Early 580-series and older w/ thin, straight-profile 9/16" barrel.

Average of five 5-shot groups. Ammo: Federal 50 grain BTHP (jacketed hollow-point).

WITHOUT STRUT

Average group size: 4.1"

Comments: This is a fairly typical result for the older Mini-14, most delivering out-of-box performance of around 4-6 minute-of-angle (about 4-6" groups at 100 yards).

OK for a plinker rifle, but not very impressive by modern standards of accuracy.

WITH ACCU-STRUT

Average group size: 1.5"

Comments: Gun now shoots at a more acceptable level of accuracy. Groups reduced about 66%.

In general we see improvements in the range of 50-75% for the older barrel.