wdoyle1980 Posted November 10, 2009 Author Share Posted November 10, 2009 I guess you don't really hold back your opinions, huh? Well, the receiver tube is 1/4" hardened 4130 chromoly steel. The barrel and bolt are both factory (and factory headspaced and hardened - again, rimmed rounds are headspaced on the rim itself - it's more of a matter of 'hold it fcking hard against what it's butting into", but you know that already). While the finish is sloppy - yes, I used a HF drill as a 'mill' and that's about as blasphemous as it gets in a metalworking forum, but I live in a shiatty 1000sf apartment with access to minimum tooling. I use what I can. While it may be 'just a little rimfire', the chamber pressure of the 22wrf is 19,000psi and the 22wrm is 24,000psi. The 45/70 is rated for max pressure of 28,000psi. This roughly puts the 22wrm and 45/70 in the same 'ballpark', as opposed to the 45,000psi of the 7.62x39 and other rifle rounds. The 4130 at this thickness was more than enough for the 22 rimfire rounds and should be plenty for the 45/70. Even in an annealed state, the 4130 should give me a tensile strength of about 81,000psi and yield of 52,000psi. In my bolt action design, the bolt cams up very tight against the breech face. Yes, there is a big-ugly open spot in the weld where the tigger housing butts up to the receiver. I hope to fill that with weld and grind smooth. For the 45-70 I had purchased 2.5" solid 4140 rods to be drilled and tapped to accept the barrel. I assumed that at this rod-thickness, I can definitely get the amount of material needed to have a strong hold on the barrel and to hold the breech , whether a bolt with lugs or a falling/rolling block, in place. I strive to ensure a safe environment with my test-fires. Even with my welded-AK kit rifle, I sandbagged it and stood behind a solid wall to shield from shrapnel in case of KB, and fired by string. I'm not one of the 'nuts' running out to homedepot to buy galvanized fence posts and copper tubing out to make a rifle. It's a shame that you merely brushed off my attempt as just a kid's tinkering. I'm sorry that the work of this 'kid' doesn't match up to the rifles you have made when you were my age. If I were in your position, I might have been inclined to help with the project and offer some encouraging words and designs, while still enforcing strong safety policies. For someone that posts 'all the time' on weaponeer, I would have pegged you for that type. I didn't see this handle on that forum. I guess I should just hike down my pants, go watch some Kanye videos, and play with my iphone like you'd expect all us kids to do. It's no wonder the progressives are winning-over all them 'techie' kids who think gun-owners are crabby old republicans. Do you spray kids for running on your lawn, too? ;-) Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted November 10, 2009 Share Posted November 10, 2009 I seem to get the impreession that you have your mind made up and are going to do this in spite of wot anyone else thinks. But could I talk you into trying one thing before you take anymore steps towards this project? Go to a gun club or shooting range,,any way you can find someone with a .45-70 and shoot it at least once. A factory gun not a home made. I believe this would help you more than we can typing ideas back and forth to you. (Gun shops or sporting good stores may can tip you off to someone that owns one.) Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted November 10, 2009 Share Posted November 10, 2009 My apologies but, I still think you need some lessons in proper machining techniques. If you want to make zip guns have at it. I have spent a lot of years shooting and building rifles and have a healthy respect for them. I still have both eyes, all my fingers and my life. Please be careful, life is short enough as it is. Go in peace. Quote Link to comment Share on other sites More sharing options...
wdoyle1980 Posted November 10, 2009 Author Share Posted November 10, 2009 Rich, that is a good idea. While I would like to do the project, I'm not 'dead set' on doing it to spite anyone's opinions. I would like to have something in a larger, straight-cased, rimmed, caliber for ease in headspacing and design. What I liked about this cartridge is that the modern-production barrel will support both black powder and smokeless powder loads - giving me some versatility in my loads. The pressures listed by SAAMI seem to be in the 'safer' range, rather than something like .30-06 or 7.62x39/54. I would like to see a live-firing of the .45-70. Quote Link to comment Share on other sites More sharing options...
wdoyle1980 Posted November 11, 2009 Author Share Posted November 11, 2009 Also, please for the love of god, do NOT call this a ZIP gun. It is NOT, by both Federal and State definitions. It is a full length, commercially/professionally rifled barrel, with a commercially manufactured bolt. It is a single-shot bolt action with a trigger/sear from a 'proven' action, like the MN9130. It's not a bic-pen with a spring and a 22lr loaded into it. Again, you seem to show your bias. I admit that I need more work (and more professional tools). Thank you for your concern and worry. I look forward to being able to say that I've been doing this for years, as well. I'm sure everyone started somewhere. Gunsmiths looking for apprentices seem to be fading out, as with most metalworking jobs being moved overseas or polit-pressure causing plants/workshops to shut down. Quote Link to comment Share on other sites More sharing options...
digunderground Posted November 11, 2009 Share Posted November 11, 2009 I actually had to join this forum when I saw what Wdoyle1980 was doing. Hats off to you sir, this sounds like an awesome project and your work sounds to be 100% in spec. I don't know what these other users are talking about while trying to discourage you. All of your calculations are WELL within spec, and will easily handle that round. I have fired many .45-70 and they are powerful, but everything you listed should easily cover the potential dangers. @bentiron1946 - Wdoyles assumption of 80,000psi 4130 handling the .45-70 is correct and sound. you sir are down right dangerous making assumptions like that, maybe you should have a grasp on engineering before you post something like that.. maybe, just maybe.. someone could help him with what he asked?!? @ wDoyle1980 I **may know someone that can point you in the correct direction. I personally am not familiar with that thread, but I have an old metalwork buddy in PA that may know the answer. Ill let you know what he says.. ill probably PM you. Either way, best of luck.. Quote Link to comment Share on other sites More sharing options...
wdoyle1980 Posted November 11, 2009 Author Share Posted November 11, 2009 HAH - in fact, since you're a weaponeer fan, maybe I should show you a user's project where he made a nice AK-style 7.62x25 pistol that used 8x rubber bands as a recoil spring. I'm sure you'd feel a nice tightening in your chest after watching that one. You'd probably shart your jorts over that guy - make my project look like something popped out from JMBrowning. Quote Link to comment Share on other sites More sharing options...
wdoyle1980 Posted November 11, 2009 Author Share Posted November 11, 2009 As promised: video of *scary* Weaponeer build. This is *not* my build, but compares how much safer mine is YouTube - BlowbAK Pistol Quote Link to comment Share on other sites More sharing options...
Bentiron1946 Posted November 11, 2009 Share Posted November 11, 2009 No matter how many calculations you make you are still making zip guns and are a dangerous group of individuals. I see a total lack of responsable action. Quote Link to comment Share on other sites More sharing options...
wdoyle1980 Posted November 12, 2009 Author Share Posted November 12, 2009 (edited) Maybe I'm missing something. Is there some kind of 'old-world' definition of 'zip gun' you're operating off of, or just being crabby? This is a 'zip gun': Note the crude barrel, probably lacking rifling, < 2" barrel (again, probably no rifling, making this a smoothbore pistol firing a cartridge = illegal), and lack of a trigger/sear engagement area. This example is illegal and is the basis of the 'zip gun' definition for the BATF and most states that define 'zip gun' in their legislature. If you call anything I make a 'zip gun' again, when it is clearly not, you will force me to contact the administrators to have your posts removed. Are you merely saying that I suck and make crappy things and therefore == 'zip' guns? You're simply likening my crappy ability to cut metal as pretty as you do with some immigrant gangmember stuffing a 12ga shell into some plumbing pipe? awesome. I honestly don't see anything I'm doing as dangerous or illegal as to what you're hinting. Have a nice day, sir. Edited November 12, 2009 by wdoyle1980 Quote Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted November 12, 2009 Share Posted November 12, 2009 Lets keep this thread civil, and don't get all pushed out of shape. Be respectful of each other , K? First off it was me who posted on Weaponeer, not Bentiron1946. I am not discouraging the build, just making sure that you get all the facts before building. On the pressures did you take into account the surface areas of each round? PSI=pounds per square inch. Two rounds rated for the same pressure, but different surface areas will have different effective pressures on a receiver. A 45/70 has a lot more surface than a .22 rimfire, and the bullet weight is 10X greater ( for every action there is an equal, and opposite reaction). Admitted when you look at a Trapdoor receiver, and the materials that were used from 1873-1890 there isn't much there, and they worked fine then, and still do. I have several Trapdoors, and they are one of my favorite rifles. The pressure curve for blackpowder is also not as steep as with smokeless powder. With that being said there are some loadings out there that would turn a Trapdoor inside out if it was fired through it. You are missing the point on using headspace gages. Without them you are guessing. Cartridge rims have a high, and a low limit for thickness. They are not all the same, and the gages allow for that tolerance. I am looking to do a 45/70 myself, but I am going to use a surplus Mauser action that I have. Personally I would make the receiver, and then send it out to be heat treated. It used to run around $50 to have one heat treated back home in CA. Material from the steel mill has internal stresses, and strains from the forming processes. After the machining is done they are still there, and I have had parts shift during machining due to them. With a proper heat treat after machining the receiver will have been normalized. 35 Rockwell is actually pretty soft for a receiver in my opinion. It may hold for awhile, but the bearing surfaces for the bolt may smash down ( psi + surface area) over some firings resulting in excessive headspace. Some actions were case hardened, hard on the outside to take wear,soft on the inside to add toughness. Do some research on receiver Rockwell hardnesses. Again, if you do this, do it right. Invest in yourself by taking a machine shop course where you can learn how to use proper machine tools. My Community College courses were dirt cheap when I went through the program. My shop class had machine tools, heat treating equipment, and the Rockwell testers to check it. Once you use proper tools, you will not look back. Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted November 12, 2009 Share Posted November 12, 2009 Yavapai comunity college near Prescott AZ has a complete gunsmithing course..takes two years and you can learn wot you want nd need to purue this dream.... Quote Link to comment Share on other sites More sharing options...
wdoyle1980 Posted November 12, 2009 Author Share Posted November 12, 2009 I've checked online for some of those courses and did see the one in Prescott. Not much in the area of Santa Barbara, CA The university and city colleges have more wood-working than metal-machining. I don't think UCSB or SBCC have anything in the realm of machinist courses. Prescott's kinda far and would only work for me if they have a weekends-only course. My jewelry casting instructor has a lathe that he's let me use with him, but the mill is currently in storage. I'd be nice to be able to do some apprenticing under someone that is willing to help and foster good habits. As I said above, I wasn't against spending the $40 or so for gauges, nor do I think they're unnecessary. I guess I was just trying to opine that I didn't think they were 'as important' in a rimmed cartridge as they would be on a round that headspaces on the shoulder or casemouth. Quote Link to comment Share on other sites More sharing options...
Rich Hale Posted November 12, 2009 Share Posted November 12, 2009 This is not a weekend course. That kind of course would take you a looooong time to get the knowledge you require for your interests. This is a 4 semester course and you would need to attend for the most part five days a week. It is a complete course covering all aspects of gunsmithing: repairs, woodwork and all the metalwork required. Each student must have a federal firearms license prior to beginning of class. This is my last post in this matter and let me say that you would be very wise to reread all of the advice that has been given to you and perhaps rethink the plan you have. It is not well thought out and may leave you with permanent injuries. It is not simply good practice to disregard the requirements that a major caliber firearm needs to work right. It almost seems that your major focus has been a name that someone tagged onto your new piece and that has taken your attention away from what I believe should really have gotten your attention. I hope I have been some help to you. Quote Link to comment Share on other sites More sharing options...
tig demon Posted January 9, 2010 Share Posted January 9, 2010 you should ask the kind folks over at homegunsmith dot com they seem pretty switched on Quote Link to comment Share on other sites More sharing options...
jason0012 Posted February 2, 2010 Share Posted February 2, 2010 I wont touch the wisdom of this project. I don't know your skill level or how careful you are. I can say something about square threads though. Square threads are cut either on a mill or in a lathe. Thread milling is something I wont get into. Suffice to say it is a fast process in manufacturing used to produce repeatable threads on many many parts fast. The tooling involved is beyond most small shops( but not impossible) Square threads are also cut on a lathe, just like 60* threads. Big difference is, they are square( I know, thats not real helpfull) I would recomend a basic lathe or machine shop text for a full description, square threads come up often and are included in most machine shop classes. They can be aggravating, esp internal threads, but aren't unmanagable. Square threads are very seldom cut with a tap. Tap cutting a square thread is only possible in a through hole, and requires a set of three taps. The first tap is standard form, the second roughs the thread to final depth, and the third finishes the face of the threads. Oh and the three piece set is VERY expensive. I would recomend using a lathe, or trying to rethread the barrel to a more standard size. If you use that route please consider the strength lost when reducing the chamber diameter. Proceed with extreme caution. Quote Link to comment Share on other sites More sharing options...
Ken Ra Posted February 2, 2010 Share Posted February 2, 2010 This may be stupid but have you checked your threads against Acme style threads ? They are old nearly square and flat bottomed. If so then you know what to hunt for they are definitely machinist territory. BB Ken Quote Link to comment Share on other sites More sharing options...
ArtWerkz Posted February 3, 2010 Share Posted February 3, 2010 Perhaps a quick flip through the latest Machinist Handbook would help in your quest. Quote Link to comment Share on other sites More sharing options...
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