Difference in 4506 and 4506-1

[BMCM]

Just by Mark2 Mod1 eyeball...

45xx wide hood vs narrow hood looking at the top of the slide...

45xx Barrels viewed from astern, note the only dimensional difference between these two is the width of the tab or hood.
Feed ramps and camming lugs are the same...

Now look at the barrel in this image. Note the saw cut behind the feed ramp. This barrel was manufactured such that a sawcut was used to establish the angle of the camming lugs. Both the feed ramp and the camming lugs on this barrel are significantly wider that those in the previous image above and will NOT fit in your frame. This is a 645 & early no dash 4506 barrel. I you see a parts kit from a de-milled 4506 anywhere and the slide has a raised rib or there's an image of a stepped frame, accompanying barrel is probably one of these.

I seen several of those early barrels listed as for 4506 so if you see one with the saw cut, pass, it won't fit your gun.

Cheers
Bill

 

[RDEMO8982]

Just by Mark2 Mod1 eyeball...

45xx wide hood vs narrow hood looking at the top of the slide...

45xx Barrels viewed from astern, note the only dimensional difference between these two is the width of the tab or hood.
Feed ramps and camming lugs are the same...

Now look at the barrel in this image. Note the saw cut behind the feed ramp. This barrel was manufactured such that a sawcut was used to establish the angle of the camming lugs. Both the feed ramp and the camming lugs on this barrel are significantly wider that those in the previous image above and will NOT fit in your frame. This is a 645 & early no dash 4506 barrel. I you see a parts kit from a de-milled 4506 anywhere and the slide has a raised rib or there's an image of a stepped frame, accompanying barrel is probably one of these.

I seen several of those early barrels listed as for 4506 so if you see one with the saw cut, pass, it won't fit your gun.

Cheers
Bill

Bill,
That is an awesome explanation of the barrel differences between the 4506 variations.
Thank you so much for investing the time in helping me understand!
I now feel confident in continuing my search for a spare barrel that will match up perfectly for my particular gun.
I hope you have a great weekend, enjoy.
Much appreciated,
Rob

 

[Ethang]

Bill is such a treasure to have here with that level of 3rd Gen knowledge.

 

[Miami_JBT]

Just by Mark2 Mod1 eyeball...

45xx wide hood vs narrow hood looking at the top of the slide...

45xx Barrels viewed from astern, note the only dimensional difference between these two is the width of the tab or hood.
Feed ramps and camming lugs are the same...

Now look at the barrel in this image. Note the saw cut behind the feed ramp. This barrel was manufactured such that a sawcut was used to establish the angle of the camming lugs. Both the feed ramp and the camming lugs on this barrel are significantly wider that those in the previous image above and will NOT fit in your frame. This is a 645 & early no dash 4506 barrel. I you see a parts kit from a de-milled 4506 anywhere and the slide has a raised rib or there's an image of a stepped frame, accompanying barrel is probably one of these.

I seen several of those early barrels listed as for 4506 so if you see one with the saw cut, pass, it won't fit your gun.

Cheers
Bill

I see my 645 is in your post. By the way, the 745 barrel you work on.... Works great!