Jump to content
Brian Enos's Forums... Maku mozo!

Montana Gold 124gr JHP.... Inconsistent finished OAL


Gman57

Recommended Posts

I have 2 cases of MG 124 JHP and finding that the finished OAL fluctuates .004 to .005

That said I'm looking for 1.140 set up and it will range 1.137 to 1.145. And should say I have more over than unders. I don't have this issue with FMJ bullets, only thing I can figure is the hollow point tip has some jagged edges and will make the difference when seating. Anyone experience this?

G

Edited by Gman57
Link to comment
Share on other sites

Are you measuring rounds that are made when all of the stations of the press are filled?

 

Other things to check/do:

Pick out single headstamp brass to measure

Make sure that your primers are at least flush/below flush

Try to feel the same amount of click/stop/thud, whatever you want to call it when you hit the bo.ttom of the stroke

 

If you're loading a compressed load, that could be the culprit as well.

 

 

 

 

Link to comment
Share on other sites

Know exactly what your talking about at the finish of the stroke. Primers no issue, I would think brass should not be the issue if it was ,002 or .004 difference in case length we are measuring OAL and the bullet would just seat more or less in the case?????

Link to comment
Share on other sites

You can have different case wall thickness with different head stamps.  That difference might affect how far the bullet gets pushed into the case by the seating die.  That (or that in conjunction with other factors) could make the difference.  

Link to comment
Share on other sites

It seems to be pretty common these days for bullets to vary slightly in length and/or ogive profile. I just ran into this with some Hornady bullets too. Bullet length varied over .010 in some instances. Since I was loading a high-pressure cartridge (357 SIG) the difference really bothered me. I was paying heavy attention to crimp location and nose length (yup, SIG) and the discrepancies really leaped out at me. Rechecking my load data I decided the differences were negligible and finished up quickly. The fact of the matter is that there's no way to guarantee that any two jacketed bullets are ever identical. I don't think any bullet maker makes every bullet from the exact same forming dies and punches. It's simply not possible.

 

You also see this situation a lot with rifle bullets.

Link to comment
Share on other sites

7 hours ago, Gman57 said:

  MG 124 JHP  OAL fluctuates .004 to .005.

  I don't have this issue with FMJ bullets,

 

Have you flipped the bullet seating stem over from round nose

to flat bullets?

 

You usually use the round nose stem for FMJ's, and flat nose

for JHP's.

Link to comment
Share on other sites

1 hour ago, Hi-Power Jack said:

 

Have you flipped the bullet seating stem over from round nose

to flat bullets?

 

You usually use the round nose stem for FMJ's, and flat nose

for JHP's.

Jack

 Thought of that and tried both ways seem to work better on the round nose side. Initially I was set up with the flat point side.

 Using a Dillon die  thought about trying another manufacture.

 It's a mystery,  with my 40 caliber 180 gr  Montana Gold  I am within .002 all the time.

G

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...