Point of Impact Change with Conversion Cylinder

[tscmmhk]

I have an 44 Uberti 58 Remy that is a tack driver with a 454 round ball and standard c&b cylinder. I recently bought a R&D conversion cylinder for 45LC and finally took it out to the range yesterday. I was using reloads of 35grs 2F blackpowder with a 235gr Goex Black Dawg bullet. I could hardly hit the paper:banghead: It was hitting way higher than it normally does with just the round ball.

Anybody have an idea why this won't shoot staight?

 

[brushhippie]

Not rifled for bullets?

 

[1KPerDay]

Hitting higher, but grouping well? Or hitting higher and not grouping at all?

If the former... seems to me it IS shooting straight.

 

[Crawdad1]

Although we need more information as 1KPerDay said, off the bat go to a lighter grain bullet. I had to drop down to a 185 grain bullet to get my revolver back on dropping from a 250 grain bullet. It might work I don't know but that's what I had to do.

Good luck!!!

 

[tscmmhk]

"Hitting higher, but grouping well? Or hitting higher and not grouping at all?"


It was hitting higher and not grouping at all. I was surprised because normally the gun shoots really well with round balls. I thought the heavier bullet would have been more accurate than what it was. I did notice more recoil for sure. Maybe the Brushhippie is right about the rifling!!

I'll try a different bullet and see if that makes a difference.

 

[J-Bar]

It's hitting higher because a heavier projectile will tend to have a higher point of impact in any revolver...more recoil = more muzzle flip = higher POI at short ranges.

Your cartridge bullets are probably .452, a bit smaller than the .454 round balls. That may have some effect, too.

Just for grins, load up a few .45 Colt cartridges with 20 grains of powder, a piece of card over the powder, corn meal filler to give compression with the bullet of your choice. I'd bet a donut that the group will improve.

 

[45 Dragoon]

I think the Hipster is right . The twist is prob. too slow for the bullet. The latest offerings from the Italians seems to have a 1 in 16 inch twist to accommodate the conversion craze!! I am glad !!!!!! All I shoot is conversions !!! Wooooo hooooo!! (Does that make me crazy?)

 

[Loyalist Dave]

I agree you need to change your bullet. You may even find that a .451 bullet works better, or that a .454 round ball loaded into the cartridges works well too.

LD

 

[Crawdad1]

All I shoot is conversions !!! Wooooo hooooo!! (Does that make me crazy?)

No it doesn't, I like em too!!!

 

[CraigC]

Bullets are heavier and will print higher. That said, I see little difference between 255's and 200's out of my 3rd Dragoon and accuracy is excellent.

 

[1KPerDay]

Beautiful hogleg.

 

[Driftwood Johnson]

Howdy

I agree. A heavier bullet causes more muzzle flip because there is more recoil, moving the point of impact up. I have two Remmies that I shoot with Black Powder cartridges with R&D conversion cylinders. Both are extremely accurate, probably my most accurate 45 Colt revolvers. I have always felt that this is because the chambers on these R&D cylinders are tighter than any of my other 45 Colt revolvers.

May I suggest that you slug your barrels, to find out what the groove diameter is you are dealing with? Since WWII, standard groove diameter for 45 Colt has been the same as 45 ACP, .451. That is why .452 bullets exist, they are .001 oversize for a .451 barrel.

My old EuroArms Remmie that I bought in 1968 has a very tight barrel, only .449, rather than .451. But it shoots fine with pure lead, .452 bullets, either 250 Grain pure lead Big Lube PRS bullets, or 200 grain J/P-200 Big Lube 200 grain bullets.

If you slug your barrel you may learn something about what diameter bullets it is looking for. Generally speaking, your chamber throats should be the same diameter as your rifling groove diameter, or maybe .001 or .002 larger. If that is the case, using bullets .001 over rifling groove diameter should serve you well.

 

[tscmmhk]

Thanks everyone for the info. I slugged the barrel and I looks like the groove diameter is about .458 so my bullet diameter .452" is probably too small. I'll try a larger diameter bullet (.454) and see if that makes a difference. Cimarron has barrel groove & twist info for Uberti products on their website. I checked because .458" seemed a little high. Here's their info for Uberti:

CAL. .44, 18"(457.20) LH twist, .44(11.176) bore dia, .458(11.64) groove dia. 7-grooves

I used cerrisafe alloy to slug the barrel. Because the barrel has 7 grooves you have to be careful how you measure the groove diameter. I measured it a couple of different ways and got the same result so I think I got it right. I use lube wads with the round ball so maybe next time I'll put a wad behind the bullet when loading the brass case. The next thing is to get some .454 bullets, load them up and go to the range.

 

[mec]

I haven't shot it very much but it does shoot higher than with a typical ball or conical bullet load. Pretty much on horizontally maybe a bit left and, in the picture I biased the groups so that they would be separate. I would consider the groups equivalent though not representative of the best the cartridge or loose change cylinders would do- only what I managed with two consecutive off- hand groups. I don't know if this is typical of conversion cylinder performance or not.

R&D and others recommend their conversions for the very puny CAS loads. This is probably a wise thing to do just to prevent loosening the guns. The loads I used are my standard Colt loads with the current type of Unique. When the "New, Cleaner Burning! Unique came out, I found that 7.5 grains delivered the same velocitiy as 8 of the old stuff all the way back to L&R Infallable did.

Point of aim would be right under the cylinder of the the pictured revolver

 

[Crawdad1]

Great shooting mec, but Holy smokes can those Remingtons shoot!!!!!