Forster micrometer seated erratic issues, solved

[Lefty Trigger]

First off I got this 6br die set used and it has performed really well but the micrometer seater has always given me weird/erratic seating issues. I have taken apart the die and cleaned and lubed it but tonight I had enough! I was going to figure it out or trash it! Well it turns out I guess the prior owner of the die set was trying to seat 6mm bullets into 20 caliber cases because the seating stem is completely mushroomed out. I did not know that the seating stem was a separate part from the floating guide, mine was mushroomed so bad it was stuck in there as one piece!,... not sure how it worked at all? I rolled it on a flat metal plate and tapped it back into "roundness" with a small hammer and the die works perfectly now, but out of commission till a new seating stem arrives. I don't think the beat back round one is too accurate anymore...

 

[Bill Norris]

Nice that u found the issue no doubt.

 

[Sandstorm]

Used stuff can lead to some amazin discoveries...No tellin what someone else had in
mind with the stuff you end up with. I try to take everything apart and clean real well before
any unknown endeavor.

 

[Mad_Charlie]

Some folks can break an anvil with a feather, always beware used parts.

 

[Capt. Oblivious]

I had the same issue with 2 Forster seating DIEs bought new, one was 243 and another 6XC. Drove me crazy

 

[SmokinJoe]

My understanding is that the Forster BR seating die stems are relatively delicate. Previous owner was somehow creating too much seating pressure and deformed the stem.

 

[Chasin Beaver]

My understanding is that these seating does won’t hold up to compressing loads.

 

[nwmnbowhunter]

My die was sticking, popping, and marring up my bullets. Called forster and they have a video that shows how to evaluate the problem on youtube.

My bullets [both hammer and berger] would not drop through the chamber portion. Tolerance was too tight. Hornady and sierra bullets did drop through. They were being forced through which put pressure on the seating stem. I sent it in to them and they honed out the chamber portion and polished the seating stem. Works smoothly now.

 

[Hohn]

First off I got this 6br die set used and it has performed really well but the micrometer seater has always given me weird/erratic seating issues. I have taken apart the die and cleaned and lubed it but tonight I had enough! I was going to figure it out or trash it! Well it turns out I guess the prior owner of the die set was trying to seat 6mm bullets into 20 caliber cases because the seating stem is completely mushroomed out. I did not know that the seating stem was a separate part from the floating guide, mine was mushroomed so bad it was stuck in there as one piece!,... not sure how it worked at all? I rolled it on a flat metal plate and tapped it back into "roundness" with a small hammer and the die works perfectly now, but out of commission till a new seating stem arrives. I don't think the beat back round one is too accurate anymore...

Even when used correctly the stem will mushroom out and you’ll have it stick in the bushing and “click” when you retract the ram. The stem has a very thin wall and this design flaw will eventually cause OAL variation you can’t eliminate. Forster tries to grab the bullet so low on the ogive that they made their stem fragile with a super thin wall. If only they made it thicker wall and grabbed the bullet higher on the ogives, these failures wouldn’t happen. But they do. Even without compressed loads or excessive neck tension. It will scuff, it will bell, and then it will crack—as sure as the sun rises.

It’s a design flaw. This is why the last mic seater I bought was Redding. The Redding stem is thicker wall and much stronger. It seats just as straight.

 

[Hohn]

My understanding is that these seating does won’t hold up to compressing loads.

They don’t hold up even without compressed loads. Mine was scuffing and flared in barely 200 rounds.

 

[TIMO]

All, Thanks for the great information. I will have to check my seater.
Tim

 

[SLuke]

I had the same thing happening to me. I called Forster and they essentially confirmed what everyone above is saying, the can stem deform from the pressure of excessive neck tension or compressed loads. They sent me a new stem at no charge

 

[Old Navy]

I had the same thing happening to me. I called Forster and they essentially confirmed what everyone above is saying, the can stem deform from the pressure of excessive neck tension or compressed loads. They sent me a new stem at no charge

Exactly! And if you are not using to much neck tension and and trying to put ten pounds in a five pound bag they will work just fine for a long time.

 

[338 dude]

Even when used correctly the stem will mushroom out and you’ll have it stick in the bushing and “click” when you retract the ram. The stem has a very thin wall and this design flaw will eventually cause OAL variation you can’t eliminate. Forster tries to grab the bullet so low on the ogive that they made their stem fragile with a super thin wall. If only they made it thicker wall and grabbed the bullet higher on the ogives, these failures wouldn’t happen. But they do. Even without compressed loads or excessive neck tension. It will scuff, it will bell, and then it will crack—as sure as the sun rises.

It’s a design flaw. This is why the last mic seater I bought was Redding. The Redding stem is thicker wall and much stronger. It seats just as straight.

I had several problems with my Forster dies it is exactly as you described ended up with a cracked seating stem I replace the stem and sold the dies I now have Redding dies and have not had a problem since

 

[Kracken McGraw]

Good information!
I have just started to change over to some regular benchrest seater dies because I like the way the sleeve lines up the case and bullet. I will now check the stem periodically.

 

[Hohn]

Exactly! And if you are not using to much neck tension and and trying to put ten pounds in a five pound bag they will work just fine for a long time.

What do you consider excessive neck tension? My stem is yielded and die bore scuffed with only 0.002” neck tension and 200-300 rounds seated. And I do not compress loads.
It’s only “excessive” because the stem is fragile.

 

[jakelly]

Yeah, I had a .243 micrometer seater for a while, I bell mouthed two stems before I figured it out. There are sure ways to have the problem, but I’m not aware of any sure ways not to.