I have the Forster Bench Rest Ultra Micrometer Seater Die for my 7 mm rem mag. I use 162 gr A-max. I realize that bullets will vary some measuring from the ogive, but too many times when I go to seat the bullet, the die will not move the bullet at all. Say I want to move the bullet .005 to get to the correct depth. I dial the micrometer and it doesn't seat the bullet the .005 nor does it move the bullet period. I adjust the micrometer again say .003 and then it may seat the bullet .008. Does this mean that I have a bad spring or what?
Forster Seating Not Seating
- Thread starter sendero72
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I have had mine do that on some highly compressed loads but I'm not sure of the cause. I hope some of the more technically savy members will have a good answer.
Hunter2678
Well-Known Member
Mine will occaisionally do that for small changes such as .005 on certain bullets..In my experience so far the Hornadys v-max are the biggest culprit...what I will do to correct it is overadjust to 10 or 15 thous. then go back to my original small adjustment of 5 thous. I think the variation in the bullet has a lot more to do with limiting the change in depth than the die does. Reason Im saying that is bc when I go to make small adjustments while loading up some bergers..I dont need to over adjust, if I want .003 deeper, I turn the die another .003 and thats what I get.
Gary Kaney
Well-Known Member
I've had the same problem with my Forster Dies and Hornady bullets. I loaded 5 rounds so they could see the seating depth variation. ( I have an advantage here. I only live 30 miles form Lanark Ill) The 2 calibers i had problems with were my 223 & 308. What Bob did was make me new seating stems to more closely match the ogive on the Hornady bullets.
Trickymissfit
Well-Known Member
don't think I'm nuts!
There will be a certain amount of backlash built into the micrometer head on any of them (all brands), so you must take the backlash out of the adjustment before making the move to the desired number. You seat a bullet, and want to come out three thousandths more, then you should move the head back about ten thousandths and then go to the desired number.
Now there was a comment about compressed loads. I can well see this, but have never had that problem. How much bullet grip have you built into the neck? Also check the seater head to make sure it is secure. Refering to the spring; I doubt it, but you might make a.007" shim and put it under the spring on one end. If it helps then maybe your onto something.
gary
Trickymissfit
Well-Known Member
what you did was to remove the backlash in the threads of the die. I usually see .003" to .005" in mine
gary
Mikecr
Well-Known Member
If you don't have a high percentage of bullets causing issue, you can dial in occasional adjustments using shellholders.
Graf & Sons - REDDING SHELL HOLDER #6 COMPETITION SET
If you do have a high percentage of offenders, then it's really time to address a root cause.
After all, you should not have to continually adjust a seater die.
You can qualify ogive shapes(radius) with a BGC: Bob Green New Products
Seating forces need to be consistent and smooth.
You can take your necks to the same & rational seating force, by NOT FL or oversizing necks, NOT 'cleaning' inside necks, and with occasional annealing -with a machine: New Page 1
Graf & Sons - REDDING SHELL HOLDER #6 COMPETITION SET
If you do have a high percentage of offenders, then it's really time to address a root cause.
After all, you should not have to continually adjust a seater die.
You can qualify ogive shapes(radius) with a BGC: Bob Green New Products
Seating forces need to be consistent and smooth.
You can take your necks to the same & rational seating force, by NOT FL or oversizing necks, NOT 'cleaning' inside necks, and with occasional annealing -with a machine: New Page 1
Mikecr
Well-Known Member
Provided the stems aren't bottoming out and contact ~half way up bullet nose diameter, they should be fine.
Clark
Well-Known Member
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- Oct 19, 2006
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I had the problem 10 years ago with a Forster 257RAI seater, and I had the same prublem recently with a Forster 260 seater.
The concave shape of the seater stem that touches the bullet does not match the shape of the bullet. So a tiny ring is cut into the bullet where the seater does touch it.
To fix this, I take the seater stem out, look at it with a microscope, then spin it in a drill while touching the contact area with fine sandpaper. I am in effect de burring the tiny burr that was made at the factory when the part was deburred.
Other guys do one better, and glass bed the desired bullet to the seating stem, with release agent.
The concave shape of the seater stem that touches the bullet does not match the shape of the bullet. So a tiny ring is cut into the bullet where the seater does touch it.
To fix this, I take the seater stem out, look at it with a microscope, then spin it in a drill while touching the contact area with fine sandpaper. I am in effect de burring the tiny burr that was made at the factory when the part was deburred.
Other guys do one better, and glass bed the desired bullet to the seating stem, with release agent.
Gary Kaney
Well-Known Member
One other thing i forgot to mention. With my 223 die i'm loading for 3 rifles. For some reason every now and then i have to clean and lube the sliding die chamber (plunger ?). I just give it a shot of brake parts cleaner and work it in and out and then a shot of WD40 and do the same.
Gary Kaney
Well-Known Member
I'm going to have to check that out. Acually i'm using LPS spray. It's a non conductive lubricant simular to WD40. Even though you would be suprised at the gunk that comes out of the seater die when you give it a shot of Brake Parts Cleaner. I assume the gunk would be caused by case lube.
