No4-L42-L39 cocking piece, what's the difference?

[30Three]

After looking at the parts books for the L39A1, L42A1 and the No4 Mk1. I noticed that the cocking pieces are all different numbers.

On my No4Mk1/2 and my L39A1, the visual appearance is similar, so I was wondering what the difference is?
Is it the angle of the face for the trigger weight?

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[Peter Laidler]

You're right. The angle of attack is 100 degrees, so that even when the sear spring is mounted in the competition recess of the magazine catch, the pressure cannot be reduced below the NRA safe limit of whatever it is.........
Additionally and I argue quite coincidentally - and by default, you might find that the cocking piece is marginally shorter. This is said to to decrease the lock time. But this is a marginal effort attempt to give the rifle a competitive edge. Whether this is by accident or design is a matter of conjecture but you'd need accurate measuring equipment to come to a conclusion. Shorten it to make any difference would upset the mechanical safety

[30Three]

Thank you Peter.
I will measure the trigger pull of of both rifles just for comparison.
I assume it would be difficult to find an original cocking piece for the L39 (not that I need one), but quite possible that it could be replaced by the wrong type if not aware.

[enscien]

The Mk 2 cocking piece, CR432, listed for the L42A1 rifle is the same as on the original No.4 Mk 1 (T) but has a modern NATO Stock number, B1/1005-99-961-8206. The front (bent) face is angled at 4 degrees from the vertical.
Referring to the L39A1, The 1971 'User Handbook for the Rifles, 7.62mm, L42A1 & L39A1' states that 'In order to obtain the lower trigger pressures the angle of the face of the cocking piece has been slightly altered': this was to 10 degrees from the vertical (or 100 degrees from the horizontal as PL states). The second recess in the magazine catch is also mentioned.
Spec for 1st pressure: 0-91 to 1.36 kg (2 to 3lb)
Spec for 2nd pressure: 1.82 to 2.04 kg (4 to 4.5lb)
The British NRA minimum is 1.5 kg (3.3lb)
Apparently the first 50 L39s had the 4 degree cocking piece and unmodified magazine catch. An EMER was issued detailing the authorised modifications.

[Sentryduty]

Spec for 1st pressure: 0-91 to 1.36 kg (2 to 3lb)
Spec for 2nd pressure: 1.82 to 2.04 kg (4 to 4.5lb)

As a fellow used to 6-8+ lbs modern military triggers this 4-4.5lb is what I consider absolutely perfect for a rifle that I would carry in the field, anything lighter I consider for bench and pure target personally. I think that 4lbs is just that sweet spot of light enough for good accuracy but heavy enough a that fellow won't send a round into the dirt if in a hurry to shoulder, sight, and take up slack.

[30Three]

Thank you for posting the details. I'll be checking the trigger weights of my rifles to see if they are correct.
It also gives me an idea of the trigger weight I should be looking to obtain for my No1MkIII* target rifle project.

[Peter Laidler]

Don't confuse the trigger weights of what the NRA, the UK National Rifle Association specify with the trigger pressures allowed when the rifle is a military service rifle.

We had this problem with No8 and L39 rifles until the definitive answer came from on high. The UK Military trigger pressures were the standard norm. The lower NRA or NSRA pressures were simply a relaxation in the standard '.......in order to allow service shooters to compete on equal terms with civilian competitors'.

And when the rifles were returned to Ordnance, they had to comply with the UK Military spec!

[30Three]

I would not consider less than 4.5 lbs to be safe for my rifle. They are only used for target shooting, no hunting etc. At that weight it remains about 1lb over lower limit for the French regulations.
Some people have been refused entries with .22 replica training rifles (Norinco) due to light trigger release. I lent one of my club mates my No8 at the last minute and he shot an all time personal best!

[Sentryduty]

Some people have been refused entries with .22 replica training rifles (Norinco) due to light trigger release.

Indeed,

I have a Norinco JW-28 which is a copy of a Browning Mark 1 .22LR, my Father gave it to me some time ago, I always thought the trigger was rather light, and when I bought a digital trigger pull gauge I was able to test it.

The results?

1.7-2.0 lbs, and this is sold as a sporting/hunting rifle, something intended to be carried in the brush chasing rabbits and other small game.

Far too light for me, it resides in the safe and doesn't get shot more than once every few years.