Matt_G
Curmudgeon in training
Got in 4 brand new Lyman H&I sizing dies last week.
The one I wanted to use today is .410 diameter.
Put it in the RCBS Lube-A-Matic and the nut that holds in the die refused to seat all the way.
There was about a .050 gap between the nut and casting.
Since the die was sitting too high, this caused the bullet to go too far into the die, even with the Lube-A-Matic adjusted for minimum depth.
As such, I was getting lube in the crimp groove of my H&G 258 copy bullets.
Took me a while to figure out what was going on.
I kept looking for foreign matter or something binding and was coming up empty.
I finally realized the issue was the die itself.
If you look at a sizing die, you'll see that the bottom of the sizing die bodies are chamfered.
On these 4 new dies, the bodies are not chamfered nearly enough.
That was what was causing the die to not seat in the casting all the way, which produced excess height and lube in the crimp groove.
Why someone at Lyman would change the CNC programming to make a smaller/shallower chamfer cut is beyond me.
I can't help but wonder if it works with a Lyman 4500 and this change was deliberate.
Now I have to modify all four of these die bodies.
Frustrating.
And no, I will NOT start powder coating.
The one I wanted to use today is .410 diameter.
Put it in the RCBS Lube-A-Matic and the nut that holds in the die refused to seat all the way.
There was about a .050 gap between the nut and casting.
Since the die was sitting too high, this caused the bullet to go too far into the die, even with the Lube-A-Matic adjusted for minimum depth.
As such, I was getting lube in the crimp groove of my H&G 258 copy bullets.
Took me a while to figure out what was going on.
I kept looking for foreign matter or something binding and was coming up empty.
I finally realized the issue was the die itself.
If you look at a sizing die, you'll see that the bottom of the sizing die bodies are chamfered.
On these 4 new dies, the bodies are not chamfered nearly enough.
That was what was causing the die to not seat in the casting all the way, which produced excess height and lube in the crimp groove.
Why someone at Lyman would change the CNC programming to make a smaller/shallower chamfer cut is beyond me.
I can't help but wonder if it works with a Lyman 4500 and this change was deliberate.
Now I have to modify all four of these die bodies.
Frustrating.
And no, I will NOT start powder coating.