Oversized cylinder mouths

[jack black]

As most of us know many 45 cal handguns suffer from the big mouth syndrome. My Colt SAA 45 has this problem .My question ,If I bump up my bullets from 452 to 454 will I increase pressure .The barrel is 451?

 

[DeletedMember275]

You'll be just fine. What size are the chamber throats? Just curious. I have an S&W M25-5 that sports .456-.457" throats.

 

[jack black]

You'll be just fine. What size are the chamber throats? Just curious. I have an S&W M25-5 that sports .456-.457" throats.

The throats come in at just a tad over .454

 

[gman]

Throats on my Ruger Blackhawk go .455 so that's what I size my bullets to.

 

[Olsherm]

I have Colts with the same problem.Shoot .454 ok if you don't get them too hard.Get you some soft bullets from Missouri Bullets pretty close to pure lead and shoot them slow with fast powders.This will bump them up to the proper size.455 will also be good if you can find them.

 

[slippingaway]

Here are some .455 bullets, they're even showing in stock:

http://www.midwayusa.com/product/1601446981/remington-bullets-45-colt-long-colt-455-diameter-250-grain-lead-round-nose

 

[Rclark]

My question ,If I bump up my bullets from 452 to 454 will I increase pressure .The barrel is 451?

You'll be just fine. The bullet will be 'moving' when it gets resized down into the barrel for a nice seal, so no problem there. More important to fit the throat so you don't get 'blow by' in the throat area and allow the bullet to be 'square' when it hits the forcing cone. So, you want the bullet to fit the throat as closely as possibly and be tight enough to 'bump up' (obturate) to seal the throat on ignition and then still seal the bore. That is why throats of .448-.451 is not acceptable as the bullet is sized down in the throat and therefore is to small to seal the bore properly.... For larger throats you just need the bullet to fit the throat as we just talked about.