Seating Depth Problem?

[engineermike]

I have a set of Hornady Titanium dies (9mm & S&W 40) and am loading the 115 grain Berry's and X-treme round nose bullets. When I use the seating pin for round bullets I can not seat with any consistency. When I am trying to seat to a depth of 1.103 I will get anywhere from 1.122 to 1.137 when using the seat pin for round bullets. When I us the seat pin for flat bullets my consistency improves and I will get from 1.127 to 1.134. I am wondering what I am doing wrong? The seating depths I have shown here are for the 9mm but I get the same results/differences when using the S&W 40 dies.

[PA-Joe]

Take the pins out of the seating die and see which one fits the best on the top you your bullets. You can also send the buillet to Hornady and they will make a special pin for that bullet. Or you can try filling a portion of one of the pins with an epoxy type glue.

[Jimro]

Your seating die should set to a portion of the ogive of the bullet, not to the tip of the bullet. If you are measuring to the tip of the bullet that is a diffent data point than your seating die is using.

Jimro

[engineermike]

[PA-Joe]

Mike:

If you look at the tips of the bullets you will see that they varry a lot. Even the bullet lengths are not the same. So a few 0.001 will not make a lot of difference. You should be able to turn your seating die istem down to get closer to the 1.103 you were trying to get. See what pin fits the bullet head better and use that.

[engineermike]

Joe,
Sorry, I typed 1.103 but meant 1.130. Your are right about the picking a seat plug and going with it. I am a little unsettled about this as even the round seat plug will not do any better using Hornady's bullets either. Just looking for another idea you know, I find that some times after I seat a bullet and take a measurement and replace the same bullet back into the press and turn the bullet and case a quarter turn (I do this 4 times) I will get another measurement. I don't know, maybe it is the way I place the bullet into the case when I first start to seat? Or maybe I will buy an RCBS die set and try that, it's been awhile since I spent a little money on this hobby for hardware.

[PA-Joe]

Do your Hornady dies have the floating stem in the seating die? That helps allign the bullet as it is being seated. Are you champhering and belling the inside of the cases neck before you seat the bullet? If you don't have enough bell the bullet can go in on an angle.

[engineermike]

I have plenty of bell, but I have not chamfered. Hell, I'll give that a try thanks. And yes my dies have the floating stem in the seating die.

[Berry's MfG]

Right on target with the noses varying from bullet to bullet. If we were to bury the bullet so deep in the final size die to where the nose bottoms out, there would be no give for a variance and the chance of cracking a die is great. That is pretty standard in bullet manufacturing, that's why you see noses that can slightly vary but the ogive and diameter are very uniform. Case in point is the Meplat trimmer made for the very accurate FMJBT-HP bullets made by companies like Sierra. I use JB weld to modifiy my seating stems for my Dillon Dies.

[engineermike]

Well, the chamfering did not make any difference. I am guessing there is some slack/play in the press or between the shell holder and ram. Or it could be the seating pin/plug, the flat seating pin/plug seems to work the best so I will probably forego the seating pin/plug modification.

[Berry's MfG]

Mike,
I load on a Dillon and know that if I run a round solo through from start to finish the OAL is longer than if I run one through with a full shellplate. This is caused by the opposing force from sizing a case on station one while seating a bullet on station 3, there is just enough slack in the shellplate bolt to make up the difference. I don't know what press you are using but this might be the cause /effect.

[wncchester]

"I will get from 1.127 to 1.134. I am wondering what I am doing wrong?"

Actually, that's not bad at all and you're unlikely to see any difference on target even if they were identical; handgun ammo doesn't need BR rifle consistancy. But, if you want to pull the bullets and start over, Berry makes a really good impact puller.

[engineermike]

Is that right Jay, you make a really good bullet puller?( I missed that on your web cite) Also I am using a single stage Hornady Classic press. You are right wncchester, that is not all that bad, but I am a little compulsive. The difference in C.O.L. has never stopped me from shooting them but I would hope that the end results would be a little better than what I am getting.

[Berry's MfG]

From personal experience I can tell you that our bullet puller will pull 2,000 .40 S&W rounds as fast as you can load the collet, which was off and on for 4-days in my case. I've not used Hornady dies or presses so I can't be of help there.

[Unclenick]

Mike,

A few thoughts:

First, just take your caliper and randomly sample ten or fifteen bullets of each kind and measure their lengths and calculate a standard deviation estimate for the population from that. The extreme spread of 95% should be within ±2 standard deviations. The result is the kind of COL variance you can expect if the seater step is pushing against the bullet ogive and not the tip.

When you seat a bullet with the flat ram by pushing on the tip, as your flat bullet seater stem is probably doing, you will get more consistent COL because COL's are measured to the tip, but if you had a gauge for the ogive position (which matters more to accuracy), you would probably find it was now worse.

You can often fudge that kind of gauge by using a spacer or you can also try resizing a case, flaring it (to avoid scratching your bullets), then inverting it over the nose of a finished round and measuring the distance from casehead to opposing casehead. Consistent measuring pressure is important as the cases are springy and often slightly out of round and are going be wedged into by the bullet. Zero on the first cartridge you measure to get an easy sense of the variation. You could also remove the seater stem from the die and use that, but then you're just asking to verify what you already know it does.

Take your seater stems and gently run the wide ends over a flat sharpening stone to level the raised edges of the stamped part numbers on top. You don't want these rocking on the aluminum stop plug during seating.

A bullet that goes in slightly cocked won't have the same COL as one that goes in straight. Check for the bulge in the case at the base of the bullet to be even all around. If it is, then you are fine. If not (if the sleeve alignment system isn't 100% perfect), use a Lyman M expander in place of the Hornady that puts a short step in the case before the flare. This ensures the bullet sits straight up on its way into the die. Midway and other common suppliers have them.

[engineermike]

Unclenick, I am guessing your last paragraph to be pretty much my problem. I have noticed (today) that my bullets do not set level/square into the flare that the hornady expander die makes and the bullet is not inserting into the case straight. (The bullet is not stabile in the case mouth) I'll look into the Lyman M expander die...

This is a little off topic but I think I need to go over to Jay's web page and look into that bullet puller...

[Berry's MfG]

Mike,
When you make an order with us let me know and I will throw in a one of a kind hammer for you. The one thing I'll ask is that you tell the forum how it works, unbiased using only the instructions provided, of course pictures would be a bonus.

Jay