Chamber reaming a kart barrel

I have a Kart E-Z fit barrel in my 45ACP S.A. Range Officer.  The barrel fits really well and gun seems to be quite accurate.  The problem I have is that there are occasional failures to chamber a round and go fully into battery.  The Kart barrel has a chamber diameter that is tighter than my original RO barrel, in addition, the leade in the Kart barrel is about 1/2 as long as the leade in Range Officer barrel.  From what I have read, many gunsmiths recommend reaming a new Kart barrel, so I purchased a Manson Finish reamer to correct this problem. 
I have reamed many holes in my pre-retirement life, but I have never used a reamer with a pilot before.   So, I started by practicing on my RO barrel and all went well.  The reamer barely removed any material (but I got a feel for the operation).  I then tried to ream the Kart barrel.  The reamer went in much harder than on the RO barrel and started making a cut just on one side of the chamber (ouch).  Upon investigation, I found the reamer pilot just barely fit the barrel end.  So I stopped and am writing this request for help.
My questions are:
1.  Is this normal?
2.  Why would the chamber be cut only on one side?
3.  Are there reamers with smaller pilots?

Are you reaming with power either the reamer or the barrel? I've had much better results when under power than by hand.

No it is not normal. But many things can cause this including the original chamber being misaligned.

Most reamer makers can regrind the pilot to any diameter you like.

Kart barrels have been running too tight. I returned 4 this year. But your pilot might be too big. Also Kart reams their chambers too deep and too fat. They don't always clean up 100%. Minimum dimension reamers are even worse. 
Jon

Thanks for the information.  I will contact Manson tomorrow and see what they have to say.  I heard they are a good company to deal with and are very helpful.

On my wad gun my Kart "Easy-Fit" (early version) was quite misaligned and the leade was cut in reference to the chamber, rather than the bore.  If you looked in, you could see the leade didn't even touch the grooves in one location, while opposite, it cut the grooves quite deeply and the lands for twice as far down the bore.  I had already installed it when I noticed, but contacted Kart.  I was asked how it shot and I had about two inches at 50 yards off the bench.  I was told that was what I should expect.  I later had the barrel tested by itself and some of my 50 yard ammo printed just less than an inch at 50 yards, so I haven't worried too much about it since.  I even shot 100 - 98 - 100 for my CF slow fires in a match with that barrel right after Dave Salyer fit a new bushing, and several other 100s that day and others.  (Hmm, maybe I should go back to that gun for a while...)

Ed,
I believe my barrel to be accurate enough but I will never have good scores with it when I have feeding alibis every other match.  Today I tried putting the original RO barrel back in and went to the range today.  I only put 50 rounds thru it today but they all fed flawlessly.  Unless someone can convince me otherwise I believe reaming the Kart barrel chamber will correct this problem. 
 
Here is what I learned today:
The NM barrel ID spec is .4410 +.0015
My Manson pilot reamer measures .4413 and it is a very tight fit into my barrel. 
I talked to Brownells tech support and was told the Manson reamer pilots they have in stock measure between .4410 and .4415, which coincides with what I measured my reamer pilot at.
Manson reamers was closed when I tried to call them today but their website says that their reamers are supposed to be below the minimum of the barrel  spec.

Is your feeding problem the cartridge only making it halfway into chamber? Stuck at feedramp/throat? Or just not seating all the way? Slide staying partially back? Will a factory round drop fully into chamber? Rear if case flush or lower than the hood?
Jon

djw1cav wrote:Ed,
I believe my barrel to be accurate enough but I will never have good scores with it when I have feeding alibis every other match.  Today I tried putting the original RO barrel back in and went to the range today.  I only put 50 rounds thru it today but they all fed flawlessly.  Unless someone can convince me otherwise I believe reaming the Kart barrel chamber will correct this problem. 
...

I had understood this, but was merely confirming that the Kart chamber and bore in another barrel were definitely and considerably not concentric.  In my case, I don't think there would be any way to make it concentric and still be a .45. I was lucky that all worked well, even though it is this far off.

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• Jon,
  
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Is your feeding problem the cartridge only making it halfway into chamber?   Stuck at feedramp/throat?  I often times get the classic 3 point jam.  My brass is full of little lines around 1/4" below case mouth.   I have just added a .02"radius at the corner of the barrel feed ramp, but have not shot the gun since. The distance from Breach face was around .220" so I believe I am safe)

   Or just not seating all the way? Slide staying partially back?  This happens a lot.  Most often when the gun is dirty but sometimes when it is clean too.  It usually happens on first round of a mag ( and when the gun is cold) I can usually push the slide forward to seat the round.



Will a factory round drop fully into chamber?  Yes but is is tight.  But I dont shoot factory anymore.


 Rear if case flush or lower than the hood?   A several thousands below flush.  I measured my chamber depth and it is .902.
Jon

What crimp are you using?
How far are you seating shoulder out of case?
Can you measure from rear of case to exposed shoulder of bullet? 
Jon

Jon,
I have been using this barrel for a year now and have 2300 rounds thru it. 

I have tried crimps from .468 to .470, all with the same results. I measure by having the tips of my calipers half on and half off of the end of the case mouth.   I am currently using .470 because it does not seem to distort the case as much.

I seat by pushing on the shoulder of the bullet with the seating die.  My case to bullet shoulder distance is .920.  I developed the OAL length by watching the shoulder of the bullet (185g Zero LSWC) touch the lands then backing off slightly.

Well that all sounds about normal/correct. I know Kart believes their chambers can be fired like they sell them but they do us a disservice selling them chambered too long and to fat. You are probably correct that you need to finish ream chamber. Thanks for sharing the data.
Jon

Jon Eulette wrote:Well that all sounds about normal/correct. I know Kart believes their chambers can be fired like they sell them but they do us a disservice selling them chambered too long and to fat. You are probably correct that you need to finish ream chamber. Thanks for sharing the data.
Jon

I am not sure what you mean by the Kart barrel is chambered too "fat".  I am interested to learn what this term means. 

Also, to close the reamer issue. I talked to Dave Manson at Manson reamers (very nice/helpful guy).  He said that Nowlin makes a barrel that has about .001" smaller diameter than other manufacturers barrels.  Manson makes reamers for these barrels that are identical to their standard 45ACP reamer except with the smaller pilot.  I have that reamer on order. 

I would also like to thank everyone who replied and helped me thru this issue.

Fat in this case means the chamber is reamed too large in diameter; so custom reamers and in some cases SAAMI reamers will not 100% clean up chamber. Nowlin lands (diameter) are what is smaller than all the other makers; tighter. 
Jon

I think the radius you added and finish reaming the chamber will help your feeding issues.. Any Kart I've ever seen that wasn't reamed leaded  up the barrel... you can finish ream it with a std. reamer and just cut the lead into the rifling without lengthening  you headspace normally.


Hopefully you have doubled checked you extractor tension and profile... it's the 1st thing I look at when you have feeding issues...

Jon Eulette wrote:Fat in this case means the chamber is reamed too large in diameter; so custom reamers and in some cases SAAMI reamers will not 100% clean up chamber. Nowlin lands (diameter) are what is smaller than all the other makers; tighter. 
Jon

Jon,
 
This makes sense considering what I am seeing on my barrel. 

The 1911 learning curve certainly is expensive.  It would have been less expensive for me to buy a 1911 from a Bullseye smith, but then what would I not have learned anything.    With that said, if my scores ever improve enough, I will most likely buy a gun from a good bullseye smith, (because it is unlikely that my skill/experience will reach pro level).

Thanks again

jglenn21 wrote:I think the radius you added and finish reaming the chamber will help your feeding issues.. Any Kart I've ever seen that wasn't reamed leaded  up the barrel... you can finish ream it with a std. reamer and just cut the lead into the rifling without lengthening  you headspace normally.


Hopefully you have doubled checked you extractor tension and profile... it's the 1st thing I look at when you have feeding issues...

Thanks for the reply.  Your question about my extractor brings up another question that I have.

I recently replaced my extractor with a Wilson bullet proof etractor.  I set the tension on it to approximately 18-20  ounces using a weigand gauge.  At this tension it passes the shake tests that Wilson talked about in their instructions.  The weigand instructions recommend setting the tension to 25 to 28 ounces.  Do you think I should increase the extractor tension to the weigand recommended value or leave it since it passes the shake tests?

Any time I have feeding or ejection problems I have to rule out the extractor. To do so if feeding issue, I will remove extractor and test feeding. If its feeding correctly without it, I know I need to adjust it more/less tension. With extraction problems its typically not enough pressure, so I will add more tension. Then it also boils down to was extractor properly fit to the case rim?
Jon

I also use the weigand gauge set.. Usually set it right around 25 ounces so I would think you're not far enough off to worry about it.

what magazines are you running and have you tried other styles(bullseye verses Hybrid)

jglenn21 wrote:I also use the weigand gauge set.. Usually set it right around 25 ounces so I would think you're not far enough off to worry about it.

what magazines are you running and have you tried other styles(bullseye verses Hybrid)

RE set force.  That is good to know.  I may bump the force up a little the next time I clean the gun.

RE: magazines I am using.  I am not sure what you mean by bullseye and Hybrid magazines.  I have two standard magazines that came with the gun and (4) Wilson 7 round mags.    I get my occasional failure to go into battery with both magazines.  More often with a dirty gun.  That is why I am working on the barrel chamber. 

  As far am my 3 point jams, they are on shot 3, 4 or 5 during timed/rapid fire.  So, I suspect that problem is me loosening my grip as I focus on the dot and trigger pull.

bullseye and hybrid refer to the type of lips on the magazine...each type releases the round differently (timing)

the Wilson should be good.

anytime you have a failure to feed on any semi auto it's always good to note what magazine was being used... as a matter of habit I mark all my mags with a number.

is you Range officer stock with original sights or does it have a slide mounted dot ? .... What recoil spring are you using?

this is a nice article on fitting and modifying the 1911 extractor by Bill Wilson

look carefully at the last set of drawings

http://www.m1911.org/technic2.htm

polishing the claw area can help too..

jglenn21 wrote:bullseye and hybrid refer to the type of lips on the magazine...each type releases the round differently (timing)

the Wilson should be good.

anytime you have a failure to feed on any semi auto it's always good to note what magazine was being used... as a matter of habit I mark all my mags with a number.

is you Range officer stock with original sights or does it have a slide mounted dot ? .... What recoil spring are you using?

The Range officer has a Marvel slide adapter with a Match dot II. 

As far as springs go, for most of last year I was using an 8 lb spring.  Recently I changed to a 9 lb to put some more force into pushing the round into battery.  The spring selection was quite a balancing act with my limp wrist tendency unknowingly playing a big part.  (At the time I did not realize I was limp wristing).

try an 11 lb spring in it..  10lb may be the most common used for a slide mounted optic gun but I generally run a bit heavier

if you are running somewhere around 4.0 of BE and a 200 gr bullet it should run fine

8 and 9 are pretty light..

jglenn21 wrote:try an 11 lb spring in it..  10lb may be the most common used for a slide mounted optic gun but I generally run a bit heavier

if you are running somewhere around 4.0 of BE and a 200 gr bullet it should run fine

8 and 9 are pretty light..

I hear you when you say 8 and 9 are light.  The slide doesn't close with authority like my other (non 1911) auto pistols do.

 I still have the recoil spring variety pack that Brownells. I think I will try heavier springs with the original RO barrel while I wait for the new reamer (It is back ordered).  That way I can get something done while I wait for the reamer.

Thanks for the suggestion.