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High pressure warnings

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The Armourer View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote The Armourer Quote  Post ReplyReply Direct Link To This Post Posted: November 08 2020 at 8:25am
This is the original article which had several No4 pictures included.

He concludes the article with :

"This post-war No.4 action is the best of the Lee Enfield bunch but if you overstress it you risk your life"


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Post Options Post Options   Thanks (0) Thanks(0)   Quote Honkytonk Quote  Post ReplyReply Direct Link To This Post Posted: November 08 2020 at 8:38am
Excellent response to the article from the NRA. Sounds like a bit of anti-British invention and design, but interesting reading. If any of the members own No4's and live in an area that many get rain and are now afraid to take your rifle outside, I would would definitely give them a nice home!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Goosic Quote  Post ReplyReply Direct Link To This Post Posted: November 08 2020 at 8:54am
Originally posted by Honkytonk Honkytonk wrote:

Excellent response to the article from the NRA. Sounds like a bit of anti-British invention and design, but interesting reading. If any of the members own No4's and live in an area that many get rain and are now afraid to take your rifle outside, I would would definitely give them a nice home!
I would also recommend that anyone who is now afraid to use their L39A1  or L42A1 because the Birmingham Proof Master has made these rifles an abomination according to the previous article, that you contact me for proper safe keeping and usage ...
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Post Options Post Options   Thanks (0) Thanks(0)   Quote britrifles Quote  Post ReplyReply Direct Link To This Post Posted: November 08 2020 at 9:17am
The only thing I agree with is that a wet or oily chamber and/ or ammunition does in fact increase bolt thrust loads.  However, the British method of measuring chamber pressure of cartridges and conducting proof tests at the time of the .303 and 7.62 conversions required the cartridge the be immersed in a light oil right before chambering.   

When I shoot in competition or in practice, I endeavor to keep rain off the cartridges and out of the action.  You will see a few MOA change in POI with wet cartridges vs dry, the other consequence of increased bolt thrust.  






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Post Options Post Options   Thanks (0) Thanks(0)   Quote Goosic Quote  Post ReplyReply Direct Link To This Post Posted: November 08 2020 at 10:06am
If anyone has Skennerton's big book, take a moment and read from page 256 to 264 and then reread the safety notice The Armourer supplied. 
The two topics cancel each other out.
To me it is as if two people got together one afternoon for tea and hashed out how to do,"this." Shake hands and leave.  They meet up the following afternoon for tea and proceed to hash out how to undo,"this." Shake hands and leave.

I totally understand the 7.62/308 controversy and I understand the controversy over conversions to 7.62/308 using the No4 actions based off of online debates and such. I also understand that if the rifle or ammunition does not conform to CIP standards, the rifle is basically trash, according to CIP standards. 
What I cannot understand is how a group of individuals can come up with a solution to a problem ,"updating the No4 from 303 to 7.62." And then basically 60 years later have a group of individuals condemn the solution unless the rifle goes through yet again more testing. Where does this end?
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Post Options Post Options   Thanks (0) Thanks(0)   Quote The Armourer Quote  Post ReplyReply Direct Link To This Post Posted: November 08 2020 at 10:27am
Originally posted by Goosic Goosic wrote:

If anyone has Skennerton's big book, take a moment and read from page 256 to 264 and then reread the safety notice The Armourer supplied. 
The two topics cancel each other out.
To me it is as if two people got together one afternoon for tea and hashed out how to do,"this." Shake hands and leave.  They meet up the following afternoon for tea and proceed to hash out how to undo,"this." Shake hands and leave.

I totally understand the 7.62/308 controversy and I understand the controversy over conversions to 7.62/308 using the No4 actions based off of online debates and such. I also understand that if the rifle or ammunition does not conform to CIP standards, the rifle is basically trash, according to CIP standards. 
What I cannot understand is how a group of individuals can come up with a solution to a problem ,"updating the No4 from 303 to 7.62." And then basically 60 years later have a group of individuals condemn the solution unless the rifle goes through yet again more testing. Where does this end?

A long story, but the original NRA warning was due to 'pressure problems' using NATO ammunition.
Bisley provide the ammunition for the competitions (to ensure 'fair play') and they were issuing 'latest' NATO ammunition which has bigger (heavier) bullets and higher pressures. Tight leades meant that the bullets were too tight, meaning that the pressure was even higher.

Anyway - once someone realised that these rifles were prooved using 'standard' 144-150gr ammunition and original pressures they specified the pressure requirements and bullet / leade size, or have your rifle prooved for the higher pressures.

Hence the debate (pages ago) about using Higher spec NATO 7.62 in 'old' barrels and actions that were not prooved for those pressures.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Goosic Quote  Post ReplyReply Direct Link To This Post Posted: November 08 2020 at 10:35am
...and now I understand a little more...
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Zed View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: November 08 2020 at 1:02pm
I have seen 7.62 Enfield conversions for sale in the UK that have been proofed to 20 tons instead of the standard 19tons as on my L39. I believe these recent re-proof's were to accomodate .308 factory ammunition. 
Personally I don't see re-proofing an old rifle to a higher pressure as good idea. 
It's a bit like raising the "red-line" on your classic car's engine so you can drive it faster! If there's no modification to make it handle the extra stress; it's not going to last very long!
It's nice to be important, but it's more important to be nice!
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Post Options Post Options   Thanks (0) Thanks(0)   Quote The Armourer Quote  Post ReplyReply Direct Link To This Post Posted: November 10 2020 at 3:36am
Originally posted by britrifles britrifles wrote:

The only thing I agree with is that a wet or oily chamber and/ or ammunition does in fact increase bolt thrust loads.  However, the British method of measuring chamber pressure of cartridges and conducting proof tests at the time of the .303 and 7.62 conversions required the cartridge the be immersed in a light oil right before chambering.   

When I shoot in competition or in practice, I endeavor to keep rain off the cartridges and out of the action.  You will see a few MOA change in POI with wet cartridges vs dry, the other consequence of increased bolt thrust.  


Looking thru the old 'Instructions to Armourers' reveals a bit about the movement on POI.



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Post Options Post Options   Thanks (0) Thanks(0)   Quote britrifles Quote  Post ReplyReply Direct Link To This Post Posted: November 10 2020 at 10:18am
Originally posted by Zed Zed wrote:

Personally I don't see re-proofing an old rifle to a higher pressure as good idea. 
It's a bit like raising the "red-line" on your classic car's engine so you can drive it faster! If there's no modification to make it handle the extra stress; it's not going to last very long!

I agree with Zed.  You are better off developing loads with mild pressures, about at the same pressure level as the Mk 7 .303 cartridge.  If you don’t reload, then try to find 7.62/.308 ammunition that is relatively mild.  That may be hard to determine since most manufacturers don’t list max chamber pressure for their cartridges.  

I’m sure I’ve said this before, but prior to each time I shoot my rifles I clean the chamber by wrapping a 3 x 1.5 in patch around a chamber brush and wet it in brake cleaner to remove all traces of oil and bore cleaner.  Keeping the chamber dry and free of oil minimizes stress on the action.  




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