45acp barrel chamber size shape

I think I might need a new barrel in my quest to reduce group size been trying different loads but still getting leading so measured chamber
and find it to be tapered .483 to.476 this seams to be excess and way over size to me, what size should it be?

I see brownells has a drop in ED Brown barrel and bushing for about 140 dollars would this be a good barrel for wad gun series 70 colt?

IMHO I would get the Kart semi drop in over the E. Brown.


Virgil

+1 on Kart easy fit

No drop in will be as accurate as one that is fit properly by a smith.

- Dave

Deerspy wrote:I think I might need a new barrel in my quest to reduce group size been trying different loads but still getting leading so measured chamber
and find it to be tapered .483 to.476 this seams to be excess and way over size to me, what size should it be?

I see brownells has a drop in ED Brown barrel and bushing for about 140 dollars would this be a good barrel for wad gun series 70 colt?

You are approx. .003 over SAMMI Spec for the case at the  base and .0015 at the neck..
The only really tight chamber I have seen is KKM.. SAAMI Spec reamers are going to put you close too what you have now.. The only way to tighten it up, is to  have a reamer purposely ground, to minimum /negative SAMMI Spec. with a projectile diameter free bore, which is what many of us do..The leade angle on SAMMI Reamers is 2.5 degree.. I think it should be 1.5°..Even then, I have seen very few barrels clean up 360° in the chamber area.

thanks for input all, is the KKM and the Kart easy fit the same thing and do you have to have a bunch of special tools to do it?

any one know of a good 1911 smith in the Wichita Kansas area?

DeerSpy
I am guessing you are new to this game...I think you should ransom rest your gun with some known (Match) ammo to get a base line...Is your gun factory stock?
Leading is a common problem.. it could be the leade..is it rough, steep angle, tight roll crimp.?? Bullet structure.. Cast of swaged.. I am a huge cast fan...
I don't use Easy fit..Some folks  like them.. I don't think KKM offers an Easy fit...

Jerry
I have been shooting bullseye for about 4 years and reload every thing I shoot, right now I am trying to use Zero 185gr swaged I have tried 4 or 5 cast brands and got leading with all of them my gun has the stock barrel I bought it in 1980 I think, colt series 70 GM
it has a ultra dot on now and port has been lowered, my reload is 3.8gr BE crimp .470 I shot 50 rounds to day at 25 yard had 8 out of the black on timed fire target, all the 8 were my bad. have not tried 50 yard with swaged yet but with cast I did not do good I need to find a ransom and test but don't have access to one right now.

Deerspy,
a
Are you willing to bring your gun to Kansas City MO?  I know an excellent bullseye smith there

Kart is by far the preferred 45 bullseye barrel.

Dave
I have installed many of each.. Each has it's own idiosyncrasy. I like them both. I am not going to say one is better than the other..Because, I have seen a lot records broken and set by each.  I really like the tight short chambers on the KKM. 
I like the extra lower lug material on the Kart. All commercially manufactured  barrels are a compromise in some form or another..mainly to satisfy the average end user, the large percentage of which are not gunsmiths..  I would like the upper lug radius to be a true radius, and not elliptical.
The only true match barrel, is custom made.

rfmiller
I might some day but for right now hope to find some one close that I can take my gun to and talk with about it, it might not be worth putting a lot of money in to if I was going to do that I would get a new one built maybe SA.