ROA cylinder mods

[M. De Land]

I cannot imagine Bill Ruger doing anything by accident and the doughnut shaped ring in the bottom of the chamber probably has a very good reason for being present.
Five grains increase of 3F BP is not going to make a hill of beans difference in velocity when you have reached the upper end of the expansion ratio of total volume of barrel and chamber to the powder efficiency but removal of the contour in the bottom of the cylinder may change things dramatically in pressure dynamics which effects burn rate.
Black powder has about a 55 percent ability to convert from solid into gas and the rest is unburned particulate and fouling ash, as I understand it. This is the reason five grains makes very little difference on the top end of the load density.
Compression level probably plays a bigger role on velocity and accuracy than does powder volume at the upper end of load density.
We certainly find this to be true in cartridge black powder shooting.

 

[rodwha]

I'm curious how 5 grains increase would work with my 285 grn WFN conical that has a max load of ~25 grns of 3F. Maybe an increase of 5 grns would be significant enough to be worthwhile.

 

[M. De Land]

Testing over a chronograph will tell the story. I was talking about round balls in my post as that is all I shoot in my revolvers.
Conicals will definitely increase pressure and pressure makes the powder burn more efficiently so it might show some increase with a bullet.
I'd be surprised if a five grain increase gained 50 fps.

 

[Dickydalton]

You are kidding me, aren't you?

 

[Dickydalton]

I didn't weigh the powder, I measured it. I was measuring volume not weight. I could have been scientific and used water if Edo Junker hadn't stolen my cylinder and it would have proven the fraud they perpetuated. I think that's why he did what he did. Do you know him Claude?

 

[gl1200a]

That is the main reason I did the cylinders is for the conicals. However I have not had time to cast any yet.
I should get some time later in the week to spend some time with the chronograph and get some accurate comparisons of the modified vs stock cylinder.

 

[rodwha]

Anxiously awaiting your response!

 

[Rifleman1776]

I'm still wondering where they could remove enough metal out of a Ruger chamber to gain ten grains of 3F.
I think that may be an exaggeration but can not prove it.

Yep, with ye there. :idunno:

 

[rodwha]

ClassicBallistix didn't use an OEM cylinder so I'm not sure what they started with, if it differed from an OEM dimensionally. So it's not as though they took metal off.

But like I said it could be they mentioned 5-10 grns depending on the varying volumes measures give, and whether or not you use a powder that compresses more than others such as Triple7 vs Olde E.

 

[gl1200a]

Frank and MD
I have shown what material on a stock ROA cylinder has been removed. By my measurements it is 5 grains.
Goex 3F is pretty much grain for grain volume and weight. My digital scale said 4.9 grains. I took the liberty of rounding it off to 5 grains.
Dumping the 4.9 grains in my adjustable measure, it was at 5gr.

How you doing Frank?

 

[gl1200a]

Finally had my buddy cast some pure lead 220 Lee conicals.
The results surprised me. Surprised me so much I had to do it twice.
Yesterday was off and on drizzle and cool.
Powder is Swiss 3F. So before anyone says "I can fit XX amount of XX powder" Swiss does NOT compress. Measurements are by volume.

The standard ROA cylinder with a Lee conical will fit 30 grains volume comfortably. Any more and there's a good chance you will have to cut the top of the bullet off.

The Clements deepened cylinder will hold 35 grains comfortably.

5 shots through the chronograph with the standard cylinder with 30 grains averaged 754 fps.

5 shots with the modified cylinder and 35 grains averaged 877 fps.

I thought this quite the increase for 5gr of powder. So ran two more shots each with basically the same results.

After I got to thinking about it, doing the math it pretty much is dead on. (if you use common core your on your own)

Your increasing your powder charge roughly 16% and receiving roughly a 16% return in velocity.
All shots were fired through the 5 1/2 barrel ROA.

An interesting discovery on the Lee 220 conical we discovered. I shot some the other day that were cast from wheel weights. (or not 100% pure lead)
They had a tendency to jump a little bit in the cylinders, making cycling difficult if not impossible.

100% lead did not have any issues and were shaving a ring that I did not notice with the non 100% lead bullets.

 

[rodwha]

Very interesting.

I'm curious how the accuracy between the two is.

Something I find surprising is the velocity you get. Mr. Beliveau used 30 grns of 3F T7 with a Lee conical and got 881 fps from a 5.5" barrel. From the few side by side tests I've seen T7, Swiss, and Olde Eynsford give very similar results.

 

[gl1200a]

As far as accuracy goes, I was not shooting for accuracy, but velocity and trying not to hit my chronograph :shocked2:
All shots were within the black at 25yds of a standard 25yd pistol target. Chronograph was at 20ft. All shots were from a rest.

Many things could contribute to the difference in my findings and someone else. Like I mentioned, the air was very heavy yesterday. Rain, fog, cool, type of chronograph, elevation etc.

I do feel I learned what I wanted to know. Regardless of conditions there is a 16% increase with the 5 extra grains the cylinder allows. Substantial IMO.

 

[M. De Land]

Wow, that is surprising and impressive. I did not think velocity would rise that much with five grains but conicals do raise pressure and thus efficiency.
Chronographs tell the story if the screens are not reading a wad or lube projectile.
Usually with muzzle loaders it is a good idea to shoot through a hole in a plywood baffle out front of the muzzle a bit so your accurately reading the ball or bullet when it goes over the screen and not ejecta.
I've gotten some funky readings on mine from not using a baffle.

 

[gl1200a]

I don't use any wads.
The readings were consistent.

I've ran into what your speaking of if the chronograph is set up to close when shooting a PRB and it detects the patch.

 

[Blizzard of '93]

interesting observations. my roa has grouped soft cast slugs as tight if not tighter than balls. either one that DID NOT shave a ring when being pressed in grouped worse.

 

[rodwha]

I'd certainly love to hear an accuracy report comparing the two, as well as using the load of the OEM cylinder in the bored cylinder to see if there's much difference.

With 35 grns of 3F T7 or Olde E and my 195 grn conical I assume, using Mike Beliveau's testing, that I'm getting about 500 ft/lbs, which seems to me to be plenty. I wouldn't cry if I could increase the volume without disturbing the accuracy I get.

 

[robertmcw]

I bought three of the ClassicBallistix cylinders last year and they needed to fix the cylinders and redo the cylinders for the barrel would line up. It took a couple weeks and I gave the fame to Edo but he made it right. With Swiss of 3fff powder, the cylinders will hold 45 grains with a wonder wad and a round ball but the tops of some of the balls are just too long and they needed just a little shaving. I think if I were to skip the wonder wad, I could put just about 50 grains in the cylinder. But I can tell this ”“ at 45 grains it was hard to shoot the gun. I have bought some of the Kado 240 gain bullets and I plan to load the cylinders with 40 grains with Swiss 3fff powder and I think I will have a really deer gun at 30 ”“ 35 yards. And I REALLY feel bad for the poor son of a b*(%$ who meets the muzzle end if he beaks in my house in night.

 

[Dickydalton]

Edo is a thief and his worthless cylinders that I had experience with wouldn't hold as much powder as stock ROA cylinders do. When he found out I had one of those defective ones he had me send it to him, with big promises to make everything OK. He stole my cylinder and I'm out the $250+ bucks it cost me. His company, Classicballistx is out of business and that dirtbag has gone into hiding. If anyone does any business with that slimy con man they are taking a big risk. Kirst pretty much pretends that they never heard of him and said they have no contact numbers for him. I am going to have some time off in March and plan a visit to his fancy north Dallas home to visit with him. I plan to have a police escort and a warrant for his arrest on fraud charges.

 

[robertmcw]

I guess I was just lucky.