Very keen to put these across the labradar and see if it improves the bc. Adding just 50m more to the usable hunting range would be a win
Attachment 226717
Dunno if anyone had tried this before. Is so, any results?
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Very keen to put these across the labradar and see if it improves the bc. Adding just 50m more to the usable hunting range would be a win
Attachment 226717
Dunno if anyone had tried this before. Is so, any results?
Ps I made a mould and added exopy in the cavity (made from a monoflex. Couldn't use superglue as it reacts with the silicon mould
Interesting idea, let us know how it goes. Would be interested in how it impacts accuracy too, will depend on how consistent you can get the tips I'm sure.
Oh dear someone has gone down a deep dark hole
Used to put Bic pen nibs in Berger VLD years ago :)
Hot melt glue would work in those cast slugs
Then spin them up and machine with a sanding block
Consider having a central shaft attached to the centre of the gas check
Cast the projectile with a hollow centre axis
Drill precisely and insert the gas check so the shaft passes through the projectile centre and becomes the meplat tip
Way more precise and you have a projectile that has a serious cavity for mushrooming
both plastic soft air gun and steel #2 shot have been used in nose cavity by me.... drop of glue to hold them in place...I did it to hopefully assist expansion but it might help BC.... but then again isnt the theory that a HP creates air pocket in front????
If they do shoot well then it's gonna be a fun thing to experiment with. I got a bunch to form quite well and the 'fails' were a result of me putting in 3x the required amount. A single blob of glue did the trick.
I might try a better pointed bullet in the next mould. And put in more bullets in as this mould only makes 10 pointies per day
Attachment 226773
Attachment 226775
I was thinking about 3d printing some the other day, using a resin printer so failing under high temp shouldn't be an issue
Gas checking them so I'm assuming you are pushing them at around1600 to 1800 fps so it might work if they're absolutely concentric. I will be corrected if I'm wrong but I believe that at subsonic speeds bullet nose shape makes bugger all difference to the areodynamics
Possibly find that it makes less of a difference than you'd think - the main thing that affects the performance is the length of the bullet vs diameter which allows the transitions in the bullet's surface to be less abrupt over it's length. Very low drag designs are long for the caliber, those look pretty standard for length but I don't know the caliber.
thats one stumpy lookin bullet.
more info would be helpfull . . cartridge, velocity etc
what are you wanting to shoot with that extra 50 yards
The biggest difference might be that they shoot like shit.
GPM.
Totally possible but the monoplexes shot very well in both my bergara and marlin (45-70). I normally use 45.14gns AR2207 and crimp. I've found 1800fts to be totally manageable.
I dunno about epoxy... it's not as hard as I was hoping.
The MP moulds have a couple of options with the hollowpoints. Would you go for a HP mould or set up a jig to drill an insert hole?Quote:
Originally Posted by makka
To be honest I've found that even at 1800fts you don't actually need checks. The bottom doesn't burn or change shape. I just like how they seat better and protect the pc layer going in. Some say the checks keep the barrel cleaner on firing but I'm not sure on that one.Quote:
Originally Posted by Marty Henry
Hollow point would be easier, send me the dimensions of yours and I'll print you some to tryQuote:
Originally Posted by T.FOYE
Attachment 226987
That's the MP keith style mould I have. I usually put a good 2thou coat on before sizing so I guess that hole diam would be -4thou from the stated dim? I'll check when I get home with the calipers.
Take a measure when you can. I will try draw something up this week.
How long do you want them?
I'm firing up the printer to do some softbait molds, will do a few test BT's for you at the same time
Attachment 228560
Somehow managed to bugger up the measurements, and did a shit job of supporting them so now I know what I need to fix for next batch!
Million dollar question, does it work well enough to justify the effort?
Probably not but I like to tinker, even on others behalfQuote:
Originally Posted by No.3
Being such a wet and crappy year it's taken me a while to get out and test. OK, so mixed results. I did get a flyer that I believe was caused by a tip coming off. Wasn't happy about that.
But the BC data from the labradar was sufficient to give deffinate results for each shape.
I sent 10 normal NOE semi flat nose bullets downrange and got an average of .250 G1. Not too shabby.
The home made pointies did noticeably better with an average of .285 G1.
The blob tips were a disaster and I stopped shooting them. I believe they were .256 but I had climbing velocity due to residue in the barrel.
Those results were all over the show but for .05 gain in bc... nah the blobs are a waste of time. But the pointed rounds I feel had merit. The accuracy was good. I was forced to only shoot in 2s as this rifle doesn't like heat at all (SBL 45-70).
I also need to check I didn't kill the scope lol. Testing for another day.
Attachment 228901
Makka I reckon your method is the safest. Although I can prove that it is worth altering cast bullets, the inserts you've made will be much safer than relying on a glue bond to PC. Main problem I had was the seating distance was irregular with my method. I had to meticulously remove excess glue that appeared. It was hard to regulate how much epoxy I dropped into the mould too so I had to fall back on culling over/under sized tips (between 353gn and 356gn)
So this would be using the keith hollowpoint mould and avoiding the mag tube. Single loading only. Gonna jump on an app and see what gains I would get on applied ballistics using those bc results (they worked out pretty well when I ran them out to 200m last time and took real world drop data
OK so feeding all this crap into strelok to get the suggested hunting zeros it came up with a very interesting result.
The flat tip bullets are best set at 106m giving 86m of "flat shooting". They drop to subsonic at 285m.
The pointed rounds are best set at 116m zero, giving 115m of flat shooting. They go subsonic at 365m.
(The flat shooting distance begins at 20/21m for both). Strikingly similar tradj to a .22lr really when you look at it. But my original aim was to get 50m extra usable hunting distance. 29m is what it turned out to be. So a 33% gain in killing distance. 28% further supersonic flight (you can't actually rely on those full distances as anything transonic / near the sound barrier can lose stability apparently)
try a plastic BB airsoft pellet.....dob of glue to hold it there.....you may be surprised in a good way.
Is that with a hollowpoint yes? That would deffinately work
safely I reckon.
while my 'blob tips' failed I did get
the strong indication that I had an issue in the barrel from something (I never normally get issues from pc). MV was jumping 100fts between shots so i just stopped.
Would try blobs again as I think they might be a good compromise. Better bc yet still fine to load in a levergun
Trouble is, if you knocked a tip off....
Up next is a run of hp with 3d tips. I reckon that will be a good combo. The only drawback with the MP keith mould is that you lose 2 full grains of powder getting them into the case. Also have to crimp on the bearing surface forward of the last canulure. Hate doing that but you gotta get a safe seating distance to the lands. Doesn't always work out perfectly for crimping alignment
yip BB into hollow point. if you already have a centred hollow point its too easy to enlarge it a WEE bit with 7mm drill bit so BB sits in nice and securely. bit hit and miss with a flat point,hard to get it centered properly.
Now that I'm playing with this stuff I don't much touch my jacketed ammo. All those months and years waiting for stock to hit the online shops. I grabbed a few boxes but I can't be bothered loading it if I know I'm only gonna be at the mercy of the market. Tbf I am still at the mercy of the weather. Can't cast lead if there's grey clouds about
Attachment 232388
Still needs a bit of tweaking, but the printed ones are getting close to being right
That looks amazing! Might even have a better bc than the previous iterations.
The killer was that I didn't support it properly so the flat part that sits on the projectile mushroomed a bit, I will add some supports and try printing some more this weekend.
