How close to the lands?

I am the fan of the running start.
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^^^This...

I won't go any closer than .025" in my heavy caliber cartridges. I don't load *to* max, but I have a .270 load that is within about 2% of max. It is the most accurate powder weight for my rifle/bullet/powder/brass combo, and if I could back off and keep the same accuracy I would.

Reloaders claim some brass by FC (pick a brand) is soft and they know it is soft because they can only get two reloads from a case before the primer pocket gets loose.
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I am one of those that claim that Federal puts out some VERY soft brass. At the third firing (1 factory, 2 reloads), I have to cull about 25% of the brass because of loose primer pockets. I did a brass life test (as I was curious) with 20 pieces of brass at the minimum load and still found I had to cull a couple of pieces (10%) after the third firing. I discard all brass after the fourth firing as I don't trust it at that point.
 
I am one of those that claim that Federal puts out some VERY soft brass. At the third firing (1 factory, 2 reloads), I have to cull about 25% of the brass because of loose primer pockets. I did a brass life test (as I was curious) with 20 pieces of brass at the minimum load and still found I had to cull a couple of pieces (10%) after the third firing. I discard all brass after the fourth firing as I don't trust it at that point.
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Around here there is no shortage of any brand and I have no reservation about using any of it but I doubt I have a case that is less than 10 years old. Again, I purchases brass that came from a salvage/recycler metal yard. I purchased what I thought were magnificent cases. I loaded 40 of them and was impressed with the results. It was about that time I was cautioned about cases that had been manufactured with suspected short cuts. Seems the manufacturer took short cuts when annealing. To soft would result in case head expansion, too brittle/hard could result in case head failure. I moved the cases to the collectable drawer, I have added 60 cases to the collection from friends that have passed on. All the cases I got from them had been fired so I suspect not all of the cases went through the short cut annealing process and the manufacturer pulled the cases for recycling.

F. Guffey
 
I'm with Mr. Guffey.
I don't jam any bullets into the lands. I do get close with a few. But not into.

Case in point. Savage 111 in 7mm Rem Mag, shooting 150gr. Nosler ABLR over Reloder 26.
Normally my Savages like 0.015-0.020" jump to the lands. I was recommended with the ABLR that they like a long jump, 0.050-0.060". Couldn't get them to group better than 1.5" at 100 yards.
Doing 3 shot groups, started at 0.015' and kept backing off 0.015" per next 3 shot group till I got to 0.075" off of the lands. Couldn't get them to group decently.
Out of desperation I decided to try a set 0.005" off of the lands. Viola!!
Instant MOA grouping.

And if the whole distance from lands makes your head spin, start doing that, along with tuning the action on a Savage with the torque on the action screws... :D
 
Not sure anyone cares what I think, but I don't have a "general rule". I seat the bullet where the accuracy is best, and if I need it to fit in a magazine, I don't seat beyond the magazine.

Usually, when I begin load development, I start with a low powder charge and then adjust seating depth to find the relatively most accurate depth. I then begin a charge weight ladder. If I have to get closer than .020 from the lands to get an accurate load, which is to say that if the bullet is extremely jump sensitive, I choose a different bullet.
 
I don't have imperical evidence but my approach has always been at least .003 of the lands OR jammed. If you are less than .003 and have bullet seating variances of .002 or more (not uncommon) some bullets will be touching the lands. I believe this increases pressure and causes erratic groups. Open to contrary opinions.
 
Pressure increases when you get close to the lands. Virtually no difference between touching and 0.003", though. If you are that close you are already about at the same pressure you will have touching the lands. It's about 20% higher than a factory load's pressure.

There are several factors contributing to this. One is that a case and bullet stretch as pressure builds, so even a case 0.003" off the lands is probably touching them before the bullet is released by the brass expanding away from it at the neck. Bullets touching the lands will be driven slightly deeper into contact before the case lets go of them.

Another factor is inertial entry into the throat. The bullet needs to pick up enough speed before it gets to the throat that it isn't stopped by the throat and having to start moving again from a standstill.

Another factor is the amount of gas that is allowed to bypass around the bullet before it moves forward and plugs and seals (obturates) the bore. On high speed piezoelectric transducer traces you can see the pressure build-up hesitate briefly while this is occurring, so it affects the timing of the bullet position and degree of expansion at the pressure peak.

Obviously, if you seat deeply enough, pressure starts to go back up also, as the bullet begins to occupy a significant amount of powder space.
 
Another factor is inertial entry into the throat. The bullet needs to pick up enough speed before it gets to the throat that it isn't stopped by the throat and having to start moving again from a standstill.
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And all of that takes time and when pressure starts to build the one thing a rleoader does not have is time. And that is the reason I have never found anything entertaining about placing the bullet into the lands. And then there are factors, time is a factor, another factor is distance. It was suggested I was into some risky stuff; I suggested by the time the case filled the chamber the crises would be over. But, just in case I called Hodgdon, it does not take Hodgdon long to look at it, They agreed but had a caution; after the cases were formed I lost the time factor meaning as soon as I pulled the trigger the formed case would have no room to expand, there thinking? My fire forming load would be above maximum after the case was formed.

F. Guffey
 
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