Crooked bullet seating?

[OKbow87]

I have been loading on my buddies press for a while now, but just recently got myself a rcbs rock chucker press this last week and all the fixins. Well i sat down and loaded about twenty rounds last night. Well after i finished loading them, i was looking them over and noticed my bullets were seated slightly crooked. I was seating them, then turning the case 1/4 - 1/2 a turn and seating them again. I looked at the die and it didnt seem to be crooked in the press. So being fairly new to the loading scene i though i would ask you guys what the deal is. Thanx in advance for your help!

 

[MagMan]

Here is a some good reading.

 

[Bart B]

MagMan's "reading" link has a lot of good information.

It boils down to the simple fact that bullets align themselves with the case neck when they're seated. If the case neck's straight with the case body axis, one stroke's all that's needed to seat bullets straight. And the type of bullet seater really doesn't matter with straight necks.

One can lap out (or have lapped out) their full-length sizing die's neck to .002- to .003-inch smaller than a loaded round's neck diameter. Then don't use the expander ball or put a smaller on on the decapping rod. Necks won't bend when sized and will be a lot straighter.

If one gets reloaded ammo with a lot of crooked bullets, they can be salvaged quite easily. Measure the neck of a loaded round then find a bullet puller collet of the same or very slightly larger diameter. For example, here's some cartridge calibers and their close-matching "neck holding collet" diameters:

.22 caliber, .257 collet for 25 caliber bullets.
.24 caliber, .277 collet for 27 caliber bullets.
.27 caliber, .308 collet for 30 caliber bullets.
.30 caliber, .338 collet for 33 caliber bullets.
.33 caliber, .375 collet for 37 caliber bullets.

The actual neck wall thickness for your specific ammo may need a slightly different diameter collet, but I think you get the idea by now. Here's what you do:

1. Check your for reloads for bullet runout and mark each ones high point with a marker pen.

2. Put the "bent" round in the bullet puller with the right collet in place such that the high point is towards the front of the press. Gently tighten the collet to just hold the loaded round.

3. Push the bottom of the loaded round back just a bit, then remove the round from the puller.

4. Check the round to see how much it straightened up. If it needs more "straightening," then do so. If it went too far, then put the round in the collet the opposite way and straighten it again.

When you're done, you'll have some very straight rounds. One can do this with factory ammo, too. It works well and nothing is hurt in the process.

 

[OKbow87]

Ok well here is a lil more information. I am loading 257 weatherby mag ammo. press is a rock chucker. dies are rcbs(i think this is my problem). #4 shell holder using imperial sizing wax. I am loading 100 grain barnes tsx, and the brass is bought weatherby brass.

What i have gathered so far from this is that my rcbs dies have the expander ball which is what is probably causing my problem here. Is there an easy way for me to fix this die, or should i just go ahead and go to some redding dies. i sized every piece of brass i had last night, but only loaded up about 20 rounds. I now wish i hadnt so i could seat a bullet in an unsized case to see if i still got the crooked seat (or what i guess is called run out, not sure about this).

The other question i have is if this run out is going to affect the accuracy of my loads, or hurt my barrel in any way? I understand that the barrels job is to stabilize the bullet, so it shouldnt have to start completely straight, but if its real bad it outta make it alot harder for the barrel to stabilize the bullet. How should i go about measuring the run out, and what is and acceptable ammount?

 

[Bart B]

OKbow87, here's some things to consider.

When a crooked bullet's shot out of the case into the rifling, it will straighten up a little bit but not all the way. It's softer than the barrel so it's going to be a tiny bit deformed as it straightens up. So it'll be a tiny bit crooked going down the barrel. Crooked bullets don't hurt the barrel as they go through them. When it leaves the barrel, its slight imbalance makes it jump a tiny bit sideways due to centrifugal force and take a direction not quite perfectly aligned with the bore. These bullets leaving at slight angles to the bore fan out and make large groups at the target.

If the bullet's pretty straight when it leaves the case it'll get really straight as it enters the bore so it's not deformed and goes down the barrel very straight and leaves that way, too. It goes out the barrel very straight and a bunch of these straight bullets cluster at the target in a very small group. And that makes us very happy.

I don't think it's your RCBS dies that's the problem. Most often the cause of crooked bullet seating is related to the cases. If the neck wall thickness isn't the same all the way around, when the sized down case neck comes back down over the expander ball its inside centers on the expander ball and the uneven thickness lets it bend more to the thin side as the ball comes up through it. It helps if the fired case mouth is passed over a spinning bore brush to clean out the powder residue and smooth up the brass, too. Bullets tend to seat and align themselves with the case neck; if the neck's crooked after sizing the fired case, the bullet's going to be seated well aligned with the case neck so it'll be crooked to the case axis just like the neck is.

I suggest having the die's neck lapped out to about .003- to .002-inch smaller than a loaded round's smallest neck diameter. I'd start at .003-inch smaller then if the neck's are a bit tight, lap the die out a bit more to only .002-inch smaller. Any gunsmith worth his shoestrings should be able to do this. Then replace the 25 caliber expander ball with a 24 caliber one.

Or buy a full-lenght sizing using a bushing with the correct diameter. The Redding Type S Full-Length Bushing Die is available for the .257 Wby. Mag.; see it at:
http://www.redding-reloading.com/pages/typesbushseatdie.html

Using your lapped out die or a full-length bushing die will make full-length sized cases have much straighter necks. One can see how crooked seated bullets are by laying the loaded round in a V-block then spinning it with your fingers while looking at the tip of the bullet. Use a magnifying glass to get a better view. An example of what's available commercially is shown at:
http://www.rcbs.com/default.asp?menu=1&s1=4&s2=3&s3=29

As the round's spun in the V-block, the bullet's tip will move about exactly like a poorly passed football. Its tip will enscribe a circle; the smaller that circle is the straighter the bullet's seated. If a dial indicator is mounted on the V-block and placed near the bullet's tip, the crookedness, or runout can be measured. The maximum runout acceptable for good accuracy is about .003-inch.

 

[OKbow87]

Well i went and bought some more unsized brass. Trimmed it square, chamfered it, and seated a bullet in it... perfectly straight as far as my eye can tell. So i call RCBS... the lady on the phone had me take out the decapping rod/expanding ball assembly of my sizing die, and then size a piece of brass and seat a bullet in it. She told me to take an assembly out of another die at work, and she is sending a new one to the store to replace the one im gonna get. Hopefully this will fix the promlem, if not im gonna get myself a redding full length bushing die.