Bullets Being Undersized During Reloading

[03lover]

Something Else To Look For Now! ! ! !

Taper crimp and cartridge brass, especially pistol, the shorter they are the worse the problem. The brass being thicker as you go toward the base and the use of a taper crimp can cause lead bullets to be undersized when loaded.

I have had serious leading and terrible accuracy, even bullets tumbling at fifty feet, because of something we probably don't even look for. UNDERSIZED BULLETS. I check for it now having had this problem more than once.

I have had 9mm, and 38 Super give me fits until I realized the bullets were being reduced in diameter by the brass shell casings they were being seated in. This can happen in the 30 Carbine also.

How much a bullet of a given diameter will be sized down by the shell casing depends on several things. How tight the sizing die is, the size of the expander die and the amount of taper crimp you apply. The hardness of the bullet has considerable affect also.

My most recent example of this problem occurred today. I had loaded four different types of cast bullets, all sized to .3565" diameter and cast of wheel weights and air cooled. In the 38 Super Starline brass, known to be a bit thicker than some other brass, the bullets I pulled measured an average of .3515" from the base to just over half way up and then the taper crimp to a case mouth diameter of .375 reduced the top of the bullet diameter even more. That is about .005" under the starting point and causes all kinds of trouble. We would not think of loading bullets that small knowing it would lead to all sorts of problems.

In the 38 Super Winchester brass the reduction in bullet diameter was much less due to the thinner brass. The pulled bullets measured an average of .355" diameter with the taper crimp area much smaller, for a reduction in diameter of .0015". Yet these didn't shoot very well either.

I know some of you will have to see it to believe it. I know it happens and todays example was dramatic with the Starline brass. I guess the day at the range wasn't a total loss. I did learn something with all the bullets I pulled. I would suggest to everyone interested or those that are having problems, to load some empty cases just as if you were loading to shoot and then pull the bullets and check the diameter against what they were before loading. You may be surprised.

Now I have to search for the right combination of sizing die, expander, amount of taper crimp and bullet hardness and still maintain enough bullet tention to avoid set-back when the auto loader cycles, eliminate the leading and provide good accuracy. That isn't asking for too much is it?

Now I wish I had only one manufacturers brass from the same lot for all of my pistols. It would make the search much shorter. As it is, I will have to find the magic number for each kind of brass.

[Earl Brasse]

I had a similar problem with trying to load .314 slugs in Win. 32-20 for an old Colt SAA. I started with Rem. brass & it was way too thick compared to Win. . They ended up @ .308 or.309. Good luck.

[44man]

I have been saying this for years. I don't shoot small cases but use a lot of neck tension. I can NOT use soft boolits. I don't get overly hard, water dropped at about 19 to 22 BHN but it is hard enough to resist the brass sizing the lead.
Remember that if you want to see if the brass is sizing your boolits, don't crimp before pulling them to measure. That will show if the brass itself is sizing.
Crimp will also make a soft boolit smaller as it tries to open the mouth of the case so you could have two problems in combination.
Some will say the brass and crimp jumps open before the boolit leaves---NOT SO, pressure will not work on the brass neck until the boolit is out of the way.
Brass that is too long for the chamber will not allow the boolit to move easy, pressure rises and the boolit is forced through a crimp that can't open, making the boolit smaller in the process. Real bad with a hard jacketed bullet.
Boolit hardness is discussed a lot but too soft is as bad as too hard. I do not believe in "bump up" for any gun. Fit the boolit and stay in the center of the hardness range. When brass does not ruin the boolit, a little change in hardness from batch to batch will not change your accuracy.
Cheap commercial boolits come in two flavors, dead soft and too hard. Only the better boolit makers use good alloys.

[44man]

I forgot to mention crimp dies and they can be a problem if too tight below the crimp shoulder. Bad idea if you are using oversize boolits.
Most of the time the crimp from the seating die will protect a boolit better then a separate crimp die.
A good die should not be sizing brass below the crimp.

[03lover]

44man,

I spent a few hours working with my 38 Super brass and cast bullets. I am currently using Starline and Winchester brass. The bullets I am using are cast from wheel weights with 1% tin added and air cooled.

The Starling brass, new or resized with a Lee carbide sizer are too tight and undersize the bullets as I indicated in my first post. I found if I used a .3563 expander, the seated .3565" diameter bullets were held tightly enough to resist set-back yet only reduced the bullet diameter to .3560". That is a start. If I water drop the next batch of bullets I cast the hardness almost doubles and that should not be reduced in size by the brass.

The taper crimp die was also reducing the bullet diameter a lot, so I am backing off from the recommended .375" case mouth diameter of crimp to .379 to .380", no crimp to .001". I like others believe the bullet fit in the shell casing provides the bullet tension needed to prevent bullet set-back and not a taper crimp. The taper crimp is the best way to remove the bell at the case mouth used to prevent lead shaving when seating lead bullets. Some even believe more taper crimp provides less tension because the brass springs back more than the lead bullet does.

My Winchester brass, being thinner than the Starline, works well using a .3555" expander and my .3565" diameter cast bullets.

Then the game really changes when I go the .355" diameter jacketed bullets. The brass prepared using the sizing die and expanders for cast bullets doesn't work with the jacketed bullets at .355" diameter. The bullets almost fall into the shell case. I can push the bullet completely into the case with light pressure from a finger.

Jacketed .355" bullets require the use of my 9mm sizer, partial sizing the upper half of the case and a .353" expander to maintain the right bullet tension.

Other suggestions are welcome.

[44man]

It sounds like you are getting it under control. The important thing is that you have identified the problem.
The expander will be where you get it right no matter what the size die does.
I made a mistake and bought a Lyman neck size die for my 45-70 revolver. It will not size near enough for any tension and my expanders just fall in a sized case. I can live with a tighter size die but not with this one.
Try the water dropped but size soon after casting and let them sit to harden. A week or two really helps.
You have a good alloy but I tried adding a little tin to WW's but never seen any difference in the way they cast or shoot compared to straight WW's. I decided to save my expensive tin. A few years ago I was paying $4 a pound for tin but holy smokes, now it scares me!

[03lover]

44man,

You are right about the expanders. The amount a sizer reduces the OD of the brass does have an affect on which size of expander will work because the spring back of the brass varies some with the amount of sizing and which manufacturer the brass is from. I thank my purchase of a good bench lathe. Without the lathe, I would not be able to modify many of the reloading tools to match my needs. It makes short work of a 38/357 mag. expander, such that it can be reduced to many of the diameters I have needed for the 38 Super and the 9mm. You can purchase just the expander without the die body from Lyman and RCBS.

I have had some problems with sizing dies also. Neck sizers have been especially bad for me in rifle dies. I shoot a lot of cast bullets in rifles and the neck sizers size way too small and that just shortens the case life with the excessive expanding required. I have gone to the bushing type neck sizers and purchase enough bushings for each that I can get the perfect fit.

I simply don't like to over work any of my brass. At today's prices, anything I can do to extend case life is usually worth the effort and cost.

It has been a pleasure exchanging ideas with you.

[44man]

Oversizing bottle neck cases and having to pull an expander out is what causes bad runout. I used to send my dies in and have them lapped for minimum sizing using my fired cases.
Every standard rifle die sizes too much at the neck.
You did the right thing with the bushing dies for the rifles. Best setup ever made.
But for straight wall cases, a little over sizing doesn't hurt.

[felix]

Short of custom dies, the best method is to size with an expander ball way less than nominal so there is no expansion upon liftout. After all cases are done, then use the same sizing die, but this time adjust the real expander such that it is set just below the neck, say 20 thousands. Full length size again, and pull case out gently. This keeps the expansion under control of the case neck itself. What this does is mimic the dies from Bonanza, my favorite standard brand. I have these dies custom made for guns worthy of this kind of attention. Not many guns qualify in my stable. BR stuff is all by hand, using no press. ... felix

[44man]

Felix, that will work! Most reloaders don't understand how easy a shoulder can bend. The very worst are the Weatherby rounded ones.
I actuall have a BR bushing die for the .44 mag! :drinks:

[03lover]

As I have mentioned above, I had found a combination of sizing die and expanders that is working with the oversize cast bullets.

That did leave me with a sizer sizing more than necessary and the expanders having to expand more that necessary.

I decided to try something and it has worked out great with the oversize cast bullets in my 38 Super. I tried sizing fired casings in the Lee 38/357 Mag. Carbide Factory Crimp Die. It is perfect. The carbide ring that is intended to take any bulging out of loaded 38 and 357 mag. rounds while crimping is the perfect diameter for the 38 Super and my cast bullets. No more over working the brass sizing therefore no excess working of the brass expanding. Bullet retension is good and bullet down sizing because of the brass is minimal, less than .0005" with air cooled wheel weight bullets.

[44man]

Sounds real good to me. Die makers just fit to commercial bullets so when us casters have to change to fit a boolit, we have to sit and think a while.
I drink while I do it! :mrgreen::mrgreen:

[yondering]

After reading this thread I checked my 45 Colt loads last night, and was dismayed to find that my ACWW boolits are being sized down to .4515" or so in the case. Even worse, the bases were being rounded over, and unevenly at that, from having to expand the brass.

This could explain why, so far, I've always had better accuracy and less leading with the really hard commercial cast stuff, despite everything I've read here about that stuff being too hard.

I'm using dillon dies in my 550B press for the 45 Colt, so I'll have to figure out some way to get/make a larger hollow expander (powder through expander setup). Maybe have a .480 Ruger expander machined down? Any ideas?

[454PB]

yondering, have you measured your expander plug? A while back, after having a squib problem in my .454 Casull, I measured all my .45 caliber expanders. They are all .449". Also, after the squib, I pulled the remaining rounds and measured the boolits. These were ACWW, and measured exactly the same as originally sized.... .452".

[Bass Ackward]

I always pull everything when I load the first one. Just to get a feel for what it will be like. Strange thing is that sometimes results aren't what you would expect, but that's another subject.

What I have to watch is falsely judging reduced base dimensions. What I found was that some minor reduction was not uniform and was really from misalignment of the seating die as the bullet was seated. Pulling that one and measuring a single dimension without going clear around it had me falsely accusing. But I believe that PB bullets are just harder to load properly.

As usual, fighting the battle that needs fought ...........

[44man]

I wonder how caliber effects the problem? Small diameter cases are most likely stiffer then large ones and need more care. I don't seem to have a problem with the large calibers like my .475. It seems to be much easier to get any boolit to shoot very accurate.
I don't have anything under the .44 so I don't know.
Maybe someone with the .357 or smaller can do some measuring to see if squeezing the boolit is a larger problem.

[yondering]

yondering, have you measured your expander plug? A while back, after having a squib problem in my .454 Casull, I measured all my .45 caliber expanders. They are all .449". Also, after the squib, I pulled the remaining rounds and measured the boolits. These were ACWW, and measured exactly the same as originally sized.... .452".

Measured my expander plugs last night, the Dillons are .448" on both my 45 Colt and .45 Auto. My RCBS plug is .449". It would be interesting to try a larger plug, but I'm not sure where to find one.

[runfiverun]

i had this problem with a 41 and just gave up and seated unsized boolits.
then partly ran the boolits and cases into a spare sizer untill they
would just chamber.
thus insuring as big of a boolit that would fit.

[03lover]

I have changed my method of loading cast bullets to what "Bass Ackward" does. That is to always pull a few bullets from the loads to be sure the bullets are not being down sized by the brass and to insure my bullet seating is not having an alignment problem. Better to know if there is a problem up front than it is to waste time and material, only to know you have a problem, but not sure what it is. In fact, I intend to make it a practice to first load two or three cartridges unprimed, no powder charge casings that are the same as those I will be loading to shoot, and seat the bullets, pull them and check for problems.

"44man", The brass sizing cast bullets down to unacceptable diameters does seem to be more of a problem with smaller diameter and shorter cartridges. Also, the problem seems to be worse with the higher pressure cartridges, perhaps because the brass is made a bit thicker and the taper toward the base is more pronounced.

My 38 Super and 9mm reloads have given me the most trouble with cast bullet diameters being reduced by the brass. 45 ACP is not free of the problem and neither are the 38 Spl., 357 Mag. with longer bullets. My 44 Mag. and 45 Colt present fewer problems because I don't shoot the real heavy bullets. I shoot 185 gr. up to 255gr. and these are not seated so deep that they get into the much thicker part of the brass.

Another variation problem is the different manufactures cartridge cases for any given caliber is not always the same in thickness and most of us know the individual casings vary in wall thickness and this can cause bullets that have been reduced in diameter by the brass to be out of round.

Cast bullet diameter reduction and bullet bases being deformed is much more pronounced in the shorter cartridges. The 45 ACP is not without this problem, considering the variables of the many different cartridge cases available. Military brass is more prone to the cast bullet problems because it is usually thicker.

Then we have the other condition that causes the bullet diameter reduction problem to be worse. That is the longer the bullet, the deeper it is seated in the shell casing. Some bullets are actually unsuitable for some cartridges because the bases are seated into the thicker portion of the brass closer to the case base web and this is will squeeze the base of the bullet down every time.

Solutions to our cast bullet problems are agrivated by the manufacturers of the dies we use. Sizing dies almost always work the brass more than necessary so they will work for the many bullets that can be used. That leaves us with the expanders as one way to combat the problem and then only if we have the ability to take one that is too large and have it machined to the required diameter. The sizing dies, especially the carbide ones, can not be opened up.

Manufacturers like Lyman will sell just the Expander Plugs for their "M" die type eixpander. I have purchased them in different available sizes an turned them down to what I need. I think RCBS would do the same and their expander plugs are much longer, providing the length to reach deeper into the case when necessary.

Loading the perfect cast bullet round is not an easy task, but it can be very rewarding.