The Art and Science of Keeping Your 1911 Running

[JTQ]

Follow up to my post from last week:

I suspect my Wilson 1911's slide might be short-stroking due to the pressure of a full 10+1 .45 mag. I was using the springs as it came from the factory (18 lb recoil spring, 21 lb mainspring). The gun feeds the top round just fine when I reload from slide lock on a full 10 rd mag, and it cycles fine with 9+1. 8 rd mags have no issues whatsoever even topped off to 8+1. It's only when I top off a 10 rd mag to 10+1 that after the first round is fired the next round nosedives into the feedramp about 30-40% of the time. This happened with multiple mags from both Wilson and CMC.

One thing that confuses me is that I had a much higher failure rate with Federal HST 230 gr hollow points compared to range ammo. I had thought the HST's would be hotter which would help the slide cycle fully.

I'm wondering why my gun would be short stroking, especially when other people's guns with heavier springs (i.e. 18.5 or 20 lb recoil spring and 23 lb mainspring) run just fine. What are things that I could try to alleviate this problem? Lighter recoil spring or mainspring?

Single column mags have a problem with nose dive. The more rounds you stack in a single column, the greater the chance of nose dive. Lots of folks use .45 Auto, 10 round single stack 1911 mags successfully, but I've always considered them novelty items.

You may want to load up your mags and let them sit for several days, full loaded, to see if that helps your situation.

Here is an article on nose dive.

https://americanhandgunner.com/gear/...e-1911-45-acp/

[js475]

Single column mags have a problem with nose dive. The more rounds you stack in a single column, the greater the chance of nose dive. Lots of folks use .45 Auto, 10 round single stack 1911 mags successfully, but I've always considered them novelty items.

You may want to load up your mags and let them sit for several days, full loaded, to see if that helps your situation.

Here is an article on nose dive.

https://americanhandgunner.com/gear/...e-1911-45-acp/

I understand the stacking issue. All of the mags in question have sat fully loaded for weeks. They're all well broken in.

My main question/problem is why the gun is feeding the top round when reloading from slide lock but nosediving after I fire the first round with 10+1 loaded. The only thing I can think of is the slide isn't traveling all the way to the rear. When I googled this issue I couldn't find many results of people having the same problem, especially with hotter ammo like HST, so I'm curious as to what makes my gun problematic compared to others in terms of slide travel.

My 1911 does have an ACRO mounted, so maybe the extra weight is the problem? I forgot to bring my torx key with me to the range last time so I didn't try it with the optic removed. Has anyone else with optic-cut 1911's had to go down on spring weight for reliable cycling?

[JTQ]

One thing that confuses me is that I had a much higher failure rate with Federal HST 230 gr hollow points compared to range ammo. I had thought the HST's would be hotter which would help the slide cycle fully.

This is perhaps the inability of your mag spring to keep up with your slide speed.

Wilson Combat has a FAQ on compact mags, but would apply to your use of a 10 round stack of high performance 230gr ammo that helps explain this.

https://www.wilsoncombat.com/handgun-faqs/

All the mechanical changes are important, but the biggest factor is ammunition selection because it affects both slide cycle speed and the magazine’s ability to lift the cartridge into position for proper feeding. Ammunition loaded with 230gr bullets generate more recoil impulse (especially +P loads) than 185gr loads, and 7 rounds of 185gr ammunition weighs 315gr less than 7 rounds of 230gr ammunition, making the column of ammunition easier for the magazine spring to lift. I hope you see where I’m going here?

10 rounds of 230gr ammo is heavier than either 7 or 8 rounds of the same. You've got to have a mag spring that can lift that heavier column of ammo and keep up with your slide.

[JTQ]

My 1911 does have an ACRO mounted, ...

The ACRO probably helps, as it probably slows your slide a bit.

[Trooper224]

Js475,

How often do you replace the springs in your 10 rounders?

[js475]

This is perhaps the inability of your mag spring to keep up with your slide speed.

Wilson Combat has a FAQ on compact mags, but would apply to your use of a 10 round stack of high performance 230gr ammo that helps explain this.

https://www.wilsoncombat.com/handgun-faqs/

10 rounds of 230gr ammo is heavier than either 7 or 8 rounds of the same. You've got to have a mag spring that can lift that heavier column of ammo and keep up with your slide.

If that's the case, a heavier recoil spring and/or mainspring should help, correct? I wish I had a high speed camera that could capture what the gun was doing. I guess I'll have to just order a lighter and a heavier recoil spring and mainspring and play around with things. Hopefully I can find a combination that will get it to work.

Js475,

How often do you replace the springs in your 10 rounders?

I have several 10 rounders that I rotate, so each individual mag has probably seen 100-200 rounds. I haven't replaced springs on any of them. How often should I be doing so?

[JTQ]

If that's the case, a heavier recoil spring and/or mainspring should help, correct? I wish I had a high speed camera that could capture what the gun was doing. I guess I'll have to just order a lighter and a heavier recoil spring and mainspring and play around with things. Hopefully I can find a combination that will get it to work.

I'm not convinced my conclusion is correct. I'd trouble shoot with 185gr ammo to see if that is the problem, and if it allows your mag spring to keep up. If that isn't the solution you probably have another issue.

10 round mags need to have their spring replaced more frequently, but I don't think your springs have enough use to wear out at this point, but I'm primarily a 7 round mag guy, and only dabble with 8 rounder's, so I don't spend any time messing with 10 rounders.

[Trooper224]

I have several 10 rounders that I rotate, so each individual mag has probably seen 100-200 rounds. I haven't replaced springs on any of them. How often should I be doing so?

10 rounder springs have dramatically shorter service lives than 7 or 8 rounders. There seems to be a definite line in the sand on how many .45 rounds a single stack spring can handle reliably. If I chose to use 10 rounders for duty, I'd arbitrarily change the springs every 4-6 months, no later. I have half a dozen 10 rounders I use for range work and their spring life is noticeably shorter.

I can't give you a definitive round count for replacement, but that's were I'd start diagnosing.

[CSW]

I understand the stacking issue. All of the mags in question have sat fully loaded for weeks. They're all well broken in.

My main question/problem is why the gun is feeding the top round when reloading from slide lock but nosediving after I fire the first round with 10+1 loaded. <snip>

The only time I have this happen is when I use the 1 Wilson combat mag I own.
Exactly the same thing happened. In fact, you can't even unload the mag out of the pistol without the rounds diving.
I've stopped using that mag, and only use Ed Brown mags now.
It's never occurred with the EB mags.
This is a 9mm 1911.

[SW CQB 45]

does it behave the same way when using 8's in the same manner?
does it behave the same way when using the 10 rnd mag with one less, or two less in the mag?

I have a Colt Series 80 that was tightened up with some welding and Kart Barrel from the 2000s. It never missed a beat with the old style CMC 10s (not RPM).

On the same Colt, I later decided to change the set up for accuracy type matches and David Sams changed the barrel. It will not feed the first round with 10s. IIRC, it nose dives.

My Springer MCOP hard used, not tight will not feed the first round reliably with 10s. The round starts and a bump of the magazine will usually get it to go into battery.

I just dont use 10s. 95% of my ammo is 230 grain. I dont have any duty or ball type in the lighter weights.


I would like to see images of your single stack Acro set up!?!?!?!?