Printable View
Although tech details mention barrel shims in two sizes (.002 & .003) I have only ever found
.002 barrel shims.
Am I just unlucky or were the .003 shims done away with to only allow a maximum of two
.002 shims ?
https://www.milsurps.com/images/impo.../08/shim-1.jpg
Anyone got any .003 shims ?
ATB Kevin
We've got .003" shims and they were available. You could use up to .005" but unlimited (within reason of course) on DP guns as I recall. However, the use of shims on 7.62mm barrels was not permitted EXCEPT for the L55 DP guns
The shim 'top hat' tool is interesting because we had to make one of those during the sheet metalwork phase of our apprenticeship. Mine was rubbish of course, looking like a ring doughnut!
Hello:
Now I know what that was that I peeled off of a barrel shank... Is there an already composed pargraph or two on why such an item was used and how its required use was identified? Is it purely a headspace tool or did it have to do with the barrel nut engagement? Other?
I'm all ears!:bow:
The shims were used so that you could get an exact fit with two barrels on the same gun using the same barrel nut. Because no two barrels were the same for example, we'd have to replace one shot-out barrel with another part worn barrel (we tried to keep matching barrels with matching worn bores or certainly within what we'd call 'quarters of life'). If the good barel was nice and tight, we'd fit a similarly worn replacement barrel. If this was slightly loose, then you could use a .002 or .003" shim - up to a total of .005" - to tighten up the second barrel. This COULD open up the CHS so you'd have to start again but generally speaking you could easily bring in both barrels to get the correct tightness and CHS.
Another thing. OFFICIALLY the second barrel had a letter 'S' stamped after the serial number and was kept in the holdall (the big long barrel bag.....) but once we were in the big bad REAL world, we were told NOT to mark the second barrel with an 'S' so that both barrels were used equally.
So if you have an old barrel with a letter S after the serial number, that's the reason why
Cheers Peter,good to know they are out there somewhere :thup:
WallyG, an extract from AP1641 -
https://www.milsurps.com/images/impo...8/AP1641-1.jpg
ATB Kevin
Yep, that's the RAF instruction. We went to .005"
Quote:
Originally Posted by Peter Laidler
Yes I have noted the difference in maximum tolerances between services Peter.......but why ?
ATB Kevin
I would imagine that it's because the RAF Brens didn't get the pounding that the Army ones got so they could relax their spec slightly. They didn't have the quantity of Armourers that we have and as a result, most of the time any repairs beyond the station 'bomb jockeys' (as RAF Armourers were called.....), the weapons had to be back loaded to a main repair depot. After the late 70's or so, after the RAF equivalent of unit repairs came under the wing of the Army so our rules counted
Thats a new one Peter, never been called a bomb jockey, i've been called a bomb 'ead and a plumber before. I'll have to remember that one!
https://www.milsurps.com/images/impo...09/small-1.jpg
Well........, I'll be blowed. Didn't know that you were a bomb jockey BP. If I'd known, I'd have laid it on a bit thicker!
What's that aeroplane? They all look the same to me. I suppose your Summer Holidays will be ending soon. Keep safe
RAF Typhoon FGR4 in Air to Ground role, 2 Enhanced Paveway 2 LGB, 2 Advanced Short Range Air to Air Missile (ASRAAM) and 1 Advanced Medium Range Air to Air Missile (AMRAAM). This aircraft isn't in its full load, it could carry (In Air to ground role) 4 Enhanced paveway 2s, 4 AMRAAMs, 2 ASRAAMs and the 27mm Mauser Cannon.
In Air to Air role it could carry either 6 ASRAAM and 4 AMRAAM or 4 ASRAAM and 6 AMRAAM as well as the 27mm Mauser cannon.
It has to be one of the worlds leading multi role aircraft at the moment, even the Americans have been worried by its capabilities.
The shims and shim tool are shown in the Illustrated Parts List for the L4A1 and L4A2.Quote:
Originally Posted by Peter Laidler
Were these also permitted to be shimed as they were issued with two barrels or were the IPL's a bit over enthusiastic :) ?
ATB KG
Interesting........ I'm not sure that shims were allowed for any of the L4 guns. Certainly not the A2's onwards. I'll check with the EMER's tomorrow
Sorry for the delay but just checked with the full set of EMER's and while the barrel washer/shims might be shown in the early L4 A1 and 2 parts lists, I can find absolutely NO mention of the barrel tightening shims being permitted for use on the 7.62mm L4 guns at any repair level. Just to double check, I looked through the tool list and neither is the special assembly tool provided for the L4 guns.
To sum up.... Officially, .303" Bren, YES, up to .006" but L4 guns, No.
But if you were a needy civillian L4 owner without access to a rack full of barrels ready to interchange as required, then so what if you did use the odd barrel shim!
Thanks for the clarification Peter :thup:
ATB KG
Funny,
The barrel that 'belongs' to my bren has a S behind the number so it's a spare barrel (It was hardly used.) and my spare barrel doesn't have the S... Oh well during re-enactment I can change them. Just need to have them correcly locked away otherwise the numbers on my license wont match...
Daniel,try and edit your post and change 'spare' to second before Peter reads it ! :D
ATB Kevin
Henous mistake calling it a 'spare' barrel. It was the SECOND barrel, as pointed out by KG! Eventally we didn't even mark the second barrel with an 'S' so that they'd just regard them both as just, well, barrels
Oeps.....
Well I'll never call it a ***** barrel again...
Sorry Peter.. :bow: