Making a Bump Die

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OU812 posted this 28 January 2017

I made a bump die, bump die stop and removing stem from  machinable 12L14 steel.  . Die and die stop fits closely inside a hollow LEE case flaring die. The matching NOE nose stem acts as a stop inside die while RCBS press cams over exactly on each bullet. Bullet is compressed about 1/32" for good results. The hollow tip of removal stem was filled with JB Weld and cured to bullet and then to protect nose during removal. Mc-Master Carr supplied the .220 and .227 reamers...very fast shipping. .2205 diameter is also available.  

The pointed NOE 80 grain bullet is undamaged and more uniform diameter entire length of bore ride section AFTER Sqeezing larger

 

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OU812 posted this 28 January 2017

Here is the die assembled. Die and NOE punch slips in and out bottom of Lee flaring die while the stop stays affixed inside top half of die. Stem used for removing bullet from die is pictured with bullet.

Shell holder is removed from press and a small piece of 1/4 steel plate is used for pressing . Die sets flat on top of small flat plate during bumping. Bullet is extracted by removing plate and inserting longer punch back into die. The small .224 bullet will fall out of RCBS Rocker Chucker ram like a spent primer.

 

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OU812 posted this 28 January 2017

Get the picture?

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John Alexander posted this 28 January 2017

This project deserves its own thread.

Interesting project. I like the innovative way you used the body of the Lee flaring tool and the NOE stem.  If I can ever find my Lee flaring tool I might be tempted to try to duplicate your work. 

With a little more detailed explanation I think this would make a good Fouling Shot article.  Please consider submitting to Glenn.

I will be very interested in the results when you shoot the bumped bullets against the unbumped.

John

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JeffinNZ posted this 28 January 2017

Nice work!  I use the body of a Lee factory crimp die to hold push through sizing dies I have made. 

Cheers from New Zealand

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Ken Campbell Iowa posted this 28 January 2017

great stuff ....  i really like the sliding insert idea ... and those of us with hobby lathes would like to hear all the details , especially how your compact lathe did for you ... and cutting tools used .

can you push out the 226 bullets by hand ?  or do you use an  '" assist " hammer ... ?  or tap on a benchtop...?  

thanks for posting ...eye candy for we  snow-bounds with cabin fever !!

ken

 

 

 

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OU812 posted this 28 January 2017

Ken,

It depends on how much you bump the bullet. The more you bump, the harder it is to remove bullet from die...imperial sizing wax helps.

To adjust die I raise the top adjusting bolt so I can bring press and bullet to top of press stroke. Then I turn down adjusting bolt inward until I feel it stop against bullet. 1/2 turn of adjusting bolt inward allows for easier hand removal of bullet, 3/4 turns inward is a little more difficult to remove, so press or tapping must be used to extract bullet.

I cut the die band area @.227 so that the top band and bottom of bullet rest flush with bottom of die. There is a small 1/16" gap between NOE punch and top of die before pressing

OU812 posted this 28 January 2017

Bullet on left is not bumped. Nose measures .2205 and bands measure .2265.

Bullet on right is bumped 3/4 turn inward of adjusting bolt. Bore ride section after bumping now measures .2205 the full length of bore ride section and bands measure .2275.

Alloy is 13-14 bhn.

Sorry about poor picture quality

 

 

Scearcy posted this 28 January 2017

Very nice!

Tom Acheson posted this 30 January 2017

I've been using a bump die since 1998 in .30 caliber and am now using one in 6.5mm. You can adjust the die as to where you want the "taper" to start on the body of the bullet and how much pressure can be applied to the bullet. Too much pressure and the lube grooves disappear. The three benefits are......you get a very flat bullet base with really sharp corners at the bottom of the gas check....the bullet is very round....and the taper or shape of the bullet body is more uniform than the "as cast" bullet. 

Mine don't look exactly like the one pictured here but that's OK. My die is mounted in a RCBS Rock Chucker which I've dedicated for bump die use only. It does help to rotate the piece that is in the ram where the shell holder usually is positioned, every 50 rounds or so, just to keep wear uniform. And the stem with the "nose punch" on the end of it is rotated 90 degrees or so every 10-rounds, again just to keep the wear uniform. Just a couple of habits of I've gotten used to doing.

In comparing the OAL of a .308 Winchester round in my Savage Model 12, using an as-cast bullet and a bumped bullet, sees the bumped bullet entering the chamber a little farther, giving you a longer OAL.

FWIW

 

Tom

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OU812 posted this 01 February 2017

The bump die was well worth the effort. Average group sizing  has been reduced by half. This 10 shot group was shot using 15 grains of old long cut IMR 4198.

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OU812 posted this 01 February 2017

Here is an example of bullets that were not bumped using 14 grains of same powder.

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Scearcy posted this 01 February 2017

OU812

Impressive work! Those two targets speak volumes.

Jim

JeffinNZ posted this 01 February 2017

Like night and day.  Great result.

Cheers from New Zealand

Tom Acheson posted this 02 February 2017

Some designs for the nose punch area use a small amount of (soft) lead poured into. Over time this area gets deformed so the lead is melted out and replaced with a new "insert". The bullets being bumped eventually form the inside profile of the "insert".

FWIW

 

Tom

SierraHunter posted this 02 February 2017

Very impressive!

OU812 posted this 14 February 2017

Here is the same 15 gr load of 4198... velocity is around 2000fps.

25 rounds fired without cleaning using 45-45-10 lube.

These bullets were bumped or compressed  about .030". More compression seems to shoot better. One full revolution of top bolt in die equals .055"

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JSH posted this 14 February 2017

This is just the type of project that I wanted to be able to do myself. Thus me purchasing the Sheldon lathe may cut into my shooting time,no pun intended. NOE pretty much made their bushing sizer the way I voiced several years back, though my thoughts were not putting it in through the bottom of the press. I have several thoughts in my head for bump dies and push through dies. Now that I have a lathe the ideas can be put to the test. Something a bit better than a knocker to expel the sized bullet is bouncing around in my head too. This thing called a "job" sure gets in the way of my hobbies and passions. Tom, good to see you. I sure miss your articles in the IHMSA news. Jeff

OU812 posted this 15 February 2017

I let the bullets harden a couple days before sizing and bumping. Gas check on bullet was seated square then sized to .2259. Diameter will increase to  diameter of die +.0004 after bumping. Here are bullets before being bumped. Bullets will age harden to 15 bhn after two weeks.

As cast bullets are a slip fit into .220 diameter die... 

 

Scearcy posted this 16 February 2017

These are about as nice of cast bullets as I have ever seen.  I am thinking you are really going to like the way the .221 bullets shoot.

Jim

OU812 posted this 16 February 2017

Thanks, The mold is NOE's 3 cavity brass version that has  been shortened to make gas check shank shorter. I made the bullet shank shorter so that maybe the long 80 grain bullet would shoot in the 1-12 twist Remington barrel. Bullet seems to shoot regardless of what you read (Greenhill formula was written for canon projectiles  during an earlier war... per Veral Smith)

The Gator gas check snaps on then it is pressed into bottom drive band and squared before sizing. I made a special bullet holder mounted in my RCBS Lubamatic to do this. The holder is made from K&S .250" OD brass tubing...with a .221 Inner Dimension. Tube was filled with JB Weld and allowed to cure with wax coated bullet inserted up to first drive band. 

Gator gas checks are about .001" thicker than the Hornaday checks and for some reason more difficult to size nose first in the Lee sizer. So first I must "crimp on"  base first In RCBS lubramatic using .227 die. Then final sizing is done nose first in the .226 LEE sizer before inserting bullet into bump die. I think the extra thickness of the 22 cal. Gator checks works better than the thinner Hornadays

I cast these bullets between 700-750 degrees...spout flow rate should be on the low side. Casting fins at nose were removed with thumb nail. Very easy to cast these bullets with practice.

I have been using NOE's matching aluminum nose punch during bumping and it seems to be holding up pretty good, but will compress and settle a little at first.

OU812 posted this 16 February 2017

Scaled up versions of this bullet would be nice (6mm, 6.5mm, 30 cal) Nose diameters should measure on the small side of bore diameter so that they could be bumped larger and more round for best accuracy. I tried twisting NOE's  arm to do this, but have not heard back.

Matching nose punches that measure close to bore diameter would be nice also. This would help make aluminum punch stronger during bumping. Why not a steel punch? Because steel is hard on cutting tools. I tried making a steel nose punch, but the JB Weld is not strong enough during bumping. I may try making a cutting blade to match nose shape and then turn in lathe.

John Alexanders excellent bullet pictured below.

OU812 posted this 20 February 2017

Here is a better picture of bullet before and after bumping. Bullet on right was bumped 1/2 turn inward of top adjusting bolt. Not pretty, but it works at the target.

I have discovered that it is best to cut the die slightly under targeted diameter (.220, .226 in my case) then polish inside of die to  larger diameter. I use 400 grit sand paper rolled on dowel.

I recut factory .223 Remington throat using a NATO 223 reamer to enlarge free bore to .227" with about 1 degree (per side) gradual taper to bore. Band measurement of bullets are .2268

Ken Campbell Iowa posted this 21 February 2017

great stuff ou .... your targets give hope to the rest of us ...

how long did you cut your 0.227 free bore ?

does your throating allow some engraving on the forward band ?

ken

 

 

 

OU812 posted this 21 February 2017

Ken, I used a PTG 5.56 NATO chamber reamer to recut throat. I stopped cutting when I felt reamer touch shoulder of chamber. My PTG reamer free bore measures .2270 diameter using cheap micrometer. Bullet bands measure .2269 before chambering. Bands do not engrave rifling when bullet is jammed into throat.

OU812 posted this 21 February 2017

Bumping bore riders more round and fitting them to gun perfectly will win matches!applause

Gary's method of running a bore snake down barrel every few shots works well also.

Ken Campbell Iowa posted this 21 February 2017

thanks ... this reamer drawing gives 0.070 in. full diameter freebore before starting the tapered section of the throat .

about right for mostly nose riders ... as your success would indicate . 

as in most things, optimization for loverin style bullets might require much longer full diameter freebore ...  or !! a bullet swager/sizer ...

ken

 

OU812 posted this 21 February 2017

IMO most bore riders have a band area that is much too long. Bore ride section should be longer than band section.

Just discovered that my rifle will chamber a larger .221 diameter bullet (throat erosion) , so I sanded the die to a larger diameter to achieve the .221 bore ride diameter.

OU812 posted this 5 weeks ago

Here is a 30 caliber design that I submitted to Accuratemolds. This bullet will be bumped to a larger more perfect diameter of my choice in bump die. Die and matching nose punch will be cut from 4140 steel.

Fill lube groove before bumping to prevent collapse

Bullet should shoot very well using 1/10 thru 1/14 twist barrel, the slower the better.

I have wasted so much money buying and trying different molds. Bumping and fitting is the trick !

OU812 posted this 4 weeks ago

For about the same price of a new rifle I purchased a small Mini Lathe to do all this. 

Ken Campbell Iowa posted this 4 weeks ago

that is such a cute little machine !!   does it do english AND metric threading ??  

cool beans ...

ken

OU812 posted this 4 weeks ago

"You can create every American Standard Unified class 2A inch screw thread from 4 to 80 threads per inch, and you can create every American Standard Metric class 6h thread from 0.3 to 8 mm pitch with the extra 21 tooth change gear that is included. Cutting inch threads is made even easier with the factory-installed threading dial."

I re sharpen the carbide bit inserts using a 1200 grit diamond stone. Just lay top cutting side side flat against stone then sharpen. For some reason the finer 1200 grit cuts faster than the more coarse 600 or 400 grit stone.

http://www.littlemachineshop.com/products/product_view.php?ProductID=5100

OU812 posted this 3 weeks ago

I made another die and nose punch for the custom "undersized" 30 caliber bullet. The as cast bullet bore ride section measures .298 before bumping. After bumping in the .3000 diameter die, bullet's bore ride section measures a rounder .3004 diameter.

As the guns throat erodes and grows larger after many shots, just hone the die larger to fit.

Bullet tip is now more uniform and slightly smaller after bumping.

Be sure to seat these inline or as concentric as possible with case (under .002 run out). Looser neck tension will allow you to adjust.

OU812 posted this 3 weeks ago

I made the nose punch by first drilling a .170" diameter hole .230" deep (11/64" drill bit).   Next I cut angle using the tiny boring bar set to15 degrees per side (30 degree included angle). Bore scope helps check work while cutting. All tools purchased at McMaster Carr

"another crossed out name on another wrinkled page"

 

Tom Acheson posted this 3 weeks ago

Another bullet bumping experience.

 

This is a Saeco #264 bullet for a 6.5mm chambering. Weight is about 133-grains in 50/50 lino/mono. In both photos,  the lower photo, the one on the left is not bumped. The one on the right has been “bumped”. You need to look real close but the start of the “bumping” is about half way between the bottom of the lube groove and the top of the gas check. This slight bumping taper continues up the ogive to just short of the bullet’s nose. Odd, but the groove above the lube groove appears narrower on the bumped bullet.

When looking at the loaded rounds, upper photo, note how much further out the bumped bullet is seated on the right. These lengths are determined by seating a bullet only in the chamber and then measuring the OAL. This right hand assembled round is just about where I’d like it to be, with only the gas check and a small portion of the area above it in the case.

One of the objectives of the “bumped” bullet design is to get the bullet up into the throat area as far as you can and hopefully end up with a “cone in a cone” relationship between the chambered bullet and the throat area.

Now to wait for decent temps to get out and shoot!

Tom

 

OU812 posted this 3 weeks ago

Yes, seat bullet long so that it is against or pushed back into case by front band against forcing cone.

I have been thinking of chambering a barrel in 300 Savage so that the longer seated bullets will clip feed from 308 Winchester well. The SAMMI 300 Savage has a long free bore (.167 long) diameter .3095 diameter.

The best thing about bore riding bullets is that throat mods (tapering) are not needed to make them shoot and you can still shoot jacketed like the rifle was intended to shoot in the first place.

 

Tom Acheson posted this 3 weeks ago

I assemble the rounds to be about 0.025" longer that the developed OAL. As the bolt closes it pushes the bullet back into the case. This gun will never see a jacketed bullet. However, I had some prairie dog rifles that shot better with the (jacketed) bullet about 0.010" off the lands, 6 BR, 70-grain bullet. This is something every rifle needs to explored with to determine the best loading condition. So far all of my match CB guns prefer the "jamm" approach when using bumped bullets.

 

Tom 

OU812 posted this 3 weeks ago

I believe no tapering of any kind is needed. Bullets need to be more round to shoot...much like jacketed bullets are more round. Bumping in non tapered die makes them more round and inline.

Although a more tight case neck to chamber wall helps. The savage has a tighter neck clearance than the SAMMI 308 Winchester.

Tom Acheson posted this 3 weeks ago

Interesting...my Savage .308 really likes bumped bullets a lot more than non-bumped bullets. This has worked pretty good in CBA Production class events. Maybe someday I'll focus on that rifle instead of my XP-100.

 

Tom

OU812 posted this 3 weeks ago

Tom, Notice the offset parting line of your bumped bore riding bullet. That is were the problem lies. Bump that area more round to fit bore and bullet well shoot even better.

Tom Acheson posted this 3 weeks ago

Maybe bump it, take it out, rotate it 180 degrees and bump again?

OU812 posted this 3 weeks ago

I have never liked  that collecting groove ahead of front drive band...I think that is a weak point.

John has it correct with this bullet. Short band area and long bore riding surface. I love this picture...could you imagine scaled  up 6mm, 6.5mm versions

Remember to use tight neck clearance.

OU812 posted this 3 weeks ago

Maybe bump it, take it out, rotate it 180 degrees and bump again?

 

You will need to squeeze down the bullet to correct. Much like my method using matching nose punch (ouch).

OU812 posted this 3 weeks ago

NOE nose sizers are crap. You must make a smaller diameter larger to work.

I ordered my 30 cal. Accurate mold slightly under size so that bullet could be squeezed larger to targeted diameter of .3000. Accurate molds is the only mold maker that makes custom diameter sizes.

My .223 has a larger throat which is why bullets can be bumped (squeezed) larger and more round.

 

OU812 posted this 5 days ago

Linotype is so much easier to cast with. Here are a few 30 caliber bullets I bumped just right after casting. Bullet on far right is not bumped and sized.

Bore ride section now measures a round .3003, bands measure .3098. These are waiting for new barrel to be installed

Scearcy posted this 5 days ago

OU812

What bullet did you start with?

Jim

Ken Campbell Iowa posted this 5 days ago

thanks ou for finding that you can swage/bump linotype successfully ...

i remember back ~ 1985 when bumping was ok but swaging was a felony ... that one reason given * against * was that you couldn't swage harder bullets anyway .

which seemed funny in that cast bullets seem to be  deformed easily enough when we shoot them ...  ( g ) ....

my efforts back then in swaging from lead blanks was with * hard ball * ::  taracorp magnum alloy ... seemed to swage just fine ... the trick is enough leverage and give it a few seconds to move in the die .....

ken

new barrel, EH ? ... keep us informed, this should be good .   learning learning learning ...

OU812 posted this 5 days ago

Squeezing rounds more round...is that a felony? Actually the fresh cast linotype (not aged hardened) is easier to extract from die after squeezing and forms to die just as good or better than softer alloy.

BTW Hornaday One shot case sizing wax works better than Redding Imperial wax...smells like wheel bearing grease.

OU812 posted this 5 days ago

I think the best barrel for this 30 cal. bullet would have Six grooves and 1-12 twist.

Two years ago I purchased a Bartlein —.30 5R 1:11.25 Twist 26" Finished, #7 MTU 1.20" x 2.75" tapering to .930" Barrel. This barrel was on sale, so I pulled the trigger. Now I am trying to decide what chamber to go with...300 Savage or 30BRX?

The 30BRX is similar to the 30BR except the shoulder has been fire formed longer, neck slightly shorter. This allows for slightly more powder capacity.

I will go shoot the 223 Remington tomorrow. After more carful measuring bullets had to be squeezed to .2215 diameter to engrave rifling when chambered.

I may purchase this Remington 700 chambered in 308 NATO (#84207), 1/12 twist, six groove rifling. I said NATO because all 308 Remington's use the larger NATO chamber (.311 diam. freebore, .186 diam. length). This rifle is also available in 223 Remington 1/9 twist 20" barrel...lots easier to shoot also.

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