Colt Gold Cup .45 after Bushing R&R

Thanks to all who have offered various tidbits of wisdom, so that I may improve the grouping performance of my Gold Cups, one in .45 and one in 9mm. Since the 9mm Trophy model ejected it’s fiber optic front sight today, I will wait until my new front sight blade arrives to range test the modifications to that model.
The .45 Gold Cup started out stock, and grouped poorly. After I Installed a KC Kustom CMP Roll trigger, the groups improved, but not enough to brag about. Last night I took an EGW bushing that I had ordered after providing my micrometer o.d. measurements and caliper-derived I.D. measurement, and modified it for a proper tight fit to the slide and barrel.
The bushing was a tight fit to the slide, needing a bushing wrench to rotate it. The stock bushing was easily turned by finger pressure alone. The I.D. was too small to allow the barrel to pass through, so I wrapped a dowel with 300 grit crocus cloth and sanded the I.D. until the barrel could pass through without binding. The stock bushing offered no resistance at all to the barrel.
About two hours into this time, I was thinking about a small combination mill/lathe that I had seen, but never bought.‍
Today, the .45 Gold Cup was tested at 25 yards, using the same sandbagged bench that it had originally been sighted in with. The original handload has not been tried yet, since I had received some Missouri lead swc that I had loaded up, and was all I had ready for use.
The group fired after the bushing work was completed, is shown. The original group from the 9mm is very similar to the original .45 group, and is attached to my earlier post New Colt Gold Cup Trophy group-How bad is it?
 100 rounds were fired, with zero malfunctions.
I liked the improvements enough that I have a Springfield Armory MilSpec that will soon receive a new bushing. 
Thanks for your encouragement!

Looks like you are on the right track, but still need to do something to shrink that group! I would try shooting a group with a 185 gr. JHP bullet.

I am hoping that a red dot and load development will help. I’ll keep plugging along:face:

Amanda:  For test loads I would load the following and then test fire your pistol.  

200 grain Cast SWC and 4.0 gr Bullseye, any primer, any case.  
    Seat the bullet so the shoulder is .915-.920 from the case head and            crimp to .467.

185 gr JHP (any make, but Speer, Sierra, Hornady and Zero are good).  
4.5 Bullseye, any primer any case.  Seat the bullet to 1.200-1.210 cartridge base to bullet front. Crimp to .469.  
   If you don’t have Bullseye powder, similar charges of WST will give equally good results. 

While these might not be the most accurate in your specific gun, these are both proven loads in many guns.  Load 25 minimum of each type of ammo and shoot them in one 25 round group for each.  The resultant for each should be a nice group (with few uncalled fliers) that will fit inside the ten ring.  If not, then your pistol may need additional attention.

You might try a heavier recoil spring. Pistols with minimal lug lockup usually benefit from warmer loads and heavier recoil springs.
Jon

lapping compound and you could have fit the barrel to the bushing by using the barrel instead of a dowel

Cmysix wrote:lapping compound and you could have fit the barrel to the bushing by using the barrel instead of a dowel

Perhaps, if the barrel would have fit into the bushing. The bushing I.D. was considerably smaller than the barrel O.D.
I only used lapping compound after I had removed enough metal to get the muzzle into the bushing.

A good tool and die maker will never use the rod that is intended to fit the hole as a lap! Don't put lapping compound on a barrel to fit the bushing! That will lead to poor fit! Best is to buy a lap from someone like McMaster Carr or other supply company that is adjustable! For about $25 including shipping it will be best way.

Like Frank said, i use blind hole hones on the bushing and other areas of the slide. MSC has them