• Winner! Quick Shot Challenge: Caption This Sniper Fail Meme

    View thread

So, uh, it turns out that decimal places matter...

BurnOut

DDOJSIOC
Full Member
Minuteman
Nov 24, 2013
1,826
809
Dallas
I have been having a problem with one of my rifles (Tikka T3) not being able to reliably fire ammo that I reloaded. I've been cussing at this thing off and on for a few months now, disassembling the bolt, polishing the firing pin, etc...

None of it seemed to work.

So this morning I decided to take a closer look at the ammo that I loaded... it seems that instead of pushing the case shoulder back .002", I had my full length resizing die set to push it back .020"... NO FUCKING WONDER I had unreliable ignition... the whole cartridge was able to basically "run away" from the fucking firing pin for .020".

giphy.gif

So, I guess the moral of the story is, pay attention to WTF you're doing at the loading bench....
 
.020" is pushing excessive headspace by a bit. Glad you caught it and shared. Never hurts to be reminded. Probably means your rifle was chambered .020 over or your dies are .020 under. You might verify either way. I like .001-.002 for bolt and .002-.004 for gas.
 
  • Like
Reactions: KZP
.020" is pushing excessive headspace by a bit. Glad you caught it and shared. Never hurts to be reminded. Probably means your rifle was chambered .020 over or your dies are .020 under. You might verify either way. I like .001-.002 for bolt and .002-.004 for gas.
I'm 99.999% sure that headspace in the rifle is fine... I came up with the .020" number by checking the base-to-shoulder measurement (with the Hornady headspace comparator set) of case that managed to fire in my rifle vs. a loaded (by me) round. I then compared several other fired cases to other unfired rounds and got the same results.

Pure boneheadedness on my part adjusting the FL die.
 
  • Like
Reactions: spife7980
What fl die bumps the shoulder .020”?????
Op ^

Check everything now, headspace your own measurements, etc..

Make sure you mark your brass because if you fired it, it will certainly start to have a premature thin spot about an .124-.25 inch up from the inside of the base causing case head separation.

If it’s hard or brass like Lapua, it may now die in just a few firings. While you can look for signs outside the brass, you should make a tool and look for a ridge inside the case by feel. It will save you some grief and shows up before the outside starts looking like the images to the right.
E9C03FFD-CD7D-4349-92AC-6DBD035E0FA3.jpeg
 
Last edited:
  • Like
Reactions: LG65CM and Bender
What fl die bumps the shoulder .020”?????
One that's seriously misadjusted? Using the Hornady comparator set, I'm measuring fired cases at 1.550-1.551 (base-to-shoulder) while previously resized/reloaded cases are showing 1.528-1.529 for the same measurement.

Fortunately, the brass is nothing special... once-fired (in my gun) Fiocchi in .204 Ruger. I have around 150 pieces that I've cleaned but haven't yet resized, so I should be in good shape. I just need to recover the powder and projectiles from my remaining loaded rounds and I should be in good shape.
 
I’d like to say that I’ve never made mistakes while loading, but I would be lying. I once ruined three or four Lapua .338 LM cases while decapping because I didn’t check to make sure that they didn’t contact the necks. Rolled those neck right over big time because I was distracted for the first few cases. Felt like an idiot.
 
I’d like to say that I’ve never made mistakes while loading, but I would be lying. I once ruins three or four Lapua .338 LM cases while decapping because I didn’t check to make sure that they didn’t contact the necks. Rolled those neck right over big time because I was distracted for the first few cases. Felt like an idiot.

I think we have all made mistakes reloading. Luckily, I think my worst mistake was having a couple rounds that I forgot to prime. I dropped powder and seated a bullet only to figure out that it wouldn't chamber worth a fuck because of the powder that was between the bolt face and cartridge.
 
One that's seriously misadjusted? Using the Hornady comparator set, I'm measuring fired cases at 1.550-1.551 (base-to-shoulder) while previously resized/reloaded cases are showing 1.528-1.529 for the same measurement.

Fortunately, the brass is nothing special... once-fired (in my gun) Fiocchi in .204 Ruger. I have around 150 pieces that I've cleaned but haven't yet resized, so I should be in good shape. I just need to recover the powder and projectiles from my remaining loaded rounds and I should be in good shape.

My shallowest die bumps the shoulder .006” if I cam over.

.020” is a lot.
 
Well, intermittent "light strike" fix proven out... didn't have a single failed ignition today.

While I feel like a bonehead for causing the problem, I'm sure glad I finally figured it out.
 
So, after reading some feedback from some of y'all, I decided to do some more investigating into what may have been the cause of my extreme shoulder bump. Not surprisingly, you guys were correct in concluding that the FL resizing die cannot be adjusted to bump the shoulder back that far. It turns out that the culprit was my Lee factory crimp die (sort of... read on).

Due to a lack of understanding regarding how the FCD actually works, I shamefully admit to shortening mine... which led to the extreme shoulder bump. I thought (for some reason) that the FCD worked off of the case shoulder to actuate the crimping functionality, but that's not how it works; it works off the shell holder. When I first got the FCD and was adjusting it, I noticed that it was contacting the shell plate prior to giving any significant crimp (duh), so I shortened the die in order to let the shoulder of the case actuate the crimping function "like it should". Jackassery ensued.

So, to make a short story long, I'm still the cause of the problem, but the mechanism that I used to actually cause the problem has been positively identified. It turns out that I'm certainly a bonehead, and fortunately, the only thing it cost me was the price of a new FCD and ~150 pieces of once-fired brass.
 
  • Like
Reactions: FishDr and lash
So, after reading some feedback from some of y'all, I decided to do some more investigating into what may have been the cause of my extreme shoulder bump. Not surprisingly, you guys were correct in concluding that the FL resizing die cannot be adjusted to bump the shoulder back that far. It turns out that the culprit was my Lee factory crimp die (sort of... read on).

Due to a lack of understanding regarding how the FCD actually works, I shamefully admit to shortening mine... which led to the extreme shoulder bump. I thought (for some reason) that the FCD worked off of the case shoulder to actuate the crimping functionality, but that's not how it works; it works off the shell holder. When I first got the FCD and was adjusting it, I noticed that it was contacting the shell plate prior to giving any significant crimp (duh), so I shortened the die in order to let the shoulder of the case actuate the crimping function "like it should". Jackassery ensued.

So, to make a short story long, I'm still the cause of the problem, but the mechanism that I used to actually cause the problem has been positively identified. It turns out that I'm certainly a bonehead, and fortunately, the only thing it cost me was the price of a new FCD and ~150 pieces of once-fired brass.
Thanks so much for taking the time to investigate and share the information. This type of comms is what the site is all about. I’ve made several reloading mistakes - thankfully non were catastrophic. Just replace some pieces for stupidity.
Love my Dillon presses - but graduating to a progressive press was a steep learning curve for me.
Thanks again for sharing.