Me thinks I discovered something

[royinidaho]

Accuracy of my 338 Win went to pot immediately after I shot 3 3shot groups @ 200 yds that averaged in the 5s. I was pretty pleased.

These groups were with new brass.

After shooting the brass once I neck sized them which as been my practice with non mag cals. Velocity fell off and so did accuracy.

I upped the powder to get back to the velocity that produced the good groups. These loads were just a bit compressed. I could feel the crunch and grind of the powder as the bullet was seated.

Had put the orginal loadings on the spinner and things looked pretty fair and thus felt no need to spin further loads.

In working with a couple of new powders (4831 and 4831sc) the SC load wasn't compressed at all. The 4831 did the crunch and grind.

For some reason I put them on the spinner. The SC uncompressed loads were straigh as an arrow. The dial indicator wobbled like a wind shield wiper on the compressed load.

Using standard die set.

Haven't shot 'em yet but I can predict the results.

Any suggestions? Thanks in advance.

 

[rwleonard]

Get a Wilson seater.

Rick

 

[Mike in Texas]

Have the same problem with my 260 rem.
By tapping the filled case to settle the powder, the once compressed charge now does not interfere with bullet seating,
and the concentricity issue is solved. At least that's what worked in my case. /ubbthreads/images/graemlins/laugh.gif

 

[Buffalobob]

The tapping of the case suggestion reminds me that there is a very old trick that I have heard of which is placing something like an electric razor or small engraving tool against the tray once the powder is in the case and letting the vibrations settle the powder to maximum density before bullet seating.

I would not let this go for more than a few minutes because most of the settling is going to occur fairly quickly and the rest of the time is just powder rubbing on powder and pretty soon you will have powdered powder.

Ball powders by their nature will pretty much automatically stack to maximum denstiy. It is the coarse stick powders that can be improved.

 

[Guest]

You can also touch the case to your tumbler for a second just before seating the bullet. I put a finger over the case mouth before touching the tumbler so no powder bounces out.

 

[LB]

I think this is a very interesting development. I occasionally use a compressed load, but, in retrospect, never did spin them? A Wilson chamber seater cure? Maybe?

Good hunting. LB

 

[3sixbits]

This is and old problem, with and even older fix. Get a long powder drop tube or a long neck funnel and slowly pour the powder into the case. Presto you will no longer have a compressed charge. /ubbthreads/images/graemlins/grin.gif

 

[abinok]

Three cheers for the drop tube!!!!
All of the ammo I load these days goes through one.
I never could figure out why all powder funnels didn't come with one.

 

[royinidaho]

Guess I'm just too much of a case stuffer /ubbthreads/images/graemlins/frown.gif

Already using a drop tube. It's pretty much afixed to my funnel.

I just hate it when I run out of powder room before I run into pressure or other limitations.

I'm kind of a velocity hog anyway. Maybe I should just upgrade to an 338 RUM or something. /ubbthreads/images/graemlins/confused.gif

 

[LB]

I think the point here is, for instance, filling a case to the neck, as long as it does not spill, and pressures are acceptable, and I am not using Wilson seating die, (of which I have several), but not for every gun I own, and so use a standard RCBS or Redding seating die. In this situation, there is generally a bit of a crunchy feeling as the bullet is seated. Because the cartridge is only supported by the shell holder, and perhaps while seating a flat based bullet, there may be a little misalignment happening, especially if the bullet is not seated deeply.

I don't know if there is run out, in that scenario, never remember checking under that exact set of circumstances? But, in considering it, I can see where it "could" (possibly) happen. I don't normally use a drop tube, or any vibrator action, IF all the powder will stay within the neck, and this is where a bullet might get seated a little catty whompus.

Something to think about.

Good hunting. LB

 

[goodgrouper]

Super compressed loads can affect runout on the bullet, but your brass should still have good concentricity. One thing I have noticed too on super compressed loads is that the powder will push the bullet out of the case or not allow the seater to seat the bullet where you want the it by ogive length. For example, if you want your bullet exactly .001" off the riflings, a compressed load may make some cartridges .002 off, and the next may be .003" into the riflings. It can mean inconsistent seating depths so just check it every time you seat a bullet.

 

[3sixbits]

[ QUOTE ]
Guess I'm just too much of a case stuffer /ubbthreads/images/graemlins/frown.gif

Already using a drop tube. It's pretty much afixed to my funnel.

I just hate it when I run out of powder room before I run into pressure or other limitations.

I'm kind of a velocity hog anyway. Maybe I should just upgrade to an 338 RUM or something. /ubbthreads/images/graemlins/confused.gif

[/ QUOTE ] I have a set of drop tubes made for my Harrel measure that are three feet long. I have powder funnels with 24" drop tubes, and when I say pour slow I was not kidding. /ubbthreads/images/graemlins/grin.gif