Has anyone seen this?

[Al Nyhus]

And I also can't thank Jackie enough for his willingness to share what he has over the years.

Amen to that!

And to all that willingly share info. -Al

 

[pipeline60]

Registered match any discipline

Jamie, before you move on may I make a suggestion? Try and get your product in the hands of a truly experienced shooter who would be willing to test it out and report back...on this forum. For instance, I shoot short range BR; See if there would be anyone willing, again an experienced shooter, who would test out your product in a proven 6ppc chamber and let them test it out...proof is in the pudding. Let them post load development and group size.... What would even be better is if they would be willing to shoot it in a registered match. There is nothing like the crucible of competition to prove a way of doing something. I'm sure there would be some takers. Anyway...Thanks. Durward

Great advice Durward, a guy that knows how to shoot small groups and chamber barrels and make benchrest grade bullets. Beer joint/coffee shop groups shot don't pack much thunder. Telling everyone their doing it wrong will always draw some fire. Stay Safe and chamber your barrels like you know how.
Happy Monday from America

 

[pablo]

Was thinking that we're soon to be at a competitive disadvantage when Mr Dodson gets his setup in the right hands and they beat all of our asses. Can't wait!

 

[Clark]

No gunsmiths like to hear this, but the mathematical relationship between eccentricity and group size is for bent cartridge necks randomly oriented into the chamber.

The math does not work for bent chambers. They might throw all the bullets into the same off center point in the target.

From American Rifleman about 60 years ago.

MATHEMATICAL SOLUTION

A laterally displaced center of
gravity moves through the rifle bore
in a helical (screw) path. The pitch
of this helix is the pitch of rifling,
and its radius is the lateral displace-
ment of the center of gravity. On
leaving the muzzle, the center of
gravity continues in the direction it
had at that point. For example, if it
leaves at top of the bore and rifling
is to the right, the departure will be
to the right. The bullet travels ap-
proximately 2l.5" in a 24" barrel,
making 2.15 turns in the 10" twist
of rifling. The number of turns
shows the orientation on emergence
compared with that in the chamber
before firing. The angle of emer-
gence is that angle whose tangent is
2 pi times the lateral displacement
divided by the rifling pitch. For
.004" point displacement and I0"
rifling pitch, the tangent is 1/8(2·pi)
(.004)/l0 and the corresponding
angle is 1.1 minutes.
The displacement on target from
this cause is proportional to the
range and can be obtained without
noting the angle. For example, ,004"
point displacement gives in l0"
rifling pitch, so far as this mecha-
nism goes, a target displacement at
100 yds. (3600") indicated by the
proportion .00l· pi /10=X/3600, from
which x =1.1".

I did not transcribe that. I had to get the machine to read the magazine.

 

[Butch Lambert]

Bent chambers? How in the "ell do you machine one!

 

[alinwa]

Clark if you're gonna' add your own dissertation to a 60yr-old article AT LEAST try to understand your subject matter

You state "no gunsmith want to hear this" like you big teacher/preacher/daddy tellin' us pe'ons how it is...... you wanna' preach??? Then get up on y'er hindfeets and explain "bent" and how you do it better.


You're not even apples and oranges here, apples and chickens more like

 

[jackie schmidt]

I think they mean crooked chambers,. That is a chamber that is not in alignment with the barrels ID.

 

[alinwa]

I think they mean crooked chambers,. That is a chamber that is not in alignment with the barrels ID.

And I think the article is talking about bullet imbalance hard to tell without the context of the article but it looks to me like another example of "the math" overriding the facts...... the old "IF the CG is offset by xxx, THEN here's the math" argument.

I just love this part....

indicated by the
proportion .00l· pi /10=X/3600, from
which x =1.1".

 

[Clark]

Bent chambers? How in the "ell do you machine one!

I chambered a 7mmRM by cutting off the tennon a Rem700 take off barrel. I should have faced off the burr, because the reamer wobbled 0.0050" all the way to headspace. To my suprise the rifle shoots sub moa. I realized I had confused the mathematically predictable and verifiable effects of eccentric ammo to believe the same effects are possible from eccentric chambers.

Clark if you're gonna' add your own dissertation to a 60yr-old article AT LEAST try to understand your subject matter

You state "no gunsmith want to hear this" like you big teacher/preacher/daddy tellin' us pe'ons how it is...... you wanna' preach??? Then get up on y'er hindfeets and explain "bent" and how you do it better.


You're not even apples and oranges here, apples and chickens more like

The subject video, I believe, confuses the mathematically predictable and verifiable effects of eccentric ammo to believe the same effects are possible from eccentric chambers.

 

[Butch Lambert]

Clark, but I only went through the 6th.

 

[Dave Tooley]

For a little humor.
Then a tweety bird farts and ruins your group.

If I get really bored I'll calculate the angular misalignment of say .002" in a case 2" long. Then I'll factor in the concentricity of loaded ammo.

 

[alinwa]

So I _think_ what ever'body's sayin' NOW is...... if you gots bent ammo, and you orient it all the same, like maybe put all the rounds in with the bullet drooping DOWN like a Concorde jet......


That this yields something quantifiable and measurable and repeatable???


I can get with tweety bird farts, but not with this Peyronie's of the Projectile idea'r....... A'tall....

 

[Bnhpr]

Amen to that!

And to all that willingly share info. -Al

Yes, thanks Jackie for all your posts, and real R&D work, solid engineering, machining and craftsmanship. He/we might be using 1880's tech, but I've seen the end result, awesome accuracy. Thanks also, to the other guys that post Al, yourself, alinwa, dave tooley, Butch, Jerry, and many more. We don't always agree, but if we did, it means one of us is not thinking. Ben

 

[alinwa]

............We don't always agree, but if we did, it means one of us is not thinking. Ben

man that's good...'Wish't I'DA said it"

 

[jackie schmidt]

I got the first piece made for my “ACE” clone.

I found a piece of 4140 at 38 RC, so I decided to make the screw on chamber in 6PPC. It’s going on my HV with the Bat Neuvo Action. I have to modify the stock’ barrel channel in front of the action to make this fit. It’s a bolt in, so no big deal.

I have a new Krieger 13.5 twist blank. Tomorrow I will do the barrel. It’s simple compared to the action extension. True the barrel, thread it for the extension, establish the throat.

Here are a few pictures.

http://benchrest.com/attachment.php?attachmentid=23521&stc=1&d=1587769325

http://benchrest.com/attachment.php?attachmentid=23522&stc=1&d=1587769371

http://benchrest.com/attachment.php?attachmentid=23523&stc=1&d=1587769424

 

[alinwa]

Absolutely smashing Jackie!

OK.... gotta' couple more items then

I have one where I punched a 1/4-20 hole in the bottom, second action screw, moves the pivot point (unsupported barrel) makes the extension into "the face of the action"

I have another where I added a recoil lug, AND a screw-down...... drilled and tapped the recoil lug.... (that's those pictures a year ago about "drilling/tapping 304SS"... you helped me on it)

I'm not sellin' NUTTIN!!! I'm just so friggin' happy to see guys trying stuff!

Thank You!




ooops, meant to say 1/4-28 hole

 

[Wayne Shaw]

I gave up reading this long thread for some time because of all the.....

Now that Jackie is doing this, can I ask where the barrel will inteface with the chambered stub? Jackie says to "establish the throat". At the end of the case neck, maybe?

 

[jackie schmidt]

Wayne, in the video in post #1, the owner states that where the barrel meets inside the barrel stub is proprietary, so I do not know what they are doing in that critical area.

I machined the face where the neck ends .020 inch longer than the end of the neck portion of the reamer, which is 1.520 from the “scratch line” on the reamer. The actual throat will continue into the barrel after it is tightened against that flat surface.

There is 60,000+ psi of pressure in the form of hot gasses at that point, so it has to be a tight joint with no space. When I do the barrel, the length of the Tenon will be exactly the same as the depth from the inner face to the outside face of the stub.

This might not work. As I said, the video stated that the inside mating surface between the barrel and stub is proprietary. Perhaps they have another method of sealing this critical area.

http://benchrest.com/attachment.php?attachmentid=23532&stc=1&d=1587817145

 

[Wayne Shaw]

Makes sense, thanks Jackie.

 

[Don Nielson]

Patent

The patent drawings show a pressure ring. Kind of like a metal o-ring. Don't know if also helps with alignment.
Pretty crud drawings for a patent. D