Bad thing to my mind,different bullet pull.

And when you read about rifles you read to put the bullet up to the rifling to get any accuracy? Wouldn't the same be true for a revolver?

This is just theory, but there are at least three things going on here. First is jump to rifling. I think the real factors here would be speed and cylinder pressure at the moment of rifling engraving. This would relate to how well the bullet grabs the rifling and whether or not it strips or twists.

The second thing going on is bullet support. This is probably more important as bullets get softer. There is a step in the revolver chamber where the chamber stops and the throat starts. The bullet should, ideally, fit close in the throat to avoid bullet tipping upon take-off and reduce gas blow-by. You can see this clearly by taking a bullet only and comparing how it fits in the front (throat) and the rear (chamber) of the cylinder.

Things will not improve if the bullet hits the throat or forcing cone already crooked. The gun is moving up from recoil and the bullet is moving forward from shot pressure. If it's not supported, it will not hit the throat or forcing cone straight.

By moving the bullet back by shortening the case, you are reducing support and increasing speed of engraving while making the required length of bullet longer in order to bridge the gap from case neck to throat without allowing a gap for pressure to bypass until the bullet hits the throat.

Bullet pull may change - if the throats are tight enough to resist the bullet leaving the case. You'd loose this "pull" as you back away from the throats.

Bullet pull or shot start pressure relates to how much pressure is bulit up before the bullet moves. Your major factor here is case neck tension.

but if it's not a big deal on the 38/357 or the 44/mag then why is it a big deal on the 480/475. I see all your points about the "pull" but all the fuss over having a cylinder the right size for the 480 just has blown my mind.

If you clean your gun regularly,I would think there wouldn't be any problems,I don't have a .480 but I shoot .22 shorts out of my .22 match barrel and .38's out of my .357 and haven't had any issues ,but I clean my guns as soon as I get home.

One of us ask why not shoot the 480 in the 475 and he said you couldn't because of bullet jump. I am just confused. we did it all these years in the others why not the 480.........sorry it just is something I can't wrap my head around and it bugs me. A lot of the others said the same. and I know its just a short 475 look at the specks.

you couldn't because of bullet jump.

The 45 Colt is .100 shorter than the 454 Casull. When shooting the 45C in 454 chambers, lead and powder residue is left in the chamber just ahead of the case. This build up of residue can restrict chambering the longer 454 cartridge and can cause excess pressure by not allowing the crimp of the 454 to easily open up to allow the bullet to exit the case.

Another potential problem is when the revolver is cooling down after firing it collects moisture. This moisture mixed with the lead and powder residue creates an acid which can etch the chamber underneath the lead and powder residue. With this condition, even if the residue is cleaned out of the chamber, the longer 454 case will now stick in the etched area of the chamber when fired and can be difficult to remove depending on the amount of etching. Over the years we have seen this problem more from guns in high humidity areas than from low humidity areas but it still occurs in the low humidity areas.

For some folks this seems to be an emotional issue and some folks even claim that all we are trying to do make extra money on extra cylinders. What we are actually trying to do is help our customers get the most trouble free life from their FA revolver as possible. I know of some customers that have shot thousands of 45C rounds in their 454 chambers with no problems but they thoroughly clean the gun when finished shooting. Other customers have ended up with one of the above problems fairly quick also. All we can do is put out the information, it is up to the individual what they do with the information.

Darrell, You were correct, that group was made with open sight 5 shot
Ruger conversion in 475L.B. firing 325gr XTP factory ammo. Never had a problem shooting "special" type ammo in "mag" handguns. However, with some of the high intensity cartridges available today it would be wise to clean the cylinders as Bob Baker states above....