Bren and L4 spring and thread sizes

[Peter Laidler]

There won't be many who need this info but if you do, here's a few important bits of info for Bren and L4 spring sizes

SPRING AND SCREW THREAD DETAILS FOR THOSE IN NEED

I can't get this to tabulate with my dire computer skills but the first measurement is the number of coils, second the external diameter and the third size, the free length

SPRING No coils approx External dia. Free length
Bipod 13.5 .484 2.2
Buffer piston 8 .89" 2.75
Catch, cover eject opening 10 .153 .51
Catch, carrying handle 15 .346 1.61
Catch. leg bipod 7 .165 .336
Catch, magazine 16 .169 .95"
Catch nut barrel 8 .272 .67
Detent, change lever 8 .13 .354
Pin firing 15.5 .228 .906
Plunger, butt bracket 11.5 .13 .52
Plunger, handle carryng 10 .232 .787
Plunger handle cockng 8 .232 .748
Plunger backsight 27 .224 1.85
Post, piston 22 .484 3.126
Retainer barrel nut 14 .189 .79
Retainer, pin locking body 18 .110 .67
REtainer, pin mag catch 9 .110 .335
Return, inner 92 .358 13.2
Return, outer 70 .477 13.2
Sear 11 .264 1.26
Stay, extractor 13 .264 .98
Trigger 13 .17 .79


SCREWS
Same again. Due to my dire computer skills, First is the TPI. Second measurement is the +/- length of the shank and 3rd measurement, the diameter
DESIGNATION TPI LENGTH DIAMETER
Screw; OF SHANK
Bracket, bipod 32 .865” to .875” .311”
Handle, carrying 48 .566” to .570” .234”
Foresight protector, Mk2 2BA .185”
Retaining mounting pin 72 .255” to .215” 1585”
Locking shoulder 32 .354” to .342” .316”
Sleeve, bipod 22 1.53 to 1.53” .315”
Spring, backsight leaf 2BA

OTHER THREADS
Return spring tube Butt slide thread 26 TPI r/h
Nut thread 32 TPI, r/h
Pistol grip, Mk1 32 TPI r/h

Information

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