Seating depth issues

[barefooter56]

I noticed quite a variation in bullet seating depth. Cases have been FL sized, necks chamfered n brushed, inside of necks are dusted with dry graphite powder. Cases are run over a mandrel that is .005” below bullet dia. Bullets moly coated. Seating dies are Redding Comp. And Forrester BR. Cases are annealed after 3 firings.

Am working with Berger 6mm 105 Hybrids in a 6 BR case. I am seeing seating depth variations of .010“ to .020” measured from the base of the case to the bullet ogive. I have a bbl. Chamber gauge the gunsmith made for me. This amount of variation seems excessive.

How do u maintain consistent seating depths.

Bob,
Like Dave Tooley said. You need a VLD bullet seating stem in your seater die. You ALSO need to check and make sure that the tips of the bullets are not bottoming out in the VLD bullet seating stem once you get it. This is the most common cause of what you are experiencing with you CBTO variation issue. Been there. If the bullet tips are bottoming out in the seating stem cavity. The only FIX is to have the bullet seating stem drilled deeper. Or you can contact WHIDDEN GUNWORKS and order a bullet seating die. John drills his stems deep to help prevent this.

 

[Bob3700]

Bob,
Like Dave Tooley said. You need a VLD bullet seating stem in your seater die. You ALSO need to check and make sure that the tips of the bullets are not bottoming out in the VLD bullet seating stem once you get it. This is the most common cause of what you are experiencing with you CBTO variation issue. Been there. If the bullet tips are bottoming out in the seating stem cavity. The only FIX is to have the bullet seating stem drilled deeper. Or you can contact WHIDDEN GUNWORKS and order a bullet seating die. John drills his stems deep to help prevent this.

Do u think that pointing bullets also contributes to this issue if the seating die stem is too shallow? I do point my bullets.

 

[Alexander-M]

Are your primers seated flush or slightly under the case base? Many years ago I found that some of my primers were protruding because the primer pockets were dirty. My COAL was all over the place. That was back when I started reloading, and used an assortment of brass from the range.
Alex

 

[barefooter56]

Do u think that pointing bullets also contributes to this issue if the seating die stem is too shallow? I do point my bullets.

Bob,
It may as you do make the bullet longer when pointing.

 

[WVRJ]

With no more neck tension than .0005,a moly coated bullet and dry graphite neck lube,your bullets can be backing up from the pressure of the powder charge or sticking a little in the seating stem.If you're jamming them,you shouldn't have anything to worry about because they're going to be seated by the lands when you close the bolt.I can't think that's anything but a recipe for inconsistent seating depth.I'd probably try a smaller mandrel and not use the case neck lube as an experiment to see if tightening them up makes any difference.

 

[Dave M.]

My misprint on the mandrel diameter. It is .0005" smaller than bullet diameter. So, Technically, I have a 1/2 thou. neck tension (bullets are soft seated).
Al, I believe it has to be the bullet. I sort the bullets for bearing surface length and all are within .002" of each other. There is a ring on the bullets, in the ogive section from the seating stem. To my knowledge, I don't have a special seating stem, just the one from the factory. With the low neck tension, the ring on the bullets (visible on the moly coating) cannot be from neck seating pressure. The weight of the press handle seats the bullets.
In my 308, it could be a combination of low neck tension, and full cases of powder that the bullets are pushing on. I use a 6 inch drop tube on my funnel and try to get the powder to compact in the case as much as possible. The powder could be pushing the bullets back up with the low neck tension.
To get the same base of the case to the ogive of the bullet, I am working the seating stem on my die to hit the target OAL. It gets there and the target reflects good scores, but it is a lot of extra work to make them all OAL brothers.

There is the problem. With only 1/2 thou neck tension, it is quite easy to pull the bullets out of some rounds by hand. 1/2 thou is not enough neck tension in my book. Also, you better be annealing after each firing if you plan to use that low of a neck tension. Make sure you have the correct stem on your seating die. Most don’t come with a VLD stem unless you specify that or order it separately.
Dave

 

[jackieschmidt]

This^^^^^^ -Al

^^^^^^^^x2

 

[D Coots]

Are your primers seated flush or slightly under the case base? Many years ago I found that some of my primers were protruding because the primer pockets were dirty. My COAL was all over the place. That was back when I started reloading, and used an assortment of brass from the range.
Alex

☆☆☆☆▪︎☆Similar instance when my priming tool moved and the protrusion caused problems.

Later
Dave

 

[big5ifty]

1. Are you compressing the load ?
2. What seating die is it ?
3. How are you measuring ?

 

[Bob3700]

The issue was the seating stem. I drilled the stem a bit deeper n issue disappeared.
the low neck tension works when seating into the lands. The bolt puts the bullets into the lands the same each time.
Neck tension is such that the weight of the press handle is sufficient to seat the bullet. It is also just enough tension so that u cannot move the bullet with ur fingers.
Been using this method for several calibers n numerous barrels and it works.
Thanks to all who replied, appreciate all of the input.

Bob

 

[BoydAllen]

What you are doing used to be called soft seating, it is a way not to have to worry about finding a specific seating depth, and keeping up with throat wear, as long as you seat long enough that the bullet is pushed back. The down side of your method is that you can end up sticking a bullet in the throat which would cause a mess if you try to unload the rifle rather than shooting the round. For your type of seating die, we have come up with a couple of things to improve the ogive to head dimension consistency and runout. Set the die body so that the press toggles lightly. Take enough off of the bottom of the sliding sleeve so that the shoulder of the case pushes up the sleeve rather than the shell holder. If there is room put a thin band of tape on the inside of the bottom opening of the sleeve to improve the fit. This is is a bit tricky, but it can be done. You want the ends to butt and not overlap. A friend did this with the textured painters tape and it was a little tight at the start but the tape compressed with use to a perfect fit. the choice of tape would depend on the fit you were starting with.

 

[barefooter56]

What you are doing used to be called soft seating, it is a way not to have to worry about finding a specific seating depth, and keeping up with throat wear, as long as you seat long enough that the bullet is pushed back. The down side of your method is that you can end up sticking a bullet in the throat which would cause a mess if you try to unload the rifle rather than shooting the round. For your type of seating die, we have come up with a couple of things to improve the ogive to head dimension consistency and runout. Set the die body so that the press toggles lightly. Take enough off of the bottom of the sliding sleeve so that the shoulder of the case pushes up the sleeve rather than the shell holder. If there is room put a thin band of tape on the inside of the bottom opening of the sleeve to improve the fit. This is is a bit tricky, but it can be done. You want the ends to butt and not overlap. A friend did this with the textured painters tape and it was a little tight at the start but the tape compressed with use to a perfect fit. the choice of tape would depend on the fit you were starting with.

Boat in the impact area !! LOL !!

 

[Bob3700]

Boyd,
u are correct, “Soft Seating” is the method where u don’t have to chase the throat wear. I am amazed at the number of shooters who will say they are jumping their bullets .003” or some low number. If ur shooting any type of “ Hot Cartridge”, the throat is Constantly moving n u are having to chase this measurement.
Boat in the impact area- been there n done that. Yes soft seating in an issue in those instances but am done at Camp Perry years ago.
Now, if my proven good load doesn’t shoot in a new bbl. there is something wrong with the bbl. Have seen this thru 3-4 bbls on my 6 mm BRX, 308, 243 SLR, and 6.5x284.

Appreciate everyone’s input.