9mm HP when seated, nose gets crushed

[Helka]

Hey Everyone

I only just noticed that when seating my boolits the nose is coming out crushed. I never adjusted my crimp from seating regular "factory" boolits. I did try the SWC stem but that just left a ring on the boolit. Using RN stem. I'm using RCBS 3 die set. I'm wondering if i need to play around with the crimp setting to lessen it? thoughts?

Attached are pics of before and after.

287380

287381

I don't think it affects accuracy but still would like to keep the nose as original as possible.

Thanks

[gwpercle]

First try seating the boolit w/o crimping and if the nose doesn't deform , crimp in a separate step .

It may be the force of simply seating the boolit is deforming the thin wall of the boolit cavity .

In that case a fitted boolit stem will need to be done . On solid nose boolits I custom fit stems with a small ball of epoxy putty placed in the nose cavity then seating the boolit about half way into the case and leaving in the press to harden ... but that's not going to work with a HP !
Gary

[DAFzipper]

I made a flat seating stem for HP cast bullets. Slightly flattens the end but doesn't reduce the diameter like a RN stem does.

Sent from my LG-H700 using Tapatalk

[ShooterAZ]

I customized the bottom of my seating stem using epoxy to perfectly fit to the nose of the boolit. You can use a small amount of petroleum jelly (temporarily) on the nose to keep the epoxy from sticking to it while it sets. It worked pretty well.

[ryanmattes]

I would also say to try seating and crimping in separate steps. If it still leaves marks, try belling the case mouth just a bit more. If it still leaves marks, it may just be really soft alloy.

Sent from my Pixel 3a using Tapatalk

[OS OK]

If we had seater stems shaped like this top punch we would be ok and have only minimal distortion.

https://i.imgur.com/mVOI60d.jpg

The wider the area around the HP Cavity, the less sensitive it is to crush. I have only these two seater stems in my RCBS dies...(before modification)

https://i.imgur.com/KMLNJog.jpg

...but I relieved the inside radius of the rim of the seater stem so that it wouldn't imprint (leave a ring around the nose) on a wide nose HP.

https://i.imgur.com/gjULSLW.jpg

https://i.imgur.com/I9ksEO3.jpg

The round nose seater stem does leave the HP closed a bit but if the velocity and bhn agree, it will not affect the performance...they just look a little weird.

https://i.imgur.com/MAIHmUJ.jpg

The above picture is of very soft lead, too soft actually but the lead below is just right...it's still affected by the modified RN seater stem and it's closed just a tad but it's all I have to work with.

https://i.imgur.com/CtetNVw.jpg

Since these pictures, I've gone to a NOE expander plug that adequately opens the case and flairs the mouth well so that it lessens the amount of force against the HP nose cavity needed to seat the cast.
I guess you just have to tinker with your seater stems some to make them work as you want them to. I'd like to have my finished rounds look perfect too but I'll settle for performance over looks.

[Helka]

Thanks for all the suggestions. I will look at changing the crimp and see if that helps, if it doesn't then i will look at the epoxy step. My HP are in the 19-22 BHN. So not too soft. Performance was great at 25 yards 4” group, from previous posts i had made.

[Johnch]

I made a custom seating punch for Hollow point 9 mm and 357 Mag cast bullets
As I used the same hollow point pin for both , it fits either the 9 MM or 357 Mag dies
I put a exact copy of the hollow point pin on the new seating punch
It stops the hollow point from deforming
Only down side is that you must have the bullet straight up when you go to seat the bullet
It dose not really slow the seating down though

John

[Bloodman14]

Didn't someone use hot glue to make a custom punch? It seems that I read that somewhere.

[Helka]

So playing with the crimp definitely helped but is still kissing the tip, I had finally got around to making some flat points, that will be interesting on how it deforms the tip. I may take a grinder to the SWC punch to bell the sides of the punch so they don't touch the boolit. we'll see

[fredj338]

Didn't someone use hot glue to make a custom punch? It seems that I read that somewhere.

Actually JB weld works better. Not sure how that would work for a penta HP but works great for round ones.

[Papercidal]

NOE makes a adapter for using a top punch as a seating stem. I believe it uses the Lee expander as a die body.

[Helka]

I've reached out to NOE via email with no response regarding purchasing a mold. they offer shipping to canada but my address is "incomplete". but it's not. Will try again.

Seem's they fixed the issue i was having.

[Forrest r]

Your issue is with the expander button/die that came with your die set. They are typically designed for the smaller in diameter, shorter in length jacketed bullets. Along with a jacketed bullet being like a bulldozer and can take extreme amounts of force before they deform during seating.

NEO bullet molds sell expanders for the different calibers that screw into a lee universal expander die. NEO likes to make an expander ball that's 4/1000th's less then the bullet diameter your using. Myself I made a custom expander for the 9mm's that is .356" in diameter for the .358" bullets I cast/use in my 9mm's.
https://i.imgur.com/aFsP8TI.jpg

Neck tension is a good thing but a excessive neck tension, not so much. Excessive neck tension can and will affect the hp nose of a bullet as you're finding out. It will also affect a bullets base by rounding/swaging it down in diameter when being forced into an under-expanded case. A hp & hb bullet loaded in 9mm cases.
https://i.imgur.com/V87WlTN.jpg

Any time I taper crimp a reload I always seat and crimp in separate stages along with using a +/- 3/1000th's taper crimp.

I really like the "640" nose style of the mihec molds. I use/shoot the 125gr 640 profile in the 9mm, the 158gr 640 profile in the 38spl's/357's & the 240gr 640 profile in the 44spl/mag's. The 9mm & 38spl/357 bullets have thin hp walls at the top/nose of the bullets. It's pretty easy to deform the noses of those bullets when cast with my typical 8/9bhn range scrap alloy. The custom expander for the 9mm works with the oversized bullets I use in the 9mm's. I use lyman m-die expanders for the 38spl, 357mag, 44spl, 44mag. I also use a lyman m-die for the 45acp.

NEO wasn't around when I bought the m-dies decades ago. The 9mm I simply made myself.

Anyway I'd be taking a hard look at the expander die. You can use all the different or make custom seating stems you want. If you have to use excessive force to get the bullet to seat in the under-expanded cases. The issue of flattening/deforming the thin walled hp nose/shape will never truly go away.