Oiling Top Round in Semi-Auto Magazines?

[JamesHH]

To clarify, and make some wild claims.

I'd expect 100% reliability for the first 100-200 rounds out of a perfectly clean gun in good condition with quality ammunition which suits the gun.

200-400 they're starting to crud up, the odd lump on the firing pin might cause a misfire, so say 99% reliability if the only factor is crud and not a worn chamber, weak extractor spring, weak recoil spring etc.

400+ you're relying on luck, there's no reason to be complaining about malfunctions.

[Dr.Don]

I'm probably in the minority here, but I disagree with oiling the top round to improve functioning. These 22 pistols are blowback operated with no lockup whatsoever. The design depends on the brass adhering to the chamber wall until the pressure peak is past. Oiling a round changes the characteristics of this adhesion, and you can expect a harder blowback and attendant wear and tear on the pistol. As simple as it seems, the 22LR is not a really low pressure round. A pistol that needs this oiling to function needs some work done in my opinion. If memory serves me, the great gunsmith Jerry Keefer was in agreement on this.

[David M]

As simple as it seems, the 22LR is not a really low pressure round. A pistol that needs this oiling to function needs some work done in my opinion. If memory serves me, the great gunsmith Jerry Keefer was in agreement on this.

You are missing one thing, in ISSF guns we are looking at the least recoil and low velocity ( down to 250ms/820 fps), for the pistol to be reliable you need every trick going for you as you can get.
Hence very low pressure rounds (fast burn rate/low powder volume) compared to high velocity 22.
If in the middle of a high level match if I can prevent a malfunction I will use the oil.
A malfunction can cost big points.

[-TT-]

...The tip of the extractor in the Benelli hits the slot in the barrel, and how much it gets deflected depends on how well the angle on the tip matches the angle of the bottom of the slot. I matched that carefully, and now the extractor deflects only slightly off the case when the slide closes.

So, you mean the inside angle, the edge which faces the bore? Or just the tip, where it becomes flat at the very front-facing area?

I've noticed that slight movement as the bolt seats into battery, but it never seemed to matter so I left it alone. I might take another look.

One area I did have to address is to add a bit more of a curve to the lower edge of the extractor hook, right where it first touches the rising brass. If it's too square, the rim doesn't ride properly and hangs up before seating into the headspace. Rounding a slight curve there made a big difference in feed reliability. I'll try to get a photo.

[Gwhite]

I have some photos of what I found & what I did. I'll try to write it up. If you look at the face of the bolt from the front, you will see that the edge where the extractor hits the case isn't vertical. If you look at the breech face from the rear, you can see that the inside of the extractor slot is also not quite vertical. To minimize the extractor deflection, you want to those angles to match.

If you look at a new factory extractor, the angle is "negative", in that it actually wants to push the round down off the face of the slide. The angle
is shallow enough that friction prevails and it apparently isn't a problem. I tried to fix that by grinding the extractor a few degrees "positive" to help hold the round up in the rim pocket. The catch that I hadn't considered is that makes the deflection when the slide closes much worse. That appears to be much moire detrimental to reliable extraction than the negative extractor angle.

The factory extractors come with an edge angle of about 10 degrees, but the inside of the slot in the barrel is at about 4 degrees. By regrinding my extractor to 4 degrees, I appear to have created an Energizer Benelli; it keeps going, and going, and going....

[-TT-]

Would love to see photo(s), even without a writeup!

Taking a close look at mine just now, with the chamber empty I don't see any outward deflection of the extractor as the bolt closes, but I do see a slight rearward movement indicating the extractor is certainly touching something in the barrel/breech slot.

With brass in the chamber, something else happens with the extractor, there is a tiny outward movement, and no rearward movement. I guess this is indicating the hook is now touching the rim (as it should), and therefore can't move rearward so it swings instead.

On the other hand, I'm not having much of any trouble with it. So I'm not going to touch anything, but I'd sure like to understand it more. If shaving a bit off the nose would improve this, it is probably a good idea.

[EdStevens]

Oiling the top round (a drop of oil on the cartridge case) certainly improves reliability of my Model 41, and many other guns on the line having malfunctions that I have seen. If you can retrieve the spent cartridge case after firing it, you can usually see it is coated in black gunk that it has removed from the chamber.

I use my Model 41 as a loaner gun for new shooters with CCI SV. Some shoot it with no malfunctions at all; others need that drop of oil now and again. A few need it all the time. Something to do with resistance to recoil, or limp wristing, or something else that varies individually.

IMO, if a drop of oil saves from you losing ten or more points in sustained fire, use it and don't feel ashamed about it.

[RMar]

I used the drop of oil tactic (Rem Oil, coincidentally) when my OEM Walther OSP barrels would erode enough to cause reliability problems. Unfortunately, that wasn’t very long, not even a half a year, and that was extremely annoying. They’d malfunction at that point using R25, but, for practice, would function CCI just fine. CCI is much hotter and the brass is thicker gauge or stiffer. Of course I had to designate one trigger for practice because CCI was hard on the trigger. Ultimately, the problem was solved by going to custom barrels. I never had to replace the custom barrels, and never had reliability issues with them. So how many rounds do you have through the barrel and what ammo are you using when the malfunction occurs? If you’re stress testing anyway, consider testing using some hotter ammo to at least rule something out.

[Spencer]

For those that oil the top round:

• What oil do you use?

• How much?

Where do you put the oil -

• a/ on the projectile

• b/ at the projectile/case junction

• c/ on the case?

[crankythunder]

For those that oil the top round:

• What oil do you use?

• How much?

Where do you put the oil -

• a/ on the projectile

• b/ at the projectile/case junction

• c/ on the case?

Hi Spencer!

The Model 41 shooters that oil their magazines in Bullseye are loading 5 rounds (as opposed to 10) in a magazine and they are placing one drop of oil on the brass case right behind the projectile. Some put a drop on every magazine, some on every other magazine, and a few on every fourth magazine but I would say the majority do it every magazine or every other magazine. The Hammerli 208/208S shooters are about the same. Only seen a couple Benneli and Walther shooters do it and do not think it is very common with those people. I have never seen anyone oil the first round on a Pardini, a FWB, or a Ruger or Buckmark. As for the Browning Medalist, I have only seen one person shoot one in competition and I did not oil it (functioned fine by the way).

About half the model 41 shooters oil their bullets, probably more of the Hammerli shooters do.

Regards,
George

[VonKasta]

Pardini recommends this technique to aid reliable operation, using Shooter's Choice FP-10 oil. My Benelli MP-90S has developed extraction problems, and I thought I would try it.

I didn't have any FP-10, and used Rem Oil. The first couple magazines went OK, and then things got much worse. The only thing I can figure is that the Rem Oil was getting cooked onto the chamber walls by the high temperature, and leaving a residue.

So, I have two questions:

1) Do you use this technique to aid in reliable cycling of your pistol(s)?

2) If so, what oil do you use?

Thanks!

Im late to the party here, but extraction issues with the MP90 could be related to the recoil buffer being worn. Ive seen it happen in multiple pistols

[Gwhite]

Interesting! I don't doubt your experience, but I'm puzzled as to what the mechanism would be. Unless the buffer has mashed to the point where the recoil spring isn't compressed as much, all of the extraction & ejection should be long over before the bolt hits the buffer. I could see it affecting feeding much more easily.

My MP90S has started acting up again. I noticed that the buffer is in one piece, but there is a pretty deep dent where the recoil spring guide tube hits it. As a quick test, I'll see if the buffer in my daughter's pistol is in better shape & try swapping them. IN the past, I've only replaced them when they start to crumble...

[VonKasta]

Interesting! I don't doubt your experience, but I'm puzzled as to what the mechanism would be. Unless the buffer has mashed to the point where the recoil spring isn't compressed as much, all of the extraction & ejection should be long over before the bolt hits the buffer. I could see it affecting feeding much more easily.

My MP90S has started acting up again. I noticed that the buffer is in one piece, but there is a pretty deep dent where the recoil spring guide tube hits it. As a quick test, I'll see if the buffer in my daughter's pistol is in better shape & try swapping them. IN the past, I've only replaced them when they start to crumble...

I doesnt make sense to me either, I fail to come up with a logic explanation as to why it should affect extraction. Its just that Ive seen it happen in three different MP90’s now that leads me to belive there are mechanics at work that I dont understand. I just wanted to mention it as the buffer gets overlooked when it comes to troubleshooting extraction issues, as it shouldnt affect it.
The only other case of extraction issues with MP90 ive seen was related to the ammunition, in this case a new batch of cci standard that had an ever so slightly rounded shape of the bottom of the brass when compared to a round of the old batch, thats a bit easier to see why it would fail.

[Gwhite]

I swapped my daughter's relatively new takedown block & buffer for mine, and just fired 80 rounds without a single malfunction. Hardly definitive, but promising. It has been only messing up in sustained fire in matches, of course, so it's not a frequent occurrence. I'll do some more testing before I replace my buffer, but it is encouraging.

The one other thing I can think of that might be affecting it is a new lubricant I'm trying. The Benelli factory oil is very low viscosity, and this stuff is a tiny bit thicker. I know from past experience when I got my first MP90S that using grease everywhere will make it mess up. I've given up on the thicker oil and I've switched back to a light weight oil (Rem Oil). However, I haven't taken the bolt apart to clean & re-lubricate the recoil spring & guide tube.

[-TT-]

I swapped my daughter's relatively new takedown block & buffer for mine

Is this the factory-style buffer, the gummy rubber one? Larry Carter did not have anything nice to say about those, and strongly recommended I install his solid one. I've had zero trouble with it.

I think the factory one is too "bouncy" and results in poor bolt timing. It gets even worse when the recoil spring tube drills a hole in it, which allows the spring to relax another few mm. Why that might affect extraction, I'm not sure however! Misalignment leading to increased friction, and therefore less travel in the recoil cycle?

[VonKasta]

I always get a misfeed first two mags after I clean mine, always. It runs best dry and dirty for some reason.
I have a hard blue plastic buffer in mine, the red rubbery model of buffer is for post 2015 models I belive.

Some benelli shooters at my range has made their own buffers out of thick leather and it seems to be working fine.

[Gwhite]

My daughter's is an LGI buffer, but mine appears to be original. I'll shoot with my daughter's a few more times to be sure, but if I don't have any issues, I'll install a new LGI buffer.

Does anyone have an slick techniques for installing them? I've done about a half dozen for myself & the team I help coach, but I always end up chewing up one of the tabs that hold them in place. I've never had a problem with one falling out from the damage, but it's annoying. I put some padding behind the block, and butt it up against the base of my bench vice. I get the first tab in its slot, and then use a large screwdriver to compress the buffer and pop the second tab down & into place.

I tried making a clamp to compress them enough to pop them into place. I got that to work once, but the clamp keeps slipping and I need to re-think the geometry.

[-TT-]

Larry's old Benelli guide had a photo attached showing how to install his buffer, I'll try to find it tomorrow.

What I recall is that it showed exactly what yours shows, but pressing the tab on the opposite side - i.e. at the "top"

[Gwhite]

Hmm... It's possible that if you work from the other side, you can pry it into place more easily.

I'd be very curious to see a copy of Larry's "Benelli Guide". Can you scan it? This is the first I've heard of its existence, despite having bought lots of Benelli parts from him & visited his shop countless times.

Thanks!

[deadeyedick]

I can’t remember how my Benelli buffer was installed but my FAS 602 and 607 had the metal backing with two tabs that through its design was prone to failure.

I sourced an almost identical material and made a new buffer that was a better fit and then cleaned all parts with acetone and applied contact cement.

It worked perfectly and even after 1000 rounds was showing no signs of wear or signs of coming loose.
I got rid of the metal retainer which usually broke after relatively little use because of work hardening, increased the surface area and made future replacement easier...and cheaper.