NOE 217-30 performance

[Franklink]

Would like to know how far and at what power you guys have seen good results with the BBT 217-30 mold.

I've got a Raptor coming that's supposed to really be able to deliver some oomph and I'm considering the 30gr mold. This particular projectile doesn't look very aerodynamic so I'm curious what you guys have seen at long range and something in the 50-60fpe realm.  (Long range being at or past 100 yards).

[oneshot61]

I have shot them out of my modified jkhan .22 @ 60 ft lbs. However only to 50 yards. I found that the hp version was more accurate out to 65 yards( far as I shot them). On all of my bbt.. .22,.25,.30,.357.. they all shot better as hollow points. It is my uneducated guess they are a bit nose heavy as a solid in regular ag barrels  as my twist rates may be a bit slow for boat tails. But as hp they shine and offer massive expansion.

[Franklink]

Thank you very much for the input.

[Hobbyman2007]

The .22 BBT in .217 and .220 are both winners in my book . Almost as accurate as a pellet .you can expect 1” groups from 50yards shooting anywhere between 750 to 1000 FPS .

[KnifeMaker]

Would like to know how far and at what power you guys have seen good results with the BBT 217-30 mold.

I've got a Raptor coming that's supposed to really be able to deliver some oomph and I'm considering the 30gr mold. This particular projectile doesn't look very aerodynamic so I'm curious what you guys have seen at long range and something in the 50-60fpe realm.  (Long range being at or past 100 yards).


And remember. Aerodynamics don't so much come into play until above the speed of sound. And why most handgun, even long range handgun bullets are flat nose for good energy transfer. 


Knife

[rsterne]

Meplat diameter doesn't hurt drag too much in the Subsonic range.... but it sure does Supersonic.... No question, a larger Meplat hits harder instead of just punching through the quarry....

Bob

[K.O.]

I Assume that it will be the L.W. barrel(choked)... if so the .217/.219 30g BBT  is probably not the mold you want...the body is a touch small(~.212)... that being said My At44L pushes them to about 42fpe... Not Sure if the barrel is Choked L.W. or just a choked L.W. Clone... well anyway tried it sized .216-.219 to unsized in .001 increments and then the same but knurled... What worked best was sized .216 and knurled .5-.75" ish at 35-40 yards... But it is running down the side of the barrel... Shown by having rifling marks just on one side of the body of a few recovered rounds... groups look like a pattern and not bunching...

The .220 BBT has a bit larger body(~.214) and should work better is less under bore size (.215) just got some cast will be testing soon... I do expect they will do better than the .217 because that .220 is better designed for the L.W. spec imo...will probably still need sized for the choke not groove diameter...

Running the .217 in My Urban (~625 fps) and Buccaneer(675 fps) well it looks like it wants to be sub moa for 3-4 shots then a flier out to .5 -.75 at same distance...

Thread about Ed's and my BSA Barrel results with the .217 30g...

https://www.gatewaytoairguns.org/GTA/index.php?topic=157925.0

[rsterne]

The body should not be touching the rifling at all, that is why it is smaller than the land diameter.... If you are finding one side of the mid-body touching the lands, I would suggest that either your sizing, or knurling, is not concentric with the bullet C/L....

Bob

[K.O.]

 Bob I would agree if I was not sizing down to .216 then Knurling to just under .217... the rifling is ~ .220-.215... and then choked down to ~.215 goove...

so in knurling the valleys are down around .215 with the peaks at about .217... after finding it was the most accurate I checked a few by chambering and then pushing back out...They load very even with no marks on the body...

So most acceleration is in the first five ten inches... and that provides the torqe load that will throw the round to the side and down...

since the knurling crushes easily it will ride one side of the .215 rifling... that alone is enough to get it close if not touching the .212 body then it hits the choke and that completes the job crushing the contact patch on one side down to make contact with the body...

Maybe sized to .219 and .218 and .217 it would not but I could not get them  to group at those sizes... It is a brand new barrel and has not been lapped... just a couple patches run thru... should pull it and check the leade and such... but seems to be loading well...

So yep that is why I think the round does not touch the groove till the tight abrupt choke... I think if it was a bull barrel you might get away with that kind of choke... But in this case well I do think the round would be much better off without it...

So any way the .220 has a .214 body... so even if it rides down the side of the bore when sized to .216 and then knurled...it will only be by about .001 instead of about .003 and will hit the choke  more on center... what surprised me was it still (tho running ~.003 or so shy of the groove depth) made more muzzle energy than the 18g JSB... I expected to much blow by for running them that loose...

so also running them that loose probably not hitting the choke exactly the same every shot... and that is probably why it is a reliable .75 group but dispersed...

so maybe with the right lube I could get it to do well with running them sized  larger also...

anyways that is how I see things... the way I am running it at the current time with the .217/.219 BBT...  but of course I could be misinterpreting the details...

[K.O.]

Just grinnin like an idiot right now... finally went up the hill to test the .220 BBT 30g in my AT 44L... took the .22 Buccaneer  couple files( for knurling) and my sizing equipment... Had a feelin about .217 because of the way the round from the .217/.219 mold behaved...e.g. working best at .216 knurled to .217... so first I try sized .217... went no further... 40 yards a sub moa 4 shot group followed by 4 more sub and just above moa groups off of a clumsy wobbly rest...also got a decent for me kneeling group... yep the Hatsan loves the .220 BBT 30g... at just a touch under 800 fps...

My Buc .22 seems to like the 220/222 mold also sized to .217... with the wobbly rest hard to tell if it or the 217/219 works best... need to do more in depth testing using a bench and rock jr rest...once again my kneeling group was not to bad...to me it looks as tho the vertical stringing is on me... I tend to do that less with a sling an neither rifle had a sling.... we will not talk about my standing group with the Buc...

Tossed a couple of the 225-37 down range out of the Hatsan... they are to long for it but with a pair of bent nose needle nose was able to finesse them in single load... only had a couple because I had some sprue lube contamination so only cast a few before I put it aside and moved on to another mold... They did stabilize out of the 17.7 barrel but 2" inches at 40 yards. sized at .217... they looked so badly cast I decided to try later for sized .216 and other and knurled...

this was a 40:1 mix at 750 *f and the .220 BBT 30g were cast first just over 350 of them... then ~200 of the .217 BBT... then ~80 223-38 & 80 with deep set hollow point (33g)... then the 225-37 ~20...then some Lee 225-55-rf both the 50g Bator RN and the new spitzer that is actually 55g...

all did cast well at 750* except the Bator and the hollowpoint 223-38...  they need more heat... got mostly mildly rejected sligthly uneven noses on the hollow pointed cavity...

I think if I set the hollow point to bout 35g the 223-39 will fit the Hatsan...need to figure a jig to cut down the base a bit for the BSA twist rate...Do not think deep setting the pin will work...

wish I had all day to test but it is looking good for the 220 30g BBT... I honestly feel sub moa with a good front rest is very possable... and may be the same with My Buccaneer and Urban...

All I can think is the .220 are better at hitting the choke the same every time... 

will add pic next post they are on other computer...actually just modded this post..  

ok so top left the Buc standing is only 4 shots... first shot of that group was a .217 sized 225-37 at a past expire date can of creamed corn(yeck)... the round fits the mag and can showed a round hole...was not keyholed at 40 yards...did not expect it to stabilize in the 19 twist... also it is 37 grains at 32 ish fpe... bottom group(at44) I feel sure the one to the left of the other three was me and the wobbly rest...the one in the target was me and Kentucky trying for a Bullseye...

the other pick is to show how the 225-37 sizes to .217... not bad at all...

for a few seconds I thought wowza because the first two shots try to fit in the same hole...but was crushed...you cans see the next three shots... will try more before saying it will not work...first will be .216 and knurled... from the pic you can see it will have full body contact... so yep will try easing it thru the choke may help...

wish I had more time for testing but lately well..   the .223-38 hp are up next

[Hobbyman2007]

Nice shooting Kirby. The 223-38 bullets have not performed well for me at all . I’m not sure what the issue is with them . Maybe I just need to shoot more and experiment . I have yet to try knurling on any of my bullets but I really should give it a try . It’s the beginning of hunting season here so testing bullets is not real high on the priority list .
This weeks weapon is the 225-39FNGC at 920 fps from the K550 , still the most accurate combo( cast bullet/gun)  I own . I hope to find something to dethrone it .

[rsterne]

I wonder if the issue with the 223-38 is the short bearing surface.... That is a heeled bullet intended to be inserted in a .22LR case to keep it straight with the bore on loading.... Just a thought....

Bob

[Wayne52]

Would like to know how far and at what power you guys have seen good results with the BBT 217-30 mold.

I've got a Raptor coming that's supposed to really be able to deliver some oomph and I'm considering the 30gr mold. This particular projectile doesn't look very aerodynamic so I'm curious what you guys have seen at long range and something in the 50-60fpe realm.  (Long range being at or past 100 yards).

Frank I've shot a lot of the hollow points recently from my Airmax Dominator that are cast from the 217-30-RF RG mold, the weights are all very close to 27.5 grain, I have been shooting them at about 820fps and at about 40 yards I can pick out a spot on a tree while sitting on a log with elbows rested on my knees and usually get right around 1/4-1/2 inch of where I was aiming.  I don't have a range or bench rest and all I do is hunt.

Here's a picture I made up of the basic slugs along with two that I was lucky enough to recover from 2 different fox squirrels, the mushroomed slug in the middle travel almost the entire length of the spine and the one on the right traveled through the skull and right front quarter of a big fox squirrel and that one was just under the skin.  The spine shot I actually had to dig out of the spine about 2 inches before his tail.

[K.O.]

Nice shooting Kirby. The 223-38 bullets have not performed well for me at all . I’m not sure what the issue is with them . Maybe I just need to shoot more and experiment . I have yet to try knurling on any of my bullets but I really should give it a try . It’s the beginning of hunting season here so testing bullets is not real high on the priority list .
This weeks weapon is the 225-39FNGC at 920 fps from the K550 , still the most accurate combo( cast bullet/gun)  I own . I hope to find something to dethrone it .

Thanks  Denis but the vertical dispersion of the kneeling groups is telling... I have over the years became a sling cripple... for not having a sling with either of the rifles I will stretch a  bit to call my contribution acceptable... I think the rifle round combo is sub moa... for balance, yep the wobbly rest groups were enough to put a grin on my face... Standing sorry that is me on a really bad day I did not even try another that session...Did have a really bad backache so will excuse myself..  

 

[Wayne52]

I know one thing I'm sure happy that Swede decided to build the RG molds for the 217-30-RF, I am enjoying shooting these slugs, there's just something to be said about not having to rely on commercially made ammo for an airgun espectially.  I ended up getting me a squirrel trifecta with em this morning, a black squirrel, fox squirrel and red squirrel.  I head shot the red squirrel at 40 yards and that really put a grin on my face.

[K.O.]

Wayne I have been running my mouth for a couple years about small bore cast and finally caught up with the others... Have also been running my mouth about a barrel being choked does not automatically make it bad for slugs... was worried about this one tho...its long with a tight abrupt choke... I think I am lucky that it does not have a prob with harmonics...and instead is my most accurate rifle/round combo currently... What feels real good is that cast is working well in three stock rifles that are not high dollar high fpe big bore air guzzlers and it shows that it is a relatively accessible endeavor... It feels good to catch up finally and help prove out what my mouth (typed here) has been saying for a while...Just had to wait for the bargain prices on the rifles.. Except for the Mrod .25s they are sub 300$ rifles...and one of the .25 Mrods was only 377$

The independence of casting your own ammo and improved performance(mainly but not just improved wind bucking) was a big part of why I wanted to go with cast...Plus it was a chance to have a challenge not faced by many yet... to test what I think I have learned over the years and apply it to sending small bore cast with air...Me I feel, sure you should work and can do better but I count 1.5 moa at 40-50 yards as a decent success... It will get ya dinner... to get moa and sub moa out of a rifle round combo... Well lets just say it sure helps make the investment in molds, micrometer, lead thermometer, pot and etc feel very worth the effort... will have fun stretching the combos legs to see what I get... chili can at 100 yrds will bring a grin...

oh what I am calling 225-37 is the same as what Denis is calling 225-39 FNGC... I do think it will do well in the long term... just did not this time... It is decently suited to the 17.7 twist at the ~725 fps it goes out at... about 1.5 for a stability factor as drawn...

http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.224&length=.410&nose=.182&meplat=.130&base_diameter=.211&angle=&boat_tail=.7&b_twist=17.7&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density= 

Since it hit with a nice clean hole I do think it will be fine stability wise as reformed by the barrels .215 choke... I did not change the gas check diam tho I think it grew a bit when I sized to .217...  but I did look at it at .215 diameter also... bout 1.35 stability factor at 725 fps...

http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.215&length=.410&nose=.182&meplat=.130&base_diameter=.211&angle=&boat_tail=.07&b_twist=17.7&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=

Since it is just a touch long for the At44L magazine I gave thought to decking mine a touch...
Since I have 19 twist barrels that will squeeze the round to .217 (BSA) I looked at removing the gas check all the way... still only got me to 1.2 for stability... so not worth it for me to go that far... especially since I will in the future have 16 twist .22lr-WMR  .220- .224 barrels... so  maybe will just make a single shot tray for the AT to use/develop  them... Hollow point would have been nice but at the time were not offered with the rg system so I passed...

http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.403&nose=.182&meplat=.130&base_diameter=.211&angle=&boat_tail=&b_twist=19&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=

If Noe had offered all my molds with the rg pins all would have been rg molds... alas they where not made that way at the time... 

To bring it back to the 30g BBT... I had a gut feeling when I first saw it that it made all the right compromises to be a very good all around air rifle round... and from the reports I have seen it seems to be true...even read a good report about it doing well in a modded disco at about 40 fpe... so that is 16 twist all the way to 20 twist at a variety of velocities and barrels/rifling styles...

[K.O.]

The .223-38 rn I did get with the one cavity hollow point cause I think it will be the one that works unmodded in the L.W. type barrel if at all... I think it needs a tight barrel and a touch more rpm than the chart says... I pushed one into the breech end of the 14" L.W. barrel I have and then back out... the rifling marks were good and deep and about .19 ish long from the rear band forwards... so with the .215 lands there is decent but not great engagement even before the choke... with the hollow point the nose is less long... so there is a chance it will work... nose looks like the choke will auto center the round some... only one way to find out... in a lightly choked or non choked barrel well... the fact is it sized to .217 like it was not there says it will need a really tight barrel... and looking at the steep climb of twist rate needed with velocity rise says to me it does need spun a 1.3 stability factor would not be enough(just my gut no proof)...

Bob there is one guy that has a barrel it might be suited for even full length and not hollow pointed... tis 16 twist and may be tight enough at .217 groove..which is close to what I think it will need if rifling is tall enough...will probably do best with the barrel doing the sizing too... But the tighter MM barrel may be a better fit...

recognize this post it is post #24 in the below linked thread... 

"
I understand the MM barrel was purpose made for the soft JSBs, and is VERY tight.... and that is why it doesn't like most other pellets.... Mike at TJ's has another .22 cal airgun barrel that Sean & I designed that is 0.217" groove diameter and 16" twist, which should handle most pellets really well.... Mike asked us to design it because the MM barrel was smaller and therefore specialized.... I have one here, but no time to mount it yet and try it.... It is available directly from TJ's as a blank, or from Sean Pero if you need it machined and finished.... I believe you can get it in 7/16" or 1/2" ODs, priced by the inch like all his other barrels....
"
https://www.gatewaytoairguns.org/GTA/index.php?topic=54693.20



What I will be trying for the AT barrel is hollow pointed as deep set as the mold will give good nose results with consistently... This batch was to deep and not hot enough... 0AL varied .09 tho most noses non-rejected rounds looked even..   can not know for sure without trying...

for the BSA barrels well it is obviously not suited... but I do have a crazy plan or should say three... a .204 drill bit, a short lenght of 16th aluminum bar stock, an Exacto saw blade and a dollar store disposable nail file and a few min of work per round... is a pain but may work... was able to get a consistent 32.5g ish round without mangling the base... the bar registers against the rear band well and the base is level... so will see if it is tight enough in the barrel...

It is going to behave something like this 

http://www.geoffrey-kolbe.com/cgi-bin/drag_working.cgi?unit_length=inches&weight_unit=grains&bullet_name=Custom+bullet&re_calculate=yes&boundary_layer=L%2FT&diameter=.217&length=.418&nose=.267&meplat=.03&drive_band=.217&base_diameter=.199&angle=8&boat_tail=0.0635&secant_radius=&weight=32&density=11.4 

twist form for 19 twist... may have a chance... and will certainly try it in the tighter and faster  twist AT barrel...

http://www.geoffrey-kolbe.com/cgi-bin/barrel_twist.cgi?diameter=.217&length=.418&nose=.267&meplat=.03&base_diameter=.199&angle=&boat_tail=.0635&b_twist=19&secant_radius=&unit_length=inches&temperature=59&humidity=0&local_pressure=29.92&pressure=29.92&altitude=0&density=11.4&custom_density=

this mod may help the round in another way... that long heel in an active barrel takes a while to clear the barrel which could mean a pressure imbalance... the shorter tail would help in that case imo... 

only one way to find out... tis fun trying even if I/it fails..