Case Bulge With U-die In .40

[TreblePlink]

Here's my setup, which I think is quite common: 550 press, station one: EGW U-die. Two: dillon bell & powder drop. Three: Lee die for seating only. Four: Lee factory crimp.

Loading Zero 180 JHP using 4.8 grains of VV320 (for my 6"). WSP primers. Mixed brass. OAL 1.183 crimp about .418 Belling just enough for bullet to sit in case.

Using an EGW four port case gauge. Problem: too many are going to the "practice" can instead of the "match" can because they won't drop into the gauge, sometimes cannot be forced into the gauge.

Problem seems to be an off-centered bulge right at the the point where the base of the bullet rests. This causes the bullet to rub in the gauge "freebore" area. It would seem that the bullet is not reliably being seated true.

I've hit the usual suspects, re centering dies, etc. It happens on about 15% or sometimes 20% of the loaded rounds. Most are perfect. Does the same thing when using Precision (coated) 170 grain bullets.

Has anybody seen this issue?

[Scout454]

Yes, and I switched to a Redding Competition Seater (that lines the bullet up with the case like it's in a chamber) and I have no more problems.

[Bear23]

Try the dillon case gauge. I tried the EGW 4 caliber gauge and found the .40 to be a little tight.. Much tighter than my barrel or my dillon gauge. The 9mm and 38 super seem to be spot on.

I take my rejects from the dillon and drop those in the barrel, and a few won't fit.

With the EGW undersize die, i found i had to put a 'little more bell' onto the case mouth, i'd get the bulge especially with lead bullets, vs. plated or fmj's.

Edited April 4, 2007 by Bear23

[Crusher]

Loose the Lee factory crimp and I bet all case gage you woes fall by the wayside.

[TreblePlink]

Well, I have tried relaxing it to about ~ .421 (to just get rid of the bell) and it didn't change it.

How could that die bulge the case?

Loose the Lee factory crimp and I bet all case gage you woes fall by the wayside.

[racerba]

Make sure your factory crimp die is as far down as possible. Also try getting rid of the U die.

Edited April 4, 2007 by racerba

[HI5-O]

Yes, and I switched to a Redding Competition Seater (that lines the bullet up with the case like it's in a chamber) and I have no more problems.

Same here.

Also, check the little paper clip looking thing where the brass goes and make sure it's pushing/holding the brass in place (in the shell holder).

Another thing to check would be in the seating die and be sure you are using the correct punch for your bullet profile.

Check your die alignment and lock rings and don't leave the shell plate too loose.

barry

[ChuckS]

I use a U die, Redding seating die and the Lee FCD. I just did a 1000 round run Monday night with zero case gauge rejects. There are no issues with the U or FCD per se, just maybe how you use them. If I were you I would focus my attention on the seating die. Perhaps the seating suface combined with the bullet shape are allowing them to skew when seated. As Bear pointed out, a little more bell may help. Or maybe clean the seater? You may want to try to borrow a different seating die from someone and see if it makes a difference.

Later,

Chuck

[AustinMike]

I use a U die, Redding seating die and the Lee FCD.

+1 I used to have problems with bullets not getting in perfectly straight using the Dillon seater, which caused bulges as described. No issues since switching to the Redding Competition seater. It aligns the bullet just right every time.

[Jaxshooter]

I use the same set up, Lee U die, Redding Comp Seating die and Lee factory crimp die. Zero rejects in the last 2000 rounds.

[kevin c]

I agree that the seating die may be the problem.

Say you're using the seating stem for flat nosed bullets. If you use a bullet with a small or rounded meplat (tip) and it contacts the flat portion of the cavity before the ogive (side profile of the bullet) contacts the sides of the stem, it might tilt, bind off center, and then be seated off center.

Bad bullets are also possible, though Zero's are generally very high quality. You can check for concentricity by turning one in caliper (micrometer'd probably be better).

Kevin C

[wide45]

Make sure you have the corect brass buttons in place at the belling, and seating stations.

[TDean]

I was getting similar issues with an excessive crimp. It would "hourglass" the bullet at the rear.

Your .421" crimp isn't over doing it though...