What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

by mikemyers Mon Jun 01, 2020 7:15 pm

A bit of history - while I was doing some work on my Salyer Caspian last year, for a month or so I was shooting my Salyer Srpingfield. The Springfield feels like it is lighter than the Caspian, and it has an Ultradot L/T dot sight on it which is also very light. With help from Dave Salyer and Terry from Magnus bullets, I eventually ended up with the following load - 4.0 grains WST, using Magnus #801 bullets. My reloading procedure remained the same as before, but instead of the RCBS Powder Check die, I replaced the combined seater/crimp die with two separate dies. Last September, everything seemed to be working well, and I loaded 100 rounds of ammo for a final test - which never got made, as I left for India.

Now that I'm back, I had a chance to try 20 of the remaining rounds in the Springfield a few days ago, and everything seemed to work well.

Today I went to the range with the Caspian, and my remaining 40 rounds. For the most part, things seemed to go OK. The spent cases landed either on my shooting bench, or a few feet behind me. Three times, the slide did not remain open after the last round.

I'm trying to think this through.
I believe the Caspian slide is heavier than the Springfield slide.
The Aimpoint red dot sight on the Caspian is definitely heavier than the Ultradot L/T on the Springfield.
Both guns should still have the appropriate bullseye spring in them, but I've never actually measured the spring tension (but I did buy the measuring kit).

Assuming the mechanical parts are all correct, and both guns have been cleaned, and I use the same magazines, then the following might be true:

If I used too little powder, the slide might not move all the way to the rear, in which case it would never lock back.
If the slide and sight on one 1911 are heavier than another 1911, I think it might take a stronger load for the gun to work correctly.
So if this is all true, maybe the powder load for the Caspian needs to be a bit stronger than for the Springfield?

Am I thinking correctly here, or am I mis-understanding how this is done. Maybe the real problem has nothing to do with the above.

My current plan is to load 25 rounds with 4.2 grains of WST, and try it out tomorrow.

My reloading notes tell me that at different times, when I was using my Baer, I was trying different loads from 4.3 grains of WST down to 3.8 - I finally settled on 3.8, but the Baer didn't have optics, just the steel sights.

I doubt it will help any, but here's a photo of the Caspian:

What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round Img_8312

by **Wobbley** Mon Jun 01, 2020 7:55 pm

Mike, As I have stated previously in many threads, the driving effort for recoil Pistols is momentum. The recoiling parts momentum equals the momentum of the bullet (and powder, to be exact, but the momentum from the powder becomes in consequential). So, what this means with Bullseye loads, is that you need to increase the velocity to increase the momentum. The only way to do that is to increase the powder OR switch to a faster powder like 700X or Red Dot.

by AHI Mon Jun 01, 2020 8:01 pm

ck your mags that could be your problem. WST IS inverse temp sensitive it may be that you are on the line so to speak to reliably function
you gun. so increase your powder charge . Will also add my mags dont lock open on purpose it interrupts follow through

by dronning Mon Jun 01, 2020 8:18 pm

Factors beside load between 2 guns that could create a function difference.
Recoil spring weight, mainspring weight & firing pin stop radius, slide tightness, total slide weight including rib and scope.

If one gun doesn't lock back occasionally increase your load .1 to .2 gr and you should be good on both guns. Or you could go down 1lb on either the recoil or mainspring on the Caspian and keep the same load.

- Dave

by mikemyers Mon Jun 01, 2020 8:22 pm

Wobbley, you have a much better way of explaining what's happening, but the conclusion is the same - if momentum is the concern, and if I don't have enough momentum to cycle the gun properly, I could use more powder.

AHI, the magazines work properly in the Springfield, but I have many more magazines I could test to see if that makes any difference. So yes, increasing the powder charge slightly might be one answer.

You've got me wondering about the last thing you said - you deliberately prevent the slide from locking up on the last round???? I can see where that would be useful, but it's the first I've ever heard of this, as far as I know. Is this common knowledge, and most bullseye shooters prefer it?

by mikemyers Mon Jun 01, 2020 8:35 pm

Dave, that's my plan for tomorrow.

I guess I ought to take a lot more measurements the next time the guns come apart for cleaning.

Yes, "occasionally" is the appropriate word with the Caspian.

The Caspian needs to be redone anyway, as I don't like the trigger I installed. There is enough space for my finger, but just barely. The only good thing about this, is my hand needs to be in exactly the right place for it to feel right. That helps assure I'm not changing my grip.

All of this is very confusabobbled. Especially the part that maybe I don't even want the slide to remain open on the last shot.. Too late, I'll head off to sleep, and think about it some more tomorrow. Thank you all!

by mikemyers Mon Jun 01, 2020 8:45 pm

Wobbley wrote:Mike, As I have stated previously in many threads, the driving effort for recoil Pistols is momentum. The recoiling parts momentum equals the momentum of the bullet (and powder, to be exact, but the momentum from the powder becomes in consequential). So, what this means with Bullseye loads, is that you need to increase the velocity to increase the momentum. The only way to do that is to increase the powder OR switch to a faster powder like 700X or Red Dot.

Wobbley, we know that momentum is:
the quantity of motion of a moving body, measured as a product of its mass and velocity.
For any given gun, the mass of the slide, sight, and the other moving parts is "fixed".
Therefore, to get more momentum, the velocity needs to increase.
Therefore, one of the available options is to use more powder.

I guess what you're saying, is there is an optimum speed for the bullet, and the tables and info that Dave and Terry used to get me to the range of 3.8 to 4.4 grains of powder are optimized for Bullseye.

I flunked the Powder Loads 101 class. I prefer to follow the advice of people who know more than I do, and to try to understand it.
I'm guessing all that data was developed while planning on a typical 1911 recoil spring for Bullseye.
It seems to me that the recoil spring is a big part of this.
I know Dave sold the Caspian to his customer with appropriate parts.
I'll have to measure the spring myself, and find out if it really is what we're assuming it to be......

by David R Tue Jun 02, 2020 6:13 am

Dave Ronning Nailed it.

A more radius firing pin stop, a lighter main spring or recoil spring will cure your problem.

I try loads for accuracy and make the gun function with them.

David

David

by mikemyers Tue Jun 02, 2020 6:49 am

David R wrote:..........A more radius firing pin stop, a lighter main spring or recoil spring will cure your problem.
I try loads for accuracy and make the gun function with them........

If I was good enough to measure my accuracy, that makes total sense.
Both Dave and Terry have recommended between 3.8 and 4/4 grains of WST with the Magnus #801 bullet.

Before I go further, I should test.

I don't have a Ransom Rest (although my club does have one I can probably borrow for a day).
I do have what is supposed to be a very good gun rest.
So, I'll load up 25 rounds with 3.8 grains of WST and another 25 with 4.4 grains, and test.

And the next time the guns are apart, I'll measure my recoil spring rate.

I'm still curious - for Bullseye Shooting, should the slide be held back after the last round?
If you guys don't want the slide held back at all, maybe I'm just wasting a lot of time and effort over nothing.....

by DA/SA Tue Jun 02, 2020 7:00 am

The slide needs to cycle through it's full travel to insure proper feeding and ejection, which in your case is indicated by the slide locking back.

If you don't want the slide to lock back, modify the magazine follower or the slide stop to accomplish that once you verify it is cycling properly.

by **Wobbley** Tue Jun 02, 2020 8:29 am

mikemyers wrote:
Wobbley wrote:Mike, As I have stated previously in many threads, the driving effort for recoil Pistols is momentum. The recoiling parts momentum equals the momentum of the bullet (and powder, to be exact, but the momentum from the powder becomes in consequential). So, what this means with Bullseye loads, is that you need to increase the velocity to increase the momentum. The only way to do that is to increase the powder OR switch to a faster powder like 700X or Red Dot.
Wobbley, we know that momentum is:
the quantity of motion of a moving body, measured as a product of its mass and velocity.
For any given gun, the mass of the slide, sight, and the other moving parts is "fixed".
Therefore, to get more momentum, the velocity needs to increase.
Therefore, one of the available options is to use more powder.

I guess what you're saying, is there is an optimum speed for the bullet, and the tables and info that Dave and Terry used to get me to the range of 3.8 to 4.4 grains of powder are optimized for Bullseye.

I flunked the Powder Loads 101 class. I prefer to follow the advice of people who know more than I do, and to try to understand it.
I'm guessing all that data was developed while planning on a typical 1911 recoil spring for Bullseye.
It seems to me that the recoil spring is a big part of this.
I know Dave sold the Caspian to his customer with appropriate parts.
I'll have to measure the spring myself, and find out if it really is what we're assuming it to be......

Bullseye Red Dot 452AA 700X
3.8 805 853 807 852
4.0 841 903 831 901
4.2 863 910 860 923

This is from my testing in a 10 inch Contender. (Velocity difference is roughly 100fps)

So use this as a guide. Quickload indicates that Red Dot at 4.2 is at the safe high end for pressures. Bullseye is much lower pressure.

by mikemyers Tue Jun 02, 2020 10:13 am

Anybody have similar data for WST ?

What are the (dis)advantages of WST vs. Red Dot ?

Around a year or so, I was wondering if I should switch from Bullseye powder. I only load for 45 (and maybe again for 38 Special). After lots of discussion and reading (such as https://forums.1911forum.com/showthread.php?t=439064 ) I switched to WST. The gun seems to remain noticeably cleaner, and as far as I could tell, it worked fine - but I needed to find the proper load.

by DA/SA Tue Jun 02, 2020 10:29 am

mikemyers wrote:Anybody have similar data for WST ?
- but I needed to find the proper load.

https://www.bullseyeforum.net/t1209-pet-loads-of-top-shooters-loads-from-the-past

by AHI Tue Jun 02, 2020 8:09 pm

MIKE I don't know how widespread the don't lock the slide on the last shot is. But after some long discussions
with AMU and Oympic coatches . Locking the slide on the last shot interups the rythim of firing a accurate shot.
This was a big help for myself and quite a few others.

by mikemyers Tue Jun 02, 2020 8:19 pm

I'll need to think about that, but the rhythm is going to be interrupted anyway as the slide closing on nothing may not feel like the slide pushing the next round into the gun. As soon as you fire that last round isn't that "the end" of the cycle?

by dronning Tue Jun 02, 2020 8:51 pm

AHI wrote:MIKE I don't know how widespread the don't lock the slide on the last shot is. But after some long discussions
with AMU and Oympic coatches . Locking the slide on the last shot interups the rythim of firing a accurate shot.
This was a big help for myself and quite a few others.

I don't disagree with the notion that when the slide locks back it certainly feels different. The bullet is probably through the target before the slide actually locks back. So any impact to the score would be due to the between the ears influence/anticipation. If not having the slide lock back eliminates that anticipation for a shooter then it's the right thing to do.
- Dave

by james r chapman Wed Jun 03, 2020 4:23 am

I’d think not having slide lock would require mentally counting rounds rather than concentrating on essentials.
Just another distraction.

by jglenn21 Wed Jun 03, 2020 5:05 am

You really don't think about it after a while.. having shot a non lock back marvel for a long time you simply are aware.of it. My trailside quit locking back a while back. Haven't gone to the trouble of fixing it

by David R Wed Jun 03, 2020 5:27 am

I load my second slow fire magazine after 4 shots.

Lock back in slow fire is only on the final shot.

David

by AHI Wed Jun 03, 2020 5:35 am

.22 marvel does not lock back . At one time European .22s did not lock back. S&W 52s are hit and miss especially the ones with
plastic followers . Most European center fire guns dont lock back. Its a non issue...... issue. Have seen a lot of people put a snap "cap"
in the magazine as the last round.So try this. Dont try this. Do what you like case that elusive load or learn how to shoot.

by mikemyers Thu Jun 04, 2020 4:20 pm

Increasing the load to 4.4 grains of WST seems to have eliminated the issue. To test, I first loaded one round in a magazine and fired, over and over, and the slide never failed to lock back. After that, I shot normally, until I got rained out.

So the Springfield is happy with 4.0 grains WST, and the Caspian prefers 4.4 WST.

I've also discovered I shoot better with the Caspian than I did with the Springfield. That might be because the Springfield has a roll trigger. The Caspian "feels" more like my High Standard, than the Springfield.

Interesting discussion whether the slide should lock back after the last shot, or not. I doubt I shoot at a level where it will make much of a difference, if any.

by Star loader Thu Sep 01, 2022 11:21 am

When all else fails discuss it with the master my old team mate from years ago , Mr . Dave Salyer ! Not only a great gunsmith but also a 2600 shooter .

by Wes Lorenz Thu Sep 01, 2022 12:19 pm

Mike,
If you are shooting one handed - you may be limp wristing, which absorbs recoil. Try your load while shooting two handed. If the slide locks back you are limp wristing while shooting one handed.

by SonOfSwede Thu Sep 01, 2022 6:59 pm

I thought dropping the slide on an empty chamber was considered bad form for long gun life. Would not having the slide not lock back be the same?

by Colt711 Thu Sep 01, 2022 8:35 pm

Watch a little baseball and one sees the "between the ears" syndrome practiced; the batter who bat must go thru several steps before each pitch, tug or adjust sleeves, hat, gloves etc. in sequence. Obviously a batter can hit w/o them but once implanted in the mind they are necessary. Shooters can be similiar, maybe just not as obvious.
Certainly' a bullet can't be helped after passing thru the target.
Ron Habegger

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What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

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Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

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Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

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Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round

Re: What factors on a 1911 are involved in finding a load such that the slide on a 1911 stays locked back after the last round