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mrdap
July 07, 2017, 01:10
Hello to All,
I have two Australian L1A1 kits I bought quite a while ago.
Now I'm finally getting serious about building up a good L1A1 rifle.
I also have a DSA L1A1 receiver from the same time frame. I'll have to dig it up to get more information on the serial number.
In another thread, I discovered that if I post the lower receiver serial numbers, someone might be able to consult a database and give me more information about these kits. So here they are:
AD6610612
AD7003472
My understanding is that these two rifles were produced in 1966 and 1970 respectively. Is that accurate?
Based on my research on the internet, and the type of flash suppressors included in the kits, I have concluded that these are L1A1-F1 kits. Is that accurate?
I've also seen some information that leads me to believe they were made for Papua New Guinea.
I understand that the -F1 variation is a shortened version of the L1A1. Is that accurate?
Are there any particular issues I will run into trying to recreate a -F1 configuration?
Any additional information anyone provide would be greatly appreciated.
Thanks.
DAP

ActionYobbo
July 08, 2017, 09:24
there is no difference in the barrels except for the key slot cut on the f1 barrel which is easy to do.
F1 uses all the same components as a standard L1A1 but has a shorter butt stock and a shorter flash hider. (flash hider itself is not actually shorter because of the bayonet it is the same length as a standard flash hider just mounted further back to make the overall length of the rifle shorter)

enbloc8
July 08, 2017, 09:56
From what I understand (somebody correct me if I'm wrong), many more F1s were converted from existing rifles than built new, and most of them had standard length stocks.

Andy the Aussie
July 08, 2017, 17:40
From what I understand (somebody correct me if I'm wrong), many more F1s were converted from existing rifles than built new, and most of them had standard length stocks. ...... yes many of the SLRs from PNG were supplied as standard L1A1s but when they went through FTR they came out with the F1 muzzle device. Most also were fitted with "N" butts. Only factory built rifles were engraved with the "F1" designation and even those were often supplied with standard butts. I would suspect that repairs undertaken for and replacement parts supplied to a number of nations saw the F1 device enter service mid-life.

I am aware of the comments in Ian Skennerton's book about the claimed accuracy loss with the F1 device however my own experience and that of several others I knew was quite different. My personal (all factory) L1A1F1 shot every bit as well as a BCF barreled L1A1 that was the property of a close friend and highly accomplished service rifle shooter.

enbloc8
July 09, 2017, 09:34
...... yes many of the SLRs from PNG were supplied as standard L1A1s but when they went through FTR they came out with the F1 muzzle device. Most also were fitted with "N" butts. Only factory built rifles were engraved with the "F1" designation and even those were often supplied with standard butts. I would suspect that repairs undertaken for and replacement parts supplied to a number of nations saw the F1 device enter service mid-life.

I am aware of the comments in Ian Skennerton's book about the claimed accuracy loss with the F1 device however my own experience and that of several others I knew was quite different. My personal (all factory) L1A1F1 shot every bit as well as a BCF barreled L1A1 that was the property of a close friend and highly accomplished service rifle shooter.

Interesting...how did it compare against your stock L1A1? Do you think it maybe improved accuracy on a stock rifle?

gunplumber
July 09, 2017, 12:31
I am aware of the comments in Ian Skennerton's book about the claimed accuracy loss with the F1 device however my own experience and that of several others I knew was quite different. .

The Aus DoD Tech brochure (green) states that the F1

2-1/4" shorter
2 oz lighter rifle (with short stock)
95% flash elimination (same as regular, no more than from gas port)
lower blast flash/ pressure to firer
20% recoil reduction

And I'm a little fuzzy on this part - pages 65 & 66
Reduced jump (harmonics) improves displacement at shorter range, but not at 600+ meters, where the standard flash is better.


While not accuracy per se, this consistency is group size, or deviation from mean, which most interpret as accuracy. I'm failing to understand the distinction they are making.

It is true that shorter barrels vibrate faster than longer barrels, but along a shorter sine wave (stiffer) which has the effect of improved accuracy. For this application, it is not the rifled portion that affects harmonics, but total length of barrel + muzzle device.

But they do point out that lower velocity causes more muzzle displacement to the vertical on firing, which is compensated by the solid bottom of the F1. But I do not understand how velocity is affected by the muzzle device as the barrel is the same - attaching something to the end should affect harmonics but not velocity.

Brian in MN
July 09, 2017, 14:24
20% recoil reduction


I'm a little skeptical on the recoil bit as well. Perhaps they meant muzzle rise rather than recoil???

Andy the Aussie
July 09, 2017, 17:32
Yes I am afraid that the intricacies of the Standard vs F1 were really lost on me. For all intents and purposes the barrel is identical. My F1 generally shot a little better than my standard rifle but in fairness I bought neither NIB (I missed shopping form Lithgow direct by a couple of years though I still remember the postman leaving an L1A1 laying on the driveway of a mate's house as he was not home to accept delivery - that was the BCF rifle that my F1 shot as well as!), I knew three others with F1 variants (two factory and one "built" by adding the FH) and all shot as well as (or better) than standard rifles. I think fitting of the FH has more overall effect of accuracy, a few folks turned brass FH spacers to get a more "exacting" fit and remove any movement from the standard FH.

gunplumber
July 09, 2017, 18:13
I think fitting of the FH has more overall effect of accuracy, a few folks turned brass FH spacers to get a more "exacting" fit and remove any movement from the standard FH.

There was an issue with the original 12 sizes of timing washers requiring too much torque to align, and slightly compressing the muzzle. So they made intermediate 12 sizes, for a total of 23(?) and a gauge to insert in the muzzle after torquing to insure no compression. I don't remember off the top of my head if the A sizes were UK only or UK & Aussie.

Andy the Aussie
July 09, 2017, 18:44
I have a tin full of those timing washers here somewhere. I will go see how they are marked, I have not opened them in probably 20 years..