1911 Rock Island Armory Slide Lock

[vietnam1947]

I have a 1911 45 acp Rock Island Army. worked fine and shot good groups when I bought it. It has started now to lock the slide back when fireing. ie Fire two rounds and still five in magizine. have to push the slide lock lever to drop the slide to continue fireing. I might get off one or two round and it will lock the slide back again.
What is causing this PROBLEM, Thanks for any help,:banghead: Fred

 

[rcmodel]

Most likely your choice of ammo.

Some bullet shapes can hit the slide stop inside the magazine well and bump the stop as they feed up in the magazine.

Take the slide off and put a loaded magazine in the frame and see what you can see.
Also look for brass tracks or rub-off on the slide stop where the mag follower hits it when empty.

You can fix it by changing ammo, or filing off a slight amount of the slide stop where the brass tracks are.

Your problem can also be caused by the way you grip the gun. Some folks have problems with the left thumb getting in the way and bumping the stop when shooting two-handed.

rc

 

[DAVIDSDIVAD]

I too started bumped the slide stop with my left thumb one time after I'd fired a bunch of heavy loads out of a PGO shotgun and my hands felt numb.

 

[The Lone Haranguer]

Some bullet shapes can hit the slide stop inside the magazine well and bump the stop as they feed up in the magazine.

I can see this with long 230-gr. JHP rounds, but if this is happening with standard 230-gr. ball, would that not be something in the gun out of spec? (e.g., a mislocated slide stop hole in the frame.)

 

[rcmodel]

The slide stop was designed to work with 230 grain FMJ-RN bullets and probably does.
If it is happening with 230 grain FMJ-RN, it is probably just a really funky MIM slide stop that is shaped wrong.

The problem came about years ago with mil-spec Colt target guns shooting 185 & 200 grain SWC match ammo.

It has further progressed with the wide, flat points on some modern JHP ammo which is loaded to shorter OAL then the old GI FMJ-RN load.

This ammo can migrate foreword in the magazine because the nose of the JHP bullet is shorter compared to the FMJ-RN.

That brings the full diameter bullet shank far enough forward to hit the slide stop unless it is modified slightly to get it out of the way.

rc

 

[vietnam1947]

1911 RIA Slide Problems

I can agree with you all but still do not under stand WHY, when I have been shooting this 45 that it just comes up all of a sudden starting to lock up and not go into battery with ammo still in the magizine, may be I am dense...
Fred

 

[rcmodel]

WHY all of a sudden starting to lock up

I didn't say that was what it is doing.
I was just throwing out ideas for you to check.

For all I know you changed ammo and it started bumping the slide stop?

You might also check the plunger spring housing on the frame and see if it is loose.
Also the plunger & spring to see if they are still working against the rear of the slide stop.

rc

 

[vietnam1947]

I thank you all for your input, any suggestions are great.
We were using reload 230 gr round ball lead when we started using the new RIA. Switched to ammo bought at gun shows which were wincherster iin 100 re boxes, and federal in 50 rd boxes. I will try the reloads again and also all the suggestion that you all have posted. I will take it on change at a time with test fireing to find the sulation to this post. Thanks Fred

 

[Drail]

Look carefully at the slide stop lug protruding into the magwell. Remove the slide and insert a loaded mag. There should be some clearance between the slide stop and the top round. If there are brass or copper tracks on the tip of the lug you will need to trim it back so that can't reach incoming rounds. If you trim too much it will fail to lock back on empty. Go slow and recheck the reach. You can also Dremel a small detent in the stop where the plunger rides to hold it down so that it can't bounce up and lock. Given a choice I would much rather have it not lock open on empty than lock open with rounds remaining in the mag. Most competition (IPSC) guns are modified so they will NOT lock open unless manually activated.

 

[DAVIDSDIVAD]

I, like a genius, decided to check how all of my magazines interacted with my slide stop on Tuesday.


Doubting the contact of a Mec gar magazine, I pushed the follower with my finger after inducing slide lock.

'DOH!


Now I have a nice, 1911 extractor shaped hole in my index finger.

 

[rcmodel]

Wow! I bet that smarts!

I saw an army private drop the slide on a 2nd. Lieutenants index finger during an arms inspection once.

The poor guy about peed his pants, and was running around in a circle screaming like a little girl, with the 1911 dangling off his finger!

Pretty comical in a perverse sort of way!

rc

 

[DAVIDSDIVAD]

Heheh, i didn't feel it at first; I just suddenly that 39 ounces of metal were now hanging from my finger.

It wasn't until I got ahold of my senses and figured out a way to open the slide that it started hurting, .

All of my buddies who know what the 1911 is got a pretty good kick out of it, hahah.

 

[evert]

its quite normal to "dimple" the slidestop, so it stays in the bottom position until the follower lifts it. buy kuhnhausens manual, it shows you how to "dimple" the slidestop. it doesnt hurt to do this on any pistol, and it helps keeping premature slidelock away.

 

[Quoheleth]

By any chance are you riding the the little "dimple" of the slide stop that you push from the right to remove the stop from the gun? I'm a southpaw, and if I'm not paying attention, get lazy, and use that for a reference point with my right thumb. I'll bump it in just enough to hang up the slide.

An idea...

Q