cone breach chamber

[TRSR8]

I'm pretty sure you are correct there. He talked about that and I think that the Rockwell might have come out of there? If not it came from one of the places he worked as a machinist. He had so many cool things he made in the shop. He showed me much of it and how it was done. I spent near two days listening and learning with him. I'm grateful and thankful for all he shared. I also have one of his reamer holders and cleaning rods that he made.

Oh and he treated me as an equal even though I was no where near the machinist he was nor had anywhere near the knowledge he had.

 

[rodstreet]

Just an example (I know you are aware, just for those who don't know what one looks like I guess)

That looks like a shielded cone. Here’s a poor photo of a shielded cone which stops the bolt face. In my example slots have also been cut

 

[kevin nevius]

Hey Kev,

I thought that was my Copperhead when I first glanced at it, but I think mine is a different serial number.

Landy

Good morning Landy:

So great to hear from you! You are correct, that's not yours (my apologies to all also, I didn't realize there was a SN in the picture).

On a side note - I wanted to thank you for your work, and all the information you share regarding this crazy sport. I feel stupid with every post - I had statistics in college, but I am nowhere near your level of understanding or intelligence. You are brilliant, plain and simple. Thanks again!

What is the advantage of a cone breech, besides indexing the barrel? PLs educate me guys!

There isn't any accuracy advantage, but there is a huge gunsmithing advantage. The tennon is normally already indexed and cutting a cone eliminated all the extra steps cutting and clocking extractor slots. My first actions decades ago were Anschutz, which had radiused extractors that fit cones perfectly (and eliminated the need to purchase radiused keyseat cutters). But as I mentioned, they IMHO do not function well with some actions.

 

[Tim Slater]

There isn't any accuracy advantage, but there is a huge gunsmithing advantage. The tennon is normally already indexed and cutting a cone eliminated all the extra steps cutting and clocking extractor slots.

Kevin,

if you'll indulge a small tangent, in your opinion is the separate chamber/barrel face on the Bleiker there to obviate timing extractor slots? I think this is the purpose on the Anschutz 54.30 (and on prototype RPA/Chombart smallbores), but I wasn't sure about Bleiker.

 

[kevin nevius]

Kevin,

if you'll indulge a small tangent, in your opinion is the separate chamber/barrel face on the Bleiker there to obviate timing extractor slots? I think this is the purpose on the Anschutz 54.30 (and on prototype RPA/Chombart smallbores), but I wasn't sure about Bleiker.

Hi Tim, great to hear from you!

The design in very interesting - after barreling mine and several others, it makes more and more sense to me. Not having to worry about timing extractors or setting headspace is a definite plus. The shortened depth of the chamber puts the leade where you can really see what's going on (finish, etc.). It also saves wear and tear on reamers with a depth approx. .300" shorter. Concentricity is maintained by a high tolerance bushing at the chamber parting line.

I am still evaluating the .118" aluminum crush washer (Blieker sandwiches a crush washer between the machined action breech face and the tennon shoulder). I have tested barrels fittted without it, then machined the setback and used the crush washer - and I believe there is a very real accuracy advantage. Not sure if it could be adapted to modern BR actions (or if it would have the same effect), but its quantifiable / repeatable.

Thanks for asking, have a great Christmas Season!

kev

 

[HuskerP7M8]

Good morning Landy:

So great to hear from you! You are correct, that's not yours (my apologies to all also, I didn't realize there was a SN in the picture).

On a side note - I wanted to thank you for your work, and all the information you share regarding this crazy sport. I feel stupid with every post - I had statistics in college, but I am nowhere near your level of understanding or intelligence. You are brilliant, plain and simple. Thanks again!

Kev,

Those are very kind words, and humbling coming from a competitor/human being of your stature.
If not for your praise and others like you doing the same, I would have quit contributing on forums a long, long time ago.
It’s been a lonely life pursuing the technical side of firearm precision. LOL

I sure hope we get the opportunity to shoot together or visit face to face again in the future.

Thank you,
Landy

 

[Tim Slater]

Hi Tim, great to hear from you!

The design in very interesting - after barreling mine and several others, it makes more and more sense to me. Not having to worry about timing extractors or setting headspace is a definite plus. The shortened depth of the chamber puts the leade where you can really see what's going on (finish, etc.). It also saves wear and tear on reamers with a depth approx. .300" shorter. Concentricity is maintained by a high tolerance bushing at the chamber parting line.

I am still evaluating the .118" aluminum crush washer (Blieker sandwiches a crush washer between the machined action breech face and the tennon shoulder). I have tested barrels fittted without it, then machined the setback and used the crush washer - and I believe there is a very real accuracy advantage. Not sure if it could be adapted to modern BR actions (or if it would have the same effect), but its quantifiable / repeatable.

Thanks for asking, have a great Christmas Season!

kev

Kevin,

Thank you.

Your thoughts on re-barreling your Bleiker (on another forum) solved a puzzle for me; I thought I'd noticed a slight thickening of the barrel at the action, but wasn't sure if this was the profile, or my imagination. Now I know it's the washer.

Merry Christmas to you, and good luck in the Roberts team trials.

 

[holstil]

Kev,

Those are very kind words, and humbling coming from a competitor/human being of your stature.
If not for your praise and others like you doing the same, I would have quit contributing on forums a long, long time ago.
It’s been a lonely life pursuing the technical side of firearm precision. LOL

I sure hope we get the opportunity to shoot together or visit face to face again in the future.

Thank you,
Landy

Don’t stop posting now fellas, I just upgraded again lol. It’s this kind of engagement that makes this forum so nice.

It’s a real pleasure reading your posts.

 

[1813benny]

Some photos of cone breaches that Kevin has done in the past....

 

[rodstreet]

Here is an unusual breech done by Bill Calfee. It has a shield and extractor cuts in the cone. Special thanks to Jerry Halcomb for sending me this barrel for my collection.

 

[MarkTrew]

Kevin,
When you did your Bleker rebarreling, did you use a new crush washer each time?

Do you know what the factory practice might be?

Thanks,
MarkTrew

 

[kevin nevius]

Kevin,
When you did your Bleker rebarreling, did you use a new crush washer each time?

Do you know what the factory practice might be?

Thanks,
MarkTrew

Hi Mark:

I don't use a new washer every time, they are very durable and resist galling well. They do have their limits though - I look for any deformation and would certainly replace them if needed. Because I am admittedly OCD, I keep a new washer with every barrel (that is used on only that one). I purchased a dozen or so from Bleiker (they were ridiculously expensive), and I have made my own. Bliekers washers are dimensionally identical (I verified the entire bag), and the way I set up the barrel tennons there is an allowance for approx. .0015" crush - they are well within that tolerance.

Speaking with Glenn the armorer for the AMU, he was of the same opinion FYI - and their entire team uses Bleiker rifles now - so he has worked with them a lot more than I have.

Hope you have a great Christmas Season!

kev

 

[Thomasconnor]

About 10 or 15 years ago I spent a lot of time experimenting with indexing. I had acquired three P94S fitted cone breech barrels (Lilja, Benchmark, and one unmarked) from a retiring Hunter Benchrest shooter.

I had a couple of P94S rifles which are ideal for this type of testing since the barrel is clamped to the receiver. For those that may not remember, I believe this is the reason why the P94S was such a force in Hunter Benchrest.

It was very insightful. For example I observed that you can rotate the barrel in one direction and the group would move in the opposite direction. Group sizes could also change with different index positions.

It was a lesson in the unpredictability of barrel harmonics since no two barrels vibrate the same. Subsequent experience showed that unpredictability also applies to barrels of the same make and model which is why top benchrest shooters (not me) can go through several of the "same" barrels looking for a winner...Tom