Bearing surface 1911 lower lugs

Hi, 

I've fit a .45 kart ez fit to a 1911.  It will put 5 shots into 1.25" at 30 yards on a bench rest with multiple types of ball ammo.  It sprays 2 types of plus p ammo into 5" at the same distance.  I'd like to take this gun hunting and so want it to be able to shoot plus p ammo accurately.   I've got a 18lb wolff recoil spring in.  I'm thinking it's because the ezfit doesn't have the long lower lug bearing that Jon Eulette has shown examples of.  I'm considering getting a lug cutter and fitting a gunsmith fit barrel to get that nice long bearing surface for the lower lugs.   What I can't understand is how the link let's the slide stop pin traverse a flat on the lugs.  It seems to me like unless the link has an oval hole for the side stop pin, that the lug feet could only be shaped along a perfect radius?  

I know this isn't directly bullseye related, but no other 1911 forums seem to care about utmost accuracy, and I'm very much wanting reliable offhand maximum 50 yard plus accuracy.   Thanks for any help you can give!

1st thing is to check the lockup on the ez-fit. Coat the lower lugs and slide stop pin with dykem
Then hand cycle the the pistol around 20 times. Now check the wear pattern on the lugs and pin for full contact with both feet. Also check your slide stop pin size for .200. If its smaller get a EGW 200 pin.

To answer your question on how a link which operates on a radius deals with a horizontal surface , two things.

One is the clearance in the links slide stop pin hole. Usually around 204 but can be 210 before it starts being an issue with timing.
Second, is the fact that the link actually rotates over center. In other words it rotates past 90 degrees off the link pin on full lockup..

Thanks for the response, I really appreciate it. So here are the pics, I'll give my best interpretation, let me know what you think. It looks to me like the two fitting pads at the top are hitting hard, dykem totally removed from those two spots. At the feet, (might be hard to see in the pics) the dykem is totally removed from both feet, equally, only at 3 o'clock, if the gun is facing barrel pointing left. The dykem looks smeared very thin, but not totally removed, around 12 o'clock on the lower lug. So I'm thinking it's not an entirely hard fit until the lower lugs hit at the rear and wedge the barrel tight up into the slide, does that sound correct? SS pin measures .198. Could that be enough to affect plus p ammo accuracy? Please let me know what you think! Thanks!

That barrel hood hurts my soul.

Get the egw 200 pin, if it doesn't help enough you will want it with a gunsmith fit barrel anyhow.

try the EGW slide stop and see how the fit goes..be sure and Dykem the pin and show it..many times the pin will show the lockup better that the feet will..it appears the left lug is being pushed up harder than the right..if so check you hood clearance when installed. while not a universal rule many folks lookfor .002 on each side of the hood for clearance.. a common problem when one foot is wearing more than the other is the hood pressing on one side.

You can put barrel in a vise and shoe shine polish the top of the barrel with sand paper to get rid of the ugly. That’s not a critical dimension.
 
Jimmy is correct about the hood causing rotation affecting bottom lugs evenness.

Kart Exact Fit barrels have excellent bottom lug bearing surface. The issue I have with it is it’s a guess on the lug height. When put into a SA RO you barely fit upper barrel lugs into the slide and you’re done. You end up with minimal lug engagement and slide comes out of battery very fast. Result is more felt recoil and pistol is less forgiving shot from hand. Similar to how old school shimmed barrels come out of battery or Bomar Tuner guns with welded up stock Colt barrels; 45 Clark’s.
I shoot a lot of guns. I’ve shot nearly every old school builders pistols and a lot of newer guns with unfit upper barrel lugs. They kick like hell. I don’t mind recoil, but shooting a gun that automatically has more recoil than necessary just doesn’t make sense. I commonly shoot my own builds and old school guns I’m about to rebuild/rebarrel with identical load. My gun treats me with respect, the other gun treats me like a red headed step child. I do it to remind me what I’m doing works and is better. And yes a pistol with minimal upper lug engagement will shoot great from Ransom Rest. You have to win the match yourself, not your pretty little Ransom target.
Barrel fitting is an art! Not many artist out there anymore.
Jon

Thanks so much for the responses everyone.  I kind of like the look of this slide (tried to post a link, forum won't let me; its the 10-8 performance .200 slide stop that was used in staccatos)  is there any reason not to get this over the egw .200 version?  

The hood is only dirty from shooting, if I clean it, it looks fine.   It's a caspian frame and I didn't lower the barrel seat any (didn't realize I maybe should have) so when I fit the barrel the hood was binding on the underside of the side.   I just kept filing and sanding the barrel hood until there was enough clearance to not rub, but there is really "just" enough clearance, is there any actual problem with that?

The height/depth of the upper lug at 12 o’clock is typically 0.045”. On gunsmith fit barrel (when gunsmith really fits it) that’s your engagement for locking/unlocking of barrel from slide. If you remove material from barrel around the chamber area you are reducing this engagement surface. You have Exact Fit barrel which is already minimized, so you could have made it worse. I normally remove approximately 0.010” from barrel bed surface on receiver when the barrel is making contact with the slide during cycling. This way I’m not losing/altering my engagement depth for lockup. The hood is the portion of the barrel that fits into the recess of the breechface. Has two sides and a rear portion the headspace is measured from provided there is no gap between hood and slide.
Jon

Jason 5881 wrote: It looks to me like the two fitting pads at the top are hitting hard, dykem totally removed from those two spots. At the feet, (might be hard to see in the pics) the dykem is totally removed from both feet, equally, only at 3 o'clock, if the gun is facing barrel pointing left.  The dykem looks smeared very thin, but not totally removed, around 12 o'clock on the lower lug.  So I'm thinking it's not an entirely hard fit until the lower lugs hit at the rear and wedge the barrel tight up into the slide, does that sound correct? 

How does it look if you do the ink test with the barrel link removed?

Perhaps your link is too long, as well as the other issues already pointed out.

An image of the barrel legs from the side might be revealing as well.

Jon, you were correct, I'm down to .0385 engagement on the upper lug because I shaved the barrel hood down to fit instead of lowering the barrel seat. I have also read where you wrote that the barrel shouldn't drop till at least .05" of slide movement rearward. Mine is instantaneous. I can't even measure it, it's like .01 or so. I'm waiting on the .200 slide stop, hopefully that will give me a second chance at fitting the barrel and I can get the lugs a little deeper, and keep the barrel locked up a little longer. I'll follow up, assuming you all like hearing this story.

Another quick question if you don't mind. Jon I've read where you say that a 5" barrel is easier to shoot more accurately than a 6" barrel due to the dwell time of the bullet in the barrel. Do you think, or have you ever played around with the 4.25" commander barreled 1911 in regards to offhand bullseye accuracy? I would assume even less dwell time, and almost the same mechanical accuracy could give an advantage over the 5" in offhand shooting? What do you all think?

I have experimented with Commander many years ago. I don’t recommend it, the government 5” is best. 
The dwell time isn’t the problem between 5” and 6” barreled pistols. Two things; 1) longer barrel equals more muzzle flip from recoil. Make a gripping or stance error and you will get higher shots than a 5” pistol. 2) Radial velocity. Imagine rigid arm pivoting freely at shoulder all degrees of freedom. Arm is moving in an arc. The longer the lever arm the higher the radial velocity of the muzzle/tip of arc. Imagine moving from right to left from natural arc of movement (wobble area). Now add slightly forced trigger pull (right handed). Combine the arc and the forced shot and shot will go further to the left from a 6” barrel than a 5” barrel. 
I know from first hand experience that this is true whether I explained it perfectly or not. Relax your grip slightly and long slide will gift you with a worse shot than the 5”. A 5” might be a 9 where a 6” will be an 8 and possibly a 7. You absolutely have to be on your game with a long slide 38 or 45. I recently built a couple long slides. I shot them side by side with newly built 5” pistols. The muzzle flip with same ammunition from the long slides were considerably higher than the 5” guns. I shot them equally well, but was only shooting 25 yds. 
I love long slides, but am aware that they come at a cost, and I’m not talking about money. They are just harder to consistently shoot better than a 5”. I’ve shot 890 with a long slide, but damn did I have to work at it. In my older age I prefer 5” guns for match’s and 6” for fun.
Hope this answered your question.

Jon

I have a long slide 45, and I’ve found that it shoots fine…..but….the advantage isn’t quite what it used to be.  In their heyday the advantage was longer sight radius and more recoiling mass which made them shoot softer.  But as Jon says, proper fit up and you get a soft recoiling pistol.  With a dot there’s no sight radius advantage.  They’ve lost their raison d’etre.  So get a good 5inch 45 and go play.

Hi, just wanted to stop by and update you all. I just recently bought a kart gunsmith fit barrel, the brownells lug cutter, and fit the new barrel. Following the advise I found on this forum, I kept a long flat on the bottom lugs and now the slide can come back .107 before the barrel drops out of battery. Just went to the range and shot a 5 shot group off a simple plastic rest with cheap magtech fmj ammo that measures less than a half inch center to center!! I couldn't be happier, just wanted to say thanks for all the great info here!!