OK you people are on top of your game, here is the question. I have a XP-100 pistol in 6.5x284. I have Redding type S dies for it. When loading how often do you use a bump die? I have run 100 new Lapua brass through the gun and am now about to load for the second time. A buddy tells me he never uses a bump die. He says being it is brass that is fire formed in his gun all he ever does is neck size and load and shoot. Can this be right? I thought eventually even though you only use it in one gun you had to set the shoulder back. Anyway is he right with what he says? Thanks a lot. I very much appreciate it!

WS

I have 50 dies sets what to do you mean by bump die. I guess I never heard of that.

Or do you mean full length resizeing die. I full length resize all my ammo. Some like your freind don't. I do.

i been reloading for more then 40 years and i never heard of a bump die either.

Bump die, body die. Used for setting the shoulder back without touching the necks.

Whopper Stopper

The case will develop a crush fit somewhere between the 3rd to 5th loading and you will have to use the body die or other die to push the shoulder back.

For example here are some measurements I took on a 30-06 when using only a Lee Collet Neck Sizer, measurement taken with the Hornady Head & Shoulders Gauge:

New cases - 4.0400" (the measurement doesn't matter, only it's relation to the other measurements)
Once fired - 4.0485"
Twice fired - 4.0500"
3 times fired - 4.0510 (slight crush fit)
4 times fired - 4.0515" (crush fit, fired cases hard to chamber)

As you can see the ability of the brass to spring back is reduced with subsequent firings until it does not spring back enough to prevent a crush fit. After the 4th time I use a Redding Body Die to push the shoulder back to 4.0510" and resize the case body. Partial Full Length Resizing.

From then on you will have to use the bump die everytime.

If your buddy does not bump the shoulder back or resize the case body, then he is satisfied with a hard to chamber loads.

Not sure what you buddy is reloading, but I don't see case trimming mentioned, either.

I shoot an Encore handgun in 6.5x284 and 6mm BR - I bump every time. Here's why, if you're interested: Mike Bellm Encore experiment for more info.

Due to the encore/contender springy frames, fl sizing is required each time. For a bolt gun, you can get away with neck only sizing for a number of shots.

Personally I don't see accuracy degraded by fl sizing, and I hate difficult to chamber brass, especially for a hunting rifle.

I can understand why some folks didn't recognize your use of the term "bump die".

To me the term has always meant a die used to increase (bump up) the diameter of a bullet. Cast bullet shooting competitors use them fairly often in that way. I have several of that kind, for both jacketed and cast bullets, but have always called my other ones (like you describe) "body" dies.

Just like a lot of other things in shooting, I guess...more than one possible meaning, neither one "wrong".

A lesson learned for me regarding the other use. Makes the day worthwhile.

Thanks for the explanation Woods. That is what I was wondering. From what I was told from others in the beginning I was going to have to bump the shoulder every time starting with the second loading. This didn't make sense to me when the cases already fit.I have also come to find that it may take up to 3 times of shooting for the case to be fully formed in the chamber, about the time fit gets overly tight. I also shoot contenders and as Paul H pointed out they are a little different breed of dog then the bolts. Alberta Canuck "Makes the day worthwhile" My sediments exactly!

WS

I've seen alot of posts where guys have said they like a little tension when closing the bolt. That's just not for me. First off I would never hunt with a rifle that had that tight of a fit of ammo. It sounds like looking for trouble at the WRONG TIME!
Secondly I've experimented a bit and found that ammo that has a little tension when closing the bolt and ammo that has just a tad of headspace seems to go to different points of impact. I've experimented with neck dies, collet dies, body dies, and FL dies. I've tuned my FL dies to make almost zero runnout by getting the expander ball centered in the spindle and set them up for .001-.002 headspace. I keep coming back to FL sizing as being as accurate in my hunting rifles as any other methods.

quote:

Originally posted by kraky:
I've seen alot of posts where guys have said they like a little tension when closing the bolt. That's just not for me......

Secondly I've experimented a bit and found that ammo that has a little tension when closing the bolt and ammo that has just a tad of headspace seems to go to different points of impact....

Kraky, your last sentence there gives great credibility to everything you have said or will say in the future, in my eyes. It shows you have actually "been there/done that" not just read something someone else wrote.

Yes, neck tension and/or bullet contact with the rifling definitely can affect point of impact (POI).

In my cast bullet benchrest rifles, which I often shot in competition with _0_ neck clearance, and/or with the bullets seated from just touching the lands up to .100" into the rifling, I eventually found I could tell if a shot was going to go high just by the way the bolt closing felt. More effort to close the bolt meant a higher shot.

Matter of fact, I kept cartridge cases of about two dozen different neck tensions on hand when I was really into competition. With each new batch of bullets cast, even though with the same metal from the same moulds, the first thing I would do during the warm-up match at any tournament, was try different cases with those bullets, to see which ones provided exactly the right "feel".

With the "right" tension, I could pretty well count on cleaning the score targets and/or shooting winning groups without "flyers" in the group matches.

Your point is something I think every accuracy-nut should squirrel away in their bag of info......

Go to a gun shop in Texas and ask for a "bump die" and you will draw strange looks. Certainly the relatoionship of the bullet to the lands is critical to accuracy but has nothing to do with head space. Merely full length sizing the case restores miminum specs, without creating a head space problem either. Fire formed cases tend to shoot better in most rifles, there are issues W/ the TC that tend toward full length resizing not........bumping!

I use the bump die when i want top benchrest accuracy or when i shoot offhand and my cases become to snug for the chamber and feeding/extraction is effected.How often I need to do it depends on the type of cartridge and how hot the load is.for a light load in a 308 I bump after about 5 fireings.