Velocities of .22 Ammo that Won't Cycle Your Pistol?

First topic message reminder :

I'm not in a position to chrono the various stuff that won't cycle my 7-inch semiauto (SK Rifle Match, Eley Club, another Eley I don't remember which but not Tenex or black box, and RWS Target Rifle), but I'm thinking the stovepipes are now solely caused by low energy/too strong a spring and not the extractor. So I'm wondering if the "vigor" of cycling the slides is well-correlated with the muzzle velocity.

The question is prompted by the fact that I found the bottom edge of the extractor chipped, after even Winchester H-S hollowpoints were stovepiping. I sharpened it up but angled it backwards in trying to match the curve of the rim under it...corrected that and then the "bite" was lacking...and finally got all that fixed.

Before all this, some ammo types would fail to eject for the first 2-3 rounds starting off the day's shooting, then run fine when the barrel was getting just the barest bit warm. Even CCI SV would sometimes do that, about 1 in every 10 first round of the day, and maybe 1 out of 50 the first round after a longer break in shooting.

So testing after this latest bit of extractor work, the first round with SK in a cold, clean barrel jammed with the casehead nicely seated in the breechface and the case mouth displaced just enough to the left to hit the back of the barrel and hold the slide open. Not far enough back to pick up the next round. Cleared that, and the second round cocked the hammer and re-fed its empty into the chamber. Rounds 3, 4 and 5 in the magazine ejected forward to about 1:00, and rounds 4 and 5 fed fine.

With CCI SV still a bit scarce, I then ran 5 rounds of CCI Blazer through flawlessly and they ejected more at 2:30-3:00 from the direction of fire. 

It will be a few days before I can really test the thing over an NMC, but I'm going to shoot the CCI for score from a cold gun, and then finish off a few loose rounds of various stuff and see what works.

Thanks!

Grumpy,

I re-read your statement, and see it was in regards to smooth chamber, not the round falling out from underneath the extractor. 

That said, read some of Jerry Keefers comments and efforts to make the extractor not move outwards when the bolt goes forward. Most/many of the .22's have interference between the extractor cut and the extractor because of angle issues and the way the items are shaped and cut, and this contributes to the stovepiping/ejection problem.  If the extractor spring has enough compression force, it might be able to cam the extractor back in place before it passes the rim.

In regards to oil on the top bullet that others have mentioned: bad.  .22LR develops in excess of 25,000 psi, and in excess of 900 lbs recoil force that the very thin casing holds in place.  SV, HV, may differ some, but it is more in the pressure curve/burn rate of powder combined with bullet weight and not so much in pressure.  Oil is not compressable, so something has to give.


-Ron
-Ron

Yeah, it's not quite like the WWI era practice of putting a LIGHT smear of grease on the BULLET (IIRC) to combat jacket fouling on the target lines. Might have had something to do with those cupro-nickel bullets. 

A smear of oil on any case wall will surely increase bolt thrust, but the key is "How much?" It doesn't worry me with  .22 (even HV ammo), but I prefer to have a gun run without such dirty tricks.

Increasing overall chamber pressure because of displacing volume in the chamber/case/burning space??? I thought that you would be hard-pressed to even measure that with any cartridge, in the amounts that can remain on a case before being chambered. Have you ever run QuickLOAD? The math doesn't predict much of a change in pressure at all with a .1 CC/ml reduction in case capacity.  Like 673 PSI.  Nevermind, that was a .50 BMG.  To get 1170 fps with Red Dot I had to go 50% more powder than what CCI uses, to 1.17 gr. reducing case capacity by 0.1 cc boosted pressure by 8365 PSI to 22,825, still well within the 29,733 max pressure for .22 LR. This might be high since I had to use a Hornady 40-gr .22 Jet bullet... Using a Lyman 37-gr GC sized right, the smaller charge needed for 1070 fps and 11,215 PSI, then jumps to 1,165 FPS and 26,516 PSI with a 0.1 CC reduction in case capacity.

Now go measure the size of 0.1 cc of oil and see if you can even fit that much between your .22 case and the inside of your chamber. That's equal in volume to about 1.5 gr. of water.

Grumpy:

"A smear of oil on any case wall will surely increase bolt thrust, but the key is "How much?" It doesn't worry me with  .22 (even HV ammo), but I prefer to have a gun run without such dirty tricks."

That is a good enough statement by itself. Half-way fixes are only half way.

Shooting at Perry several years ago, they stuffed us on the 600 yd line with it raining, and raining very hard. All prone with muzzles horizontal for the most part, and yet there were several people who had severe pressure problems to include blown primers, difficult extraction, and other problems associated with the small amount of water that was introduced as the rounds were loaded, or got splashed in.  It is not just a matter of the weight of the water, but where it is. The case has to expand and if is does not, it does not stick to the walls, and it does not necessarily let the bullet loose as easy, and pressures go up. .22LR cases are not very thick and the rims are a huge stress riser......every case I have seen failed was at the rim, where the priming compound goes.

Anyway, I hope you are able to get all of the problems solved, and I think that most of the ammo varieties you have mentioned, should run your pistol. Please continue as you proceed.

-Ron

Using oil Federal Target on my 41 cause some cases to bell on the bottom.

GrumpyOldMan wrote:DavidR:

I checked it AGAIN night before last and the chamber accepts and releases new rounds solely by Earth gravity impulse. No shaking needed.

Next, please read the thread.  HV from Winchester is now quite reliably unreliable. First round re-chambering the empty repeats with the Winchester HV with 5 prior rounds in a clean chamber, and again with 30 rounds "dirty". 

Plans are that I will start with the CCI in a cold clean chamber and confirm that it works even then. I don't have the tools to test if their brass is harder than the other stuff, but the longitudinal expansion marks on fired cases go further back towards the rim on the other stuff recently fired.

Ive never found Winchester or Remington to be reliable 22, imo they are only good for plinking. test some hv CCI or other you might get better results, but the recoil spring is the key imo

I am in opposition to oiling the ammo and reducing the recoil spring force.... Fix the gun...so it operates with the factory rated recoil spring..

I started with the M41 newer model around the 2000 year or newer.
Very good and accurate pistol but with some alibi issues.

Cleaning the crud ring(at the case mouth in the chamber) helped a lot.
Note that I do not like over cleaning or cleaning a .22 barrel at all(just where the crud builds up).

I replaced the extractor with a factory one and also pinched it in a vise to get the extractor to engage the case rim more effectively.
This really helped.

Still had some occasional alibis that looked like odd stove pipes(where the cases were left, right, right side up or even upside down).
This was due from trapped cases from them being ejected up into the sight extension and bouncing back down into the action.

Lessons learned on the M41 :
1- ammo fps means nothing(different burn rates of powder, slow, fast can get to a certain fps).
    too fast and the extractor will slip off the rim if not holding enough tension.
2- no oil on the top round, no need, why, find the reason it does not function and fix it.
3- sometimes after cleaning the crud ring, or barrel, it would take up to 3 rounds to start functioning properly(cause there is no lube in the chamber       from the lube on the bullets to overcome the friction/ expansion of the cases).
4- switching different brands of ammo during the same sitting will cause issues also until the new ammo lube has overcome the previous ammo lube.
5- finally replacing the factory barrel with a Clark which had no sight extension solved all alibis.

Final opinion of the M41:

Pistol can take you to Master when set up properly using the factory recoil spring.
Before I went to a Marvel conversion was shooting in the 860 to 870's firing CCI-SV with the Clark barrel.
Add, no alibis.
Chambers are tight on the factory barrel and may need to be cleaned up cause different .22 ammo cases can be different lengths when expanded/ fired causing them to stick and not extract properly(is the fired case mouth opening up into the lands/grooves ?)bore scope helps, yes I have one.
May need to get or have the chamber reamed instead of chasing your tail.
After replacing extractor, extractor spring and barrel went alibi free with good scores.

Why did I go to a Marvel conversion ?
Cause I won a SA .45 and sent it off to Dave Salyer for the converson build, did not need two .22's

The Marvel has been accurate and flawless which happened to be what I was shooting to earn my Master card.
The conversion is less picky about ammo and just plain works.

M41, good pistol, work the bugs out.

Clarence

Update:

CCI SV runs from the first round.

RWS Target Rifle didn't eject the first round (#6 of the day, so 5 rounds-fouled chamber...), it was re-fed forward into the barrel face *as the slide picked up the next round*.

Winchester HV HPs all fed right after that.

So I'm going to declare the pistol fixed for my SV ammo, probably requires a lighter spring (but not by much) for the non-CCI target ammo that has given it trouble.

Every fired case shows signs of positive extractor engagement. Problems all now appear to be some ammo causing the slide to short-stroke. Although the chamber still does not have a "mirror" polish from my limited polishing compound on the cleaning patch work, performance is improved enough for me to conclude that it helped solve the problem.

AND I will totally ignore velocity data in trying to guess whether ammo A or B will or won't cycle the 41.

The extractor before this work began (and through the first extractor re-sharpening) would sit in the slide tilted a bit downward from horizontal. I did change that so it now is almost exactly horizontal, which puts the edge pretty much parallel with the case wall now. That might be making the cases eject more horizontally out under the barrel extension.

Now I will shoot a few NMCs and see how it does with more rounds per session.

About that 'Drop Test'

Do rounds really drop into and out of your chambers? With what kind of ammo?

I replaced my extractor (haven't gotten the new spring and plunger yet, or figured out how to remove them) and tried my 41 out last week, a very cold morning and the CCI sv did not function the first few rounds but then improved somewhat. A friend handed me some Winchester Power Point ammo and it worked great with them and continued to work great after going back to the CCI.
Figuring that cold and wax was not a great combination, I scrubbed the chamber this evening and decided to try that drop test.
With CCI sv 13 out of 25 rounds would drop into and out of the chamber. It did not require much pressure to seat the ones that would not 'fall in' but they would not go of their own accord. I dug through my limited supply of odds and ends and came up with more candidates. CCI Pistol Match dropped in and fell out just fine but I don't know where I would get any more, the 2 1/2 boxes I have were priced at $3.50. Eley Pistol Match would not even drop far enough for the bullet to be out of sight but here only the slightest of pressure was needed to seat them and they did not fall out afterward.
Maybe my chamber is too tight, it looks to be very smooth as best as I can see but .......

Bruce

Fire Escape wrote:About that 'Drop Test'

Do rounds really drop into and out of your chambers? With what kind of ammo?

[snip]

Oh yes, by gravity at latitude 37.something north and altitude of maybe 900 meters or so.

I don't even need to get the barrel fully vertical before they drop either way (except sometimes going in, if the round is not lined up).

Pretty sure there's no influence by the Coriolis effect.

All types of ammo, too. CCI SV and Blazer, the SK stuff, the RWS, the Winchester.  Probably should dig out the CCI Mini-Mags and check them for function too. And drop-in/out.

The rear of the chamber shows a small 45-degree chamfer.  Fired cases show a little more expansion just forward of that area, but I have not tried to isolate whether that is expansion on the first little bit of slide travel.  Some, um, experiments with a rifle in my youth showed that some brands of ammo under certain circumstances could be sort of timed to fire just as the bolt was trying to bounce a little, resulting in 2-3mm of the case wall just in front of the rim getting so expanded that it was impossible to rechamber the fired empties for snap cap use.  I was fast...

Anyway, to pull your extractor and spring and plunger, I know that the early ones require driving out the cross-pin in the slide, catching the firing pin and spring before they roll under the bench, and then sliding the breechblock forward. It's fitted tight. The spring and plunger *should* fall forward out of their slot--it's NOT a long hole like what a 1911 extractor runs in.  If stuck, I suggest a carb cleaner flush followed by gentle persuasion with a heavy straight pin. You should be able to see the spring's coils through the slot that keeps the track from being a long hole.

Hope this helps.

GrumpyOldMan wrote:

Fire Escape wrote:About that 'Drop Test'

Do rounds really drop into and out of your chambers? With what kind of ammo?

[snip]

Oh yes, by gravity at latitude 37.something north and altitude of maybe 900 meters or so.

I don't even need to get the barrel fully vertical before they drop either way (except sometimes going in, if the round is not lined up).

Pretty sure there's no influence by the Coriolis effect.

All types of ammo, too. CCI SV and Blazer, the SK stuff, the RWS, the Winchester.  Probably should dig out the CCI Mini-Mags and check them for function too. And drop-in/out.

The rear of the chamber shows a small 45-degree chamfer.  Fired cases show a little more expansion just forward of that area, but I have not tried to isolate whether that is expansion on the first little bit of slide travel.  Some, um, experiments with a rifle in my youth showed that some brands of ammo under certain circumstances could be sort of timed to fire just as the bolt was trying to bounce a little, resulting in 2-3mm of the case wall just in front of the rim getting so expanded that it was impossible to rechamber the fired empties for snap cap use.  I was fast...

Anyway, to pull your extractor and spring and plunger, I know that the early ones require driving out the cross-pin in the slide, catching the firing pin and spring before they roll under the bench, and then sliding the breechblock forward. It's fitted tight. The spring and plunger *should* fall forward out of their slot--it's NOT a long hole like what a 1911 extractor runs in.  If stuck, I suggest a carb cleaner flush followed by gentle persuasion with a heavy straight pin. You should be able to see the spring's coils through the slot that keeps the track from being a long hole.

Hope this helps.

That does help! I could see the spring and plunger when I changer the extractor but they did not seem to want to come out the front of the slot. I wondered if perhaps they needed to be pushed back and exit through a wider part of the slot but that did not work either. I expect that the front of the slot has become peened enough to retain them, having broken a few things in my younger days I now seek advice before reaching for the bigger hammer. Knowing which way something is supposed to move adds considerably to confidence in these matters. I did flush a LOT of old crap out of the gun while I was in there, figured Ballistol would clean and leave some lube in the places I was not yet ready to dis-assemble. I don't know how old a "UAR" prefix 41 is but this one seems to have been shot quite a bit so it must have been reliable at some point and will get back there!

I expect that all the ammo I tried in the 'Drop Test' would work if I wiped off the lube first (haven't tried that though ... yet) but I am guessing that is not how most of you do the test?

It's been a long time since I had match .22 ammo with enough goobery lube to drag on the chamber. All the stuff I've tested slips in and out without lube interference.

This morning, 5 RWS Target Rifle or Rifle Target rounds all ejected from the cold dirty-ish chamber. But I did cheat--dragged the tip of my finger across the bullet of the top round in the magazine, down onto the brass. Whether that replicated the dirty trick of the drop of oil, to a much smaller degree, will be investigated further. The stuff grouped great at 50, too.