Physical silver supply is as tight as it has been in years.  I personally cannot remember virtually all forms of silver being delayed this long.  Delays are as follows:
Silver Eagles:                      3-4 weeks minimum (premium $4.00 minimum)
Silver Maple Leafs:           10 weeks or more (premium approaching $4.00)
Silver 1 oz. rounds:            7  weeks minimum (premium of $1.59)
(I have silver rounds bought and paid for from the beginning of July that I have not received yet. )
Silver 100 oz. bars:           At least 4 weeks (premium at $1.29)
90% ‘junk silver’:               Indefinite – likely many months (premium of $5.00)
The premiums have increased dramatically on all forms as noted above.  Should the silver price continue to decline, premiums will rise further and delays will expand.
Why the lack of supply? 
1.  Availability of bulk silver for fabrication by private and government mints is beginning to tighten.
2.  Virtually no holders of 90% silver are selling, hence delays in excess of 3 months and premiums of $5.00 or more.
3.  There is tremendous selling of silver in the futures and ETF markets. Investors are reacting to the market correction,  in some cases selling indiscriminately. Others are faced with margin calls and have to raise cash no matter the asset.
All Things Considered – John’s Commentary:
The good news – in 20 years dealing with the country’s largest wholesale distributors and representatives for all the world mints, there hasnever been a single ounce that wasn’t delivered.
You just need to be patient.