A simple DIY QD bolt action brass catcher (magnet mounted)

CollarChoke · Friday at 9:39 PM

EDIT: updated version and instructions available at: https://www.snipershide.com/shootin...-catcher-magnet-mounted.7241362/post-11924356

So I like using a brass catcher, but I hate the ones that mount via picatinny. Even the old MPA folding one is cumbersome and can get in the way and when running Spuhr mounts and other picatinny hogging stuff you often don't have anywhere to keep the brass catcher. They also get in the way when storing the rifle and it's just a pain to take them on and off in general.

I wanted something I could use easily across rifles, that would stay put during positional shooting, but also easy to rip off in case of anything. So I found this AR brass catcher print on thingverse: https://www.thingiverse.com/thing:3675277

Scaled that down to 70%, epoxied some magnets to it, added some male-velcro top and bottom to keep the mesh bag from sliding off and low and behold it works pretty good! You simply just plop it onto the side of your bolt action ejection port. The magnets are strong enough to hold 12 loaded rounds in the mesh bag, so spent brass shouldn't be an issue. The little roof ensures there's enough space for the brass to eject properly and I can't get it to fail in dry cycling practice anyways.

I'm sure someone like @pfl338 could turn this idea into a better executed version, but even this dumb prototype is pretty functional. I'm going to replace my old MPA catcher with it and if it's reliable enough I'll spend some time adding some proper magnet mounts and all that as well.

Figured I'd share in case other folks want to give it a go as well.

GenericBadGuy · Friday at 9:50 PM

Where did you source the magnets anx the netting?

CollarChoke · Friday at 10:09 PM

GenericBadGuy said:
Where did you source the magnets anx the netting?

The magnets I had laying around, they're just little rare earth magnets, you can find them on Amazon as well just search for rare earth magnets and get some that are the appropriate size. For the netting I just got some of these: https://www.amazon.com/gp/product/B007Q8L4VI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 because I only need it to hold 12 rounds max, but you could of course strap something bigger to it as well

GenericBadGuy · Friday at 10:21 PM

CollarChoke said:
The magnets I had laying around, they're just little rare earth magnets, you can find them on Amazon as well just search for rare earth magnets and get some that are the appropriate size. For the netting I just got some of these: https://www.amazon.com/gp/product/B007Q8L4VI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 because I only need it to hold 12 rounds max, but you could of course strap something bigger to it as well

I appreciate where you are coming from on this. I had the MPA brass catcher. Brass would bounce back in the action and get jammed up.

CollarChoke · Friday at 10:33 PM

GenericBadGuy said:
I appreciate where you are coming from on this. I had the MPA brass catcher. Brass would bounce back in the action and get jammed up.

Yeah I had the same experience with the MPA from time to time. I'm going to play with this prototype and run it through its paces, and then I'll make something that looks prettier and funnels the brass down and out a bit more as well, probably also go with a largely larger mesh bag just so there's bit more wiggle room for the brass coming in.

Char'ed Cuterie · Saturday at 9:54 AM

Consider me subscribed to your newsletter. I am terrible about losing my brass at field matches and putting knarly case mouth dings when ejecting onto concrete floors at the flat range. Something like this could really help.

I know that trying to tighten up the dimensions is probably a maddening fool's errand with all the different custom actions, faceted receivers, different ejection ports, etc... but have you considered using magnetic tape instead of the rigid magnets so that you can get more contact surface around the ejection port?

This might not work at all, I see in your photos that you started with two magnets, but in the shot with it on your rifle, there are three, looks like the polymer needed to be stood off the action a bit more to clear your stock and optic mount properly.

CollarChoke · Saturday at 10:50 AM

Char'ed Cuterie said:
Consider me subscribed to your newsletter. I am terrible about losing my brass at field matches and putting knarly case mouth dings when ejecting onto concrete floors at the flat range. Something like this could really help.

I know that trying to tighten up the dimensions is probably a maddening fool's errand with all the different custom actions, faceted receivers, different ejection ports, etc... but have you considered using magnetic tape instead of the rigid magnets so that you can get more contact surface around the ejection port?

This might not work at all, I see in your photos that you started with two magnets, but in the shot with it on your rifle, there are three, looks like the polymer needed to be stood off the action a bit more to clear your stock and optic mount properly.

View attachment 8574216

Yeah I'm just prototyping until I draw something in Fusion360 that combines everything that works. So far I'm settling on a shelfed design. The magnet stack isn't _THAT_ critical because as long as they're strong enough they actually stay put even without contacting the Action (I tested it across some different height optics/rifles/etc), but what I think I'll do is add wings with mounted round magnets that maybe have a screw in the back so you can set their height before locking them in place.

I'm also playing with the idea of a having a lower shelf so that brass falls into a compartment of sorts with no chance of bounce back into the port. The challenge here is that I want it to be small enough to be match compatible without interfering with your bolt operation even if you like to come up on the bolt with your index finger etc.

I think it's pretty close so I'm going to fab some stuff off of this basic concept and see how it runs

In the picture that's 12 pieces of 6.5CM brass which are captured in the lower compartment and then when you're done you just shake them out.

CollarChoke · Saturday at 5:08 PM

For the folks following along, tinkering around in Fusion and based on testing printing up the following:

Will report back how it works out haha ... it'll hold a specific brand of magnet so if it's working fine I'll post that + a link to the cad files so folks can print their own.

Edsel · Saturday at 5:13 PM

Nice...

Fusion's easy to learn?

CollarChoke · Saturday at 5:27 PM

Edsel said:
Nice...

Fusion's easy to learn?

Yeah it's not too bad I learned it when I needed to make magwell adapters for my AXSR and it took about 2 evenings of yelling at the screen before it started making sense.

CollarChoke · Sunday at 8:20 AM

Made some more tweaks to account for scabbards/match-saver access as well as variations in scope height/sizes ... taking it to the range today to see how it performs under live fire will report back

CollarChoke · Sunday at 4:58 PM

Happy to report everything worked out pretty well under live fire. Everything stayed put, but got some good insights on where to tighten things up to make sure nothing can bounce through or back up into the action especially when really yoking the rounds out with a mechanical ejector.

Making those changes now and then running that for a few positional range sessions and if it's good to go I'll make the plans available here

Stuey · Sunday at 5:00 PM

CollarChoke said:
Happy to report everything worked out pretty well under live fire. Everything stayed put, but got some good insights on where to tighten things up to make sure nothing can bounce through or back up into the action especially when really yoking the rounds out with a mechanical ejector.

Making those changes now and then running that for a few positional range sessions and if it's good to go I'll make the plans available here

Looks good. I appreciate you making the plans available.

wyliecoyote · Sunday at 10:12 PM

That looks awesome! All the things you mentioned about the MPA brass catcher are spot on and the exact same frustrations I’ve dealt with. Thanks for making that print file available. Now I need to find someone who has a 3D printer. Any plans to sell any of these?

CollarChoke · Sunday at 10:54 PM

wyliecoyote said:
That looks awesome! All the things you mentioned about the MPA brass catcher are spot on and the exact same frustrations I’ve dealt with. Thanks for making that print file available. Now I need to find someone who has a 3D printer. Any plans to sell any of these?

Oh nah not looking to make any money, I'll definitely keep a couple in my bag to give to folks at the range and whatnot. I already had some dudes asking about it when I was testing the first version today. If someone with actual scaled print/fabrication capability wants to run with the base design/idea and do something commercial with it I highly encourage them to do so.

I'm waiting on some stronger magnets to arrive tomorrow and then I'll post the print file for what I think will be the final version. It holds twenty spent 6.5creedmoor brass comfortably without bounce back which should be more than enough to get through any stage in anything people are shooting currently I reckon. But I want to run it with some movement to make sure it's solid first

loveha · Sunday at 10:59 PM

Kind of surprised you are the first person I have seen come up with this. This seems like something MKM would have designed. Something I would buy for sure. Always been hesitant on the current offerings because of complaints and price. Same boat, no printer to make it.

CollarChoke · Sunday at 11:08 PM

loveha said:
Kind of surprised you are the first person I have seen come up with this. This seems like something MKM would have designed. Something I would buy for sure. Always been hesitant on the current offerings because of complaints and price. Same boat, no printer to make it.

When it's running well I'm happy to make a couple for the folks in this thread and send them out at shipping cost. I have like 30 of the N52 magnets coming tomorrow so I'll have some to spare. I'll post here when it's that time. I've done similar things in the past with a limited run of AXSR thumbshelf I made in the AI thread

Char'ed Cuterie · Monday at 9:03 AM

CollarChoke said:
...holds twenty spent 6.5creedmoor brass comfortably without bounce back which should be more than enough to get through any stage in anything people are shooting currently I reckon. But I want to run it with some movement to make sure it's solid first ...

This is my biggest question - can it keep brass from falling back in with 10+ spent brass inside when going muzzle up, as you would between firing positions on a stage? Roughly half the stages out where I am feature multiple movements per stage.

Honestly, even if it doesn't tolerate going muzzle up very well, I'm still 100% interested in giving it a try, because it'll still be fantastic for all the OTHER situations where I'm having damage/loss of brass.

CollarChoke · Monday at 11:09 AM

Char'ed Cuterie said:
This is my biggest question - can it keep brass from falling back in with 10+ spent brass inside when going muzzle up, as you would between firing positions on a stage? Roughly half the stages out where I am feature multiple movements per stage.

Honestly, even if it doesn't tolerate going muzzle up very well, I'm still 100% interested in giving it a try, because it'll still be fantastic for all the OTHER situations where I'm having damage/loss of brass.

I was actually just thinking about that myself so I'm settling on 2 basic designs, one that is a self contained unit and doesn't need a mesh and then one that is much smaller but funnels into a mesh, so that when you go muzzle up the mesh takes care of not pouring brass back out. The one on the left you would put some male velcro strips and then strap a mesh bag of your desired size to it. The brass would be dangling in the bag so when you go muzzle-up it's not going anywhere you don't want it to I reckon. It's also considerably smaller so probably more match friendly in that regard as well.

CollarChoke · Monday at 11:48 AM

Trying to think of a name ... my wife is suggesting "Brass Bucket" but I'm leaning towards "Brass Goblin" ... because it gobbles brass and it will also make your local range brass goblins very sad.

CollarChoke · Monday at 2:15 PM

@Char'ed Cuterie so here's what I'm thinking for a more movement compatible version, I can move it any direction that the rifle would go during stage movement without the brass falling out. If you have any additional thoughts let me know

Note: putting some female velcro on the inside takes the majority of the brass bounce out of play so that's a good idea for anyone that's going to make one themselves.

memilanuk · Monday at 4:54 PM

Conaso said:
Ambidextrous for left-hand ARs? I would buy two.
View attachment 8575885

Where do you think the magnets are going to stick?

usmcgeek1775 · Monday at 5:04 PM

Did a similar layout, but drew it from scratch. Fits like a glove on my Zermatt TL3 SAs. Internal magnets with a cover over them. Here's what I used: (Printed in PETG-CF17) 3mf attached in Zip:

Magnets: 10mmx3mm https://www.amazon.com/gp/product/B07842PSJD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
Mesh bags: https://www.amazon.com/dp/B0DF7VZWD8?ref=ppx_yo2ov_dt_b_fed_asin_title

CollarChoke · Monday at 5:15 PM

usmcgeek1775 said:
Did a similar layout, but drew it from scratch. Fits like a glove on my Zermatt TL3 SAs. Internal magnets with a cover over them. Here's what I used: (Printed in PETG-CF17) 3mf attached in Zip:

Magnets: 10mmx3mm https://www.amazon.com/gp/product/B07842PSJD/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
Mesh bags: https://www.amazon.com/dp/B0DF7VZWD8?ref=ppx_yo2ov_dt_b_fed_asin_title
View attachment 8575896 View attachment 8575897

nice! will try yours as well, definitely much more compact, thanks!

usmcgeek1775 · Monday at 5:48 PM

CollarChoke said:
nice! will try yours as well, definitely much more compact, thanks!

Sounds good, feel free to reach out of you need anything!

ma smith · Monday at 6:03 PM

Thanks OP and other contributors.
This looks great for .223 bolt guns...

CollarChoke · Monday at 7:03 PM

EDIT: 12/23/2024 updated the print files a bit to lower the shelf for broader action/chassis/stock compatibility
EDIT: 12/24/2024 updated the print files to have a stronger curve on the shelf to prevent bounce back better, swapped the magnet holes to install from the back instead and added more space so you can stack multiple magnets if you need additional strength
EDIT: 12/24/2024 updated the print files to make the magnet wall thinner for better adhesion

See attached for the print files for my brass catcher designs as discussed in this thread.

Note: these are larger than @usmcgeek1775 design in https://www.snipershide.com/shootin...-catcher-magnet-mounted.7241362/post-11924177 so pick your poison!

Needed components:

- N52 magnets: https://www.amazon.com/dp/B0DC65Z3SF?ref=ppx_yo2ov_dt_b_fed_asin_title ... you'll want to stack two or three magnets per side for a secure fit. I personally run three on each side (6 total) for a very secure fit.
- For the open/funnel version, mesh bag: https://www.amazon.com/gp/product/B007Q8L4VI/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 I like this particular one because it grabs very well on velcro strips ... if you prefer a looser/larger bag that will guarantee nothing falls out during dynamic shooting get these instead: https://www.amazon.com/dp/B0D9WBHJ4W?ref=ppx_yo2ov_dt_b_fed_asin_title
- velcro strips: https://www.amazon.com/gp/product/B0C53YS1H4/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1
- epoxy to set the magnets in place, I've had great success with gorilla 5 minute epoxy for 3D printing use

Instructions: Print your desired brass catcher. Put male velcro around the edges of the open/funnel design to ensure the mesh doesn't slip off. On both versions, put some of the female (soft) velcro on the area of the catcher that the brass bounces into. This will significantly reduce chances of brass bounce back into the action. You can also line the inside of the catcher with female velcro as well to even further ensure a soft landing of your brass.

When epoxying in the magnets, I like to coat the entire surface and top of the magnet with a little layer of epoxy as well. You can also put a piece of the female velcro on top if you're worried about scuffing your action. The latest version mounts magnets from the back so you have some material between the magnets and the action regardless. Make sure you scuff up the magnets a bit with some sandpaper so they bond into the epoxy better.

The end result should resemble something like this (note shown here is an older version, current version mounts magnets from the back and has a more aggressive shelf curve, but same instructions apply):

Notes on reliability:

If you're looking to move around a lot during shooting (e.g. PRS) then I would suggest the mesh bag/open version. This will funnel the brass into a mesh bag that will dangle when you go muzzle-up thus preventing brass from pouring back into your action.

If you really want to be sure and don't mind the extra real-estate on your rifle, then get the larger bag as discussed, this will ensure no brass can come out during movement as the bag will swing itself shut when you go muzzle-up:

If you decide the run a longer/larger bag, you'll want to triple up on magnets as the brass now has a better lever on the pull of the magnets vs the smaller bag. Especially when moving around the swing of the bag may pull off the catcher, so triple up on your N52 magnets if you go that route. The latest design has space to accommodate 6 magnets total (3 on each side) internally, but since they now mount from the back end you could feasibly stack even more if you need the added strength. I run 6 total and can throw the rifle around without worrying about the catcher coming loose.

In my testing, the other main culprit of malfunctions is brass bouncing back into your action off of the plastic. The way to address this is to put some male velcro on the inside anywhere that brass might impact hard. This will eat some of the velocity and spring back of the brass and makes the unit much more reliable when running the bolt fast and hard. You can play around with velcro placement to "tune" the catcher for your ejection pattern. See below for an example.

Note that with the latest design, which features a more aggressive shelf curve, even without velcro I've had no malfunctions in testing so far. The catcher window is designed to accommodate a broad array of actions and heights and it can be seated low and high pending your stock/chassis/action clearances.

If you run into problems or have ideas for improvements, let me know and I'm happy to iterate on the design.

@Char'ed Cuterie, @wyliecoyote and @loveha, I'm happy to print one of mine or @usmcgeek1775 catchers for you just drop me a DM with your shipping address and which one you want and I'll let you know the shipping cost.

Char'ed Cuterie · 2024-12-24T09:53:22-0500

I'll take you up on that, will DM you here shortly. Thank you both for working on these, I think they'll be very helpful in certain applications.

The addition of soft/female side velcro is fantastic - in addition to calming down the bounce, I think it'll do wonders for quieting down the sound. That's more of a quality of life thing for me than any real practical application, but I saw it and liked it. I'll probably more or less line the entire inside of mine for that reason, I have a pile of misfit/offcut velcro that will be perfect for this.

I'm attracted to the much smaller size of usmcgeek1775's design, but I'm wondering if the consistent and predictable nature of the TL3's CRF/Mechanical Eject allows for that much smaller "window" to be possible. I know I have at least one traditional push feed/spring eject action that will reliably fumble 1 in 10 ejections, I'm sure that one needs as large of an opening as it can get haha. My problem child aside, consider me very interested to see that design tested on traditional actions and honestly I hope it works out great.

[ETA - Brass Goblin for the name, 100%. No one believes the brass goblin is real until they end a day at the flat range missing three Lapua cases.]

Thanks for making cool shit and putting it on the internet!

CollarChoke · 2024-12-24T13:22:31-0500

Char'ed Cuterie said:
I'll take you up on that, will DM you here shortly. Thank you both for working on these, I think they'll be very helpful in certain applications.

The addition of soft/female side velcro is fantastic - in addition to calming down the bounce, I think it'll do wonders for quieting down the sound. That's more of a quality of life thing for me than any real practical application, but I saw it and liked it. I'll probably more or less line the entire inside of mine for that reason, I have a pile of misfit/offcut velcro that will be perfect for this.

I'm attracted to the much smaller size of usmcgeek1775's design, but I'm wondering if the consistent and predictable nature of the TL3's CRF/Mechanical Eject allows for that much smaller "window" to be possible. I know I have at least one traditional push feed/spring eject action that will reliably fumble 1 in 10 ejections, I'm sure that one needs as large of an opening as it can get haha. My problem child aside, consider me very interested to see that design tested on traditional actions and honestly I hope it works out great.

[ETA - Brass Goblin for the name, 100%. No one believes the brass goblin is real until they end a day at the flat range missing three Lapua cases.]

Thanks for making cool shit and putting it on the internet!

Look forward to you testing it and whatever feedback you might have, thanks!

Yeah so I have a bunch of different stocks/chassis/actions that I need this thing to work across. I've been testing between spring ejection and mechanical ejection as well as various angles for round vs faceted actions and space available between e.g. a high and tight stock like the centurion and a low and roomy chassis like the whiskey 3.

Movement wise, even with a small/tight bag and even when the brass does come up some, it pretty reliably stays put at this point.

If you really don't want the brass to ever come up at all, you can run a larger bag, but note you're gonna wanna double or even triple up (which is what I did on mine) on the magnets with that setup because now the weight of the brass is on a longer lever vs the pull of the magnets e.g.:

CollarChoke · 2024-12-24T17:30:52-0500

K think final revision is done for SA at least, I did a lot of measuring and ejection arc testing to get the most forgiving shape for the catcher window that works across a broad range of rifles and actions, regardless of how high or low you put the catcher, as long as it catches metal.

Case in point, in this test I just slapped it way too low to the side of my Long Action AXSR. I was expecting to have to make a LA specific version (which I probably still will) but low and behold it worked just fine

Holliday · 2024-12-24T20:50:35-0500

Stuey said:
Looks good. I appreciate you making the plans available.

I must be thick tonight. Where are the online plans?

Thx

CollarChoke · 2024-12-24T20:53:51-0500

Holliday said:
I must be thick tonight. Where are the online plans?

Thx

They're attached to this comment: https://www.snipershide.com/shootin...-catcher-magnet-mounted.7241362/post-11924356

I'll add a link to the first post as an edit as well haha

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A simple DIY QD bolt action brass catcher (magnet mounted)

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