I think it's important at this point in the overall game plan of evaluating balls in the "Question" thread.... to find out if the newer Lobo's I have currently on hand are the same as the Argentina balls which failed so miserably in your D-350 in the breach fit.
I presume they were seated but rolled back out when rifle was tilted up.
In any case.... I would like to send you 5 Lobo balls picked at random from my supply for you to try again the same way in your test with the D-350.
Can you e-mail me your mailing address so that I can send the balls to you wrapped in cotton?....(to avoid damage by postal workers handling the letters).
Any failure to seat makes the ball worthless in comparing pellets to balls as you know. -LarryS