pros cons

[double g]

coned or extractor cuts on 22 lr

 

[1813benny]

Both work. Only potential issue is during dry firing is that you can ding the end of the cone if you don't use either a spent cartridge or snap cap.

 

[TRSR8]

You don’t want a cone. Too easy to ding it,zero advantage, Most done by guys not willing to make extractor cuts and the whole indexing thing has faded over the years.

 

[USMCDOC]

You don’t want a cone. Too easy to ding it,zero advantage, Most done by guys not willing to make extractor cuts and the whole indexing thing has faded over the years.

Richard still does it don't he?

 

[ljmontano]

Kevin Nevius chambered his 2013 Anschutz with a coned tenon

 

[TRSR8]

Richard still does it don't he?

You know, I’m not entirely sure. Last I heard, some but again not sure.
Again, I‘d love for somebody to give a single valid reason for it other than to save steps. They can be super finicky for extraction unless you leave precious little metal next to chamber.
Way back, Billy Myers , probably among the first, did one for me and basically stated he “ really did not have time to cut slots”.
Not ideally what you want to hear .

 

[1813benny]

Per my prior post, a cone breach works fine. I have been using a cone breech for over 10 years without a single issue. As for a "valid reason", it simplifies barrel changes and mitigates minor misalignment potential vs extractor slots.

An updated design used by many, including Kevin Nevius, is a modified breech where each side of the barrel tenon is milled away rather than cutting slots. A very suitable compromise.

A drawing is in Kevin's post on Rimfire Accuracy.
https://www.rimfireaccuracy.com/Forum/index.php?threads/2500x-extractor-cuts.29772/post-208454

 

[Frankr]

Cone for me. I have been told either way is fine but with the cone the barrel is already set up and indicated in the lathe. Cut the cone and time the barrel exactly where you want. A few smiths I talked to said their personal Rifle was coned.

 

[Alex Wheeler]

Personally I will not cut a cone. Yes, its easier. But thats the only pro.

 

[Frankr]

I honestly didn’t like the idea
Me trying to convince myself to go with a cone. lol.

 

[bugman]

If you want to take advantage of a good condition, then shooting fast and smooth is needed.
A coned breech will definitely be better in this scenario.

 

[Todd Earhart]

We have done very little testing with true cone breach. We do know several rifles that are winners that are cone. The issue that has kept us from testing it is lack of support behind the case rim and the thought of effect on ignition.
Todd

 

[BowChamp]

If you want to take advantage of a good condition, then shooting fast and smooth is needed.
A coned breech will definitely be better in this scenario.

How does a cone help aid in fast and smooth shooting?

Thanks,

 

[kevin nevius]

Kevin Nevius chambered his 2013 Anschutz with a coned tenon

Just a few thoughts FWIW:

First of all IMHO, there is absolutely no accuracy disadvantage to a properly installed coned breech, as long as the action design has sufficient extractors / extraction capability to make it work.

The design of the extractors in Anschutz actions are some of the best out there, and the extractors are radiused to fit a cone profile perfectly. The key to the cone profile is to make it thick enough to provide proper backing of the rim (for good ignition), while making it thin enough for the extractors to purchase on the spent cartridge. I use a 30 degree cone, at a dimension of approx .255" on the small frustrum diameter. In addition, you have the tennon in the lathe already spining on axis - it is exceptionally easy to turn a perfect cone at this point in the process.

And just for clarification, I tested barrel indexing years ago and could not (for myself) validate any consistent / reliable improvement from the process. The cone would facilitate this testing, but that's not why I use them.

Anschutz actions are currently the only actions I use cones on (for the reason mentioned above). Most current RFBR actions do not have sufficient extraction to support the use of a cone. The 2500X / Trident actions need extractor slots IMHO, the web at the extractors must be extremely thin for extraction with these (which means the small frustrum diameter would need to be too small for acceptable ignition).

Food for thought I hope,

kev

 

[flatlander]

Not exactly the same thing, but Vudoo Gun Works supplied barreled actions with a semi-coned breech a few years ago, leaving plenty thick enough surface around the chamber so that there was no issue with ignition, enough so that it still required shallow extractor slots. Their reason for this style breech was to provide an area for suppressor crud to fall into when a shooter set his suppressed rifle (with the suppressor still attached) butt down into a rifle rack during a match. With a conventional flat breech with slots, the crud that often fell out of a suppressor when the rifle was racked would tie-up the bolt because of the tight bolt/breech dimensions. The semi-cone provided an area for the crud to fall into.

I set 22RF bbls up in a super spacer/indexing fixture on the mill table to cut extractor slots. When cutting slots for a custom action where the maker supplied me with a drawing giving breech dimensions (Stiller 2500XR, Vudoo), having a good DRO like the Newall simplifies things a good deal, but it's still a bit nerve-wracking to cut the slots to leave only .005" between the edge of the chamber & the slot. For factory actions like CZ457 and Win M52, I've just copied as close as possible the slot dimensions of the factory bbls. It still makes me wish for a CNC mill and the programming skills to set up RF barrels...lol

Kevin's cuts look to me to be an excellent compromise between a flat & coned breech - leaving plenty of flat breech surface for reliable/consistent ignition, yet with a good deal more leeway for slight variation in the indexing of the bbl in the action for extraction.

 

[Tony K Harper]

Not exactly the same thing, but Vudoo Gun Works supplied barreled actions with a semi-coned breech a few years ago, leaving plenty thick enough surface around the chamber so that there was no issue with ignition, enough so that it still required shallow extractor slots. Their reason for this style breech was to provide an area for suppressor crud to fall into when a shooter set his suppressed rifle (with the suppressor still attached) butt down into a rifle rack during a match. With a conventional flat breech with slots, the crud that often fell out of a suppressor when the rifle was racked would tie-up the bolt because of the tight bolt/breech dimensions. The semi-cone provided an area for the crud to fall into.

I set 22RF bbls up in a super spacer/indexing fixture on the mill table to cut extractor slots. When cutting slots for a custom action where the maker supplied me with a drawing giving breech dimensions (Stiller 2500XR, Vudoo), having a good DRO like the Newall simplifies things a good deal, but it's still a bit nerve-wracking to cut the slots to leave only .005" between the edge of the chamber & the slot. For factory actions like CZ457 and Win M52, I've just copied as close as possible the slot dimensions of the factory bbls. It still makes me wish for a CNC mill and the programming skills to set up RF barrels...lol

Kevin's cuts look to me to be an excellent compromise between a flat & coned breech - leaving plenty of flat breech surface for reliable/consistent ignition, yet with a good deal more leeway for slight variation in the indexing of the bbl in the action for extraction.

Flatlander,

The trash can collector idea is certainly out of the box thinking.

If the extractor and ejector are located at 180 degrees in the bolt, cutting slots is just as easy as cutting a cone. If they are set at an angle, it can make it a white-knuckle process.

As far as I know the angle serves no purpose other than to frustrate smiths working with manuel machines. It is certainly not done to make loading easier as proven by later Turbo designs.

TKH

 

[VLNBYR]

If a barrel has a cone and the shoulder is cut back a few .000 that barrel can be shimmed to fit any Turbo or 2500x.

 

[Tony K Harper]

If a barrel has a cone and the shoulder is cut back a few .000 that barrel can be shimmed to fit any Turbo or 2500x.

John,

Not trying to be contradictory, but please let me add a comment to your post.

Barrel to action shims is not the best idea.

The shims have to be very precise and absolutely flat and even all the way around.

Very thin shims (.001-.0010) can wrinkle when you screw the barrel and action together causing the barrel to be cocked to the action face.

Proper shims can be made by starting with a shim at least .100 thick. Then add to or subtract from the amount you need. Then cut the barrel shoulder back accordingly.

This allows for a shim that has enough structural integrity not the wrinkle or be compressed when the barrel is torqued to the action.

But again, shims are a poor band aid. Give the barrel makers the business and buy a new blank. On the other hand, if you can simply remove metal and get to where you need to be, go for it.

TKH

 

[TRSR8]

Per my prior post, a cone breach works fine. I have been using a cone breech for over 10 years without a single issue. As for a "valid reason", it simplifies barrel changes and mitigates minor misalignment potential vs extractor slots.

An updated design used by many, including Kevin Nevius, is a modified breech where each side of the barrel tenon is milled away rather than cutting slots. A very suitable compromise.

A drawing is in Kevin's post on Rimfire Accuracy.
https://www.rimfireaccuracy.com/Forum/index.php?threads/2500x-extractor-cuts.29772/post-208454

You might take note as to why, I suspect, Jerry does that.
The 2500’s are about the only threaded action made with tolerances so close you can reliably swap barrels between them, i.e. action specific.
That said, with different approaches to tighten the barrel, the fit is fine but the extractor slots may not match up perfectly every time, especially if cut close, thus the milled breach, eliminating the issue…..kind of an exception to the “ rule” if you will.
Barrels done properly, with proper slots, in my experience, don’t get misaligned, but guys that swap barrels use anything from “ snap tight” to 100lb’s+ so slots can get tighter than ideal.

I’m with TKH. I want that barrel to butt up tight to the action face. If I want to swap barrels it’s with another fit to that action.

 

[VLNBYR]

Yes you can wrinkle a .001 shim if you're not careful. In a perfect world I agree with your thoughts. Most of the smiths I know of are so backed up they don't need or want another project, build waits running up to a year.