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View Full Version : Browning 12ga rifled Choke tube info



Adam604
10-30-2008, 08:54 PM
Hi Folks,

In my last message about results of using .735 round ball, I commented that the Browning Rifled Choke was torqued down too tight to remove at the range by hand.

Well I had some time today and made a tube wrench out of a 2x4 to clamp onto the choke tube. The Browning Rifled choke tube extends 3 1/2 inches past the end of the barrel so there was plenty of material to grab onto with out a problem.

I drilled a 7/8 inch hole through the 2x4 and cut through the hole, bisecting it the hole and then cut off one part to about 5 inches long to create a movable part. The two pieced provide a even clamping surface and a lever arm to twist it. I had to clamp it pretty tight to be able to remove the choke tube.

I had to use the "wrench" far more than I thought I would. It was more than "just torqued" down. The design of the choke has the rifling start inside the threaded portion of the choke where the metal is thin and tapered. I was able to see on the outside of the threaded portion and the smooth insert portion of the choke tube that the choke has been "swaged" by the hard round ball over the rifling lands. I used my micrometer and was able to measure a .002" bump over each of the "lands" of the rifling at the edge of the threaded area. Further towards the end of the smooth area the bump tapered off to 0" (I believe that was the end of the internal choke taper, and the start of the parallel section of the choke)

So it looks as if this particular brand of Choke tube may have the taper section too steep for hard round ball. I'm going to lap mine a few thousands to extend the taper further into the choke where their is enough metal to do the job of swaging the ball

I examined the barrel of the shotgun with a 10x loop and was unable to see any problem with the barrel. I could not use my micrometer as it doesn't reach that deep. I did measure the outside of the shotgun barrel and was not able to measure any distortion.

I also searched a good bit on the Internet to find more about the choke, but could not find anything, even on Browning's own web site. This may be an obsolete part or hard to find one. It seems it is rifled at 1 in 35 like most rifled chokes

I'll attach a couple of photos.

Adam

klausg
10-30-2008, 09:11 PM
Adam-
Try a little never-seize on your choke threads, that may preclude you having to use your "wrench", it should at least make things a bit easier.

-Klaus