+ Reply to Thread
Results 1 to 5 of 5

Thread: Can someone explain Barrel Nuts and their numbers?

Click here to increase the font size Click here to reduce the font size
  1. #1
    Legacy Member AmEngRifles's Avatar
    Join Date
    Jul 2010
    Last On
    03-31-2023 @ 06:50 AM
    Location
    Florida
    Age
    63
    Posts
    336
    Local Date
    03-19-2024
    Local Time
    01:53 AM

    Can someone explain Barrel Nuts and their numbers?

    This is in reference to my experience with Semi-auto remanufactured Bren guns here in the U.S., but the question should apply and actually originate from the original full auto Bren gun as there is no modification in that area of the U.S. conversion.

    I see that barrel nuts (locking levers) are available from those with no numbers stamped at all ("originals" perhaps when a gun is new?), and then some having "0" stamped" and versions with numbers "1" thru "5".

    I had thought these barrel nuts pushed the barrel slightly towards the rear (into final locked position) and allowed for another way to tighten headspace. I am now thinking that is not the case. So can someone explain to me how these barrel nuts worked in the process of locking a barrel? I mean I understand the overall method of interrupted threads and how the basic locking works. But what happens in the nuisance with these numbered locking nuts?

    I have barrels that I have tried in my Mk I body, but the original barrel nut won't completely close on some of these extra barrels. I tried a "3" marked nut and it wasn't any better, in fact may have actually been worse, in the fact it did not get any closer to locking closed. The original barrel nut has no number stamped on it at all.

    I looked up "barrel nut" in the search, but found nothing that explains what the alternative numbers mean or how they work.
    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.

  2. # ADS
    Friends and Sponsors
    Join Date
    October 2006
    Location
    Milsurps.Com
    Age
    2010
    Posts
    All Threads
    A Collector's View - The SMLE Short Magazine Lee Enfield 1903-1989. It is 300 8.5x11 inch pages with 1,000+ photo’s, most in color, and each book is serial-numbered.  Covering the SMLE from 1903 to the end of production in India in 1989 it looks at how each model differs and manufacturer differences from a collecting point of view along with the major accessories that could be attached to the rifle. For the record this is not a moneymaker, I hope just to break even, eventually, at $80/book plus shipping.  In the USA shipping is $5.00 for media mail.  I will accept PayPal, Zelle, MO and good old checks (and cash if you want to stop by for a tour!).  CLICK BANNER to send me a PM for International pricing and shipping. Manufacturer of various vintage rifle scopes for the 1903 such as our M73G4 (reproduction of the Weaver 330C) and Malcolm 8X Gen II (Unertl reproduction). Several of our scopes are used in the CMP Vintage Sniper competition on top of 1903 rifles. Brian Dick ... BDL Ltd. - Specializing in British and Commonwealth weapons Specializing in premium ammunition and reloading components. Your source for the finest in High Power Competition Gear. Here at T-bones Shipwrighting we specialise in vintage service rifle: re-barrelling, bedding, repairs, modifications and accurizing. We also provide importation services for firearms, parts and weapons, for both private or commercial businesses.
     

  3. #2
    Legacy Member Brit plumber's Avatar
    Join Date
    Dec 2009
    Last On
    03-04-2024 @ 02:19 PM
    Posts
    1,807
    Local Date
    03-19-2024
    Local Time
    07:53 AM
    I think you can ignore the numbers, I think Peter L said they actually made little difference. If you have some that are tight, try placing sand paper on a surface plate or glass surface and then rubbing the back face of the nut in one direction and then at 90’. There’s also a sleeve that can be pressed over the breech end of the barrel to help bring back the head space and tighten things up, Kev Groom used to have these.

  4. Avoid Ads - Become a Contributing Member - Click HERE
  5. #3
    Legacy Member AmEngRifles's Avatar
    Join Date
    Jul 2010
    Last On
    03-31-2023 @ 06:50 AM
    Location
    Florida
    Age
    63
    Posts
    336
    Local Date
    03-19-2024
    Local Time
    01:53 AM
    Thread Starter
    Thank you Brit plumber for that. Here is what I observed with the barrel shims (wafers), as I purchased a couple from a company called BRP here in Georgia. They carry quite a few Bren parts.

    Those very thin barrel wafers get snugged up against the shoulder of the barrel, forward of the locking threads. This also means they are on the forward or "muzzle side" of the barrel nut, not between the "rearward side" of the barrel nut and receiver body. So that seems to me that while they may be another way to tighten the interface between the barrel nut and the barrel, they in essence, push the barrel ever so slightly FORWARD, right? How would this tighten the head space?

    I can get easily confused by all this forward and backward motion. But it would appear that supposedly the numbers mean the barrel nut attempts to push the barrel back into the receiver body against the bolt face, to achieve a slightly tighter interface? I can see that this might all be theoretical and as you say, may have no bearing at all on how a barrel seats up agains the bolt face.

    OR maybe it is more the instance of cutting various barrel nuts in an attempt to simply match a barrel nut to fitted barrel, as the barrel can be determined to headspace correctly without a barrel nut, but then you must have a nut that holds the barrel in place firmly, but not SO firmly as to take a lot of force to lock or release the barrel. So the numbers may only reference that you can loosen your barrel (by the numbers?) to have less force in lock up?

    Anybody else confused?

    I am trying to wrap my head around this as we say...

  6. #4
    Legacy Member MGMike's Avatar
    Join Date
    Jun 2008
    Last On
    03-05-2024 @ 06:06 PM
    Posts
    153
    Local Date
    03-19-2024
    Local Time
    01:53 AM
    The locking nuts are selectively fitted only to ensure a snug fit (and eliminate wobble) of the barrel to the receiver. This can be roughly gauged by "feel"; the amount of force necessary to lock and unlock the lever should be enough to firmly secure the barrel but not so much that the lever has to be pounded open or closed.

    This has nothing directly to do with setting headspace, which is adjusted by changing out the locking insert in the receiver, using a gauge.

    M

  7. #5
    Legacy Member AmEngRifles's Avatar
    Join Date
    Jul 2010
    Last On
    03-31-2023 @ 06:50 AM
    Location
    Florida
    Age
    63
    Posts
    336
    Local Date
    03-19-2024
    Local Time
    01:53 AM
    Thread Starter
    Thank you Mike.

+ Reply to Thread

Similar Threads

  1. Please explain.
    By CINDERS in forum The Watering Hole OT (Off Topic) Forum
    Replies: 35
    Last Post: 06-27-2017, 03:37 AM
  2. Nine hole Mk5 Sten barrel nuts
    By Vincent in forum Other LMG/HMG and SMG Forum
    Replies: 13
    Last Post: 02-03-2017, 08:45 PM
  3. Barrel Nuts / Headspace and such
    By DOD 7.62 in forum The Bren LMG (Light Machine Gun)
    Replies: 7
    Last Post: 09-20-2012, 06:51 PM
  4. Remington 1903A3 Serial numbers, barrel date
    By clarkmilitaria in forum M1903/1903A3/A4 Springfield Rifle
    Replies: 8
    Last Post: 04-16-2012, 07:20 PM
  5. Can Anyone Explain What This Is?
    By tlvaughn in forum The Lee Enfield Knowledge Library Collectors Forum
    Replies: 5
    Last Post: 02-20-2011, 12:02 PM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Raven Rocks