the inner tubular member 348 seals 374 and 376 straddle a pair of ports 380 radially extending through the inner tubular member 348 from inner diameter 378 to a polished outer diameter 382 of the inner tubular member the ports 380 provide fluid communication between an annular chamber 384 and the inner flow passage 368 when the actuating rod 352 is moved axially downward relative to the inner tubular member 348 after the gun 340 fires and the gun release 336 releases as further described hereinbelow the annular chamber 384 extends radially between the outer diameter 382 of the inner tubular member 348 and a polished inner diameter 386 of an outer tubular member 388 outer tubular member 388 is in a coaxial telescoping and overlapping relationship to the inner tubular member 348 seal 412 is disposed in a circumferential groove 414 formed on a radially reduced upper portion 416 of the outer tubular member 388 and is in sealing engagement with the outer diameter 382 of the inner tubular member 348 seal 418 is disposed in a circumferential groove 420 formed on a lower radially enlarged portion 422 of the inner tubular member 348 and is in sealing engagement with the inner diameter 386 of the outer tubular member 388 the annular chamber 384 extends longitudinally between a shoulder 390 on the inner tubular member 348 to shoulders 392 and 394 on the outer tubular member 388 the annular chamber 384 is substantially filled with a substantially incompressible fluid 396 for example oil or silicone fluid the fluid 396 does not permit the outer tubular member 388 to move appreciably.