Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )



Author Topic: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )  (Read 1224 times - 2 votes) 
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Offline K.O.

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #20 on: November 02, 2018, 04:15:23 PM »
Getting macro to focus, just put it close to a back ground and a steadied camera...
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Offline Habanero69er

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #21 on: November 02, 2018, 07:23:45 PM »
Very cool Scott. I really like the idea of a heavier .20 pellet.  8)
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Offline Nvreloader

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #22 on: November 03, 2018, 01:41:30 PM »
Scott

Thank you.........great Ideas...........Guys

Has anyone tried taking a pellet that Don't shoot accurately, in the intended rifle/cal,
then apply the same process, and see the results?

I realize you are experimenting with 20 cal etc, could the same process be used for a 22 cal, or for any caliber,
bumping the head/skirt diameter up for better accuracy?
As it seems that there is no shortage of undersized pellets etc.

Your thoughts on the lead HARDNESS, that may have an effect on the process?

Tia,
Don
  • Western  NV
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Offline rsterne

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #23 on: November 03, 2018, 02:15:37 PM »
I made a die for bumping up .30 cal JSBs to .308 cal....



The pellet sat on a tapered post that fit inside the skirt.... You lowered the top half of the die over it and gave it a tap.... It only touches the end of the pellet, the ID of the die is oversize (so the pellet doesn't hang up in the upper, female portion). The height was adjustable, and you set it to create a slight Meplat on the pellet when it squashed it lengthwise, which increased the diameter of both head and skirt....



There is a pellet sitting on the post in the second photo, some resized ones on the left, and a comparison between a resized one (nicely engraved) after pushing through a .308 barrel, compared to a stock one pushed through the same barrel (virtually no rifling marks). The bumped up pellets shot a LOT better in the .308 PB barrel I tested them in....

Bob
« Last Edit: November 03, 2018, 02:17:40 PM by rsterne »
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Offline K.O.

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #24 on: November 03, 2018, 02:45:29 PM »
here is another approach to bumping up...

I like the pedestal but would rather have a bit/punch in one of my drill presses than the hammer and BB.. ;)

  • The Great Northwest, United States, Washington
PC77 steel breech 18.7" barrel,  700 fps @ 15 & 755 @ 20 pumps with 7.4g Crosman points

1322 steel breech 14.5" barrel, 640-650 fps @ 22 pumps w/14.3g CPHP

1322 MLT steel breech 19" barrel, 682 fps @ 22 pumps w/14.3g CPHP,  13xx/66 hybrid

1322XLT 22" barrel, 700 fps  @ 11 pumps & 750 @ 16 w/14.3g CPHP,   13xx/2100 hybrid

MK-1322 steel breech 22" barrel, 750 fps @ 17 pumps & 805 @ 22 w/14.3g CPHP,   Mk-177/2240/13xx hybrid

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Offline ken47

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #25 on: November 03, 2018, 04:33:22 PM »
KO. The video just proves the point that undersized pellets don't engage rifling and that the slightly modified undersized pellets perform better.  I've been developing Swaging kits for pellets and I have a database of various sizes of pellets and its heads, what's interesting is that the skirt diameter proves to be the most critical factor. Because the skirt seals the barrel and gets sized back by the choke.  While the rifling engaged by the head help in preventing the pellet bounce inside the barrel. So if the diameter of the entire pellet is the same viz. Head and the skirt, then it is going to affect the accuracy.
Passion leads you to your goal

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Offline K.O.

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #26 on: November 03, 2018, 09:01:43 PM »
The pellet head imo can be just big enough to bore ride with minimal engagement... the skirt well it needs full engagement for sealing... however the rifling is not all that tall and if the skirt and the head are the same size and ride the top of the rifling the skirt will get the necessary  obturation in most pcp rifles... meaning they will get hit with 2000-3000 psi and expand to fit to the grooves... so as long as the skirt is not under bore size as long as all are the same size  there is no problem imo...

now springers  might get some benefit from having fully sealed skirts when chambered...

If you look down many barrels there are all sorts heck many of my crosman 15$ barrels had very little difference between bore and groove... I mean like .0002-.003... and they did fine for pellets at the low fpe they were designed for...

look at the old Dianna 52 barrel in this  linked thread... to me the sealing does not happen until firing, not as you seat the pellet... those very small grooves will just barely have lead in them... then the blast hits and then there is enough lead in the grooves to impart the spin for these 20 fpe rifles... but that is just my opinion in the end...

https://www.gatewaytoairguns.org/GTA/index.php?topic=77016.0


unless you are using very hard lead( and I would not) the obturation will happen...
  • The Great Northwest, United States, Washington
PC77 steel breech 18.7" barrel,  700 fps @ 15 & 755 @ 20 pumps with 7.4g Crosman points

1322 steel breech 14.5" barrel, 640-650 fps @ 22 pumps w/14.3g CPHP

1322 MLT steel breech 19" barrel, 682 fps @ 22 pumps w/14.3g CPHP,  13xx/66 hybrid

1322XLT 22" barrel, 700 fps  @ 11 pumps & 750 @ 16 w/14.3g CPHP,   13xx/2100 hybrid

MK-1322 steel breech 22" barrel, 750 fps @ 17 pumps & 805 @ 22 w/14.3g CPHP,   Mk-177/2240/13xx hybrid

U.S. Shooting Team 953  reduced valve, 525 fps w/ 7.4g points

Offline K.O.

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #27 on: November 03, 2018, 09:06:44 PM »
and once the pellet is in the barrel the skirt and head are the same size or very nearly so... because the barrel has sized them... the head being undersize for the bore is the biggest enemy of accuracy...
  • The Great Northwest, United States, Washington
PC77 steel breech 18.7" barrel,  700 fps @ 15 & 755 @ 20 pumps with 7.4g Crosman points

1322 steel breech 14.5" barrel, 640-650 fps @ 22 pumps w/14.3g CPHP

1322 MLT steel breech 19" barrel, 682 fps @ 22 pumps w/14.3g CPHP,  13xx/66 hybrid

1322XLT 22" barrel, 700 fps  @ 11 pumps & 750 @ 16 w/14.3g CPHP,   13xx/2100 hybrid

MK-1322 steel breech 22" barrel, 750 fps @ 17 pumps & 805 @ 22 w/14.3g CPHP,   Mk-177/2240/13xx hybrid

U.S. Shooting Team 953  reduced valve, 525 fps w/ 7.4g points

Offline rsterne

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #28 on: November 03, 2018, 09:56:53 PM »
Most pellet heads, as made, are larger than the land diameter but smaller than the groove diameter, in most barrels.... However, they vary a lot, and what one gun likes, another doesn't.... The skirts are almost always groove diameter or a bit larger, but of course end up sized by the barrel, but with the shape blown out somewhat by the air pressure....

Bob
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Offline Back_Roads

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #29 on: November 03, 2018, 11:08:58 PM »
 " My MaMa always said , life is like a tin of pellets , ya never know whatcha going to get ."  ???
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Offline Nvreloader

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #30 on: November 25, 2018, 12:51:38 PM »
Hey Guys

Any more updates or info?  ???

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Offline Motorhead

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #31 on: November 25, 2018, 07:52:26 PM »
Hey Guys

Any more updates or info?  ???



Not really ... Tried it & it  works ... so when i need some heavy 20's know what to do and tooling to do it  ;D
Found soft lead works better than hard ... Steps in die need to be gradual so lead evenly gets choked and you don't end up folding the pellet in its waist area when forcing threw the die.
« Last Edit: November 27, 2018, 07:22:12 PM by Motorhead »
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Offline Nvreloader

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #32 on: November 27, 2018, 03:10:06 PM »
Thanks Scott

I have an old Thalson single stage press, being a front feed, (open view) I will make up some sizing dies,
to see if I can bump up the heads for a better fit and more uniform results etc.

I know I can set an adjustment post (for the correct length) to get the correct sizing at the head and skirt at the same time,
and I think I can get a semi automatic sizing dies, size the skirts first, and at the same time, bump up the head size,
with 1 down stroke of the handle. then lift the handle and the pellet drop free etc.

You have given me an itch that needs scratching, just to see, if nothing else.
I only have the 2 calibers, 17 & 22 to work with at this time, but a 25 caliber bug is crawling around in my OLD mind....
LoL.

Tia,
Don
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Offline Nvreloader

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #33 on: December 04, 2018, 01:16:02 AM »
Scott
Questions for you, If you don't mind,

I use a 22 cal 79/HPA OEM bbl,

I want to enlarge the head diameters a couple of thousands, to fit the bbl,
the pellets I am using just about slide thru the bbl, .217" dia (measured) with little or NO land engagement/marks, on the head,
you can use 2 fingers to push them thru etc.
I have not found a pellet head that will leave good land engagements/marks, on the head, out of 30 some different brands,
tried so far etc.

If I use a 25 cal, very SOFT pellets, (have a couple of cans and I don't have a 25 cal), yet.
Head dia measure .242 to .245",

Would 1, 2, or 3 steps be advisable for step downs in diameter to .218"?
I would have approx .028"+, to size down to .218", to start with.


I am figuring a .218" head dia as a starting point,
have numerous dies and hones that I can open up to a larger dia, ie; .2175 or larger", as needed,
(to find the bbl/head dia to start with), then work from that point.

I will be able to use a round coned punch inside the pellet skirts, that fits the inside taper etc
and make it just long enough to displace (swag) some of the lead of the (POINTED head) larger,
and round the pointed head into a semi dome head at the same time etc.

Or would I better off, on head bumping/swagging a .217", 22 cal up a couple of thousands,
to find the correct size?

Not worried about the skirt dia, as I know how to swag them larger etc.

Your thoughts or suggestions,

Tia,
Don
  • Western  NV
Hammerli 850 Air Mag -17 cal x 2, 22 cal
QB-79 - 22 cal
AF Recon Condor 22 cal- pending
CF 4500 45 min SCBA tanks x 3, w/SB F-10 compressor

"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker,
It is time to restore the American precept, that each individual is accountable for their actions."
Ronald Reagan
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Offline Motorhead

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #34 on: December 04, 2018, 10:30:06 AM »
Not done a .25 to .22 and no clue how much shape shift will happen doing so ???
I did find that those pellets when resized that LOST most of the Diablo waist profile while gaining more a bullets straight sided profile shot the worst.
Would think, if you can stabilize / hold the pellet is such a way that a slight crush to the head expanding it a smidge may be the better choice in your case.
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Offline K.O.

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #35 on: December 04, 2018, 04:11:55 PM »
I think it may be worth a try .25 to  .22... But we will not know till it is tried and in our specific barrel/rifle...  All the guys I knew over the years would size in two steps if they had to size more than ~.005 ish... so when I do try it will do it in 3-4 steps most likely... the smaller contact patch may handle sizing in bigger chunks..? in the end only one way to find out...

do not know if you have ever seen the Paco Kelly setup it bumps up .22lr... just presenting it  and a few other for general bumping up tech/ideas...





the Waltz die the one I like seems a lot safer...


« Last Edit: December 04, 2018, 04:15:06 PM by K.O. »
  • The Great Northwest, United States, Washington
PC77 steel breech 18.7" barrel,  700 fps @ 15 & 755 @ 20 pumps with 7.4g Crosman points

1322 steel breech 14.5" barrel, 640-650 fps @ 22 pumps w/14.3g CPHP

1322 MLT steel breech 19" barrel, 682 fps @ 22 pumps w/14.3g CPHP,  13xx/66 hybrid

1322XLT 22" barrel, 700 fps  @ 11 pumps & 750 @ 16 w/14.3g CPHP,   13xx/2100 hybrid

MK-1322 steel breech 22" barrel, 750 fps @ 17 pumps & 805 @ 22 w/14.3g CPHP,   Mk-177/2240/13xx hybrid

U.S. Shooting Team 953  reduced valve, 525 fps w/ 7.4g points

Offline Nvreloader

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #36 on: December 05, 2018, 01:03:24 PM »
KO

Thanks
I have seen those videos before, they all make my pucker factor go on the + side,  ;)
as you are basically dealing with a RF chamber, making those conversions, with loaded ammo etc,
the die one would be a better solution, IMHO.

I have some dies coming so I can try sizing (head bumping) the pellets,
I'll have already made a die to fit the Thalsen press, I have converted over,
if everything goes correctly, I can head bump and size the skirt in 1 pass thru the die,
with a automatic ejection of the pellet, after head and skirt sizing.

I have some .200" round pure lead balls, that I will head bump, up in size first, to find this bbl's true diameter,
which I know is over .217" dia, by how much unknown at this time.......

I should be fairly easy to polish the die up to the size needed, as I have ball hones in several grit sizes/diameters,
that I used to make sizing dies for some of my CF wildcats cases I shoot etc.

Waiting on parts to get here, as usual............ ::)  All I need is a couple of more irons in the fire,
any I would busier than a long tailed cat, in a room full of rocking chairs,  ;)
More later.

Tia,
Don
  • Western  NV
Hammerli 850 Air Mag -17 cal x 2, 22 cal
QB-79 - 22 cal
AF Recon Condor 22 cal- pending
CF 4500 45 min SCBA tanks x 3, w/SB F-10 compressor

"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker,
It is time to restore the American precept, that each individual is accountable for their actions."
Ronald Reagan
-----------------------------------------------------
"Speeds fine, but Accuracy is final"

Offline Yogi

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #37 on: January 19, 2019, 11:56:02 AM »
Scott,

Just wondering if you lube the pellets before resizing?  I would assume that it would make thing easier....

-Y
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Offline Motorhead

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #38 on: January 19, 2019, 12:39:12 PM »
Scott,

Just wondering if you lube the pellets before resizing?  I would assume that it would make thing easier....

-Y


Did so using pellets previously treated with Finish Line Krytec wax lube.  As shown in picture the resulting surface finish is super smooth showing no scuff or lead tearing.
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Offline prosportfan

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Re: Making a Semi-Bullet out of a pellet ... ( calber changing a pellet )
« Reply #39 on: January 26, 2019, 02:46:38 AM »
I am a firm believer in necessity is the mother of invention. And motorhead, thanks for even contemplating let alone going through with it and the detail and time that it has taken.
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