Titanium Recoil Lug

[Dave Hoback]

Touched on this in my barrel thread but thought I’d do a new thread with some pics, while I’m waiting the many weeks for my barrel, LOL! I’m making a new Recoil Lug from 6AL4V Titanium. I can absolutely tell you why you won’t find a single other Titanium Recoil Lug besides the bottom style for the Tikka T3 on the market. Because machining Titanium is one thing; but Drilling big large holes through thick portions of Titanium? Whole new ball game! Even going super slow, (maybe 200rpm, I still overheated & broke one of the Tungsten teeth on an Annular Cutter. Just no way a company can make them for Savage 110/Rem 700, sell it even double normal cost and make money. There’s no way. I’m only doing it because I can.

Started with an 8mm x 4” square flat bar of Titanium.
https://i.ibb.co/qBpjxGV/65162561-06-B8-4982-90-D4-7136-E7-B9-B873.jpg (https://ibb.co/4WptJy3)

Cut a 1.375” x 2” rectangle & machined the sides square. Centered and machined with 1–1/16” Annular Cutter. Lots of oil!
https://i.ibb.co/cgWTJ9B/C5444392-81-A6-46-D3-810-C-339573-BC9-BF0.jpg (https://ibb.co/WxrKnXh)

Here’s the finished hole with all the lively Ti curls. And that’s just the circumference! Imagine the discarded material from boring the entire 1-1/16” hole!
https://i.ibb.co/gV9RVNm/C59-BB9-FB-2338-4185-98-DD-0-E83-CA266378.jpg (https://ibb.co/BN3CNbc)

Here’s the part in the jig I spoke of making in the other thread. This is a steel backed jig plate to hold on the magnetic chuck for my Surface Grinder Attachment. I already was using the grinder earlier today to face the steel plate in the jig. So I can get the Recoil Jig very flat & Square.
https://i.ibb.co/DGtj9TS/0015-C68-C-F70-D-4246-AD5-B-CD74-CE251022.jpg (https://ibb.co/n3bK7t5)

[Hdskip]

I feel your pain . I've done some machining on Titanium.

[Robinhood]

i have been waiting for this to come up. I think it is really a good idea. Have you thought about lazer or water jet cutting. Sell enough to pay for material and machine time and to keep a few. Plus, do you still need a .250" thick lug if it it Ti. maybe .187"

[Dave Hoback]

Nah.. that’s just more money. I’m not looking to make & sell these. Just wanted to make one to see how it goes. Depending on that, I may do 2 or 3 more in the the future & sell them just to recoup material cost. But for this one, it’s all hand grinding on my 2x72 belt grinder. And boring with Annular cutters on my mill. Yes, I’m still doing .250”. My Chassis is already set up so the pocket is fit exactly for .250”.

[BobT]

i have been waiting for this to come up. I think it is really a good idea. Have you thought about lazer or water jet cutting. Sell enough to pay for material and machine time and to keep a few. Plus, do you still need a .250" thick lug if it it Ti. maybe .187"

If water jet cutting you would still need to finish machine the hole, reaming or boring would probably be easier than the way Dave did it though. I don't know about laser cutting, Titanium is pretty flammable and once it gets going it's a bear to extinguish (don't ask how I know).

It's looking good Dave!

[charlie b]

Laser cutting you'd probably still need to finish the hole as well. I don't remember any issues with laser cutting titanium other than it is really difficult. It has a really high melt point. The lasers we used at work had a bit more power than most :) Titanium powder is an issue, but, I don't know where the dividing line is between flammable and not.

[Dave Hoback]

Oh Bob’s right Charlie. Titanium is a reactive metal. Not just the powder being flammable. Hell.. Aluminum POWDER is flammable! With Titanium, even the largest chips & curls catch fire as you are machining it! Just from the friction heat! In the picture I have above with the rat nest of Ti coil chips. An open flame would set that off like Wild Fire! This is a big problem with machining Ti. I’ve been machining it for several years now, and done quite a few projects, so I’m well versed. Everything must be done super slow. Use plenty of cutting oil, and best if a water supply can be run. I don’t have that, but I always use a spray bottle of water to wet it down & cool ever pass or two. Even in the water, being sprayed, you can hear & see the Titanium popping & cracking with sparks flying… just trying to go up in flame! When I first started machining it, I did have a very minor fire. Nothing in my shop room caught blaze. Just a localized to the Titanium chips. But it was under the milling vice bolted down, LOL! Never again.

I’ll say this though guys.. I’m doing this “just because”. I’m not. Trying to prove anything or revolutionize any market. I don’t send anything out to be water/laser jet cut. To me, that defeats the purpose. I’ve been a custom Knifemaker for many years now & have Saw/Grinder cut & machine ground every blade by hand on my 2x72 belt grinder(which I also built from scratch!) I enjoy making things. I really enjoy making things that look & more importantly, WORK like the best parts that can be purchased. Again, I’m not doing this to get in business. Shoot, I’m not even in business selling knives! I make them here and there when I get the itch. But I haven’t made a knife in over a year now because any pain free time I’ve had has been focused on Gun projects. Anyway… this is just all for fun.

[charlie b]

Thanks Dave. I thought that might be the case. Interesting that 'cutting' it with a laser won't light if off like magnesium. Must be a surface area thing.

[Dave Hoback]

Exactly why! Same reason it can be Tig welded but not Mig or ARC welded.

[charlie b]

Had to look up why not MIG. Found this on a welding site.

Welding Processeshttps://www.azom.com/images/Article_Images/ImageForArticle_1245_447923403610763858558.gif

Titanium and its alloys are most often welded with the gas tungsten-arc (GTA or TIG) and gas metal-arc (GMA or MIG) welding processes. Resistance, plasma arc, electron beam and friction welding are also used on titanium to a limited extent. All of these processes offer advantages for specific situations.
-------------

BUT..... only the gas shielded methods really work due to oxidation embrittlement. There has to be enough gas to shield the weld until it drops below a specific temp (600F??). Probably would not trust a Harbor Freight MIG welder to do the gas shielding well enough. :) One big pipe welding site used submerged arc welding successfully. The pictures showed an automated welder.

Another site mentioned laser and ebeam welding. I remember watching an ebeam welding titanium at Lockheed many years ago (1970's). It was done in an argon filled container.

[Dave Hoback]

Yes, as long as there is no Oxygen the Ti cannot react. Now I won’t lie, I love Titanium. It has a coolness factor that I am hooked on. Of course in most cases, it’s not that the Titanium is any stronger… only per-weight is this absolute. For instance, the steels I use for my making my custom knives is tremendously stronger than Titanium. However, in small parts Titanium is ideal. And besides it’s strength to weight, it has some other very unique qualities as well. It possesses a quite high damping effect compared to either 416 or 4140 steel. This is another reason I’ve thought it to make a good Recoil Lug for some time.

[Fuj']

Wire EDMs are used for critical titanium parts. There is a de-ionized water flood used.

[Robinhood]

Wire EDMs are used for critical titanium parts. There is a de-ionized water flood used.

Funny you mentioned that. I was looking to make 150 of the titanium lugs over the last several months. Unlike Dave, my intent was to see if there is a market and what price point could be achieved. I had one guy tell me he could hold .005" with his lazer and waterjets. Me and a work mate were discussing that we were not sure he could do it and a vendor who was in the room mentioned EDM. The other issue was flatness on the pieces near the edge of the sheet.

Like Dave says throw it out there and see what dialog comes back.

[charlie b]

Laser cutting is indeed precise but depends on the mechanism more than the laser. The 'kerf' on our CO2 laser was .005" or so. The mechanism driving the head is the critical dimensioning part. The larger the laser cutting area the less precision in cut location. Some are 8ftx8ft while the smaller one we had was only 2ftx3ft (and only 75W so no metal cutting). We could hold dimensions for a single part to .005" or less. At one point I measured a variation between parts of 0.001".

The problem with lasers is it takes a lot of power to cut 1/4 steel and probably a lot more for Ti. Thousands of watts.

[Robinhood]

The problem with lasers is it takes a lot of power to cut 1/4 steel and probably a lot more for Ti. Thousands of watts. Impressive! I guess the data one needs from here is, What would the cost of material and the cuts turn out to be.? Good stuff Charlie.

[prdatr]

Funny you mentioned that. I was looking to make 150 of the titanium lugs over the last several months. Unlike Dave, my intent was to see if there is a market and what price point could be achieved. I had one guy tell me he could hold .005" with his lazer and waterjets. Me and a work mate were discussing that we were not sure he could do it and a vendor who was in the room mentioned EDM. The other issue was flatness on the pieces near the edge of the sheet.

Like Dave says throw it out there and see what dialog comes back.

Chad at LRI has been making them. I'm not sure when he started offering them but he is constantly coming up with new pet projects.

https://www.longriflesinc.com/collections/products/products/lri-heavy-tactical-recoil-lugs-for-m700-actions

[Robinhood]

It has been so long since I spoke with Chad I don't even remember what It was about. He has educated Me and so many people about Bolt action and the way they function. Most of the shit we know came from him and the guys over at Patriot Valley. Everybody else keeps info tight. That guy will bring you into the real world for free. His CNC action truing was the stuff and ground breaking back when he introduced it.

Definitely worth the price of admission for his products. I believe the Mountain Rifle will be getting an upgrade soon.

[Dave Hoback]

Chad at LRI has been making them. I'm not sure when he started offering them but he is constantly coming up with new pet projects.

https://www.longriflesinc.com/collections/products/products/lri-heavy-tactical-recoil-lugs-for-m700-actions

Notice there is no online choosing for which material? Just the one price of $49.99. I bet that price is for 4140 steel. It likely goes up a good bit more for Stainless, and the price is likely astronomical for Titanium. Just as the Murphy Titanium Picatinny rail. How badly I want one.. but at $234.. for a scope rail!!? Just can’t bring myself to spend that. I’m curious… may call them just to see. Anyway, this is all just fun for me. I don’t mix gun hobby and $$. Just strips the fun right out of it. Any others I make at most would only be sold for material cost.

[prdatr]

Notice there is no online choosing for which material? Just the one price of $49.99. I bet that price is for 4140 steel. It likely goes up a good bit more for Stainless, and the price is likely astronomical for Titanium. Just as the Murphy Titanium Picatinny rail. How badly I want one.. but at $234.. for a scope rail!!? Just can’t bring myself to spend that. I’m curious… may call them just to see. Anyway, this is all just fun for me. I don’t mix gun hobby and $$. Just strips the fun right out of it. Any others I make at most would only be sold for material cost.

Dave I would say to give LRI a call. Chads better half Kalli can answer any questions and if you call in the morning Chad might call you back around lunch time. I had him flute the bolt on my Axis when I bought it in 2017 and he has also done the one for my 700. Great pricing and quick turnaround. The guy is a class act and Marine Vet. When he got his last CNC Machine he donated his old one to the local high school.