Need Machinist to make a Pellet Swager



Author Topic: Need Machinist to make a Pellet Swager  (Read 4469 times - 2 votes) 
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Offline darkcharisma

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Need Machinist to make a Pellet Swager
« on: July 19, 2018, 02:30:11 AM »
So, I was watching Matts video on youtube and saw a set of pellet swaging dies. oh my word i want a set for myself. the tittle of the video is "A Lesson in the Wind | Stories From Patagonia, pt.4" from AirarmshuntingSA

at 7:40 is where Matt's buddy starting making his own pellets.

I wonder if someone here can tackle the task in a week or so either with a manual milling maching or CNC.
I am willing to pay for the prototype and test it out myself. as long as it's reasonable. maybe we can mass produce it to the airgun forum members here. I know there are pellet swaging dies from Corbin that would cost at below $300, but that's not for Diabolo pellets, but rather bullets with hollow base.

any takers? if so please pm me and maybe we can workout something that benefits airgunners.
  • Sachse, TX, USA

Online Wayne52

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Re: Need Machinist to make a Pellet Swager
« Reply #1 on: July 19, 2018, 03:47:24 AM »
Those dies from China are about $800 but then you'll need the arbor press and whatever else to go along with it.

I've had really decent luck casting 25 cal diablo style and 22 cal boat tails from molds that I bought from NOE. rsterne (Bob) design's some fantastic molds but not any for the 22 cal diablo yet.

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Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #2 on: July 19, 2018, 04:15:28 AM »
I read a post on that mold you were referring to from NOE. everyone said they were nose heavy and wasn't accurate. now, yours has a flat nose. how do they group at 100 yards? or 50?

 I contacted the seller he called them HEN molds. he did say $800 not including shipping. we don't have solid accuracy data on that HEN mold yet anywhere so I'd rather not spend that much money, unless the HEN molds were doing sub moa at 50. the alternative is Corbin swaging die at $289 currently, but those pellets won't qualify for competition and I have a smooth twist barrel, not going to work. Since i don't hunt, i am not leaning for the Corbin yet. I can buy loads of JSB, but that's not the point. I want to be able to make my own. If only the HEN could be somewhere max $300, ideally $200!
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Online Wayne52

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Re: Need Machinist to make a Pellet Swager
« Reply #3 on: July 19, 2018, 04:37:20 AM »
The pic of the mold I posted here is the new one, I've got the old nose heavy mold and it's basically a paper weight now but I'm going to bring it over to my brother and see what he can do with it, he's got total access to a mold shop that he helped a friend of ours put together.  He even rebuilt a lot of the machinery for him, my brother was a wiz in the mold business and he really does know his stuff.

I think that if you're in need of match grade pellets swaging good pure lead would probably be the most accurate.  Next time I get a chance to stop over to my brother's place I'll put a copy of that youtube video on disc and see what he thinks.

I was kinda wondering about them those boat tails if they'd even be legal for competition airgun shooting because they're extremely accurate but you have to make them yourself ;)
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Offline ken47

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Re: Need Machinist to make a Pellet Swager
« Reply #4 on: July 19, 2018, 07:32:46 AM »
Guys hold on for a week, .22 cal (head 5.52mm) 18.52 grain 5 cavity mould is under development. Its for my own use I have a local machine shop assisting me to make it. 0.01mm tolerance is difficult to maintain on a manual milling center so they are using a Japanese 3 axis CNC for it.
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Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #5 on: July 19, 2018, 01:41:22 PM »
wanye, you forgot to mention about the accuracy of the new pellets. i am sure the boattails wont qualify for competition. at least for AOA extreme bench resst, they want diabolo pellets with skirts only. Utah challenge, i saw tethered lines...! so maybe their rules are different. IMO, you cannnot do anything to the old mold, since the head of the pellet is up, not down like traditional bullet molds. i was going to suggest putting pins in for hollow point. you may want to try making a plate for it on top and swage down the heads for hollow point right after casting and cuting the sprue plate. i dont know how the mold will hold. i am sure it will be fine since little force is needed. try that Wayne! and tell me about the accuracy please.

Ken! i am going to hold you to the “week” timeline. please get in touch with me/us as soon as you have the mold perfected! i do shoot .22 but id rather have lots of .25. why dont you push them to make .25 in the 35grains while your at it? anyhow please report back!
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Offline ken47

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Re: Need Machinist to make a Pellet Swager
« Reply #6 on: July 19, 2018, 02:32:58 PM »
Sure, .25 is possible. Just let me know how long you want it to be, to fit the mag. accordingly I can work on the design and FEA,CFD analysis of the pellet (that's how a JSB is designed and made, Rigorous computer assisted analysis and simulations)
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Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #7 on: July 19, 2018, 02:45:28 PM »
Ken, you can either copy the dimensions from the JSB .25 34 grains. or use Bob's pellet design for Hatsan magazines. the length is .420, see the attachment below. credit goes to BOB. The only thing i would modify on his design is making it DOMED instead of flat head, I like it domed.  and I want the hollow base depth at 0.050, not 0.150! that way we can use 3 different hollow punchers to work it's weight accordingly. Its good to have you work on this KEN! you have no idea how hopeful i am right now!
« Last Edit: July 19, 2018, 03:51:09 PM by darkcharisma »
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Offline ken47

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Re: Need Machinist to make a Pellet Swager
« Reply #8 on: July 19, 2018, 03:51:21 PM »
These are the specs. and the pics

the domed design with .250 as its radius doesnt fit in under length .420, its goes beyond it. so i made the changes that are proportional to the drawing
« Last Edit: July 19, 2018, 04:06:48 PM by ken47 »
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Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #9 on: July 19, 2018, 04:07:41 PM »
dude, that's quick. looking at the first picture. it doesn't show any turbulence airflow behind the head, does that mean it's going to be stable in flight? or is this simulation only and needed real world testing to compare? what are your thoughts?
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Offline ken47

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Re: Need Machinist to make a Pellet Swager
« Reply #10 on: July 19, 2018, 04:24:23 PM »
Yes the area behind the head has zero pressure and there is little or no air acting on that area, I have been doing a research analysis using CFD on same subject for Fluid flow. The airflow shows a symmetric vorticity in the wake at the tail, it means that nothing is abnormal with high drag design (which looks like a parachute), yet the pellet shoots like shotgun? why... many reasons some being the inconsistent casting and deformed heads which deflect the pellet due to spin and inertia. the domed one looks promising (with slight changes to skirt it will be perfect).
« Last Edit: July 19, 2018, 04:26:45 PM by ken47 »
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Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #11 on: July 19, 2018, 05:48:27 PM »
the skirt needs more mating surfaces. like the ones shown here, instead of relying on the ends of the skirt to squeeze and mate with the barrel for stability. if i can, i'd rather get rid of the skirts and have a bullet design with two sections of small mating surfaces, one behind the head, and one at the tail to reduce drag in the barrel but still keep it tight to the bore from breech to muzzle end until it gets choked down. But that's just me.

 bullet balance and weight designed for the twist rate is a good start for accuracy. bullet tolerance and aerodynamic is the second. airflow and muzzle blast would be third when the bullet exits the barrel. ah...i don't want to think about it. there's probably more to it than that lol.
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Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #12 on: July 19, 2018, 06:40:45 PM »
Those dies from China are about $800 but then you'll need the arbor press and whatever else to go along with it.

I've had really decent luck casting 25 cal diablo style and 22 cal boat tails from molds that I bought from NOE. rsterne (Bob) design's some fantastic molds but not any for the 22 cal diablo yet.




WAYNE, I am still waiting for you to chime in on the accuracy of the molds you showed. any infor would be appreciated.
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Re: Need Machinist to make a Pellet Swager
« Reply #13 on: July 20, 2018, 01:28:21 AM »
everyone said they were nose heavy and wasn't accurate.
....
I have a smooth twist barrel

With a smooth twist barrel and its low effective spin rate; you want "nose heavy" and a conventional "waisted" shape, optimized for drag stabilization.

The revised "Monster" ultra heavy JSB pellets have very short waists and long conical skirts.  They are much more accurate than the ones with the long cylindrical "fat" waists.  Especially from FX ST barrels. 

Wayne's cast pellets (Bob's) look like JSB pellets known to produce good accuracy from FX ST barrels.

The shape of pellet you presented (below) may work with conventional rifling, but will not work very well with smooth twist barrels:




« Last Edit: July 20, 2018, 02:53:45 AM by subscriber »
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Offline ken47

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Re: Need Machinist to make a Pellet Swager
« Reply #14 on: July 20, 2018, 02:51:33 AM »
everyone said they were nose heavy and wasn't accurate.
....
I have a smooth twist barrel

With a smooth twist barrel and its low effective spin rate; you want "nose heavy" and a conventional "waisted" shape, optimized for drag stabilization.

The revised "Monster" ultra heavy JSB pellets have very short waists and long conical skirts.  They are much more accurate that the ones with the long cylindrical "fat" waists.  Especially from FX ST barrels. 

Wayne's cast pellets (Bob's) look like JSB pellets known to produce good accuracy from FX ST barrels.

The shape of pellet you presented (below) may work with conventional rifling, but will not work very well with smooth twist barrels:



Thats true.
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Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #15 on: July 20, 2018, 03:56:39 AM »
i agree. it will be semi okay at shorter ranges up to 25 yards probably even with smooth twist. but its a compromise unless we get a custom unchocked barrel. thats going further than the intended purpose here. these slug types of bullets sized for .223 will be perfect for my condor .223 barrel though. but thats easily done with casting. onto the topic at hand. Ken, your progress is eagerly awaited
« Last Edit: July 20, 2018, 03:59:04 AM by darkcharisma »
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Offline ken47

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Re: Need Machinist to make a Pellet Swager
« Reply #16 on: July 23, 2018, 12:14:33 PM »
Punches are ready, Mould will be ready in next 2 days.
« Last Edit: July 23, 2018, 12:35:52 PM by ken47 »
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Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #17 on: July 23, 2018, 03:42:13 PM »
That looks awesome from here dude! Nicely grounded and polished. needs to be mirror polished though. the nicer looking the better! keep it up dude. post a video review of the pellet accuracy here or pm as soon as you can!
  • Sachse, TX, USA

Offline nced

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Re: Need Machinist to make a Pellet Swager
« Reply #18 on: July 23, 2018, 05:06:33 PM »
Guys hold on for a week, .22 cal (head 5.52mm) 18.52 grain 5 cavity mould is under development. Its for my own use I have a local machine shop assisting me to make it. 0.01mm tolerance is difficult to maintain on a manual milling center so they are using a Japanese 3 axis CNC for it.
I ran into the incredibly precise tolerance when making my own pellet head sizer with my small benchtop lathe and a small milling machine. With my lathe I couldn't bore a hole within a couple .01mm using a small boring bar so I started with a piece of O1 tool steel and drilled a 4 mm hole in the center. Then I reamed the 4mm hole with a home made piloted "D' reamer that created a stepped ream with an undersized "sizing ring like this sketch........

The sizing ring in the die was then lapped till a pellet head pushed through the sizing ring had the size I wanted (rather long/tedious process). Here is the result showing a few versions of the sizer and various "D" reamer designs I tried ...........


To use I first drop an unsized CPL into the die................


The "ram" is inserted in the die............


Then I insert the "ram" to push the pellet head through the sizing ring and expand the pellet skirt while making it perfectly round. The ram is at a fixed position in the holder so only the pellet head gets sized..........


Then the sized head is pushed back out of the die.................


The sizing of each pellet takes about 5 seconds while watching YouTube airgun, machining, whatever videos.......... 


Here are some 1250 count boxes of CPLs that were headsized watching videos and later sorted by weight...........


The reason I'm mentioning my CPL pellet head sizing process is simply because I found it extremely difficult to get a pellet head of a specific size till I added a "sizing ring" to the die that could be lapped to the proper size. I'm wondering if a person could make a "5 pellet mold" (mould indicates casting to me) with consistent pellet heads with a 0.01mm tolerance, even with the larger .22 cal. I'm thinking that a .22 cal swaging die might give 0.01mm accuracy, however that would indicate a single die with a complicated high pressure press.

Anywhoo.........even the "big pellet swagers" (like JSB & H&N) have issues maintaining a consistent .177 pellet head and this JSB Exact pellet sort shows a .10mm variation with most varying about .04mm straight from the tins.........

Offline darkcharisma

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Re: Need Machinist to make a Pellet Swager
« Reply #19 on: July 23, 2018, 06:28:23 PM »
Thanks for sharing an excellent point about how precise these molds needed to be. IMO, i think that may be another needed step once the pellets are swaged. If in case the pellet swaging molds do not provide a consistent headsized to pellet specifications. It's actually ideal to have a head sizer, that way we have some control over the finished pellet. it's also not bad for 5 secs per pellet to be sized. ha, I haven't thought about that at all...that's brilliant, mate!
  • Sachse, TX, USA

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