, such as a tight neck chamber, I suspect your not going to gain any substantial benefit for a significant amount of work. I'd suggest buying quality brass, such as Lapua, Peterson, Alpha Munitions, etc., and not spend a lot of time or money getting set up to turn necks for a factory rifle.
The Redding Type S Match die sets are quite good, that's pretty much all I use for F-TR loads with .223 Rem and .308 Win. Depending on your choice of brass, you will probably need a bushing of 0.335", 0.336", or 0.337" for un-turned necks. If you choose to turn necks, slightly smaller bushings will be necessary. For un-turned Lapua brass necks, I have always found a 0.336" bushing to be the best choice to give approximately .002" neck tension (interference fit). I have spent a lot of time testing various methods and approaches to improve consistency of my reloads, including the notion of sizing the necks down slightly smaller than normal with a bushing, then opening up the necks with an expander mandrel that is .002" under bullet diameter as the final sizing step (i.e. 0.306"). In the method I tried, I used either a 0.334" and 0.335" bushing to size down the necks of Lapua brass, then used a 0.306" carbide mandrel to open tham back up in the final sizing step. In my hands, the mandrel approach gave no better consistency in terms of neck tension than using a bushing die, and it was twice as much work. In addition, using a mandrel that is exactly .002" under bullet diameter will actually give you somewhere in the neighborhood of .0025" to .0028" neck tension, because necks actually tighten up a bit due to the brass springback after the mandrel step, which is the opposite of what they do when squeezed down from the outside with a bushing. So I went back to using a Type S bushing die with a 0.336"bushing as my sole re-sizing step. If I turned necks, if I used a different brand of brass, if my chambers had tight necks, if I had some other problem that created excess runout (I don't), it is possible that the mandrel approach might have been of benefit. However, I didn't find the extra step offered any improvement over using the bushing die alone with my setup. More often than not, excessive runout has more to do with the sizing die or the sizing die setup than with seating bullets later. In other words, the case neck concentricity or straightness is often the underlying issue and you can usually do a little stepwise troubleshooting to identify exactly where in the process the runout occurred and correct the problem. I use a Rockchucker press with the Redding Type S Match dies (i.e. nothing fancy) that were set up exactly as described by the manufacturers' and have never had any issue with excessive runout.
Finally with regard to fire-forming brass, I don't want to waste a lot of time, effort, and reloading components to fire-form brass for a .223 Rem or .308 Win F-TR rifle without getting something in return more than just the satisfaction of seeing a puff of dust when the bullets go into the dirt. Frankly, you're probably not going to get any quantifiable benefit whatsoever from fire-forming brass in your setup. I prep virgin Lapua brass by the following method:
1) I open up all the necks using a Sinclair Oversized Expander mandrel (i.e. .001" under bullet diameter, not a neck-turning mandrel) in their Gen II die.
https://www.sinclairintl.com/reload...ls/generation-ii-expander-dies-prod38807.aspx
https://www.sinclairintl.com/reload...inless-steel-expander-mandrels-prod33134.aspx
2) I then size the necks back down with the appropriate bushing die (i.e. Redding Type S Match die with a 0.336" mandrel for .308 Win).
Afterwards, cases are further prepped by trimming, chamfering, etc., as you normally would. The necks on virgin cases prepped this way are very uniform and I shoot prepped virgin brass pretty regularly in local matches with good results, as well as in practice. There is no question that the load will have to be re-tweaked once all the brass has been fire-formed. In my hands the charge weight will usually need to drop by a couple tenths of a grain or so to maintain velocity in the fire-formed brass, and I always do a seating depth test. My point is that you can get a lot of good use out of properly prepped virgin brass, and you'll be learning what the rifle likes and doesn't like. I have never personally seen the benefit of putting hundreds of rounds into the dirt while fire-forming brass, when there is an opportunity to get something more useful in return.
.308 precision loads
- Thread starter Loudcherokee
- Start date
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