1911 Drop in Barrel

[Old Fuff]

>Often times fixing a gun over the internet is somewhat akin to tuning a guitar by mail.<
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Tuner is much better - at both - then I am. I can handle a "victim" pistol laying on the workbench, but trying to fix one over the Internet takes a special (and seldom found) skill. Unless of course both the problem and solution are obvious. It is one thing to work with something that you're pretty sure is dimensionally correct and matches "the original maker's or USGI blueprints." It's something else again when all bet are off.

 

[45auto]

Ha, you "guys" do a great job and much appreciated. Learned a lot and I "be" the victim, or gun anyway. You won't get this type of help/knowledge on other forums.

When I saw two different ramps on my Colts, all I thought was "Springfield".

If you think it about it, there aren't many new 1911 choices under $1,500 that don't have external extractors, power extractor type nonsense and FP safeties activated by grip safeties. That's not a good trend IMHO.

 

[Old Fuff]

I think your "victim" will live. That breed are very hard to kill off.

I'd start with the hammer dropping problem first, because it isn't safe to fire until that's taken care of. Jammer's thread will give you a lot of help with this, as will Kuhnhausen's book. Start by using your marker to see if both hooks are bearing on the sear nose. Hopefully the hammer is O.K., and some mild stoning on the sear nose will get things workng. At worst, you may have to get a new sear. If you buy one from the same outfit that made the hammer it will likely come close to fitting. The angles that are cut on some of the aftermarket stuff reflects more on what the part maker thinks is right, then on the original blueprints, or Colt does. Also look out for undersized hooks combined with too much break away angle on the sear. Colt, it should be noted, uses little or no break-away angles on their service pistols.

 

[45auto]

Old Fuff,

I tried another hammer and it stopped following, at least the 5 times I tested it. In fact, any combination of hammer/sear 'works', except the original with all the "mileage" on it. I'd say the sear is bearing about 75% on the hammer...on the original set. Blued hammer so it's easy to see. Use to be less by the way...perhaps 60%. And, the work was done by a gunsmith.

"Works" means it doesn't follow, not that it's a good trigger pull. The sear clearly needs some stoning. The other sear does not fit with the thumb safety. I'm not sure it's worth it to buy stones and a jig to redo one sear and hammer...perhaps.

My experience with local gunsmiths(2) is just okay. I now know that there are fewer smiths that really know a 1911 than 'advertised'. IMHO, a lot of them get by because most people don't shoot enough rounds through one gun to really 'test' the work.

Thanks

 

[Old Fuff]

If the "other sear" works, and is a spare - not one removed from a working gun - it can be modified so that the manual safety will work. Usually this is done the other way around (safety fitted to match the sear) but in your case the reverse might be better. At least it is an option that doesn't requre any special tools, jigs, fixtures, etc. If you decide to go that way, Tuner (who has already posted something on this) or I will work you through it.

 

[45auto]

Great,
Thanks. I'll see where I end up with this semi-rebuilt gun.

 

[Old Fuff]

As for the trigger pull itself - I wouldn't worry about that at this point. When the pistol can be safely fired you can shoot it and address the problems surrounding the new barrel. When that's done you can go back to adjusting the trigger pull.

 

[45auto]

Well, long story short, my 'friend' exchanged the bbl for a Springfield stainless bbl(new) that he had. The other bbl "needed a lot of work" and was not well "suited", pushing down on the bbl hood had too much movement.

Regardless, the Springfield dropped right in and works fine. Fired about 70 shots and reliability was 100%. Little to no bbl hood movement.

But, there's always a "but", the bbl shoots about 4" higher than the original bbl. The firing pin hits are off centered. I assume they are "high" since the bbl must be tilted up a bit?

Any suggested course of action now?

Sidenote: No hammer follow. That's good.

 

[1911Tuner]

re:

"Little to no barrel hood movement."

Meaning...Is there any movement or not? If there is...even the tiniest bit...you're at the limit on vertical adjustment, and even if it's right on the edge of downward movement, your aggregate vertical dimensions are giving you all the lockup you'll get with that barrel in that gun...at least without some pretty extensive work. Welding the lower lug to get the barrel to sit higher in the slide. Swaging the frame rails down to get the slide to sit lower on the frame in order to take up the slack, and then maybe filing the slots between lugs a little deeper in order to adjust the barrel's final height...or all of the above.

Off-center firing pin hits generally aren't too much of a concern as long as it's not TOO far off. Since the gun is shooting 4 inches higher, it indicates that the barrel isn't tilting upward into lockup quite as much as the other one was.
A .200 inch diameter slidestop pin will raise it by half the amount of the difference between the original and the new one...probably not more than .002 inch. Not enough to make a practical difference.

Sounds like you need a hard-fit barrel to bring everything into line. Sometimes that's the way it goes though...Tolerance stacking can work for you or against you. Luck of the draw.

More of a concern is how much vertical lug engagement is there...and how many lugs are taking the shock of recoil in the horizontal lockup. You'll need to gauge the slide and barrel to find out how they're doin' in the horizontal...but the vertical is a little easier.

Draw the slide to the rear far enough to slip in a piece of wood or flat metal stock that's about 1/8th inch thick and let the slide rest against it. Measure from the top of the slide to the top of the barrel hood. Remove the shim and let the slide go to battery, and measure again. The difference is the depth of lug engagement. .045 to .050 is good. That's pretty close to 100%. If you've got at least two lugs bearing equally in the horizontal plane, you're good to go with a little less...about .042 inch. With all three...which isn't likely with a drop-in barrel...you can go down to .040 and still be okay for standard-pressure ammo. With only one lug bearing the brunt...AND less than .045 vertical engagement, you can expect shortened barrel life due to increasing headspace as the gun is fired. Ask the smith what the headspace was in the new barrel. If he didn't gauge it exactly, have him do it, and have him check the horizontal engagement too, if he has the gauges.

 

[Old Fuff]

>> Sidenote: No hammer follow. That's good. <<

So did you change sears or what?

Check the new "Springfield barrel, and see if the hood is longer. Better yet, measure from the front of the front (locking) lug to the end of the hood on both barrels.

 

[45auto]

Hi Tuner,

No movement, just checked it again. The slide stop is already a .200...EGW.

I'll have to find a shim to measure the way you detailed. I did pull the slide back to where the bbl hood has moved down, marked the breachface. Then released the slide and marked the breechface again. Almost a 1/8" difference in height. That make sense?

However, I'll have someone check it. If that's the way the bbl has to be, without extensive work, what about a taller front sight? I recall having to file down the sight to bring down the POI about 3"-4".

This may become my "bedroom" gun, shot very little, early retirement.

 

[Old Fuff]

4" higher at what distance?

Depending on how high it is, and how it is attached to the slide, it might be easier to change the rear sight for a lower one.

 

[45auto]

Old Fuff,

I changed the hammer. I'll check the bbl measurements of the Springfield to the old Colt bbl as a comparison.

That's 4" high at 25 yards. Good point on the rear sight, but I like the height and style of the one I have now.

Thanks

 

[1911Tuner]

re:

45Auto said:


>I did pull the slide back to where the bbl hood has moved down, marked the breachface. Then released the slide and marked the breechface again. Almost a 1/8" difference in height. That make sense?<
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Yep, but it won't tell you anything useful. You need to put something between the slide and barrel to get the hood butted against the underside of the slide's first lug....measure...then release it into battery and measure again.

 

[45auto]

Back in business with the Springfield bbl, appears to be a good fit and reliable...about 700 rounds through and no problems.

New Nowlin sear has good contact on both hammer hooks(old hammer), which I never had before. Sear dropped in and fit the thumb safety...lucky. Should have replaced the Colt sear a long time ago.

New .200 front sight brought the groups back into the black.

Thanks to Tuner and Old Fuff for the help. Learned a lot!