147gr HST issue

[KyleC]

I am getting a noticable, concentric ridge in my brass once I seat a bullet. The ridge is from the base of the bullet. Imagine the "Dillon coke bottle" but with a very noticable ridge in the middle of the brass.

Brass is being sized to within all saami specs on a 550b with Dillon carbide dies.

All bullets measure 0.354

I've tried more bell and less bell, shorter and longer COAL, more and less crimp. I e also adjusted the sizing die.

When I seat a bullet, there is noticable ridge in the brass at the base of the bullet.

Once the bullet is seated, the case mouth measures 0.384 - 0.386.

The ridge measures anywhere from 0.386 - 0.390

[anachronism]

Most, if not all carbide case sizing dies resize the cases smaller than the finished OD of new ammo built in new brass. Check and make certain the ridge from the bullet base is equal, all around the case. If it is not, then you are tipping bullets as you seat them. If so, and the loaded cases pass your case gauge, then this is a normal situation, and you are good to go. There are a number of similar questions like this on a regular basis here, and on other reloading boards. As I said initially, most, if not all carbide case sizing dies resize the cases smaller than the finished OD of new ammo built in new brass. Another potential condition could be that you are seating your bullets a bit too deep and are running afoul of the 9mm cases inside taper. You didn't specify which bullet you're using, so there's no way for us to work off that angle.

[KyleC]

The ridge is concentric, so the bullet is seated correctly.

 

I've searched and read those threads. The ones with pictures are nowhere near what I'm getting.

 

147gr HST is what I'm using, as stated in the thread title.

 

This issue is causing chambering issues.

 

I'm using mixed brass, COAL varies from 1.120-1.130

 

I tried to post a pic, but all of them I have are too large

Edited January 2, 2020 by KyleC

[4n2t0]

Resize the picture and post it.

 

How did you determine the OAL? Does your sizing die touch the shellplate? Are you using the semi-wadcutter stem in the seating die? The case mouth measurement after crimp should be .380 MAX.

Edited January 2, 2020 by 4n2t0

[KyleC]

I determined COAL by going with the COAL of factory loaded 147gr HST. I'm using mixed brass, so it varies slightly.

 

My sizing die does touch the shell plate

 

Not sure on the seating stem. I'll check. 

 

The casemouth measurement after seating and the measurement of the ridge is what has me dumbfounded. The only thing I can come up with next is really dial back the bell to almost nothing and increase the crimp

 

[wurm]

How long are those HST bullets?  147 grain bullets are pretty long in general, and if seated to the same length as a shorter bullet, the base of the bullet will sit deeper in the case than with the shorter bullet.  Case walls taper and get thicker as they get close to the bottom.  This thread on 1911forum has a nice cross section of a case.  https://forums.1911forum.com/showthread.php?t=465525  Seat a bullet deep enough and it will get into the section of the case where the walls start to thicken.  Couple that with a bullet with a flat base and little to no chamfer, you may see a decent bulge.

 

I had a similar problem with 147 grain black bullets i was using.  Good bullet that worked great in my 9mm 1911, but when I had to load them shorter for a CZ and Tanfoglio I started having bulges and rounds failing my case gauge.  I switched to a SNS bullet with a chamfered base and different profile that let me load longer and my bulging problem went away.

 

Try loading those HSTs a bit longer and see if the bulge lessens.  Take a look and see if certain brands of brass have it more or less too.

[4n2t0]

First, determine your OAL (See below). You can't duplicate a factory round unless you're using all the same components. You only have to flare the case mouth slightly when using FMJ. After crimping the case mouth measurement should be approximately .377 - .379.

 

- How to determine OAL: https://czfirearms.us/index.php?topic=34225.msg189131#msg189131 (If your bullet doesn't easily collapse just use the seating die to shorten the OAL incrementally until it plunks)

 

- Plunk test:

 

 

[4n2t0]

A picture of your round(s) is still worth a thousand words...

[KyleC]

I started fresh this morning and I think I have it figured out. I took 10 different measurements throughout the sizing and loading process of 9 different headstamps. I'm not going to post all those measurements, it'd take a while to type it out and it'd take a lot of space. From what I can tell there is a brass issue and a die setting issue. On my end the issue was belling and crimping. I was belling too much, and crimping too little. Aguila, CBC, and S&B headstamps are an issue. The ridge for Aguila measures 0.391, CBC 0.390, S&B 0.388. The case mouth for all of these measured 0.378 after crimping.  None of these will chamber in my AR9 or CZ P 10C. Win with a ridge that measures 0.386 will chamber.  Win, Geco, PMC, Speer, Blazer, FC all function fine. The case mouth measurement on these varies from 0.376-0.3775. The ridge measurement varied from 0.382-0.386 Speer Nickel shows to have the smallest ridge. followed closely by Blazer. Going forward I will only load these 2 headstamps with this bullet. Feel free to ask any questions. Hopefully my experience can help out someone else.

[Sarge]

Sounds like they are maybe a little too deep. Maybe the HST factory cases have thinner walls further down to accommodate the long bullet.

[HesedTech]

5 hours ago, KyleC said:

Aguila, CBC, and S&B headstamps are an issue

Yep.

 

If you search this forum you’ll find those are always an issue with deep seated bullets. And you can’t fix the bulge by using a Lee FCD.
 

I have to assume you got a good deal on these bullets. There are better options in 147 which load longer. 
 

Sarge I believe HST are Federal bullets and yes their cases are designed for them. 

Edited January 2, 2020 by HesedTech

[KyleC]

I searched, I didn't see that. Wished I had, it would've saved me A LOT of trouble and time, but I did learn a lot through this process.

 

The bullets were $0.08/rd. The only issue I can find wit the bullets is that overall length varies. I haven't measured ogive to base. However, the variance in bullet over all length hasn't changed the ridge measurement. This makes me wonder if the pulling process has more effect on the "petals" outside of the case than the bullet base inside the case. Diameter is spot on for every one I've measured, 0.354. 

 

So far today I've loaded Speer Nickel and FC. No issues, full function in my CZ P10C and AR9. I haven't fired them in my 2 Walthers, but the chamber and eject fine.

 

 

Edited January 2, 2020 by KyleC

[KyleC]

4 hours ago, Sarge said:

Sounds like they are maybe a little too deep. Maybe the HST factory cases have thinner walls further down to accommodate the long bullet.

 

After all of the measuring I've done today, I believe this to be that case. If I had some factory HST rounds here I would pull them and find out.