bad crimping?

[machinegunjohn]

hey guys, I finally loaded my first set of cartriges(44) for my 629-4, I loaded winchester brass(1st reload), 245g cast lswc(dont know who made them), 19grains of 2400, wlp primers. I made sure my casings were at 1.285", I set my bullet depth so the mouth was in the middle of the crimping groove. total lenght was 1.685"
I believe I was either crimping to hard or had to mouth expanded to much, when the bullet would come out of the crimper, it had a sliver of brass at the mouth that you could grap and peel off. It was a very small sliver, but was on all 6 that I loaded. The brass did not look distorted like i have read will happen, other than the damage mouth.
Any ideas of what that could be? I am using rcbs carbide dies.
also , when making a recipe, should you pay special attention to overall length? Is there a maximum length that you should never go over? minimum?
Is case length more important than overall?
Thanks for the help

 

[ajpelz]

I am sure that some "experts" will chime in soon, but I can tell you that overall length (OAL) is a absolutely crucial part of load data. More so than case length. Increasing the OAL will decrease pressure, while decreasing OAL will cause pressure to rise, possibly with very dangerous results. By keeping OAL the same, the case volume (air and powder filling the case) will remain constant, even when using brass of varying lengths. Some will be seater deeper than others due to the stretched brass, but the case volume and thus pressure will remain for the most part constant.

From what you have described, it does sound like you are crimping a little too hard. Try backing off the crimp a little and see if things change.

Since you are loading for a revolver, I would see no reason to change the OAL from what is outlined in the load data. As far as case length, my book shows 1.285 as maximum case length, 1.275 as trim to length, and 1.610 as Max. OAL.

Hope this helps. Good luck.

 

[forsyth793]

Did you "debur" the inside of the mouth of the case? I was seeing a fine line line of lead at the same place you described that would easily come off.

 

[machinegunjohn]

I never seen any lead after the bullet was pushed in, I did debur. It was deffinately a brass sliver , like the top .001" of the case was partially scheered off.
also what if I have my case length between that 1.275-1.285 and my overall length at max-1.610 and my crimping groove does not line up with the mouth? You cant pick the wrong groove can you? Lenght would be way out to lunch, wouldnt it?
Thanks for all the input guys.

 

[flagman1776]

You want the case to grip the bullet without a crimp. You want just enough flair to start the bullet base, so that as you seat the bullet it's tight in the case neck. I like to seat the bullet separately... back this off & go a little at a time until the case mouth is in the crimp groove.
Back the crimper off... & start adding crimp a little at a time. I prefer a taper crimp.
Russ

 

[BruceM]

"I am sure that some "experts" will chime in soon, but I can tell you that overall length (OAL) is a absolutely crucial part of load data."

This is not the case, especially with revolver ammunition!! Uniform OAL is critical to accuracy, however.

Be sure your sized cases are the correct length. Then adjust the seating stem of the seating/crimping die all the way up. Adjust the seating/crimping die so that it barely touches the empty case mouth and applies zero crimp at the top of the ram's stroke. Lock the locking ring & then seat the bullet, adjusting the seating stem to seat the bullet into the case until the case mouth lines up correctly with the top of the crimping groove on a cast bullet or cannelure on a jacketed bullet. Back the seating stem out several full turns so that it does not touch the seated bullet. Now loosen the die's locking ring and turn the die down a quarter turn at a time until the right amount of crimp is obtained. At that point, lock the die's locking ring and with the round still in the die and the ram up, turn the seating stem back in until it firmly touches the bullet without pushing it deeper into the case. Lock the seating stem.

Remember, all adjustments are made with the press's ram fully up. You always work with complete strokes of the press's arm. It's best to make these die adjustments with a "dummy" round (just a sized & expanded case & bullet). Check the loaded "Dummy" in the cylinder of your revolver to make sure the bullet's nose does not protrude past the face of the cylinder, etc.

Similar setup procedures are applied to loading ammo for autoloaders. The COAL dimensions listed in loading manuals are guidelines. Many times you may have to play slightly with the OAL's, especially when loading SWC's for autoloaders. The three governing parameter for autoloaders are A-will the loaded rounds fit in the magazine, B-will the loaded rounds feed properly and C-do the bullets clear the barrel (rifling) when chambered? You want the loaded ammo to be as long as possible and still meet these requirements. This is because making the rounds as long as possible gives you the greatest case capacity with the bullet being used. Hitting a specific dimensional OAL is not critical per sae but uniformity in OAL is. Remember, you are building optimum ammo for your particular gun. After you get the correct OAL for your gun and components, it's time to experiment with powder charges.



Bruce

 

[flat top]

Even new cases are not identical in lenght. I always trim, deburr, and size even new cases. When you set up your expanader plug, make sure the "bell" on the case mouth is "just enough" to allow the bullet to seat in the case without shaving lead off of the bullet. Set up your crimp as the final step in the process, and insure that the crimp is firm enough to prevent jump (in a revolver) or set back (in an auto loader). I do the crimp as a seperate step, but I use a seperate die to do so.

 

[ajpelz]

Can someone explain why you would arbitrarily change the OAL in a revolver? I understand the OAL needs to be consistent, (it was in my first post) but I do not see the reason to deviate from the suggested OAL in the load data for revolvers. In autoloaders, it is one thing if your round will not fit in the mag, or you are trying to get the ogive to the rifling, but I am fairly certain these reasons do no exist in a wheel gun.

So I guess my question would be why change the OAL data for revolver use?

BTW, I agree with flat top and too much belling could also cause the sliver that you are experiencing.

 

[BruceM]

"Can someone explain why you would arbitrarily change the OAL in a revolver?"

What does the actual dimension in inches have to do with anything anyway? What you want is the bullet to sit in the correct location in the case relative to the crimp groove or cannelure. The actual number usually means zero. If your using proper load development procedure, the final OAL means precisely zero as long as the finished round is functional. The same goes for rifle ammo. You almost invariably want the finished round to be as long as possible and still cycle in your gun and not have the seated bullet engage the rifling of the barrel. This can sometimes result in a cartridge which is longer than the listed maximum OAL but who cares as long as the finished product functions reliably in your gun. The dimensions listed in loading manuals were developed in order to standardize ammunition so that commercial loads will chamber & fire in any gun built to standard dimensions. When you are loading, your building ammo for YOUR GUN and not anybody else's.

Bruce

 

[flat top]

Ajpelz; I shoot many different weight bullets in my 44 Mags, and depending on the weight of the bullet (heavier the bullet, the longer it is) and the cylinder length of an individual revolver, the OAL does change. I not only shoot Smiths (44 Mag and Special), but Super Blackhawks, and Redhawks as well, and my bullet weights range from 240 to 405, so depending on the weight and the gun that OAL does change.