GTA
All Springer/NP/PCP Air Gun Discussion General => Projectiles => Boolit and Pellet Casting => Topic started by: Hobbyman2007 on December 21, 2018, 03:56:32 PM
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Got a chance to cast a bunch today. I haven’t even had the time to measure or weigh them . I did notice during the casting session that the mold is etched as 225-37 fn . I was in a near panic until I cast a few for inspection . They are indeed the mold I ordered just labeled different . Can’t wait to test ,but it’s snowing and probably won’t until the end of the weekend .
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According to the NOE website, that bullet is supposed to be 39 gr. in PB (which you have) and 38 gr. in GC.... I have the GC version and it casts at 38.3 gr.... The bullet is a copy of the Lyman 225107.... I had some Lyman GC's given to me and they are 39.3 gr.... My NOE box and mould is also marked 37.... ::)
bob
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Bob , have you tested them ? If so how well did they shoot?
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Yes, the Lymans are excellent, no reason the NOE copy shouldn't be as good.... The 225107 is kind of a "go to" bullet in .224 cal like the 257420 is in .257 cal....
Bob
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Sweeeeeeeeeet. I bought it on a whim . Hopefully it will work in a 1:15” twist with a slight choke .
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I have the 225-37 cast a few did not weigh any tho... just wanted to push a few thru my small collection of 22lr/WMR/Hornet barrels...dug up 3 that I did not remelt and they are 36.9g to 37.2g... lee scale...
Mine is from the early drawing with a tapered gas check cast with 1.5 % tin... am hoping later to get about 650 fps with them out of the urban and a 23"-24" barrel...faster out of a Mrod and same barrel length .160 ish porting.... hope for at least 700 fps...
Then maybe with a 15lb spring and 1:14 24" hornet could get the 50g Bator to 700 fps...ish
Right now did a chrony run stock out of the box the Urban is sending the .217 BBT 30g out at 24.9 to 25.7 fpe around 2600 psi...
the 25.4 monsters I sent first at ~2900 psi and averaged 24.5 fpe checked the JSB 15.89 at ~2200 and got an average of 24.9 fpe for five shots... I think the barrel under the can is 15.5 inches...
which barrel is 15 twist in .22..? my Beretta barrel was advertised( in the 50s-60s) as 15.75 twist...
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The barrel is in an Evanix K550 , don’t quote me on the twist rate as it was a rough measurement .
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Did some homework...Did you get the BBT to drop large enough... did you slug the breech and choke..?
https://www.gatewaytoairguns.org/GTA/index.php?topic=143416.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=143416.0)
did you pick up the .223-39 rn I think I want to deck mine and bring the heel length down to about .105"- .110"-.115" from .125" ...then eventually send it to hollow point services... do not need so much heel since no seating in a case... but yep something in me wants the little bit of velocity that being 4g-5g lighter will bring in a more sedate rifle... also it would bring both the Cg and Cp forwards... could just try setting up a jig to cut the nose some to about .250".. ;)
right now it is patience needed have more ideas than $...
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KO,
My barrel slugs at .221 at the breech and .220 at the choke . The bbt’s are at .220” so same as the choke . They do shoot pretty good out to 50 yards at just over an inch . These new bullets are dropping at .225 right on the money so I’m having to size them down in two steps , .223 then to 221 . Hopefully they shoot well ,today is not the day as it’s extremely windy .
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Kirby, FYI, removing half the gas check stub from the 39 RN heeled .22LR bullet to make it similar in length to a GC stub would lighten it about 5.5 gr.... LOA would be just under 0.400" for the HP version.... and about 0.430" for the RN.... It would make about a 2" difference to the minimum twist rate.... Shortened that much, it should be fine in an 18" twist below about 1000 fps....
I have that bullet mould (with HP), and the only thing that concerns me is that with the long nose, the bearing area in the rifling is very short.... only about half a caliber.... Removing half the base won't make any difference in that, of course.... because the heeled base is less than the land diameter anyways.... The heeled base, located within a .22LR casing, would normally keep the bullet straight when chambered, something our airguns won't do.... I haven't cast any yet, so I don't know if my concerns are valid or not....
Bob
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How hot are you pouring the .220 BBT... I poured mine pretty hot and I got .2205-.221 on the band and a few that were near .221/.219 band/nose this was the 222/220 mold... not the .219/.217 that fell a little small also when poured hot... even at not so hot (780*-790*) they are falling just a teenie bit small... need to find out how cool I can run the mold and melt and see how they Drop then... only did the one practice run with the 222/220.... just ran out of the .217 ran at 1.5 tin and 790* they are perfect in a disco barrel... need sized down for the tight Max Barrel
Might try running hot with pure lead and see how small I can get them to drop for that barrel...
Bob I do have the one jug hollow pointed ( Al ) but the other is not eventually want both hollow pointed... yeah I do like it at about .110 long for it's counter balance effect on the round that will be coming out of the full nosed jug...
The .223-39 rn should do well in .220 groove and tighter barrels with(my estimate) ~.195 contact patch at .220 a bit more depending on rifling height / how tight a bore...
I think in my marlin barrel .220 groove/ .2185 bore it will be fine with the counter weight...
lotta old barrels tended to run tight about like the Shilen .22 barrels at .2215 groove...
Sammi is .222/.217 if I remember right... reality.......... it is all over...
so the advantage is might be able to take heel all the way down to gas check length in a .219/217 barrel especially if it is choked...
But yep that is just thinking about it as drawn cause I have not cast with it yet and do not know how true it will drop...
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These 225-39 will certainly launch well I bet... no in barrel wobbly danger as a plain base...
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Ran a sting through the K550 and I think they are a bit oversized at .221” . With an average speed of 760 fps for just over 50 ft/lbs energy . This rifle I should usually a 55 ft/lb . I’ll size the next batch at .220” and see if I can gain some speed . I was impressed with the K550 and these at 42 shots with an Es of only 26 fps .
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Kirby, removing only 0.015" from the heel will only lighten the bullet by about 1.3 gr....
Bob
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Sweet Shootin iron there Dennis...about 3% es should be good for near no stringing at 100 yards and minimize any differences in barrel harmonics... gives ya one part of the accuracy equation.. ;D are you running a lube... I feel may be more needed in a choked barrel... just one of my gut feelings...
I wonder sometimes that with air rifles having no hot wash like powder can have enough build up from wax based lubes to avoid wax lubes...need to get a tub of the to try Hornady case lube looked like it might of helped 30g BBT out of a BSA barrel... MSDS says Tallow/mink oil based...
Yep Bob that is why I was bringing up that I could make a jig to cut off the nose some probably about .017 or so... that would leave .250 forwards of the grease groove... probably approaching a 70% meplat... then could go with a .8-.9 heel..? OAl would be about .402 ... rough estimated pic below...
leaving less to need to counter balance would mean able to shorten the heel more and between the two...just trying to maintain sort of a balance between heel and nose... keep an aero balance (70% or less meplat) while bringing down the weight to about 35 g...if the Cg and Cp move a little more forwards of the drag at the drive band /grease groove I like that also...feel it may be just a bit more aerodynamically stable that way... My gut also says it might have a very slightly shorter CG/CP lever which means a touch less overturning moment... do not have the software to check tho.. ;)
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I think it might be enough counterbalance left with a .08 heel with the hollowpointed jug...
::) ?
I think if I was running the 225-39 FN as a plain base instead of the gas checked version I would deck the base to between 2/3-3/4 of what it is...
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Thanks Kirby , I use 10w synthetic shock oil for lube and have been for a while thanks to the heads up from Knifemaker . The stuff really stinks but does wonders for having to clean my barrel less often .
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Denis, when you say stinks, are you taking about aroma? Reason I ask, the Lucas brand I am using seems to my nose to have no aroma at all. Just neutral.
I am seeing swirling of my bullets when shot against a dark background in bright light. GRRRR!!! Yet accuracy is good. Can't be good for BC though.
Mike
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Denis, when you say stinks, are you taking about aroma? Reason I ask, the Lucas brand I am using seems to my nose to have no aroma at all. Just neutral.
I am seeing swirling of my bullets when shot against a dark background in bright light. GRRRR!!! Yet accuracy is good. Can't be good for BC though.
Mike
Ya Mike the smell of the stuff is like old differential oil . The swirling is probably due to such a short bullet , maybe the twist rate is a little fast . That’s really to bad , I had high hopes for a short 257 bullet . I think I’ll try to find some Lucas brand oil , I’m using the “cheap” stuff .
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Mike, can you post a sketch of the bullet you are seeing wobbling or spiralling, with dimensions.... and also post the twist rate.... I would like to run it through the Kolbe Twist Calculator and see what the SF is.... It is likely becoming Dynamically Unstable downrange as it slows....
Bob
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Mike, can you post a sketch of the bullet you are seeing wobbling or spiralling, with dimensions.... and also post the twist rate.... I would like to run it through the Kolbe Twist Calculator and see what the SF is.... It is likely becoming Dynamically Unstable downrange as it slows....
Bob
Bob , I think mike is using the 1:14 TJ’s barrel and the mold is a decked down 257420 to weigh close to 50 grain . I would bet it’s pretty close to .4 “ in length as it’s bing shot from an Evanix magazine .
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I have been using Ace pure silicone lube spray(aerosol can)... had it for car door locks... seems to work... but want to experiment... Have any of you folks tried any of the spray silicones...
looked at the MSDS and to me it looks like every thing else will flash off leaving just the Polydimethylsiloxane... ??
Acetone 35.0 67-64-1
Hexane 23.6 110-54-3
Propane 15.0 74-98-6
2-Methylpentane 10.9 107-83-5
Poly(dimethylsiloxane) 5.0 63148-62-9
3-Methylpentane 4.0 96-14-0
2,3-Dimethylbutane 3.4 79-29-8
Cyclohexane 1.4 110-82-7
2,2-Dimethylbutane
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Ahhhhh, OK.... If he decked the mould to the back of the middle drive band, he would shorten the bullet to about 0.39" LOA and the weight would be about 49 gr.... Even driven right at Mach 1 (worst case for stability), it would only need a 23" twist.... In a 14" twist, at 1000 fps the SF = 4.7, about 3 times what it needs to be.... and at 900 fps the SF = 5.... That is getting into the region of spinning way too fast.... and when the bullet looses velocity (but not RPM) as it goes downrange the tendency to become Dynamically Unstable and start spiralling would be extremely high....
Bob
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Mr. Bob, I have three bullets for the 1-14 twist TJ's bbl right now. 43.6 gr 44.6 gr. and a 51 grain. GRRRRR!!! The longest is .416 long at 51 grains.
My attempt was to get a decent amount of shots (a full mag) for the Squirrel woods. LOL! Not to mention just to fit the mags with some mod's.
Oddly enough, the Factory Rainstom barrel was a 1 in 14.2. but it was a laser with pellets. Bothe the .25 gr and the Mark II's.
Mike
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Dynamic Instability is one of the least understood things in ballistics.... It is so complex it cannot even be predicted with computer programs, from what I have read.... Most often, it is brought on by spinning a bullet too fast for it's length and velocity.... That is why it often appears as spiralling which gets worse the further the bullet travels downrange... because the forward velocity decays much faster than the RPM....
Bob
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Thank you Bob. If I remember correctly, TJ's carries both 10 and 14-1, so I may very well be sol!
I'll give Mike a call after the first of the year.
Mike
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You may have misunderstood me.... If you want to shoot a shortened and sized 257420 you should be looking at a SLOWER twist rate.... something in the 20-23" range.... Mike at TJ's has a 22" twist in .25 cal that could be ideal, and it shoots pellets like a laser as well.... It is 0.250" groove and 0.243" lands....
Bob
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You may have misunderstood me.... If you want to shoot a shortened and sized 257420 you should be looking at a SLOWER twist rate.... something in the 20-23" range.... Mike at TJ's has a 22" twist in .25 cal that could be ideal, and it shoots pellets like a laser as well.... It is 0.250" groove and 0.243" lands....
Bob
No Sir, I didn't misunderstand. I can't find a slow enough twist as he only offers 1-10 and 1-14. I need much slower. I know he supposedly made a few custom. I need to call him.
I not wanting to shoot shoot a .25 in the Rainstorm, but rather .257. I have quite a few molds in .257 and none in .25. I do make .25's but it is a lot of sizing to do right, and is borderline for what I am wanting to do. GRRRR!!
Mike
I don't get to shoot much beyond 199 yards, so I may just stay with what I have as it will shoot right at 1 inch at that range. But would like better. ;)
Oop's, should have read 100 yards. About 1 1/2" with the RS.
Mike
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Sorry, I didn't understand that the 50 gr. was for a .257.... I thought you made that bullet because you needed a lighter bullet for a .250 cal barrel.... Is it just that you want a lighter bullet with less FPE for your .257 cal?.... I know it's more money for the metal, but how about casting the 257420 out of pure tin.... It would be just under 50 gr. and the 14" twist barrel should be perfect for it.... It would have a better BC than the greatly shortened bullet in lead.... and pure tin is about BHN 9-11.... The "Popcorn" tin I got from Rotometals was 11 when I tested it with the pencil scratch method....
Bob
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Now that right there might just be the ticket Bob . Wonder is there’s a better place to source pure tin other than rotometals . It’s beyond pricey for shooting stuff.
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still following and visualizing the 225-39 FN making one .22'' hole at 50 yards...
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Denis
IIRI, those tubes of different creams/medical creams use to come in pure tin tubes,
this was discussed on a casting site I visited in the early 70/80's. LOL ;
But now a days, everything is plastic. :(
What about pewter, I see it on several sites or solder, might be worth looking, depending on your needs.
Just some random thoughts..........
Try here:
https://www.ebay.com/itm/1-Pound-TIN-metal-ROUND-ingots-99-97-pure-Bullion-Ingot-453-6-grams-lb/192232468707?hash=item2cc1f2b0e3:g:YJ0AAOSwRLZUD0yQ:rk:47:pf:0 (https://www.ebay.com/itm/1-Pound-TIN-metal-ROUND-ingots-99-97-pure-Bullion-Ingot-453-6-grams-lb/192232468707?hash=item2cc1f2b0e3:g:YJ0AAOSwRLZUD0yQ:rk:47:pf:0)
or here,
https://www.ebay.com/sch/i.html?_from=R40&_nkw=tin+&_sacat=182920&rt=nc&LH_PrefLoc=1 (https://www.ebay.com/sch/i.html?_from=R40&_nkw=tin+&_sacat=182920&rt=nc&LH_PrefLoc=1)
Tia,
Don
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And also wishing all a Merry Christmas
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well different alloys of pewter are different... but it is basicly about 20-25 BHN iirc... way to hard...
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Kirby
Don't you use just a percentage of tin per lbs's of lead?
Depending on the hardness/filling the mold blocks out, you want?
I don't know the percentages of tin -vs- lead or the correct formulas.
Tia,
Don
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No way I can afford to shoot tin. LOL! I shoot cast because it is so inexpensive.
I will contact Mike at TJ's after the first to see what he has to offer. I know he made a different twist for Jim Gaska. We'll see. ;)
If nothing else, I can go with a .25 barrel and size down again. GRRRRR!!!
Mike
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Don, Lead/Tin alloys for the most part end up harder than pure Tin.... with the exception of those with only a very small percentage of Tin (which are very heavy compared to Tin).... It's kind of the opposite of the melting point of solders.... an alloy of tin and lead melts at a lower temperature of either pure tin or pure lead.... Alloys do NOT have linear properties.... A small amount of lead in pure tin makes it a LOT harder....
Bob
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Knife , if you’re interested in getting another barrel . You might want to look at a Hatsan .25 barrel as most are same spec as LW in .254 /.248 in a 1:17.7” twist . Lots of room for engagement and can size most .257 bullets to fit . They are choked so you would probably want to remove that . I have a barrel and rifle prepped to shoot them if you need a tester . ;)
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First range report , not too bad and better than the 38 gr that I have . I’m having issues with smearing of lead on the bases and the next time out I’ll be sizing base first in three steps instead of two. Groups are averaging 1” at 50 yards . I’ll also try sizing them a tad bit smaller as there were pretty close to choke size at .220” . I’ll try them at .2195” . The pic is of three shot groups . Again I’m not the best shot to start ,these were shot from a bipod with no rear support.
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Thanks Denis!
I have a L/W barrel here in .25 if I should decide t go that way. ;)
My groups @ 80 yards are about like you are showing. But a bit tighter. Not that there's anything wrong with your groups what so ever. I'm just an accuracy snob. LOL!!!
My .257 T/D will print 1/4 to 1/2" or under at the same 80 yards. But that is with 80 gr bullets. (Noe RanchDog FP and HP). With the 1-14 twist TJ's bbl. and is pretty much what I am looking for. The Rainstorm is printing right at an inch on average. Man, when the bbl. starts leading, it scatters!
I'll get there! ;)
Mike
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I am wondering about the choke and the long contact patch of the base... thinking sizing under and knurling might be just the ticket..? along with minimal tin in the melt..?
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I am wondering about the choke and the long contact patch of the base... thinking sizing under and knurling might be just the ticket..? along with minimal tin in the melt..?
Yep, chokes can be a pita in slug guns! None of mine have chokes. the nose on the NOE gets more contact area than the rest of the bullet. Quite a bit actually.
Mike
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I do also wonder if sometimes a thicker tallow type lube would be better in a choked barrel... I do not think that silicone is a good soft metal to hard metal lube... in a non choked barrel not much lubrication is needed... with the choke a harder lube will be more effective because it will not be as displaced as the silicone... so yeah lube type may be worth a look also..?
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Mr Bob, do you think that going to a 1-17 would help if I can't find a 1-20 twist?
I could size the bullets down and test them in the T/D. Just have to change the barrel. It is a bbl. I've had for years. No doubt it is still choked. It is 24 inches, so would have to loose 2 inches to go into the RS. (The breach slide area on Airforce guns) + the choke area. Shorter than I really want.
Mike
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I will not put out words other than mine but some what over spun is better than under spun.. ;)
Being slightly over spun sometimes will work well till long distances and steeper angles of drop... So in my opinion yeah 1 :17 is good...
Being way over spun well any imbalance in the round gets it wobbling... that just gets worse with increasing drop angle...less spin less wobble... and more ability to nose over and less flying nose up as the round drops...
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Thanks Kirby. To answer your earlier question, yes, I have tried different mixes in the lead. Settled on 1 to no more than 2% tin to pure.
Mike
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Mike, going to a 17.7" twist in an LW barrel would probably exhibit less tendency to wobble than your 14".... Either way, it's still a pretty short bullet in .25 cal, so you don't need to spin it that fast.... I agree with Kirby, too fast is better than too slow.... better a bit of wobble downrange than tumbling....
Bob
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thank You bob!
I was shocked at how much better the TJ barrel shot the cast NOE .25 pellets. Much more accurate and predictable in the Rainstorm than from its factory barrel. Oddly, both are 1-14 twist. Even odder, the NOE's out shot the JSB's in the TJ barrel, while the factory barrel was a real shooter with the JSB's.
Just goes to show, you really never know what a barrel is going to like.
Mike
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thank You bob!
I was shocked at how much better the TJ barrel shot the cast NOE .25 pellets. Much more accurate and predictable in the Rainstorm than from its factory barrel. Oddly, both are 1-14 twist. Even odder, the NOE's out shot the JSB's in the TJ barrel, while the factory barrel was a real shooter with the JSB's.
Just goes to show, you really never know what a barrel is going to like.
Mike
Now that is exactly how I’ve been feelin . I’m gonna have to get a .25 mold ,just hope the Evanix barrel likes them .
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Just curious, I have yet to see a case where an airgun bullet is underspun. Any examples of bullet+barrel combo that didn't stabilize at useable velocities?
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I tend to think that the K550 is designed to send large head Eun Jin... does it do well with the Kodiacs..? I do not think it is the choke it is the 24" barrel/diameter + choke... it needs less fpe loss for sure... force loss at the choke needs to be closer to that of an Eunjin 28g...Should calm the barrel some and tighten thing up some...
Ditch the shroud and put a toilet plunger on the barrel..? Limbsaver of course...Might tighten things up...
https://limbsaver.com/collections/firearms-products/products/sharpshooter-x-ring-barrel-dampener...
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Just curious, I have yet to see a case where an airgun bullet is underspun. Any examples of bullet+barrel combo that didn't stabilize at useable velocities?
well there have been only a few folk down at .22 where a lee 225-55- rf might be to long for a 1:16 twist... and I think most that have tried .22 have gone with the .22 Hornet barrel... not .22lr...
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Denis, I ordered some some Imperial Sizing wax. It came highly recommended by RoachCreek.
You simply rub some on your fingers and slide the bullets thry your fingers when feeding them into the sizing dies.
Now that I have an upside down sizing press, I use a bent Q-Tip to paint the inside of the sizing ring. Just a quick dip does it for about 30 bullets at a time.
The Wax really cuts down on smearing. Even worked with no sizing from 260 down to .249. Which is supposed to be impossible. With no smearing what so ever. I also polished the inside of the die to a mirror polish suent pure green chrome polish. (Used in the Custom Knife industry for the final, cloudless/spotless finish).
The bullets come out as if polished on the driving bands. they look down right pretty! ;D