Are Custom Rifle Barrels "Choked"?

[HTSmith]

That is the bore diameter is slightly smaller at the muzzle end? I have heard this but I cannot remember from where. The reason I'm asking is I'm considering shortening a Hart barreled rifle I have, but don't want to if it will impact accuracy. Thanks a bunch.

 

[Dusty Stevens]

That is the bore diameter is slightly smaller at the muzzle end? I have heard this but I cannot remember from where. The reason I'm asking is I'm considering shortening a Hart barreled rifle I have, but don't want to if it will impact accuracy. Thanks a bunch.

Good centerfire barrels arent

 

[natdscott]

It might depend on how you view a "choke". "Chokes" are used in shotguns. They are measured in 5's and 10's of thousandths of an inch.

So no, rifle barrels are not choked.

That being said, if you are talking about a slight reduction in bore diameter--on the order of a TEN thousandth or two-- yeah, that can be done with careful hand-lapping. Whether or not it's a good idea, or even has any effect, is open to interpretation.

What is NOT open to interpretation is that the lands at the muzzle cannot be shorter than they were at the leade, the bore cannot be appreciably larger, the twist rate cannot be shallower at the muzzle, the land's width cannot be narrower, the internal finish should not differ, and the overall straightness of the bore should be held as tightly in line as possible.

And more that I'm sure I am forgetting. My point is that there's plenty to worry about other than bore diameter at the muzzle for centerfire rifle barrels.

Now for rimfire barrels, I might change my tune.

-Nate

 

[swd]

Throught out the years some makers have intentionally lapped their barrels to be a few tenths tight at the muzzle. Yes, called choked as the OP asked about. It was moderately popular for high end rimfire barrels at one time, I don't know if it still is. Now a days pretty much all the big name CF barrels are very even all the way down. We seem to be in the golden age of barrel making right now. They seem to keep getting better and better. I think the new Sunnen barrel hone may have something to do with it? Maybe Alex W will chime in.

As far as lopping off your Hart, go for it.

 

[RWO]

The only commercial barrels that I ever heard of available as choked were air gun barrels and the feature was optional. Lothar Walther was a supplier and there could have been others: https://www.lothar-walther.com/gun-barrel-blanks/airgun-barrels/polygon-profile-with-choke/
It is interesting to note that apparently none of their firearms barrels are available choked.

RWO

 

[BoydAllen]

I take it that most of you have not actually cast laps or slugged a large number of barrels. I have a friend that routinely casts laps in barrels and uses them to survey their dimensions and where they are tight or loose. Recently he told me that a barrel that he just got was the first of all that he as "mapped" that was perfect. That is not to say that the others did not shoot, but for the finest results, especially when driving long bullets hard, he has found that having a good bullet to grove diameter fit is important. Based on what he has observed, and told me, I believe that one of the most important and critical steps in the manufacturing of a top grade barrel is the final lapping, and how it was done. Top grade barrels are generally lapped or honed after drilling and reaming. This means that the bore diameter can vary depending on how the lapping is done. The same holds true for the groove diameter based on how the final lapping, after rifling is done. Some time back I asked one of the largest manufacturers of cut rifled barrels to confirm that the use of cast laps or lead slugs to evaluate barrels can provide additional information beyond what an air gauge will show. He did.

 

[natdscott]

Gosh, so you're telling me that all those slugs I push through prospective barrels might be worth something?

 

[JohnKielly]

That is the bore diameter is slightly smaller at the muzzle end?

(Some) manufacturers who lap barrels recommend/require that the first inch or thereabouts of a barrel is removed as part of the barreling/chambering process. This because the lap is not driven right through the barrel but logically stopped short of that so it can be reversed again & again. This results in some degree of choking both ends. Chambering cleans up one end & cutting off the other.

 

[Dusty Stevens]

Way more damage can be done to a barrel by “evaluating” it than just trusting a reputable maker

 

[IdahoSharpshooter]

Dusty,

does that mean you don't consider Bartlein barrels accurate? IIRC, they are. Any barrel that is hand lapped as a final step will have a wee bit of "choke".

 

[natdscott]

Way more damage can be done to a barrel by “evaluating” it than just trusting a reputable maker

Can.

 

[Stan Taylor]

Humm I guess I need to recalibrate my air guage I haven't never seen any taper in my groove dimensions from one end to the other as far as bore I only pin guage each end to make sure there is no taper in bore but if the groove is right the bore should be that's in button rifle barrels we don't lap.

 

[1shot]

One of the top barrel makers said on their web site something to the effect of their barrels are never bigger at the muzzle. I don’t know which company it was, or if the website still reads like that.
If that was accurate, it would leave a person to assume that the barrel was “choked”.
I hope this helps,
Lloyd

 

[alinwa]

Dusty,

does that mean you don't consider Bartlein barrels accurate? IIRC, they are. Any barrel that is hand lapped as a final step will have a wee bit of "choke".

Dunno where this tidbit came from, but obviously not from anyone close to barrelmaking. The lapping artifact you're referring to is called "the lapping bell" by every big time barrel maker on the planet (including Bartlein) and is an ENLARGED section easily found, measured and removed by anyone qualified to install an accurate barrel. By "enlarged" I mean it's the exact opposite of choked..... they open up like a blunderbuss. Jack Sutton was known to claim that his wife "could lap a barrel without a bell"..... but he was openly biased

 

[Dusty Stevens]

Dusty,

does that mean you don't consider Bartlein barrels accurate? IIRC, they are. Any barrel that is hand lapped as a final step will have a wee bit of "choke".

Never seen a bartlein with any “choke”. I have a large set of deltronic pins. Bartleins are some of the best. They are lapped to perfection and have a perfect bore dia once you cut the required 1” off the muzzle

 

[IdahoSharpshooter]

It could be that you are cutting the choke off. The muzzle end is where the constriction is.

Please, for the rest of us who lack your experience; mike the next Bartlein barrel you get at the muzzle before cutting it off.
I look forward to your response.

Rich

 

[HTSmith]

Thanks for all the feedback. I had no idea an old man getting tired of hauling a long, heavy barreled rifle up into a deer stand would generate such a discussion. Maybe I should just get a winch

 

[watercam]

Those of us who use bands to attach match front sights are essentially 'choking' a barrel when the band is tightened. Never thought about it before until I saw one of John Whidden's barrels. He counter bores the muzzle an inch or more so that the band will not squeeze the muzzle (or so I am told). Certainly not much of an effect I am sure.

 

[dkhunt14]

When i get my Broughton barrels they come with numbers for each end. The muzzle end is always tighter. It is a 4 digit number and only a tenth or so difference. Matt

 

[LA50SHOOTER]

As Matt stated, I've had Broughton and Benchmark barrel blanks and they were stamped with 4 digit dimension numbers at both ends. Muzzle end always being smaller in numerical value than the chamber end. (in the ten-thousands range).