I have run almost 1k rounds of m855 through colt usgi mags w/ zero problems.
What does that have to do with the D&H question? 
I’ve got 4 D&H mags, 1 from 2009 and 3 from 2012 that have run flawlessly through 2000+ rounds with brass and steel-cased. Yes, it’s a small sample size with a low round-count, but it’s data nonetheless.
I dont have access to measuring calipers so anything id try with a ruler would be ballpark only.
Looks like someone slept at a Holiday Inn last night…
“Lean manufacturing systems deployed and 5-S program implemented. …”
I just sat through an 8 hour class on “Lean Manufacturing” …Good concept, but in a nutshell , it tries to have everything work perfect, turning people into robots. One SNAFU and the whole line shuts down.Obviously the QC portion is not working out…
This issue would be in thousandths of an inch at best and hundredths at worst. A ruler is barely accurate to 16ths.
That said, if the mags are causing an issue and bought recently enough, reach out to the retailer or mfg and see what they offer as a solution. Many places want happy repeat customers.
I have close to 70 D&H 30rd magazines (love that DSG L/E discount) and rotate them after 5 fully loaded cycles (function check) and so far I have not had a single magazine related failure of any kind using IMI M855 and Federal M-193.