Do You Cast .22 or .25 bullets or pellets?

[rsterne]

I don't have a program that computes the CG or CP of a bullet.... NOE does, and so does NSA, it is available from TMT here....

http://www.tmtpages.com/#draw

Nick says that keeping the CG back as far as possible yields better accuracy.... Who am I to argue?....

Regarding using a gas check stub on this design, I wouldn't draw it up that way.... The bearing length is already relatively short, and removing some of that just to make a GC stub has a good chance of trading off loading the bullet crooked, or having it yaw in the bore because the bearing area is too short.... just to try and get better accuracy from a cleaner base with no sprue cutter damage.... The absolute minmum bearing length I would use is 2/3rds of the caliber, and 3/4 - 1 caliber is preferred.... The only time I use 2/3rds of a caliber is if the LOA is 1-1/3 calibers or less.... ie the bearing length is still at least half the bullet length.... For a .250 cal, 2/3 of that is 0.167", which is only .033" less than I have now.... If I shorten the bullet by 0.015" to reduce the weight of the HP to 35 gr. then the bearing length would only be 0.018" longer than my absolute minimum.... GC shanks in .25 cal are a minimum of 0.050", so there just isn't enough length for a GC on a 35 gr. bullet in this caliber, IMO....

How would you have enough bearing length but still keep it a lighter bullet AND have a GC shank base?

Cast it out of pure Tin....  …. Then the bullet could have the shape of a 50 gr. bullet but only weigh 33 gr.... 

Bob

[Kinetic45^]

I'll repeat, I liked what you drew up Bob and if NOE offers it as a regular mold I'll buy it.
Or, less satisfactory, if a group buy, I'm in

For that matter, if anyone comes up with a good improvement you incorporate, I still want it.

[rsterne]

If you would like me to submit the design to Al, let me know if you want it as is, or 0.015" shorter to bring the weight of the HP down to 35 gr.... I will then put it in the Group Buy Discussion section, and if there is any interest it will progress to a Group Buy.... The only way to bypass this system is to pony up $300 for the tooling costs.... If you do that, then you can purchase a mould at the regular price, and Al will put extras in the store when he makes yours....

Bob

[KnifeMaker]

Mr. Bob, you lost me here. No one said a thing about a GC base preventing damage from the spru plate. No one. If you are having spur plate cutter damage, you are either cutting too hot, aor the actual thru hole that cuts the lead needs to sharpened rather than used as supplied. 


 Please re-read what I wrote. You seem to have missed most of what I wrote. In fact, just about all of it.


You already add a boat tail to your bullets. No different than a gas check shank in preventing damage, and no difference in adding length, other than I suggest a very short area where the Gas Check wold normally be.


The Gas check area needs be no more than .020 to .025 loing. Not much at all.  In fact, in several of the bullets I cast, the GS section is actually a taper, or just a very short Boat Tail. You yourself have acknowledged repeatedly in print the success several of the long range shooters are having with bullets with a GC shank. Yet you now reverse this. Why? It works well. While the Boat Tail designs work sometimes, in some barrels. I don't get it. Please tell me who you are aware of other than Myself, tofazfou, Noble, RC.  and rifle 50 has gotten better,or eve near accuracy for an AG. And who with boat tails? I only know of one, and it is still not up to what we have already established.


The MP BT works well in my barrel. Apparently not so well in the Huben is is designed for. Nick himself tells me that he has tested many-many different BT' and only a very few work well and give acceptable accuracy. And this is with due diligence in testing. Not from some chart or graph. 


 Please Sir reread what I wrote. I am  going on actual test in shooting for accuracy. Not theory or what some program says  should work. Theory is fine, an fun, not cannot replace real world testing.


In actuality, the bearing surface in a small bullet needs to be at or slightly over  the ida of the bullet. Not the length And weight has nothing with the stability. None, unless we are talking about wind drift. A heavier bullet will fare better, and exactly why a longer bullet made from tin would be a step backwards. Not forwards.   

Respectfully, Knife

[Kinetic45^]

If you would like me to submit the design to Al, let me know if you want it as is, or 0.015" shorter to bring the weight of the HP down to 35 gr.... I will then put it in the Group Buy Discussion section, and if there is any interest it will progress to a Group Buy.... The only way to bypass this system is to pony up $300 for the tooling costs.... If you do that, then you can purchase a mould at the regular price, and Al will put extras in the store when he makes yours....

Bob

Honestly, sometimes I think the Group Buy at NOE is where a lot of discussions go to die.  JMO

I actually want it wait a few days and see if anyone has anything to add on the design and see what interest is generated HERE with the shooters of GTA.

Yes, I was willing to pay the $300 for the redesigned .357 152gr BBT but Al decided to just do it without my investment.  That is sort of a specialty mold for a calibur that is just growing in popularity.  {Note that the bullets have been quite good performers in both my Pitbull and FLEX and several other people's rifles - I hope those I've sent bullets to and liked them buy the mold for themselves}.
This .25  mold would be different because it is much more common calibur and I think it will sell itself on the merits if enough members become aware of it's possibility.

On another note, I agree with KnifeMaker on the gas check shanks.  I found years ago shooting benchrest that for some unknown reason the GC shanks were the most accurate over BT, flat base or especially bevel base.  And I and some other shooters found it can be shortened 1/2 and still work.  Why? Never knew, just is.  The Accurate 36-168J has such a shank and is proving itself.
I await an alternative design vs the one proposed and  want to see what you and he work out before I commit.

[rsterne]

Michael, I realize that GC bullets have a reputation for being more accurate than PB bullets.... Whether that is from having a perfect release point where the last band leaves the crown or not I don't know, but I have seen lots of PB bullets that have imperfect bases from the sprue cutter, and that doesn't matter with a GC stub or a BT, because the base never touches the bore.... I use a rebated boattail so that the last band has a clear, sharp edge, just like a GC bullet, and for the same reasons.... There are lots of high speed photos of rebated boattails leaving the muzzle, showing clearly that the muzzle blast is directed to the sides, rather than forward enveloping the bullet.... I have no doubt that a GC stub works the same way.... There is a standard minimum length for gas checks, which varies with caliber, and I have never seen one on a .25 cal shorter than 0.050".... That is what my comment was based on.... If you are using shorter ones successfully, that's great....

You state that the minimum bearing length should be "at or slightly over the ida (sic, I presume you meant diameter) of the bullet", and I completely agree, that is ideal.... If you notice, I said that the only time I use a shorter bearing area is where the bullet overall length is short enough that at least half the bullet length is supported.... Using your 1 caliber rule, the minimum bearing area would be 0.250" long.... Try for that on a 0.340" (or shorter) bullet, and you will have a VERY short nose, and nothing left for a gas check stub.... A RN .25 cal design, with a 0.250" bearing length, would be 0.375" LOA.... So, thanks for confirming what I said.... Using a GC on this short a bullet is a non-starter.... unless you want a semi-wadcutter nose....

As far as making a bullet of a given WEIGHT from Tin, instead of Lead, you are wrong.... The Tin bullet, being longer and slimmer, will have less drag.... It will still have the same Sectional Density (same weight punching the same size hole through the air), but a better Form Factor.... Since the Ballistics Coefficient depends on BOTH factors, a Tin bullet of the same caliber and weight as a Lead bullet, can and should have LESS drag, and therefore be better in retaining velocity and energy and resisting a crosswind....

If you are talking casting the same bullet, from any given mould, in Tin or Lead, you are right, the Tin will slow down quicker, because the SD is lower, because it only weighs 65% as much as the lead bullet.... However, if you make two 35 gr. bullets, one of Lead and 0.340" long and the other of Tin and about 0.10" longer.... the Tin one can definitely have less drag, and a better BC....

Bob

[rsterne]

Carl, I am not about to try and change Al's business model.... If you were successful in getting him to make a design "on spec", that's great, but I am not about to ask him for that kind of a favour…. There are LOTS of my BBT designs I would like to get, but if nobody else is interested enough, then I am comfortable that Al won't make a profit, and I'm not about to ask him to take a chance on something I am the only one that want to see made.... as much as I would like to at times.... If NOE make too many moulds that don't sell, then they could go out of business, and I certainly don't want to see that....

You didn't answer my question about if you would sooner see this design or the shorter one at 35 gr. for a HP.... Let me know and I will send it to Al, or I can draw it up for you, and you can send it to him yourself....

Bob

[Kinetic45^]

I would be fine with the 37gr design but before you submit I wanted to see what others preferred since a wrong choice will kill it.

Maybe we should have a poll to see what the Darkside people want?

Not in this one, start a new one just for the .25 design and just ask what they would vote for
1.  35gr?
2.  37gr?

I could OP a thread and quote your drawing (with your permission) or perhaps you could start a thread and ask?

I'll look tomorrow to see what you answer is, as I've got to shut down tonight.

[rsterne]

I'll draw up the other one and run the poll....

EDIT: It's up and running for 7 days....

Bob

[rsterne]

Guys, I just ran across this bullet in 9mm that bears looking at....



http://noebulletmolds.com/NV/product_info.php?cPath=34_260&products_id=376

If scaled down to .250 diameter it would be 39 gr. as a FN and 37 gr. as a HP.... Make the midbody a bit bigger and eliminate the middle drive band, and you have almost exactly what I designed.... Want to see something cool, though, if you don't remove the middle drive band?....

Chop off the design and you get this.... 

http://noebulletmolds.com/NV/product_info.php?cPath=34_255&products_id=2201

In .25 cal it would be 28 gr. as a HP and 30 gr. as a FN....  …. Two bullet designs for one set of tooling.... 

Bob

[Kinetic45^]

Guys, I just ran across this bullet in 9mm that bears looking at....



http://noebulletmolds.com/NV/product_info.php?cPath=34_260&products_id=376

If scaled down to .250 diameter it would be 39 gr. as a FN and 37 gr. as a HP.... Make the midbody a bit bigger and eliminate the middle drive band, and you have almost exactly what I designed.... Want to see something cool, though, if you don't remove the middle drive band?....

Chop off the design and you get this.... 

http://noebulletmolds.com/NV/product_info.php?cPath=34_255&products_id=2201

In .25 cal it would be 28 gr. as a HP and 30 gr. as a FN....  …. Two bullet designs for one set of tooling.... 

Bob

I have that first mold in .357 and shoot it in my Pitbull. 359-115-RF 2 cavity flat nose, casts 117gr in 1:40 alloy

I considered the lighter/shorter version but decided not to buy it because I've had bad luck ie: no accuracy in bullets like that that have a very short bearing length vs the bore size ratio.  You might think it's like the EPP/UG bullet but the EPP has less nose out front so effectively the front band is further forward and more stabilizing

Secondly, sorry but my sausage fingers cringe with the thought of trying to fumble and get a .25 short bullet version of that nose first into the loading port... you could video it and put it on the Internet as a comedy and get lots of thumbs up

Less nose, more cylindrical body works for me like with your starting designs in the first posts

[rkr]

That short 88 grain bullet has been very accurate in .357 Evanixes.

[Kinetic45^]

That short 88 grain bullet has been very accurate in .357 Evanixes.

Send me some, I'll honestly try them

[Back_Roads]

 Thanks for pointing out that 115 gr HP Bob, looks like it will be a good match for my Recluse

[Sbak]

Guys, I just ran across this bullet in 9mm that bears looking at....



http://noebulletmolds.com/NV/product_info.php?cPath=34_260&products_id=376

If scaled down to .250 diameter it would be 39 gr. as a FN and 37 gr. as a HP.... Make the midbody a bit bigger and eliminate the middle drive band, and you have almost exactly what I designed.... Want to see something cool, though, if you don't remove the middle drive band?....

Chop off the design and you get this.... 

http://noebulletmolds.com/NV/product_info.php?cPath=34_255&products_id=2201

In .25 cal it would be 28 gr. as a HP and 30 gr. as a FN....  …. Two bullet designs for one set of tooling.... 

Bob

Chop off off just the last drive band leaving a "gascheck" at the base and you effectively get three

[rsterne]

Yes, I know that the 88 gr. scaled down to 30 gr. would be very short.... but comparing the 115 gr. to what I designed is the proper comparison, as it would be 39 gr. in .25 cal.... It was just a thought, when I found it, I felt I had to share it with you guys.... I still like the new one I designed for the purpose stated....

Bob

[KnifeMaker]

Looks almost identical to what I ended up with the experiment with the NOE RD decked. It didn't shoot well, until I tried another mold and left what looks like a gas check on the base.


this was done by milling the last driving band off, and leaving the lube grove. HP'd, this bullet weighs 44.3 grains, and started life as a .257 and sized down to .2500.


It is explosive on vermin, as the mold had been HP's by Eric in all five cavities.   


Oddly enough, I have a mold here that started out as a 105 gr spitzer, and the mold was damaged when owned by RoachCreek. It was too bad to repair by Al, so RC sent it to me for possibly bringing it back. Well, it was toast!


Fast forward, and in testing for the .257 barrel, I decked it enough to remove the damaged cavities. It was a dismal failure in the .257. Forward again, and I decided to try it in the .25 barrel.


The bullet only has two very small driving bands left. It is long, with a very shallow tapered ogive. It was to small in dai. after decking for the .257, but yet fit the .250 without sizing at all. It turned out to be my second most accurate bullet, just behind slugs cast in the MP mold that D-Rig sent for testing.


I don't see how it can be accurate, as the body of the bullet does not engage the lands at all. Only the very rear at the driving bands. Yet it is very accurate, and is very good in the wind. Odd to say the least!


No mag. I have cn use it, so it has to be single loaded. I may make a single shot tray for it next week, or in the near future. It is that accurate, that the effort will be worth it.   


Knife

[KnifeMaker]

Here are the NOE RD's before the decking work.


https://www.gatewaytoairguns.org/GTA/index.php?topic=116289.0




And the Spire point I am getting such fantastic accuracy from. I also have this mold decked to 84 grains for my .257 Talondor. It is very much like the Ideal 388 in the accuracy dept.
I would love to get this mold HP'd,.


http://noebulletmolds.com/NV/product_info.php?cPath=26_173&products_id=1236&osCsid=6moel2o6nhkf8jag5j5a6hj0j7

[Lion]

I wonder if one of you had tested de .25 ACP slug 51 grains in an air rifle.

[Kinetic45^]

I wonder if one of you had tested de .25 ACP slug 51 grains in an air rifle.

Yes, I have the Lyman .25 ACP mold and if shot at 800 or above it does OK.  Honestly, it's not a tack driving bullet in any one of my .25s.  I'm going to send it to Eric at hollowpointmold but it may or may not help to change the accuracy by changing the CG by doing that.

If you are looking for a good 50, the boattail Bob/rsterne designed for NOE does well in my higher powered air rifles but is too heavy for stock Marauders and similar powered rifles.  Which is what the effort to get a lighter slug that will work for more shooters guns

NOE 250-50-FN-BB3 2 Cavity is what I was mentioning