Ruger Mark IV Lug Bumper?

[SGW Gunsmith]

For lack of a better term, or part name, 'cause this part is not listed in the manuals schematic, I'll call it a "lug bumper" until I'm corrected.

This was not a really well thought out addition to the Ruger Mark IV as to what it's supposed to do, I think. This little black "bumper (?)" has the consistency of chewed chewing gun, and you'll notice the tiny hole in the top of the bumper. A little steel ball goes into that hole so that when you replace the gummy bumper, the punch used will not poke through the soft rubber bottom of the alleged bumper. This bumper has survived around five re-assemblies of the upper, so I was told by the owner.

I've been experimenting with various durometer readings involved with plastic round stock when attempting to make a longer lasting bumper.

Yes, I know, you can probably call Ruger and get a replacement, and I'm sure it will be the same as the one to be replaced, so, ask for a dozen or so of the originals to get you through the month. :wink:

 

[22/45 Fan]

I don't know what that previous owner did to his gun but my MkIV Target has been way, way more than 5 disassemblies/reassemblies of the top end and the rubber plug is still in fine shape.

Hey, as long as i have your attention, I have another question. I'm left handed so I can't remove the right side ambidextrous safety lever. However, i have the same problem that right handed shooters complain about, the off-side (left side in this case) lever tends to get bumped by my hand while shooting and applies the safety when I don't want it.

I realize I can't remove the left-side lever like I can remove the right side one since it connects to the internal safety parts. But, could I grind off the thumb tab on the left-side lever, leaving it nearly flush and unlikely to be bumped on? I'd buy a new safety lever/shaft from Ruger to try this on rather than take a chance on ruining to original one.

Have you ever done this? Foresee any problems? Comments?

 

[SGW Gunsmith]

I don't know what that previous owner did to his gun but my MkIV Target has been way, way more than 5 disassemblies/reassemblies of the top end and the rubber plug is still in fine shape.

Hey, as long as i have your attention, I have another question. I'm left handed so I can't remove the right side ambidextrous safety lever. However, i have the same problem that right handed shooters complain about, the off-side (left side in this case) lever tends to get bumped by my hand while shooting and applies the safety when I don't want it.

I realize I can't remove the left-side lever like I can remove the right side one since it connects to the internal safety parts. But, could I grind off the thumb tab on the left-side lever, leaving it nearly flush and unlikely to be bumped on? I'd buy a new safety lever/shaft from Ruger to try this on rather than take a chance on ruining to original one.

Have you ever done this? Foresee any problems? Comments?

Actually, the right side safety lever is the ONLY one that's removable, thus the washer you received with the pistol to replace the removed right side lever. It's for the right side of the pistol.

Who wrote anything about a "previous" owner? This is a customers pistol. :roll: If you've had no crushing of that bumper, then consider yourself very lucky as far as that bumper goes. I've had eleven Ruger Mark IV pistols cross my bench , so far, and all of them have damage to some degree from being squashed. Could be your upper isn't even reaching down far enough to touch that bumper.

As far as removing the left side safety lever on the safety shaft, NO, it would not be a good idea. Do I see any problems with that? Only one BIG one. Try buying a restricted part from Ruger.

 

[22/45 Fan]

Actually, the right side safety lever is the ONLY one that's removable, thus the washer you received with the pistol to replace the removed right side lever. It's for the right side of the pistol.....

As far as removing the left side safety lever on the safety shaft, NO, it would not be a good idea. Do I see any problems with that? Only one BIG one. Try buying a restricted part from Ruger.

I know only the right side lever is completely removable and I know what the little washer packed with the gun is for. That wasn't my question. I wasn't proposing removing the left side lever, only grinding off the thumb tab to prevent accidentally applying the safety with my left hand. Any problems with that approach?

If the left side lever/shaft is a restricted item, that's interesting since Ruger's owner's manual doesn't list it as such. I'll have to confirm with Ruger whether I can buy a replacement before I start Dremeling on the original one.

Who wrote anything about a "previous" owner? This is a customers pistol. :roll: If you've had no crushing of that bumper, then consider yourself very lucky as far as that bumper goes. I've had eleven Ruger Mark IV pistols cross my bench , so far, and all of them have damage to some degree from being squashed. Could be your upper isn't even reaching down far enough to touch that bumper.

Sorry, I thought you wrote that the gun you were working on had been owned by a "previous owner" and then by the customer who sent it to you with the damaged bumper.

The little bumper on my MkIV is obviously compressed a bit but still functions properly and that's after many more reassembly times than the 5 you noted. I'm sure my upper is reaching it since there is absolutely no play or wiggle between the frame and upper and the bumper apparently still is doing it's job. My comment was noting the gun you have seen are damaged so rapidly while mine seems to be holding up quite nicely.

 

[farley]

My Mark IV has been disassembled many times And the "bumper" is working just as intended. It has compressed and formed itself to the shape of the barrel. Seems just fine.

 

[22/45 Fan]

As far as removing the left side safety lever on the safety shaft, NO, it would not be a good idea. Do I see any problems with that? Only one BIG one. Try buying a restricted part from Ruger.

Grrrrr. You are right. I called Ruger's customer service and the very nice lady I talked to was sympathetic but confirmed that the left side safety lever/shaft is indeed a restricted part and they won't sell it to me. The owner's manual doesn't list it as restricted but it is. Too bad as I wanted to have a spare to experiment with.

 

[clemency]

Just checked, and my 22/45 Mk IV doesn't even have one of the bumpers. There's a hole for it, but nothing there. What exactly is the bumper's purpose?

 

[RalphS]

My 22/45 Mk IV doesn't have one either.

 

[SGW Gunsmith]

Just checked, and my 22/45 Mk IV doesn't even have one of the bumpers. There's a hole for it, but nothing there. What exactly is the bumper's purpose?

Excellent question. The dang thing isn't even included on the schematic in the Mark IV manual, so how can anyone order new ones? I'm guessing here, only because from what I've seen with those Mark IVs I've worked on, some of those little black "questionable purpose" gizmos are crushed quite badly and some have a faint imprint from the underside of the receiver.

From what you two Mark IV 22/45 owners have posted, and due to the fact you both have Zytel grip frames, I can only surmise that the reason the bumper is there, on the metal frame pistols, is to prevent metal to metal contact. Obviously, that can't occur with the Zytel grip frames, but then one must wonder "why they have a hole for one".

There definitely has been a few strange things done concerning the Ruger Mark IV, and I'll bet the actual purpose of "WHY" will never be exposed in ink.

The ONLY reason that I've been looking and playing around with an alternative material, is because of the condition I've seen with the rubber ones, on those pistols I've had on my bench. Maybe, I'll find out that it all doesn't matter a dang bit, but it's fun experimenting, if only to find out why that rubber doohickey is even there. I am experimenting with various thickness' involved with the area of contact height for the "bumper", and just to see if there is a variance with that height..............or not. As time allows and my work load is not pressing, I like to get some of the questions, I have, answered as best I can.

 

[mohavesam]

Remember the "Mk IV" was being developed for a few years. I know some different variants made it to test-fire back a couple years before it was announcedThen S&W announced the Victory 22 and the MkIV was rushed into production.

I believe the engineering wasn't finished, and I've been told the design was compromised when Ruger execs decided to sell some of the patents to S&W in some sort of hush-hush dealings that nearly ended the MkIV as we know it. Some Prescott engineers nearly "retired out" but a deal was made to avoid losing a chunk of the engineering staff.

Anyway, the present hook-n-pin hinge setup is only one of the "hinge-opening" revisions to the MkIII. I don't know if it was the best design for production (Ruger's primary concern) or just whatever was on the drawings that didn't infringe on the S&W deal. The guys I happy-hour with don't talk about it much anymore. The MkIV is not the point of pride insdie the walls, that we might dream it.

Still a nice gun and over-engineered for casual use. They still shoot very well regardless.

 

[SGW Gunsmith]

I think we've all heard the stories about the Ruger Mark IV being rushed to distributors due to the Smith & Wesson SW22 Victory pistol introduction. I don't see that theory holding any viable truth until the 'real' story is actually published from those involved.
The Victory needs a hex wrench to get the barrel off, the Ruger Mark IV needs a "thumb". As far as I can tell, I see absolutely NO similarities between the two pistols, and the Ruger Mark IV is 10-times more cosmetically appealing than the Smith, for these old orbs. The Ruger bolt only needs a finger to get the recoil spring assembly free, and not a punch as shown in the Smith video. So, where exactly are the parts that share patent rights?
While there are a few "quirks" involved with the Ruger Mark IV, none are insurmountable for moderation, and I see Volquartsen already has an array of aftermarket parts to fix the "fugly" involved with the Smith. The price of the Smith Victory will play a more relevant part as far as choice goes, I'm sure, but as soon as I can get one of my customers to loan me a Victory, or if I can get one as a trade-in on a Mark IV, I'll surely run a heads-up test on my Ransom Rest for an accuracy comparison between the Victory and the Mark IV. Maybe even burn a little "midnight oil" to get a Victory for the test.

 

[mohavesam]

Never said the two share patent rights. I said Ruger sold or gave some patents to S&W (and lent some employees to S&W for the pistol which became the Victory).
And don't hold yer breath waiting for a published story, staying clear of insider trading laws.

I only glean what I can via AZ employees. Not paid magazine writers & internet reviewers.

 

[Highstandardguy]

Saw on another forum that the parts are Grip frame Bumper (A404451) and Ball (A405552). Don’t know if that is correct. It also seems that Majestic Arms already has a solution for around $50.

 

[SGW Gunsmith]

Never said the two share patent rights. I said Ruger sold or gave some patents to S&W (and lent some employees to S&W for the pistol which became the Victory).
And don't hold yer breath waiting for a published story, staying clear of insider trading laws.

I only glean what I can via AZ employees. Not paid magazine writers & internet reviewers.

Well, if that really is true, that Ruger actually lent employees to Smith & Wesson to either develop, or build, the Victory Model 22, it certainly would be interesting to find out the intent of that "lending".
Apparently, there was nothing involved with the building, design, or assembly of the Smith & Wesson Victory that was astounding enough to incorporate into the Ruger Mark IV. Some would look at that involvement as an opportunity to either find out about any impressive features in the Victory, or see which features could be prone to future failure, but then remain "MUM" about it. In any event, the Ruger Mark IV comes out on top, except for the price point.

 

[irish1223]

Newbie here. I just purchased my first gun — a Ruger Mark IV Hunter model. This may be a stupid question, but here goes anyway. When I broke the gun down (just to understand how it’s done), I noticed that little rubber lug bumper was loose (lying completely out of the hole) and the little steel ball was also loose. I had no idea what they even were, as I didn’t see them listed in the parts manual.

Now that I know what they are from the above posts, can someone please tell me how to put them back together. Where does the steel ball go and how do you get the rubber bumper back in the hole opening? I can’t seem to get in in there simply by pushing on it. Does it hurt to use the gun without it? TIA!

 

[SGW Gunsmith]

The steel ball goes inside the rubber bumper through that hole in the top. The steel ball is there so that the 1/8-inch punch used to set everything down into place doesn't poke through the rubber bottom. Kinds a hokey deal, I know, but unless some other plan comes along, I guess we're stuck with what's present?

 

[irish1223]

Thank you for the explanation. It does seem kind of hokey. But, oh well....

 

[Mike Wazowski]

I believe that this rubber bumper does pretty much the same thing as the accurizing wedge does for a loose upper to lower fit in AR15's. It takes up a little slack to help minimize wobble between the upper and lower parts.

 

[SGW Gunsmith]

I believe that this rubber bumper does pretty much the same thing as the accurizing wedge does for a loose upper to lower fit in AR15's. It takes up a little slack to help minimize wobble between the upper and lower parts.

Well, if that is the case, and I think you're probably correct, the "rubber cushion" in the Ruger Mark IV leaves much to be desired from the many that I've seen.