New FsN mags don't like my reloads

[JollyRogers]

I have been reloading 5.7x28mm for over a year now and have loaded around 2K rounds. I usually shoot them in my USG or PS90 for plinking, with no issues whatsoever, but haven't been using them in my FsN mkII. So yesterday was beautiful and when I got home I asked the wife if she wanted to target shoot some. She did!!! She had recently shot the PMR30, which she loved and calls the "fun gun", so I told her she would really love the FsN. She brought her BG380 out and I brought out both FsNs to shoot - his and hers so to speak.

Well I loaded up a mag for the USG and fired 10 rounds, and she shot 10… Started loading the MKII's mag and when I got to 15, the mag started hanging up, something was binding the cartridges or the follower was hanging up on something. I tried other new style MKII magazines, and they where all the same!!! A WTF moment for me. I have never had issues with the MKII with factory ammo, but had never shot reloads through it at this point, as my USG gets that duty. So we used the old mags without issue, and my wife loved the FsN (calls it the big fun gun!), and really she did a good job with it hitting cans and steel plates, she is a dead eye shot with the FsN and the PMR30 - not so good with her BG380, but OK with it also… and complains about running out of ammo to quickly :-)

So now I am going to measure my cases after resizing. My theory is that because my Lee dies do not get cases down to factory size, they are binding in the new MKII magazines because the tolerances are tighter in the newer mags. My Lee dies do not always get the case to where it will just slide in/out of the EA case gauge, however, they barrel check OK in my 5.7 firearms. Since my Hornady dies tend to strip lacquer unless I have the case perfectly straight, I use the Lee, but they do get the cases resized so they slide in/out of the EA gauge perfectly. To stop the lacquer stripping, I had tried polishing the hornady resizing die, and even slightly beveling where the case enters the die, to no avail.

I am starting to think I may look into another die set, maybe the one EA sells (though I am not up for the wait time - as the website says it may be 6 weeks since they come from an outside source). Are the dies EA sells getting the case to the correct size, and not so prone to stripping the lacquer coating? Thoughts?

[JollyRogers]

OK, I beveled the entrance to my Hornady resizing die and polished the heck out of it. It is no longer stripping the lacquer off my cases as long as I make sure it is centered properly on the EA 550B shell holder as it goes into the die. The resized cases also drop in/out of the EA gauge easily like they should. I did a mag test with the newer MKII mags, and loaded up 20 with absolutely no issues with binding in the mag or feeding issues.

Problem solved, and lesson learned. I'll shoot the other reloads I have up eventually and will just use my Hornady dies from now on.

Thanks grimmond for the PMs, they were helpful.

[bruteandbear1]

Thats cause Grimmond is the man. He is good guy to have on the forum.

[shopsmart]

I'll second on grimmond. Helped me with some loads I was trying to make.

[grimmond]

:thumb: Thanks for the Kudos guys. :thumb:

[sean48238]

Hey what do you use to polish the inside of the dies??? I have some flitz that i use to polish feed ramps. Will it work on dies?

[grimmond]

I use .30 call brush wrapped with a patch with some mothers mag wheel buffing compound spinning it in my drill. After a couple of seconds I clean it out completely and use a new .30 brush and wrap with some JB bore polishing compound for a minute. Make sure you keep it centered and shift the brushes in a in and out motion while it is spinning. If the dies get hot you are using to much pressure. Clean, lube the die and check periodically with a case to see if your issue is resolved. If it's scraping the lacquer pay close attention to the die edges.

[GONRA]

GONRA sez be sure to rotate the shell holder to find any available
axial alignment / centering "sweet spot"
to (possibly) get rid of cartridge case coating scraping.
Hope the press was machined accurately, with a nice uniform "centerline".

[grimmond]

GONRA sez be sure to rotate the shell holder to find any available
axial alignment / centering "sweet spot"
to (possibly) get rid of cartridge case coating scraping.
Hope the press was machined accurately, with a nice uniform "centerline".

:thumb: +1 I forgot to mention that. By the way Gonra STP works pretty good in the CH4D dies. A little on the messy side though. :laugh:

[GONRA]

Whilst GONRA is a STP Oil Treatment "case lube promoter" remember that
Tri-Flow synthetic grease (3 oz. tubes available in bike shops, maybe Auto Parts stores?)
is really good too!
Preferred lube for .50 BMG. 3 oz. tube does at least 1200 "scrap dealer case resizing preps".
Tube makes it really easy to dispense a small gob on large cases. Verks fine on smaller stuff to.