Using Google search I found: 03:45 Dec 2, 2009
MEASUREMENT OR PEA, TENDERNESS II: A Review of Methods*
volume of water displaced by 500 g of peas. Walls and Hunter (1938b) found the ... Makower (1957) used sucrose solutions and concluded that reliable mea- ... Loading was by pouring lead shot into a container supported by the pea. ...
doi.wiley.com/10.1111/j.1745-4603.1973.tb00663.x - Similar -
Althoug I couldn't get access to the full article, and there is no mention of "lead shot" in the available abstract, it seems to be a physical method for determining tenderness of pea crops, done by mixing -and later somehow "measuring"- peas and lead shot, which are probably metal balls, similar to "perdigones"; you could use "balines" | 
The translation workplace 
