Checking for reloading press alignment?

[jason]

Does anyone know a good way to check for reloading press alignment? I am using an RCBS Jr. Press. It appears that the decapping pin on several different dies I use is not perfectly centered in the case mouth when I raise the ram. Granted - it's not a lot but enough that it is immediately apparent. I am working up some .270 loads and have checked the bullet concentricity on a Sinclair concentricity gauge. It seems like a total crapshoot - I will get a batch at less than .002 runout and, using the same equipment, have some as much as .009 runout. I am using both Lee and RCBS dies.

Any thoughts would be appreciated.

[Pepe Ray]

Jason;
Don't forget to include the brass in your investigation. Unless it's been turned (NOT reamed), you'll never find uniformity in the neck thicknesses. Some boxes are better than others, never related to Brand.
Your beginning to invade the bench rester's domain. Beware!!!

Missed Billy's show. You gave me the wrong date. For shame:veryconfu
TTYL
Pepe Ray

[Forester]

I would try to eliminate everything else before worrying about the press.

Start with fired brass and see how straight it is, then check the brass at every step to see where the runout is being introduced.

Try a rubber O-ring between the die and press for a simple fix.

You really are about to go down a rabbit hole that leads to spending lots of money if you decide to try to fix one problem after another in hopes of straighter or better ammo.

[WILCO]

You really are about to go down a rabbit hole that leads to spending lots of money if you decide to try to fix one problem after another in hopes of straighter or better ammo.

That's true! I've often referred to the bench rest activities of co-workers as "Voodoo Magic!".

[deltaenterprizes]

Neck turning and a Bonanza or Redding Benchrest Seating die will help.
The Lee collet neck sizing set works pretty good for the price.

[flashhole]

When you screw your die into your press, just before you get ready to cinch the lock ring, note that you can move the die around quite a bit in the press. The movement is the result of the tolerance you get with the threads. I run a case up into the die to center it before I lock it down. You don't want undue stress on the case as you go through a sizing operation. It helps a great deal in making concentric ammo.

The same goes for the decapping assembly in the die. It can move around in the die before it is locked down due to thread tolerance. Again, I will run a case up into the die before I lock the decapping assembly in place.

It helps in both examples if you use a known good case before you lock things down. Nothing magic about this, it's just learning the querks of your equipment and how to properly deal with them.

[Baron von Trollwhack]

Occasionally one gets a shellholder where the base the case rests on is not parallel with either the top surface of the holder or the ram slot. Bvt

[Geraldo]

There are tolerances on everything you use in the process of reloading ammo: the press, ram, shellholder, dies, brass. If you start worrying about all of them you'll wonder why your ammo works at all.

My question is this: what rifle are you shooting and will any of this produce a noticable change in how that rifle shoots? I used to shoot at Kelbly's rifle range (not in the benchrest competition), and I learned the difference between what a hunting rifle, a factory varmint rifle, and a custom BR rifle were capable of. Trying to make one into another can be very frustrating.

[dudel]

Might be in how you set up the sizing decapping die. I keep the lock ring loose until i run a case fuly into the die. At that point, the die is concentric with the case. Then I tighten down the lock ring.

[jason]

Thanks for all the advice. It all sounds good. This particular batch of ammo was for a .270 - Win Model 70. I just loaded a batch this weekend with new Winchester brass and the results were much better (on the runout gauge). I was working up varmint loads with a 110 gr. Sierra bullet. I must have done something right because after some decent and not so decent results I stumbled across a 3/4 inch group using some IMR 4064 that I had on hand.

I am going to try tightening things up once I have a case fully inserted in the die. May even try a new shell holder for good measure.

In this case it's not so much that I am just freaked out by the runout - I was really more concerned that there was something wrong with the setup. I am trying just to have fun, though I must confess I find myself having evil thoughts and going down that slippery slope where the bench rest guys hang out.

Pepe Ray - sorry about the wrong date. I missed Billy's show myself. I got my 38-55 back today. Drop me a line you can point me in the right direction with the old Lyman 310 dies. I don't have any instructions to go with them and couldn't find much online.

Jason

[1hole]

All a press does is push a case into the die and pull it back out. Any run-out comes from the dies or, more commonly, the cases themselves.

Lee's collet method of holding the decap-expander rod, and Hornady's copy of it, is intended to keep that rod better centered; it works too.

[jason]

For the price I and everything I have heard I will give the Lee Collet die a try and compare the results.

[1hole]

Jason, the Lee Collet Neck die is a fine tool and I recommend it without hesitation for neck sizing. (I find it MUCH better than any vastly more costly "bushing" neck sizers.) But. what I was refereing to was the small friction collet that holds the decapping rod in Lee's FL die.

Another feature of that Lee decap rod is the long cylindrical expander section so many "hate". It is made that way to insure the finished necks are as straight as possible and it sure helps. If more people would actually THINK about some of Lee's engineering designs and didn't listen so much to all the knee-jerk errors spouted on the web it would do them some good.

Lee's tools aren't glittery pretty, and the prices reflect that, but they work VERY well if used correctly and most of us know it! ;)

[Trifocals]

Jason: Yes, it is possible that a press can be out of alignment. My favorite press is a Bonanza Coax. Everything "floats" and finds alignment with this press. They are a great press. I've had mine since the mid 70's and I won't part with it. I also have, and have used many of the more "conventional" presses. Without exception the Bonanza Coax press produces ammo that is better aligned. But of course there are variables that even the Coax press cannot correct or compensate for ie: burrs on the shell base, crooked case necks on previously fired brass (usually caused by a bad chamber or bad dies), uneven case neck thickness, dies machined out of alignment (I have encountered them), etc., etc.. There are many pieces of equipment available that can aid in turning out more precisely aligned reloads ie: neck reamers and neck turning tools, dial gauge tools that can check bullet alignment, neck runout, case wall thickness, etc.. Given a rifle with a decent barrel and chamber and bedded correctly, it is usually not too hard to turn out reloaded ammo that will group in the minute of angle range if your reloading equipment and skills are up to par. This is more than sufficient for the average hunting scenario. A varmint hunter may demand more precise accuracy and a benchrest shooter the ultimate. Naturally these more stringent demands for more accuracy entail much greater outlays of cash and effort and superior skills. The bottom line is to obtain the type of equipment necessary to satisfy your particular demands and skills and learn to use it properly. LOL :)

[Franklin Zeman]

I think it was Elmer Keith that suggested orienting cases the same way every time you fed one into the chamber. Do the same when setting cases into the shell holder. Mark the dies so they are in the same place in the press if you are using a single hole press. SO MANY VARIABLES !!!!!!

[jsizemore]

Great suggestions all.

A couple more suggestions. The fired case is an almost exact copy of your chamber. The less you change it, the less error is introduced into the almost exact copy. This is kinda obvious, but hasn't been mentioned.
The other suggestion is to set aside brass that doesn't shoot to group or exhibits unacceptable runout when loaded. Don't throw it away, but check it for weight, which could be thick web or non uniform case walls, neck walls not uniform enough, flash hole with a burr on the inside that's affecting ignition, etc. Why mess with your good groups if your vamint hunting. Good Luck

[flashhole]

The neck sizing vs FL sizing issue, what's best for my gun, can be a bit onerous to figure out. I have a 221 Fireball and a 223 Remington (Remington 700 and Kimber Longmaster Classic) both of which have tight chambers and FL sizing produces the most accurate ammo. My Ruger #1V 25-06 on the other hand benefits greatly from neck sizing only and I use the Lee Collet Neck Die with great success. Measuring the fired case against a FL sized case is pretting telling as to what your gun may prefer for accuracy.

[scb]

In cases I want to squeeze the last ounce of accuracy out of I've started sizing with Redding bushing dies. I de-cap with a universal de-capping die then size. This eliminates the expander ball and the tolerance build-up of usually 3 matting threads. Granted when the case is that far out of the die the case "should" have enough free movement in the shell-holder that it "should" self-center over the expander ball but I think this just removes one potential cause for misalignment. They've worked very well for me. Along with Vickerman or Redding Benchrest seating dies.

[HeavyMetal]

An RCBS tech at a gun show I went to, more years ago than I want to admit, spent quite a bit of time explaining to anyone who would listen, not many, about the "correct" way to set up a sizing decaping die.

In his world the die was adjusted down into contact with the shell holder, full length resize 44 magnum die set, Once down the ram was backed off the die taken in a half turn, or more, the ram raised to put pressure on the base of the die and then the lock nut was tighten while the pressure was held against the die.

The idea was to take the "slack" out of the die threads and use the ram to self align the die with the ram.

Hope that makes sense.

Been doing that since that day and never been sorry to do it!

[jason]

Heavy Metal - thanks for the information. I will try that and see if it makes a difference.

[pjh421]

Jason

You can probably remove a lot of the measurable bullet run out by seating the bullet halfway to where its going and then partially withdrawing the cartridge from the die. Next, turn the base of the cartridge in the shell holder 180 degrees and then complete the seating of the bullet. If the bullet was beginning to lean in one direction in the case neck, spinning the case half a turn will cause it to lean the other way. Using an RCBS Case Master tool, it looks like I often get zero run out using this method. Of course it only resolves to one thousandth of an inch.

Paul

[leadman]

Check your shellholder too. They have a way of building up crud in the recess. I have found corncob media in the recess also.