L4 flash eliminator question

[scoobsean]

Attachment 69790Attachment 69789Attachment 69787Attachment 69788
I bought an L4 flash eliminator. It appears to have no thread inside the tube (just a few scratches). I was under the impression that it would be threaded? Do I just push it onto a turned down barrel and weld or pin in place? There would have to be recesses for the lugs.

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[Vincent]

The two I have are just like yours, not threaded. I think they are just pinned.

[ActionYobbo]

they are pinned. there should be a hole thru the front sight base for the pin. get it fitted up to your barrel (lugs in the recesses) and then drill the hole thru which will put a slot in the barrel for the pin.

[tankhunter]

These were NEVER threaded on the L4 or Bren series. As Mr.E point's out. They were held in place with a pin.

REMEMBER!..It is a TAPERED Pin!

[Peter Laidler]

You are implying that there are no lug recesses in your barrel. Is this correct? If not, you'll (or the man who's doing the machining will...) need some further advice.

You've got the morse taper pin and it looks as though the eliminator is pre-drilled for it.

[scoobsean]

You are implying that there are no lug recesses in your barrel. Is this correct? If not, you'll (or the man who's doing the machining will...) need some further advice.

You've got the morse taper pin and it looks as though the eliminator is pre-drilled for it.

Yes, I have the pin and the sight housing has the hole.
The barrel I have is from a South African 7.62 Bren and is the same design as the one discussed in this link. It is a straight tube and I was hoping to somehow get it reprofiled to mimic the L4.

http://weaponsonline.proboards.com/t...an-7-62mm-bren

[Vincent]

These were NEVER threaded on the L4 or Bren series. As Mr.E point's out. They were held in place with a pin.

REMEMBER!..It is a TAPERED Pin!

That’s good to know. Do you know what size Morse taper finishing reamer is needed to taper the notch in the barrel for the tapered pin?

[scoobsean]

Here is a photo of what I currently have
Attachment 69842

[Peter Laidler]

Ah, thereby hangs the problem Vince. As you're aware, the taper now has to be cut half thickness, vertically don't forget, across the solid part of the barrel and you can't cut it with the reamer. That's why in production the FE was fitted tight into the splines and THEN drilled, taper reamered and pinned. And this is the reason why the FE was not available as a spare part (yes, there was a part number but as I always say, the parts list is a list of parts and not a list of AVAILABLE parts).

To fix this problem you have got to accurately needle file the half diameter across the barrel to mate up reasonably well with the hole/half diameter already cut within the F/E. THEN when both half radiusses are close, then put the morse taper reamer into the hole and turn to cut the correctly aligned taper.

I was asked to convert a dewat Mk2 barrel into an equally dewat/look-a-like L4A4 barrel. Machining down was a doddle, as was the shortening and EXACT alignment of the opposite locating splines (more later.....). The buggerance factor was cutting the new half diameter taper across the barrel so that the taper pin would align the half diameter in the F/E and barrel exactly. This is exactly what Scooby has got to do next.

But Scooby doesn't have the benefit of existing splines to guide the cutting of NEW splines! And if the splines aren't EXACTLY square-on/upright or opposite then the foresight will be canted over. So here's what you must do Scooby...... Tell the man cutting the splines that to get this correct, the datum from which he works MUST must be taken from a horizontal line that follows the line of the gas port through the underside of the gas block, across the gas plug opening, back into the gas block and into the barrel. I used an exact fit steel rod to get this horizontal datum to calculate the exact square for the splines.

Sorry to be so long winded but have read and re-read this and can't simplify it. And before you ask, nope....... didn't get it right the first - or even the second try but managed it exactly the third go!

Just seen the photos Scooby. Just go carefully and you'll do it. Shame you don't live around the corner or I'd have it done by this evening!

[Vincent]

Thank you so much Peter. I wouldn’t have thought of using a needle file. You save me a lot of time and aggravation.