Rimx with ModX conversion likes Vudoo mags better than RimX Mags

[DrA1]

The title says it all.

I just picked up a Rachel Precision Brux on a RimX action with the ModX bolt.
The guns shoot beautifully- tight groups at both 50 and 100 yards.

But here is the issue — I have 2 RimX mags with extensions and they are well built, but no matter how I adjust them, they do not feed consistently, so I decided to try a polymer Vudoo mag, as I had some with me and BINGO—- flawless feeding—— has anyone else experienced this.

When watching the rounds feed, it appears that the round hits the chamber a little low and shaves some lead and the cartridge hangs on the lower (6 o clock) aspect of the chamber. Probably about 1 in every 20 rounds does it. SO…… I adjusted the mag to sit as high as possible however that did not fix the problem— I believe the issue is the angle on the front edge of the rimx mag.

The Vudoo mag on the other hand feeds flawlessly over hundreds of rounds.

Thoughts??

 

[Hgrubbs22]

Buy more Vudoo mags and sell the RimX mags. . No more thoughts today.

 

[DrA1]

Buy more Vudoo mags and sell the RimX mags. . No more thoughts today.

That’s exactly what is about to happen — just looking for some feed back or ideas on getting the rimx mags to be more consistent.

 

[Csafisher]

Does it only happen on full mags?

 

[DrA1]

Does it only happen on full mags?

Reply — it can happen at anytime, first round, last round or anywhere in between and it doesn’t matter how many rounds are in the magazine.

I’m going to video some slow motion feeding to see if I can identify exactly wvhat is happening

 

[DownhillFromHere]

Try taking the extensions off, assuming you have the original floor plates. I only experience feeding problems with my RimX with the Zermatt 5-round extension in place on one magazine, and it can happen anywhere in the cartridge stack. The round pops off the stack in front of the extractor and gets shoved into the chamber, requiring steel fingernails or a tool to pull it out.

 

[pronelife]

does the chassis have an adjustable magwell such that chassis adjustments would raise the mag?

 

[DrA1]

Try taking the extensions off, assuming you have the original floor plates. I only experience feeding problems with my RimX with the Zermatt 5-round extension in place on one magazine, and it can happen anywhere in the cartridge stack. The round pops off the stack in front of the extractor and gets shoved into the chamber, requiring steel fingernails or a tool to pull it out.

Do you have the modX conversion or the factory original bolt face?

does the chassis have an adjustable magwell such that chassis adjustments would raise the mag?

it does not.

 

[DownhillFromHere]

Do you have the modX conversion or the factory original bolt face?

It's the original bolt face... although my point stands. I suspect that the original spring isn't quite strong enough for the height/weight of the additional cartridges.

 

[DrA1]

It's the original bolt face... although my point stands. I suspect that the original spring isn't quite strong enough for the height/weight of the additional cartridges.

I wasn’t implying that the bolt face was my issue, just wasn’t sure how many of the ModX rifles have made it into the wild.

I believe you are correct, based on speaking with several other shooters that have had similar issues with extension and feeding difficulties.

I’m going to remove the extension and shoot it today (but I also ordered the tandemkross green springs as the hopeful solution with the extension)

Thank you for the help

 

[DownhillFromHere]

I wasn’t implying that the bolt face was my issue, just wasn’t sure how many of the ModX rifles have made it into the wild.

I believe you are correct, based on speaking with several other shooters that have had similar issues with extension and feeding difficulties.

I’m going to remove the extension and shoot it today (but I also ordered the tandemkross green springs as the hopeful solution with the extension)

Thank you for the help

Please post back with your results - I'm interested for sure.

My feed failures with the extended magazine are frequent enough that I wouldn't even think about running the rifle in a match with "normal" par times. I did use it in a little monthly match series in 2023 which had long par times... and I usually had one or two failures every match, always with the extended magazine.

 

[Csafisher]

I guess I’m lucky. My 15rd rimx mag has been great. I’m using it in a XLR envy chassis. It has an adjustable mag catch. Have it set with very little vertical play.

 

[DrA1]

Please post back with your results - I'm interested for sure.

My feed failures with the extended magazine are frequent enough that I wouldn't even think about running the rifle in a match with "normal" par times. I did use it in a little monthly match series in 2023 which had long par times... and I usually had one or two failures every match, always with the extended magazine.

I wouldn’t consider using those mags in match, but hopefully will get it sorted out.

At least I have other mags that do run well.

I’ll let you know the results.

 

[KnowNothing256]

I run a ModX in an ACC Elite with a RimX mag fitted with the +4 extension from Zermatt, and see no shaving.

My only reliability issue is the bolt moves so freely that shoving it firmly into a bag on a solid prop can send a round halfway forward, and if I back the bolt up from there I get a jam. Would love to have a detent bolt retention mod done to it, probably have a smith look into that for me sometime this year.

 

[DrA1]

Update — so I was impatient while waiting for new stronger springs — so I modified a Vudoo follower (by cutting off the side tab) and it fits perfectly in the RimX mag, it allowed me to use a much heavier square spring and it changed the feeding angle enough to make it feed perfectly.

I spoke with Johnathan Elrod and he agreed the issue was spring pressure or feed angle in my particular chassis and the way the RimX mags sat in the mag well despite a nice snug fit with zero slop.

 

[DrA1]

 

[Csafisher]

View attachment 8732083

Where’d you get the new spring?

 

[DrA1]

Where’d you get the new spring?

I can’t even remember — had 2 of them in my “spare” parts bin along with several different followers from Vudoo and MKM.

I’ve got a set of green springs coming from tandemkross — when I get those, I may try to modify the rimX followers and give them a shot with the new springs.

I recorded my mis feeds in slow motion and could see that my round presentation was too nose up and wouldn’t seat all the way into the bolt face, so I went to work trying different things to make the rounds feed “less nose up” and changing followers allowed the rounds to feed at the perfect angle —- I’ve cycled a couple hundred rounds through it now without a misfeed, but I wasn’t shooting because I was at my home. I’ll get back to the range latter this week and confirm it is just as consistent when firing.

 

[Dan.Engellant]

We are using one of the new ace of spades from Alta arms in a RimX it has been flawless.

 

[RAVAGE88]

I can’t even remember — had 2 of them in my “spare” parts bin along with several different followers from Vudoo and MKM.

I’ve got a set of green springs coming from tandemkross — when I get those, I may try to modify the rimX followers and give them a shot with the new springs.

I recorded my mis feeds in slow motion and could see that my round presentation was too nose up and wouldn’t seat all the way into the bolt face, so I went to work trying different things to make the rounds feed “less nose up” and changing followers allowed the rounds to feed at the perfect angle —- I’ve cycled a couple hundred rounds through it now without a misfeed, but I wasn’t shooting because I was at my home. I’ll get back to the range latter this week and confirm it is just as consistent when firing.

I’ve been following along and was attracted to jump in when you said, “too nose up.” Forgive me if I missed somewhere above, but what stock/chassis are you using? Is there an adjustable release in addition to the adjustable catch on the RimX magazine?

“Too nose up” isn’t always (more rare than one might imagine) because of the magazine.

MB

 

[DrA1]

I’ve been following along and was attracted to jump in when you said, “too nose up.” Forgive me if I missed somewhere above, but what stock/chassis are you using? Is there an adjustable release in addition to the adjustable catch on the RimX magazine?

“Too nose up” isn’t always (more rare than one might imagine) because of the magazine.

MB

The mag release isn’t adjustable.

The chassis is an MDT that was a special build for Faxon at some point and it is no longer produced. It is a blend of the LSS and the Elite as far as features are concerned. I had previously used it with a B14R custom.

I also follow your post concerning DDG and your future products, as I also shoot a 360.

I believe the true issue is the mag well geometry, but I love the balance and feel of the chassis, so I made the mods to the follower and spring to get consistent feeding.

So here is my synopsis of everything to this point — the mag catch height on the rimX mag is set to be snug when the bolt is in the closed position. There is almost no lateral play in the mag. When I see the “problem” feeds the bullet orientation is slightly nose up as it enter the chamber and the rim is not fully seated into the bolt face. This can happen at any point throughout the magazine. Which makes me think it is not a spring pressure issue, but a timing problem based on the bullet presentation.

The bolt nose / face is ModX. I checked it’s function and geometry outside of the action to see that rounds will easily and fully seat in the face and sit appropriately between the face and extractors.

When I put a 10 round poly Vudoo mag in this chassis, I can see that the “lie angle” is about 10-15 degrees less nose up as compared to the RimX mag. So I tried to replicate the Vudoo mag presentation in the RimX mag — fully knowing this is likely a chassis issue, based on all the data acquired to this point.

I’m going to try the barreled action in another chassis this afternoon with all original RimX mags and see how it works in that chassis and report back.

 

[RAVAGE88]

The mag release isn’t adjustable.

The chassis is an MDT that was a special build for Faxon at some point and it is no longer produced. It is a blend of the LSS and the Elite as far as features are concerned. I had previously used it with a B14R custom.

I also follow your post concerning DDG and your future products, as I also shoot a 360.

I believe the true issue is the mag well geometry, but I love the balance and feel of the chassis, so I made the mods to the follower and spring to get consistent feeding.

So here is my synopsis of everything to this point — the mag catch height on the rimX mag is set to be snug when the bolt is in the closed position. There is almost no lateral play in the mag. When I see the “problem” feeds the bullet orientation is slightly nose up as it enter the chamber and the rim is not fully seated into the bolt face. This can happen at any point throughout the magazine. Which makes me think it is not a spring pressure issue, but a timing problem based on the bullet presentation.

The bolt nose / face is ModX. I checked it’s function and geometry outside of the action to see that rounds will easily and fully seat in the face and sit appropriately between the face and extractors.

When I put a 10 round poly Vudoo mag in this chassis, I can see that the “lie angle” is about 10-15 degrees less nose up as compared to the RimX mag. So I tried to replicate the Vudoo mag presentation in the RimX mag — fully knowing this is likely a chassis issue, based on all the data acquired to this point.

I’m going to try the barreled action in another chassis this afternoon with all original RimX mags and see how it works in that chassis and report back.

Thank you for the details, it helps ring all this out.

It's definitely a timing issue and definitely not a spring issue. I doubt it is follower angle. It'll be interesting to see if the interface pad on my magazine is providing a rearward load into the release (it has to be touching the forward face of the mag well in the receiver), as the RimX mag doesn't have that feature. That will help validate the mag well dims/constraints. Without the interface pad, the mag release pushes the magazine forward in a sloppy mag well, which throws off feed timing and can/will cause a nose up presentation.

Changing mag height on the RimX mag could help with the nose up condition, but it depends on how sloppy the mag well is; however, I know little to nothing about the ModX conversion.

MB

 

[DrA1]

Thank you for the details, it helps ring all this out.

It's definitely a timing issue and definitely not a spring issue. I doubt it is follower angle. It'll be interesting to see if the interface pad on my magazine is providing a rearward load into the release (it has to be touching the forward face of the mag well in the receiver), as the RimX mag doesn't have that feature. That will help validate the mag well dims/constraints. Without the interface pad, the mag release pushes the magazine forward in a sloppy mag well, which throws off feed timing and can/will cause a nose up presentation.

Changing mag height on the RimX mag could help with the nose up condition, but it depends on how sloppy the mag well is; however, I know little to nothing about the ModX conversion.

MB

Thanks for the input Mike - I appreciate it.

I can’t wait to see the new Mags and DBMs that you will be putting out in the future.

 

[021411]

This isn’t new info for seasoned RimX owners but for those who are new to the Zermatt extension.. pay really close attention when installing them. The spring is known to pop out of place when installing it. It’s fit together fine but the lower section of the spring will be out of place.

 

[RAVAGE88]

Thanks for the input Mike - I appreciate it.

I can’t wait to see the new Mags and DBMs that you will be putting out in the future.

Thanks, Dude, the new 10 round Mag is in phase two of prototyping and validation. Once it's through phase two, it's eligible for pre-order (if I elect to do one based on level of interest) and officially in production phase, starting with an LRIP. The LRIP is when I could be looking for a few testers, but typically the testers aren't necessary.

The DBMs are through phase one prototyping and proceeding to phase two when the mags go to LRIP.

MB

 

[DrA1]

Well — all that screwing around and no dice with the Vudoo follower in the RimX mag — still timing issues — 200 rounds fired and 7 misdeeds despite the flatter presentation from the follower

Trying a different chassis this evening to see if that is the issue

Very frustrated at this point but will get it figured out eventually

 

[Masojoh]

Is there a reason why you didn’t try the Rimx follower as I had explained?

 

[DrA1]

Is there a reason why you didn’t try the Rimx follower as I had explained?

View attachment 8733495

Yes — the green springs haven’t arrived yet but I’ve identified another issue and corrected that issue and makes it run with the rimX follower and regular springs

The magwell on my chassis has a bit more play than I realized — which allowed the front of the magazine to drop down in relation to the chamber despite the rear being totally snug from the mag catch adjustment. When I run the bolt, it causes a rotational type of motion I didn’t initially see until I had someone else shoot the gun while I watched the interaction between the bolt, magazine, bullet and the chamber.

After reading through some of @RAVAGE88 posts I realized my “nose up” scenario was the result of the mag fitment in my chassis and not the direct cause of the problem.

I added pieces of tape, 1 at a time until all play was gone and the magazine feed and shot well — 100 rounds this evening without a misfeed.

That 0.0245” made all of the difference— I ran it hard and fast and also very slowly — all good now.

Thanks for everyone’s help

Hopefully— I didn’t waste anyone’s time, but hopefully it’ll help out someone in the future.

Now I need to find a semipermanent shim at 0.0245” that is better than my tape solution. Any thoughts here would be great?

Thanks

 

[KnowNothing256]

Yes — the green springs haven’t arrived yet but I’ve identified another issue and corrected that issue and makes it run with the rimX follower and regular springs

The magwell on my chassis has a bit more play than I realized — which allowed the front of the chassis to drop down in relation to the chamber despite the rear being totally snug from the mag catch adjustment. When I run the bolt, it causes a rotational type of motion I didn’t initially see until I had someone else shoot the gun while I watched the interaction between the bolt, magazine, bullet and the chamber.

After reading through some of @RAVAGE88 posts I realized my “nose up” scenario was the result of the mag fitment in my chassis and not the direct cause of the problem.

I added pieces of tape, 1 at a time until all play was gone and the magazine feed and shot well — 100 rounds this evening without a misfeed. View attachment 8733646
View attachment 8733647
View attachment 8733648

That 0.0245” made all of the difference— I ran it hard and fast and also very slowly — all good now.

Thanks for everyone’s help

Hopefully— I didn’t waste anyone’s time, but hopefully it’ll help out someone in the future.

Now I need to find a semipermanent shim at 0.0245” that is better than my tape solution. Any thoughts here would be great?

Thanks

That’s a real bummer, I had the same issue with my Vudoo and implemented an almost identical solution, although the issue only manifested when the front of the mag pressed into a bag and I needed a lot more tape.

I chewed on this for awhile, and the solution I wanted to pursue before I switched to a DPX build was to mill a dovetail in the back of the mag, then slide a 3D printed trapezoidal shim into it. The location of the shim (and the dovetail cutout needed) I believe are chassis-dependent, but it seemed a good way to handle it.

I also considered nylon screws threaded into tapped holes in the back of the mag to achieve the same purpose, but the shim seemed more durable and easier to control the critical dimension protruding above the rear spine of the mag.

 

[Masojoh]

Good to hear.

Velcro would be what I would use. The hook side. Get the really good stiff, and I would expect it to stay put.

I shoot with a guy who has the similar fix on his mags. He uses flashing tape. That stuff takes a lot of arm power to remove. Be warned.

 

[DrA1]

Good to hear.

Velcro would be what I would use. The hook side. Get the really good stiff, and I would expect it to stay put.

I shoot with a guy who has the similar fix on his mags. He uses flashing tape. That stuff takes a lot of arm power to remove. Be warned.

I tried Velcro but it was too thick.
Flashing tape sounds like a reasonable idea.

 

[DrA1]

That’s a real bummer, I had the same issue with my Vudoo and implemented an almost identical solution, although the issue only manifested when the front of the mag pressed into a bag and I needed a lot more tape.

I chewed on this for awhile, and the solution I wanted to pursue before I switched to a DPX build was to mill a dovetail in the back of the mag, then slide a 3D printed trapezoidal shim into it. The location of the shim (and the dovetail cutout needed) I believe are chassis-dependent, but it seemed a good way to handle it.

I also considered nylon screws threaded into tapped holes in the back of the mag to achieve the same purpose, but the shim seemed more durable and easier to control the critical dimension protruding above the rear spine of the mag.

I’m thinking the weight of the RimX mag when combined with the bolt running made the issue show up — I have a grey ops bag stop so I don’t load directly into the mag.

 

[Emerson0311]

I’m thinking the weight of the RimX mag when combined with the bolt running made the issue show up — I have a grey ops bag stop so I don’t load directly into the mag.

Very interesting. I need to look again at the mag sitting unusable on my bench.

 

[RAVAGE88]

Yes — the green springs haven’t arrived yet but I’ve identified another issue and corrected that issue and makes it run with the rimX follower and regular springs

The magwell on my chassis has a bit more play than I realized — which allowed the front of the magazine to drop down in relation to the chamber despite the rear being totally snug from the mag catch adjustment. When I run the bolt, it causes a rotational type of motion I didn’t initially see until I had someone else shoot the gun while I watched the interaction between the bolt, magazine, bullet and the chamber.

After reading through some of @RAVAGE88 posts I realized my “nose up” scenario was the result of the mag fitment in my chassis and not the direct cause of the problem.

I added pieces of tape, 1 at a time until all play was gone and the magazine feed and shot well — 100 rounds this evening without a misfeed. View attachment 8733646
View attachment 8733647
View attachment 8733648

That 0.0245” made all of the difference— I ran it hard and fast and also very slowly — all good now.

Thanks for everyone’s help

Hopefully— I didn’t waste anyone’s time, but hopefully it’ll help out someone in the future.

Now I need to find a semipermanent shim at 0.0245” that is better than my tape solution. Any thoughts here would be great?

Thanks

Glad you’re getting it sorted. Nose up issues are rarely ever the magazine, and most feed issues related directly to the magazine (since not that long ago) are due to the adjustable catch that no one has provided an adjustment procedure for (there’s another thread that illustrates this perfectly). Same goes for adjustable magazine releases. These two unnecessary gadgets are not a solution and it's interesting that the race is on to see who can come up with the best adjustable gadget instead of making things to the proper dimensions.

When it comes to these adjustable catches (L3i and Zermatt), there’s no way to position the magazine properly based on key dimensions, mark the position of the catch, remove the mag and tighten the locking screw. Instead, one has to use the hope and pray method, and the "hope" part is that one doesn't get too frustrated before it works at least a little bit before throwing it in the corner.

With the L3i, using the “width” adjustment can cause feeding issues, so set it to its most “narrow” position and leave it there.

The sloppy positioning (relative to the receiver face) and dimensions of the mag wells are difficult to rectify without actually throwing the chassis or DBM in the trash can. So, shims of some sort have been the common route for quite a while and my prediction is, one of the popular chassis makers is about to be lead down a path that could make things worse.

There are numerous types of adhesive shim stock available (brass, stainless, etc.), but in your case, the closest I found to .0245” is .022”, but there’s .002” and .003” options (depending on which way you deviate) that you could layer on top of the .022”.

The issues that the community has been forced to deal with are ridiculous and its crickets coming from those that created the problems.

MB

 

[M-ro]

I can’t even remember — had 2 of them in my “spare” parts bin along with several different followers from Vudoo and MKM.

I’ve got a set of green springs coming from tandemkross — when I get those, I may try to modify the rimX followers and give them a shot with the new springs.

I recorded my mis feeds in slow motion and could see that my round presentation was too nose up and wouldn’t seat all the way into the bolt face, so I went to work trying different things to make the rounds feed “less nose up” and changing followers allowed the rounds to feed at the perfect angle —- I’ve cycled a couple hundred rounds through it now without a misfeed, but I wasn’t shooting because I was at my home. I’ll get back to the range latter this week and confirm it is just as consistent when firing.

Did you order the springs directly from TandemKross? When I wrote them about this they responded they didnt know anything about this spring ? Im wondering if i give them a specific part number that may help? Thanks!

 

[DrA1]

Did you order the springs directly from TandemKross? When I wrote them about this they responded they didnt know anything about this spring ? Im wondering if i give them a specific part number that may help? Thanks!

https://tandemkross.com/green-springs-magazine-springs-for-smith-wesson-sw22-victory-3-pack/

 

[Masojoh]

Did you order the springs directly from TandemKross? When I wrote them about this they responded they didnt know anything about this spring ? Im wondering if i give them a specific part number that may help? Thanks!

The piece that hasn’t been made clear regarding the TK spring is you will need to modify the RimX follower so that it fits flush. If you look up at post 27, you can see the bottom of the follower where I trimmed it to be flat. I had an extra follower as I have the L3I 2 round extensions that come with a new one.

I have two 15 round mags that run flawlessly in both of my ModX rifles. A very good friend, who competes at a very high level, did the same with similar results.

 

[DrA1]

Further update — now 300 rounds with the “shim” in place and ZERO misfeeds.

I’ll put this one to bed and consider it done.

Once again— thanks for all the replies.