Enfield-Rifles.com Homepage
Forum Home Forum Home > Enfields > Enfield Gunsmithing
  New Posts New Posts RSS Feed - Criterion Barrel
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Criterion Barrel

 Post Reply Post Reply Page  <12345 6>
Author
Message
britrifles View Drop Down
Senior Member
Senior Member
Avatar

Joined: February 03 2018
Location: Atlanta, GA
Status: Offline
Points: 6539
Post Options Post Options   Thanks (0) Thanks(0)   Quote britrifles Quote  Post ReplyReply Direct Link To This Post Posted: February 04 2020 at 6:01pm
 Here are three of the relevant pages from Reynolds book, “The Lee Enfield Rifle”.  

Page 84, describes the SMLE introduced December 1902.  Note the groove depth at the breech is 0.005 and at the muzzle is 0.0065.  I have some written notes in the margins obtained from other pages in the book.  Notably the tolerances in bore diameters.  




Pages 93 and 94 discussing results of trials conducted in 1902 and experiments conducted in 1904 that were reported to the Small Arms Committee by the Superintendent of the RSMF, Enfield:





Note that bore and groove depth was smaller at the breech than the muzzle and not fully corrected until 1917.  Note the reasoning given for this desired taper in reducing barrel vibrations and increased muzzle velocity.  




Back to Top
Zed View Drop Down
Special Member
Special Member
Avatar
Donating Member

Joined: May 01 2012
Location: France
Status: Offline
Points: 5585
Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: February 04 2020 at 11:37pm
Thanks for posting that info. Very interesting stuff!
It's nice to be important, but it's more important to be nice!
Back to Top
The Armourer View Drop Down
Senior Member
Senior Member


Joined: June 23 2019
Location: Y Felinhelli
Status: Offline
Points: 1246
Post Options Post Options   Thanks (0) Thanks(0)   Quote The Armourer Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 1:45am
I have a book (re-published) dated 1916 and titled

"Machining The Lee-Enfield Barrel"
"Operations And Fixtures Employed"


I don't recall any mention of internal tapering but I will have a read back thru' it and see if anything is mentioned.
Back to Top
Zed View Drop Down
Special Member
Special Member
Avatar
Donating Member

Joined: May 01 2012
Location: France
Status: Offline
Points: 5585
Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 4:10am
How would they calculate the muzzle velocity of a round a century ago? I would be interested to know the procedure!
It's nice to be important, but it's more important to be nice!
Back to Top
The Armourer View Drop Down
Senior Member
Senior Member


Joined: June 23 2019
Location: Y Felinhelli
Status: Offline
Points: 1246
Post Options Post Options   Thanks (0) Thanks(0)   Quote The Armourer Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 5:27am
Originally posted by The Armourer The Armourer wrote:

I have a book (re-published) dated 1916 and titled

"Machining The Lee-Enfield Barrel"
"Operations And Fixtures Employed"


I don't recall any mention of internal tapering but I will have a read back thru' it and see if anything is mentioned.



There does not appear to be any reference to tapered rifling in Lee Enfield barrels in the sections on Drilling, Rifling or Lapping.

Just a couple of examples (out of the 60 odd pages devoted to barrel manufacture).



Back to Top
englishman_ca View Drop Down
Senior Member
Senior Member
Avatar

Joined: September 08 2009
Location: Almaguin
Status: Offline
Points: 1089
Post Options Post Options   Thanks (0) Thanks(0)   Quote englishman_ca Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 8:14am
I wondered how the heck they would measure bullet velocity too, clock work Chrono?

What I found that was that they used something so simple, it is brilliant!

The device that they designed was basically a cup on a mechanical pendulum into which the bullet would strike. The deflection was measured off a scale giving the Force used to move the pendulum. The Mass (weight) of the bullet was known, so some arithmetic gave the Velocity. 

By all accounts, it gives a pretty accurate measurement too.
.
.
Look to your front, mark your target when it comes!
Back to Top
britrifles View Drop Down
Senior Member
Senior Member
Avatar

Joined: February 03 2018
Location: Atlanta, GA
Status: Offline
Points: 6539
Post Options Post Options   Thanks (0) Thanks(0)   Quote britrifles Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 10:06am
Not likely that Maj Reynolds imagined this.  He refers to a report from the Superintendent at Enfield; he had access to these documents and worked there during No. 4 rifle production.
 
He said the SMLE Mk I bore was "lapped" for the last 14 inches of the barrel to .304 to .306; the same as used in the MLE (long rifle).  And it was this lapping process that likely bell mouthed the muzzle. 
 
Several other references in his book to this, but he states bore and groove all made parallel by 1917.  So perhaps the 1916 book was written at the time they changed over to parallel rifling. 
Back to Top
britrifles View Drop Down
Senior Member
Senior Member
Avatar

Joined: February 03 2018
Location: Atlanta, GA
Status: Offline
Points: 6539
Post Options Post Options   Thanks (0) Thanks(0)   Quote britrifles Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 10:38am
Well, I "pulled the trigger"; ordered the Criterion barrel today.  Came to just over $400.  Yes, that's a lot of money for a barrel, since they sell new barrels for the 03 Springfield for half that amount.  I understand they don't have the sales volume here in the US for a No. 4 Enfield barrel that they have for US service rifles and they have to recover the development cost.  But, it will be nice to have a new very well made barrel to compare results to.  And if it works as good as I expect, I'll be buying a few more of them to have as spares.
 
I still have to order a chamber reamer, the barrel is short chambered by about 0.1 inches.  I'm trying to decide if I will modify the SAAMI chamber reamer dimensions, I can get a custom made reamer from Manson for a reasonable price.  My thought is a slightly reduced body diameter, and shoulder moved back slightly.  The idea is that a case F/L sized in my dies will be just smaller than the chamber and this will minimize case distortion as we have seen from some of the war time rifles.   
 
I intend to follow the recommended procedure to break in the barrel; in my experience, this results in reduced copper fouling buildup. 
 
Back to Top
The Armourer View Drop Down
Senior Member
Senior Member


Joined: June 23 2019
Location: Y Felinhelli
Status: Offline
Points: 1246
Post Options Post Options   Thanks (0) Thanks(0)   Quote The Armourer Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 10:44am
Originally posted by britrifles britrifles wrote:


Not likely that Maj Reynolds imagined this.  He refers to a report from the Superintendent at Enfield; he had access to these documents and worked there during No. 4 rifle production.
 
He said the SMLE Mk I bore was "lapped" for the last 14 inches of the barrel to .304 to .306; the same as used in the MLE (long rifle).  And it was this lapping process that likely bell mouthed the muzzle. 
 
Several other references in his book to this, but he states bore and groove all made parallel by 1917.  So perhaps the 1916 book was written at the time they changed over to parallel rifling. 


I am not questioning Reynolds, (it is an excellent book) but as you say he was involved with the production of the No4 rather than the Mk1 / No1 and would probably be relying on old documents.

The booklet I have refers to the No1 rifle, not the Mk1, maybe that is the difference ?

The No1 barrel was lapped throughout its full length.

As is usual there is contradictory information from different sources.
Back to Top
Zed View Drop Down
Special Member
Special Member
Avatar
Donating Member

Joined: May 01 2012
Location: France
Status: Offline
Points: 5585
Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 11:00am
I had the pleasure of breaking in a new barrel (old stock) on my No1MkIII* a few years ago.
Very careful cleaning after every outing. I'll be taking it out this weekend for a test with some new powder (Vitavhouri N140)
It's nice to be important, but it's more important to be nice!
Back to Top
britrifles View Drop Down
Senior Member
Senior Member
Avatar

Joined: February 03 2018
Location: Atlanta, GA
Status: Offline
Points: 6539
Post Options Post Options   Thanks (0) Thanks(0)   Quote britrifles Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 11:12am
Armourer, that may be the difference.  I can't recall when the nomenclature was changed from SMLE Mk I to No. 1 Mk I.  I thought that was after WWI (1926?), so the booklet you have (if dated 1916) would have referred to the SMLE Mk I, II or III?    Certainly, if the booklet refers to the No. 1 rifle, these would have all had parallel rifling if they were built as a No. 1 and not a SMLE Mk I. 
Back to Top
The Armourer View Drop Down
Senior Member
Senior Member


Joined: June 23 2019
Location: Y Felinhelli
Status: Offline
Points: 1246
Post Options Post Options   Thanks (0) Thanks(0)   Quote The Armourer Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 12:23pm
Originally posted by britrifles britrifles wrote:


Armourer, that may be the difference.  I can't recall when the nomenclature was changed from SMLE Mk I to No. 1 Mk I.  I thought that was after WWI (1926?), so the booklet you have (if dated 1916) would have referred to the SMLE Mk I, II or III?    Certainly, if the booklet refers to the No. 1 rifle, these would have all had parallel rifling if they were built as a No. 1 and not a SMLE Mk I. 



I believe you were referring to the "Sht LE Mk1" (or known as the SHTle Mk1) which predates the SMLE
There was no such things as a No1 Mk1

The MLE was introduced in 1895 and upgraded in 1899 becoming the MLE Mk1*




A modified MLE design was introduced in 1904 and was known as the Short MLE Mk1
(known as SMLE MK1) Almost immediately development work started on its replacement and the Short MLE MkIII was introduced in 1907 and was subsequently modified in 1916 and called the SMLE MkIII*






In 1926 as part of the nomenclature standardisation the SMLE MkIII / MkIII* was renamed the "Rifle No1 Mk3" (Or 3*)

At the same time many MkIII's were modified to .22rf calibre and were called 'Rifle No2' (with various modifications it became the No2 MKIV*)

At the same time the "Pattern 1914" became the Rifle No3

In the late 1920's a replacement for the No1 Mk3 was being investigated, and in 1930 the "Rifle No1 MkV" was trialled with 20,000 pieces being sent out to various branches of the military.

The No1 MkV was eventually developed and manufactured as the "Rifle No4 Mk1"

As you can see the nomenclature (and even the type of numerals III or 3) is quite important when looking at the LE history.

The Book I have on the barrel manufacturing is based on SMLE MkIII barrels (later to become the Rifle No1 Mk3).


I could be that the 'special' taper of the rifling was so secret that the Engineering manuals of the time did not mention it, or that it was just taken as the norm, or that it didn't happen.

The book goes into details of the dimensions of the reamers and rifling cutting tools even shows the sizes of swarf, and the very small fractions of an inch that each different cutter removed.





I am wondering if the term "Lead Lapping" mentioned above, refers to Lead as in 'molten lead' mentioned on the next page, or lead as in 'leed in' the first part of the barrel, or 'lead' as in the transition between barrel and chamber.

I just don't know and can only work on the documentation I have available.
Back to Top
Goosic View Drop Down
Senior Member
Senior Member
Avatar

Joined: September 12 2017
Location: Phoenix Arizona
Status: Offline
Points: 8792
Post Options Post Options   Thanks (0) Thanks(0)   Quote Goosic Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 12:58pm
Do you think that Kevin Bacon refers to his nipples as Bacon Bits?
Back to Top
englishman_ca View Drop Down
Senior Member
Senior Member
Avatar

Joined: September 08 2009
Location: Almaguin
Status: Offline
Points: 1089
Post Options Post Options   Thanks (0) Thanks(0)   Quote englishman_ca Quote  Post ReplyReply Direct Link To This Post Posted: February 05 2020 at 6:53pm
Lead as in as in a long plug of soft cast lead alloy that fits snug both bore and grooves. The plug is dusted with a very fine abrasive flour and run up and down the bore rotating with the rifling. Lots of oil. The abrasive embeds itself into the lap surface. 
It knocks off every microscopic jagged edge and crest of metal, it polishes and removes very little material.

That is what I understand to be lead lapping by hand.
.
.
Look to your front, mark your target when it comes!
Back to Top
The Armourer View Drop Down
Senior Member
Senior Member


Joined: June 23 2019
Location: Y Felinhelli
Status: Offline
Points: 1246
Post Options Post Options   Thanks (0) Thanks(0)   Quote The Armourer Quote  Post ReplyReply Direct Link To This Post Posted: February 06 2020 at 12:13am
Originally posted by englishman_ca englishman_ca wrote:

Lead as in as in a long plug of soft cast lead alloy that fits snug both bore and grooves. The plug is dusted with a very fine abrasive flour and run up and down the bore rotating with the rifling. Lots of oil. The abrasive embeds itself into the lap surface. 
It knocks off every microscopic jagged edge and crest of metal, it polishes and removes very little material.

That is what I understand to be lead lapping by hand.



Thanks - That was my understanding, but I wondered if that had somehow got changed around to "the first 8" of the barrel was especially lapped".

I guess unless someone has an assortment of old barrels from (say) 1907 - 1920 that can be measured for tapering rifling, it will remain a mystery.
Back to Top
Zed View Drop Down
Special Member
Special Member
Avatar
Donating Member

Joined: May 01 2012
Location: France
Status: Offline
Points: 5585
Post Options Post Options   Thanks (0) Thanks(0)   Quote Zed Quote  Post ReplyReply Direct Link To This Post Posted: February 06 2020 at 4:16am
Englishman; thank's for finding out how they calculated the velocity. It would be interesting to see the rig in use.
In todays world of digital technology; a lot of the old basic mathematic formula's seem to get forgotten.
It's nice to be important, but it's more important to be nice!
Back to Top
 Post Reply Post Reply Page  <12345 6>
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.04
Copyright ©2001-2021 Web Wiz Ltd.