Pardini .22 magazine modification?

[Ricardo]

Anybody have a photo of Robert Brown's Pardini magazine modification? I'd like to try something like it for a Benelli, and though I think I get the gist, his instructions on www.starreloaders don't apply.

[sparky]

What modification? Why?

[Ricardo]

The modification is to have the slide lock back after the last round. Pardinis (as I understand) and Benellis (as I know) don't lock back and, though I usually am able to count to five, sometimes I lose track. This can lead to breaking the firing pin. I found the Pardini mod by chance and it seemed like a fun little hack. The slide doesn't end up locking for real, but it's prevented from closing completely after the last round. The link is http://www.starreloaders.com/edhall/pardini22lb.html

[Dipnet]

Ricardo,
Would you please post a picture of the modification? [This is done by choosing a file in the "Upload attachment" box below this one, select your image file (save as a .jpg), and then click "Add the file."] Thanks much, dipnet

[Dipnet]

Ricardo,
I've read and re-read the description of the mag and get the gist of the idea, but stumble at understanding some critical points, namely:
1, "...grind off one end of it [bolt stop plate] to the shape of the rime of a .22 case (not critical)." See Figs 1 & 2 showing my interpretation.
2. Remove the follower and find the location of a hole to drill that'll let about 1/8-inch protrude above the follower. How can it protrude 1/8-inch above follower when the bolt stop plate is only 0.018 to 0.025 inches thick?
3. Is the "dimple" you refer to a V-shaped groove at the top rear of the magazine (see Fig. 1, "1"). Why does that need to be flattened?
4. I'm guessing that the "shape of the rim is simply a rounded front (or rear) of the bolt stop plate.
5. Should the "bolt stop plate" be placed flush to the top-rear of the follower or located slightly forward?

I want to make this modification, but considering the price of the SP magazines, I want to get it right. I do carry a spare firing pin, but would hate to change it in the middle of a match. Thanks for your help. dipnet

[Dipnet]

I sent the above query to Ed Hall, and asked if he could forward it to Robert Brown and Ed kindly provided the following explanation, which makes sense.

"Dipnet"
Unfortunately, Bob passed away a few years ago, so he can no longer help us.

From looking at your Fig.2, it appears you are understanding the steel to be on top of the follower. The positioning is actually along the vertical back of the follower. This allows the rounded end (toward the right in Fig.2 top) to take the place of the rim of a .22 case, when the mag is empty. I don't have a Pardini, so I can't provide any pictures, but if you use the lower (Side) image of the follower in your message as a reference, the steel would be placed vertical along the back edge (left in picture) where "Side" is shown. If you look at your magazine, with a .22 round in it, from the back, the rim of the round fills the opening between the lips. The new piece of steel will fit in that area in the same way as the .22 rim, when the mag is empty, but it needs to allow for stripping of the last round when not empty, so it needs to clear the bolt on that last round, while catching the bolt after the last round.

I'm not sure, but I think the reference to the dimple is to show how much material to remove from the rear surface of the follower to allow for the steel to have room in the magazine tube.

I hope this was helpful. Let me know how it works and, if possible, please provide me with some pictures. I'd like to put some pictures with the instructions, if possible.

Take Care,
Ed

I now understand why the V-shaped groove at the top rear of the magazine has to be flattened with a punch, to make room for the metal placed on the rear ind of the follower. So, I'm going to modify a magazine and will report on the results. Thanks Ed Hall. dipnet

[j-team]

Honestly, I wouldn't ruin a Pardini with this modification.

What this modification is doing, is have the returning bolt crash into the back of the mag follower!

This is not how normal "hold open after the last shot" pistols work. They usually have the button on the follower push up a properly designed lever to catch the bolt/slide.

No modern target pistols have a last shot hold open. Reason (apart from it being unnecessary) is that you get a different recoil feel when the bolt/slide only completes half it's cycle.

[Dipnet]

Well, I'm going to 'sacrifice' one mag to see if it works. I'm not worried about the bolt crashing into the back of the "bolt retaining piece" as the recoil on a 22 isn't that much. Besides, you can load the pistol (with slide locked back), pull trigger (to activate the disconnector) and drop slide. Doing this, the trigger pull for the first and subsequent shots should be equal. Having a button that pushes up the follower after the last shot (like in the Walther GSP [an add-on]) is only different in that its spring activated. The little tab is not in the way of the bolt face until after the mag is empty.

I'll report what happens to the community. The only thing I'm concerned about is whether the dry fire piece will still work. If it works, I'll be grateful to the late Robert Brown. dipnet

[Ricardo]

I asked my coach a few weeks ago, and Dipnet has the right interpretation. The steel piece goes along the back of the follower with a raised rounded "bump" to replicate the profile of a loaded cartridge. And, yes, the mod works by having the bolt slam into that steel plate. Seems to have been a popular mod at least at some point. I haven't done it yet, since I'm a bit concerned about the outcome as well!
Thanks to all for figuring it out/finding out.

[Dipnet]

I more or less followed Robert Browns directions and it works great. The magazine locks back after the last shot, and as stated, you have to pull the bolt completely back and lock it before removing mag and inserting a fresh magazine. The one problem I encountered is that I did not use sufficiently strong steel stock (I modified a hinge that I thought would be strong enough; it wasn't). You really need to use hardened tool steel for the tabs that hold back the bolt. I had to hand file the stock to obtain the thickness of 0.025-inches.

Dimensions of tab (inches): 0.220 wide X 0.475 long X 0.025" thick, allowing for the top 0.125-inch of this bolt-stopping tab to protrude above the follower. The upper 1/8th inch is what stops the bolt.

Screws: they have to be micro screws (I used 1.4 X 10mm long self-tapping screws); (see http://www.metricscrews.us [20665, 1.4x10]); this is the only screw that will allow the beveled head to be ~flat with 0.025"-thick stock.

I glued the bolt stop to the follower before drilling holes (using super glue). I used urethane glue ("shoo glue") to fill in cavity in void underneath the follower to help further anchor screws.

The design would have worked if I had begun with sufficiently tough steel; goess I will have to ask a machine shop about making these small bolt stops. Hope this helps. The attached figures should be self explanatory.

In flattening out the "V"-shaped groove at top rear of the magazine, the punch never completely flattened the outside although the inside of the magazine was flat; I also file this area (Figs. 1, & 2).

Fig. 3 shows the micro screws and the dremel bit I sued to bevel the screw holes. I can tie small flies but this minute machine work was challenging. Cheers, dipnet

[Gwhite]

I heard about this only recently, and was looking into it. It may work fine initially, but after the last round is fired, the bolt will be riding back with a piece of hardened steel rubbing on the rib on the bottom of the bolt. I suspect this will cause wear on the bolt, especially if the top of the steel insert isn't rounded & polished.

Now that this modification has been out "in the field" for at least two years, I'm wondering if anyone is still using it, and if they've noticed undue wear on their bolts.

I've been considering trying to 3D print Pardini magazine followers. It would be easy to add this modification to the design, but it will take REALLY strong plastic to survive for long.

[mr alexander]

No modern target pistols have a last shot hold open. Reason (apart from it being unnecessary) is that you get a different recoil feel when the bolt/slide only completes half it's cycle.

j-team,

Yes, some shooters may feel a different recoil effect when the bolt/slide only completes half it's cycle.

However, by the time this is experienced, the bullet has already exited the barrel. Considering this fact,

just how can a pistol's last shot hold open feature be a detrimental one? The bullet has been long gone

by the time the recoil effect is felt. After the last round has been fired, the bolt/slide is slamming shut

on an empty chamber on those "modern target pistols". I was taught to never allow this to happen, as

it delivers a harmful shock throughout the firearm. There is no slide slamming occurring with my High

Standard Victor, due to the presence of a slide stop. With this pistol, there is no need for me to count

my shots. My focus can be directed solely on sight alignment and trigger control. Recoil is completely

ignored.

[JamesHH]

The slide slams hard shut on every .22 target pistol and rifle with every round, often so hard it rebounds to the extent that the new round is pulled up to halfway out of the chamber.
The friction of the round loading will be close to trivial.
For example
https://www.youtube.com/watch?v=OOyfYHhX4b4
https://www.youtube.com/watch?v=giENV_Zm5uA
https://www.youtube.com/watch?v=aDjzaAq8P0M
https://www.youtube.com/watch?v=KLfANbOQk6A
Adding a slide stop does nothing except screw up your magazines, 4/5 of your shots still will still slam hard.

[j-team]

The slide slams hard shut on every .22 target pistol and rifle with every round, often so hard it rebounds to the extent that the new round is pulled up to halfway out of the chamber.
The friction of the round loading will be close to trivial.
For example
https://www.youtube.com/watch?v=OOyfYHhX4b4
https://www.youtube.com/watch?v=giENV_Zm5uA
https://www.youtube.com/watch?v=aDjzaAq8P0M
https://www.youtube.com/watch?v=KLfANbOQk6A
Adding a slide stop does nothing except screw up your magazines, 4/5 of your shots still will still slam hard.

+1

[mr alexander]

The slide slams hard shut on every .22 target pistol and rifle with every round, often so hard it rebounds to the extent that the new round is pulled up to halfway out of the chamber.
The friction of the round loading will be close to trivial.
For example
https://www.youtube.com/watch?v=OOyfYHhX4b4
https://www.youtube.com/watch?v=giENV_Zm5uA
https://www.youtube.com/watch?v=aDjzaAq8P0M
https://www.youtube.com/watch?v=KLfANbOQk6A
Adding a slide stop does nothing except screw up your magazines, 4/5 of your shots still will still slam hard.

JamesHH,

Thank you for posting the links to those interesting youtube videos. Obviously, "bolt/slide bounce" really does occur when live

rounds are being chambered in .22 caliber semi-auto firearms. Unaware of this phenomenon, I was under the mistaken impression

that their recoil springs were strong enough to prevent this from happening. Your reply prompts me to ask two more questions:

1.) How does adding a slide stop do nothing except screw up your magazines?

2.) I've been shooting Bullseye since 1979. While participating in three different leagues since then, I personally have never seen

a 1911 Wadcutter Gun, Smith & Wesson Model 52, Beretta Model 92, et al that had their slide stops modified in such a way as

to defeat the last shot hold open feature they all possess. Doing so certainly would provide the same recoil effect from the first

shot to the last one. Have you or j-team ever encountered pistols like those mentioned that were setup in this manner?

Thank you.

[j-team]

The 1911 and Beretta 92 are military/combat pistols, the S&W 52 is really just a "targetised" military type pistol. So their design is suitable for the intended purpose, that is, a quick reload and making the shooter aware that the mag has run dry in a military/combat application. You just happen to also use them for target shooting.

The Pardini is a pure target pistol and as such, the design is one that is most suitable for that application. holding the slide back on the last shot not needed or desired by the target market. Remember that this is an ISSF pistol that only gets used for Bullseye in the US, the rest of the world uses them for ISSF Standard Pistol, Rapid Fire and Sport Pistol. No one shooting those events wants a last shot hold open.

[Dipnet]

Re last round slide stop:
I tried this modification because I was concerned about firing pin damage from firing on empty chamber. Having modified one magazine, the procedure is not worth the effort (I restored my mag to original condition). I probably fire on an empty chamber once or twice/match (usually 2 matches per month), and rarely during practice. My original firing pin shows no sign of adverse wear after maybe two cases of ammo fired through pistol. My take is don't worry about the issue.

The only "wear" on a stock item I've experienced is the recoil buffer, which I have replaced once, primarily due to wear caused by the recoil dampening rod smashing against the buffer (part 770; see http://www.targettalk.org/viewtopic.php ... il#p257365. I asked Alex about this and he said I could remove the dampener and 13 o-rings, but I should check the buffer regularly to make sure is is OK. dipnet

[-TT-]

I tried this modification because I was concerned about firing pin damage from firing on empty chamber.

The Pardini firing pin, like the Benelli, doesn't strike the face of the chamber when dry-firing so there is much less of a risk to shattering than in other designs such as the Hammerli and many US rimfires.

The main risk in dry fires in the Pardini/Benelli is the undampened shock wave that flies through the pin when the hammer strike doesn't land on anything but the rear face. Over time, the pin will actually lengthen and may break along the shaft somewhere. But generally that's a long time in happening. Personally, I change my firing pin, broken or not, once a year or so.

That said, I'm tempted to do the hold-open on my Benelli (original question in this thread, actually!). Because the Benelli magazine holds six rounds, my idea is to use an aluminum dummy round, attached to the follower with a roll pin or small screw or two. No modification to the magazine itself would be needed, just a spare plastic follower with a hole or two drilled. Haven't gotten around to actually executing on this plan, though.

[dronning]

I researched the hold open mod, because that is what I was use to, but I abandoned it because I believed the mod would actually cause more damage than the occasional "dry fire without a plug" that might happen during sustained fire. Turns out the only time I loose track of round count is during slow fire.
- Dave

[j-team]

Here's the Pardini slow motion: https://www.youtube.com/watch?v=2XdMgUtO2Fo