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Thread: Revisit - 9mm Brass to .308 Jackets

  1. #1
    Boolit Master



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    Revisit - 9mm Brass to .308 Jackets

    There have been a variety of threads over the last 10 years about using 9mm brass to make .308 jackets. Most have been notional discussions; others have been the actual production of a set of dies and testing. Three of these can be found at the following links:

    http://castboolits.gunloads.com/show...from-9mm-brass

    http://castboolits.gunloads.com/show...to-308-jackets

    http://castboolits.gunloads.com/show...-rifle-jackets


    My wife wanted to know what I wanted for last Christmas; and Dave Corbin had a sale going on, so I ordered a set of .308 RBT Swage dies, and also his 9mm brass to .308 jacket dies. Last week I got a ROUND-TUIT and pulled out the 9mm to .308 die set. Sorted through a 5 gallon bucket of 9mm brass and picked out over a hundred “Blazer” 9mm Brass cases to use as donors for making .308 jackets. I annealed all of these 9mm cases by holding them in a 1lb propane burner flame, with the point of a 16d nail in the brass, and used a set of pliers to hold the nail until each case was a Bright Orange – then dropped it into a water pan to cool.

    The Dave Corbin 9mm to .308 die set uses a tapered/rounded punch with a small tip on the end as a punch (the tip just sits in the flash hole, and the case totters on the tip) to push the 9mm case through the die. The tip on the end of the punch is used to support/center the brass case as it is pushed up and into the sizing die (Single die where several others have used multiple dies to size down in incremental steps) as it is reduced to .308 jacket size. Primers are removed before sizing (I removed them before annealing).

    I initially sized about 15 cases to make .308 jackets just to explore the dies. Followed by swaging cores into the jackets, formed RBT bases, and pointed them up. Almost all of these had bases that were lopsided (one side longer than the other).

    This morning I swaged an additional 20 jackets and about 1/3 had bases with one side severely elongated, 1/3 with minor elongation, and 1/3 that were flat or almost flat at the base. Careful attention to setting the 9mm onto the punch and steering it into the mouth of the die produces fewer dramatic “Cull’s”; but I am not confident that the bases are going to be acceptably “Flat” on the bases. I am not shooting any of these as I feel they will probably be poor performers and a waste of powder and primers with the current production results.

    My current thoughts are that I may try using a Lee .357 (or .358) sizing die as an intermediate sizing operation. Thinking is that perhaps I can get a “Straight Entry” of the 9mm case into the Lee .357 sizing die (not skewed off line); then a run through the Dave Corbin 9mm to .308 die set. The Lee punch is flat so it may be that I can align the 9mm case more concentric to the sizing die. My speculation is that with the Dave Corbin die set, any blemish on the flash hole of the 9mm case is causing an off center entry into the sizing die. I do not fault the Corbin die set; after all Dave Corbin in his literature specifically calls out that the set will not produce “Match Jackets”; rather it is intended for making short range plinking/hunting/survival bullets.

    Although there are differences in the dies and techniques; we do see dies available to reduce commercial .30 jackets to .285, 7 mm, etc.. Why can this be successful, yet reducing a 9mm to .308 is highly problematic.

    Anyone getting “Fair” to “Good” accuracy out of .308 bullets made from 9mm to .308 Jackets? BTSniper seems to have settled on the 5.7 x 28 case for making jackets; but they are more difficult to come by compared to 9mm cases being everywhere on many ranges. May try some of the “Best” jacket bases to make up some .308 Winchester rounds and see if they can be kept on the paper.

    It would really be nice if we as a community could improve this to the point where 147/150 grain .308/7.62x51 rounds for use in M1A (m14’s) were feasible with, accuracy rivaling milspec ball being achieved from home made swaged bullets. After all, tremendous improvements have been made in cast boolits, PC’d Boolits, and home Swaged bullets.

    For Discussion in this Thread:

    What ideas are out there on improving the base of jackets produced from 9mm brass?

    How about ideas on how to “Iron Out” the off center/skewed jacket bases?

    Anyone getting “Fair” to “Good” accuracy from incremental sizing (Multiple dies) of 9mm brass to .308 jackets?
    Mustang

    "In the beginning... the patriot is a scarce man, and brave and hated and scorned. When his cause succeeds, the timid join him, for then it costs nothing to be a patriot." - Mark Twain.

  2. #2
    Boolit Buddy


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    Mustang,

    I saw that sale too and was tempted to buy one myself.

    A few thoughts. Call and ask to talk to John Watson. He is their production manager and can tell you anything that might help to make your project work as it should

    Second, the web of a 9mm case is pretty thick. If if were me, I think I would turn off much of it in a lathe getting down to the bottom of the primer pocket. My guess is that you aren't drawing any of that brass, and it is causing problems entering into the die. Are you using a hand press for this or a hydro? If you are using a hand press, I'm sure it will be much easier to draw them after a lot of that brass is gone.

    As others have discussed in the pinch trim discussion, perhaps try to draw them before you anneal them. Some pictures of your process would help. I'm sure the guys at Corbin can help you if you give them a ring. Sadly, that will have to wait until next week as they are closed on Friday.

    Zbench
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  3. #3
    Boolit Master

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    I have been using BT's incremental set of dies making jackets from 9mm and .380.

    Can't give any MOA of flight reports because I have been using the bullets for close in off hand, and rapid fire, practice in AR-10.

    I can shoot a rifleman score on the appleseed course of fire most of the time, this level of shooting only requires 4 MOA, but requires the shooter to deliver it with transitions, mag changes, three diffrent slung positions for support, and time limits.

    I recognize that the weak link is me, the operator.


    Mostly working on getting the rifle to function reliably, and the head games of how dynamically the bolt closes. Every time the bolt slams home while I'm slung up, it puts the fear in my mind, despite the facts that the rifle is a sweatheart to shoot, and has never bit me.

    When I received the dies from BT, he supplied two push through punches, and recommended useing the largest diameter sizing to .375 and then to .348. Then the next smaller punch to .328, .318, and 301.

    The first sizing pass on a punch worked good, the second and third passes crimped the web onto the punch and the jacket was stuck on the punch.

    I called up Brian and he supplied three more punches, and the sizing process went smoother but still long with five annealing, cleaning, sizing passes.

    Have to wonder if the corbin process with one pass and the case teetering on the flash hole would work better if the flash hole was more uniform. Flash holes are just punched through the brass in the manufacturing process.

    It might be possible to uniform position of the punch by using a lathe and a 1/4" spotting drill fed into the mouth of the case, and just cutting a dimple.
    Last edited by clodhopper; 06-29-2018 at 10:39 AM.
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  4. #4
    Boolit Master



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    Below is a picture of the bases for some of my initial 9mm to .308 jacketed bullets. The Jackets were formed in the Corbin 9mm to .308 Jacket die set; then a core swaged into the jacket with the correct Corbin Punch that came with the die set. Then these were processed in the Corbin .308 swage die set. As you can see in the picture below the results for forming the bases were from Terrible (on the right) to ehhh – OK looking on the left. Note on the right the about 30 degree extreme base tilt on the bullet. Neither the 9mm to .308 die set core swaging operation; nor the two step RBT base sizing operations in the RBT Bullet Swaging die removed any of the tilt/skewing of the base. Just too much thick brass for them to have an evening effect.

    Click image for larger version. 

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    One can only anticipate that the extreme base tilt/skewing will have a horrific impact on accuracy; so shooting these is not on the agenda. May in a couple of weeks try taking some of the bullets with the best looking bases and see how they might perform. Trouble is this is a LOT OF WORK for an “OK” rate of about 30%.
    Mustang

    "In the beginning... the patriot is a scarce man, and brave and hated and scorned. When his cause succeeds, the timid join him, for then it costs nothing to be a patriot." - Mark Twain.

  5. #5
    Boolit Master



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    Thought I would revisit the Multiple Step sizing of 9mm brass to .308 jackets so I dug out a set of Lee Cast Bullet Sizing dies in .358, .323, and .314 to use for incremental step sizing of 9mm brass. My thinking was that maybe I could avoid the base skewing by going to a multi-step process as opposed to the one step on my Corbin 9mm to .308 jacket die.

    I heated five 9mm cases to a bright glowing orange and water cooled each. Lubed using a swaging lube and attempted to size using the Lee .358 die bullet sizing die. I used the Lee Base Punch from the .323 die set. (Had I tried to use the matching punch for the .358 Lee Die; it would have been impossible to fit the walls of the 9mm Jacket between the .358 die and the Punch).

    No-Bueno. Set the mouth of the 9mm case over the Lee .323 punch and cycled the press action driving the 9mm case into the .358 Die “Base First”. The punch on the Lee Dies set has a sharp leading edge that bites into the brass inside of the case; brass will flow under the sizing pressure locking the 9mm Case onto the punch – next to impossible to remove. Fortunately, I only attempted to move through the sizing a die on the press stroke a couple thousandths of an inch; so I was able to break the bond between the punch and inside the 9mm case wall/base.

    Encountered a couple of problems that apply to all attempts:

    (1) I was using my Corbin CSP-1 Swage press. Insufficient stroke length so I had to change the system from Swaging position to Reloading position to get enough stroke to push the case into the mouth of the Lee Die
    (2) The Lee Punch is short. Unable to push the 9mm Case fully through the sizing portion of the Lee Die, have to use a short piece of Drill Rod as a punch to get it through the die.
    No-Bueno Dos. Retrieved the original Lee Punch that matches the .358 Lee Die, and placed the base of another 9mm case onto the top of the Lee .358 punch, and then cycled the press action driving the 9mm case into the .358 Die “Mouth First”. Despite having annealed the 9mm cases to bright orange; they were next to impossible to drive through the Lee .358 Die Mouth. There is a small distance between the .358 Lee Punch; and the .358 Lee Sizing die; which resulted in shearing a Ring of Brass off the base of the 9mm case as it was pushed through the die.

    No-Bueno Dos. Retrieved the original Lee Punch that matches the .358 Lee Die, and placed the base of another 9mm case onto the top of the Lee .358 punch, and then cycled the press action driving the 9mm case into the .358 Die “Mouth First”. Despite having annealed the 9mm cases to bright orange; they were next to impossible to drive through the Lee .358 Die Mouth. There is a small distance between the .358 Lee Punch; and the .358 Lee Sizing die; which resulted in shearing a Ring of Brass off the base of the 9mm case as it was pushed through the die.

    Click image for larger version. 

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    Mustang

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  6. #6
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    No Bueno Tres. Given the effort to push the Annealed Cases through the .358 die set; I gave up on the .358 die and .358 punch for sizing the 9mm cases down as a 1st step. I next used the .358 Lee sizing die, and the Corbin Punch from that 9mm to .308 set. I changed the press from the “Reloading Configuration” to the “Swaging Configuration” because the Corbin Punch is much longer than the Lee Punches. Pushing the 9mm case through the die was much easier; but the results were the same as using the Corbin dies, the base was skewed. Below in the picture you can see this with the case on the left being the one in the test/configuration, and the base is skewed after sizing to .358. The case on the right is the one from the NO Bueno Dos test/configuration.

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    Mustang

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  7. #7
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    Because of Brass Flow; none of these Processes are going to produce jackets and bullets with good bases. At least the failure/cull rate is far higher than I am willing to accept. With my Corbin set of Dies; it seems that the problem is that the brass case sitting on the dimple will rarely allow a straight and square push through of the 9mm case into and through the die. One can see this in the pictures below. The first intentionally exaggerates the case angle sitting on the Corbin Punch with Dimple; and the 2nd shows a slightly skewed case with the flash hole sitting directly over the punch’s dimple. The last picture is poor (took 11 and still could not get a really good pic) quality, but one can see the dimple where the bright spot is on the end of the punch.

    Click image for larger version. 

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    Mustang

    "In the beginning... the patriot is a scarce man, and brave and hated and scorned. When his cause succeeds, the timid join him, for then it costs nothing to be a patriot." - Mark Twain.

  8. #8
    Boolit Master



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    My thoughts are that one could attempt to "Straighten" the base with a punch in the formed Jacket and then cycling the press to push the base against a flat surface causing it to flow straight; even if this works this could be problematic as the internal portion of the case may have thick and thin places causing an imbalance. Perhaps better than what I am currently getting; but "Not Match Quality".

    An alternative option might be to have a "Machined" punch with a rounded tip that is made to tight tolerances so that the punch width, plus the two side walls of the 9mm Case will come out to the desired dimension (.306/.307/or .308?) allowing insertion into core seating/base forming/point forming dies. The problem here will once again be "Brass Flow. All cases will not be uniform at the base (Inside and Outside), and the mouth may now be skewed instead of the base when the jacket is formed.

    Just pondering and seeing what others may come up with in their thoughts.

    The use of 9mm Brass for Jackets is intriguing; but proving once again to be problematic. Of course, my secondary thoughts of cutting .223's down and using them in place of 9mm for jackets to allow for greater weight bullets becomes even more problematic. I can console myself for some time as I am currently making jackets from 5/16 copper tubing, and bullets from my Corbin 8S .308 Swage dies that are ever bit as good, and as accurate as Sierra Match King 175's from a couple different .308 Winchesters I shoot. But..... I sure would like make near FREE bullets from range pick up 9mm and .223 brass; If I could just get the bases to be flat.

    Others thoughts and discussion are welcome. Still looking for that Guy/Gal who s getting acceptable accuracy making bullets from 9mm Jackets. BTSniper's 5.7 brass to .308 is interesting; but I've only collected 127 pieces of that brass in 5 years - not a good alternative option for some of us.
    Last edited by MUSTANG; 07-01-2018 at 09:08 AM.
    Mustang

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    I bought 1,000 5.7 for like 80 bucks.

  10. #10
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    I too am working on these bullets with the same equipment as you. (Except my set is flat bottom, not boat tail yet) But I am not anywhere near the accuracy department yet either.

    When I first started punching brass to experiment with my die, I stood the brass mouth down on an aluminum tray I made from an aluminum sign and fired them with a propane torch in my basement. My result where about the same as yours, but not that extreme. After I decided to ramp up production a little bit more, I started to anneal my 9mm brass in bulk in a table top kiln in the garage, and that seemed to reduce the severity of the skewed bases. I couldn't figure out anything else at the time that would of changed enough to stop or reduce what I was seeing in my results. So at that time I just assumed that I was annealing them skeewampus with that torch.

    I just figured I could straighten it out by filling the case with lead and seating the core against the internal punch of the core seater. But I have been playing with so many different weights, and experimenting with ways to plug the primer hole on my flat bases, I haven't got that far yet. I'm not saying that's your problem, just sharing my results. With a 308 project and 7.62x40 WT also, I'm real interested in this and hope someone with more experience can help us both.

  11. #11
    Boolit Master



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    Quote Originally Posted by BlackoutBuilder View Post
    I bought 1,000 5.7 for like 80 bucks.

    5/16" copper Refrigerator tubing costs me $0.08 to $0.09 per jacket when cut. So the 5.7mm at $0.08 is about the same cost. I am using a 1.3" cut 5/16 ACR tube to make .308 jackets (optimized for 175 Grain RBT Bullets) using a Jacket Maker Die made by BTSniper. Really pleased with Bryans jacket maker die set, but always looking for a means of making less expensive bullets.
    Mustang

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  12. #12
    Boolit Man
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    table top temp

    What temperature are you setting your table top kiln at for annealing? I have been experimenting with mine at 800 to 1000. Found that to be too high and made the brass "sticky" so I lowered it to around 600. Seems better, but still not perfect.
    Terry

  13. #13
    Boolit Master



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    Quote Originally Posted by MUSTANG View Post
    5/16" copper Refrigerator tubing costs me $0.08 to $0.09 per jacket when cut. So the 5.7mm at $0.08 is about the same cost. I am using a 1.3" cut 5/16 ACR tube to make .308 jackets (optimized for 175 Grain RBT Bullets) using a Jacket Maker Die made by BTSniper. Really pleased with Bryans jacket maker die set, but always looking for a means of making less expensive bullets.
    Just looked at Internet Sites for 5.7 Brass. Three sites; cost was $0.06, $0.07, and $0.08 per case; but of course you still have to pay shipping which as I said above; leaves me to where I can form Copper Jackets from 5/16 ACR tubing for the same or less than fired 5.7 brass. Of course copper has been trading in a fixed range over the last few years; should it go up the delta between my copper tubing and the 5.7 prices could change. But...... range pick up is cheaper than any of the "Store Boughten" options.
    Mustang

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  14. #14
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    One thought I had on trying to square the bases of the 9mm to .308 Jackets was that it should be possible to “Press” the skewed base back into place. My thoughts were that a flat punch inside of the formed jacket could be a problem as the inside of the 9mm cases is dished, and remains so when drawn from 9mm to .307 in the Corbin Die. Got to thinking that my BTSniper 5/16 copper tubing Jacket Maker dies might be able to fulfill the task of squaring the base of the 9mm to .308 jackets. The copper tubing jacket die has a punch (1st steps) that is rounded at the end; this folds one end of the copper tubing to create a partially closed end. There are two “Top Punches” in this set of dies. One is cupped to form the copper tube into a rounded end; and the 2nd is flat to close the rounded end into a Flat Base.

    I selected the flat Top Punch, and the rounded bottom punch in the BTSniper copper tubing die set so that when the press was cycled with a 9mm to .308 jacket on the punch; it would compress the base of the jacket – flattening it out. This worked, the9mm to .308 jacket base was flattened and the skew on the base disappeared. The change can be seen in the following two pictures. The first is a skewed base from the Corbin 9mm to .308 die set. The 2nd Pic is a flattened base after being run through the BTSniper 5/16” copper tubing jacket maker die set.

    Click image for larger version. 

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    Mustang

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  15. #15
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    Encouragement. Now the brass had to go somewhere, so I got out the measuring tools. The first picture, is a case as it came out of the Corbin 9mm to .308 jacket maker. Measures .307 in diameter. The next picture shows measurement of a 9mm to .308 jacket after I “Squared the Base” in my BTSniper 5/16” copper jacket making die set.

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    So, the process I used to flatten the bases causes the diameter of the jacket to grow from .307" to .314". Now the jackets are to wide to fit into the Bullet swaging dies!!.
    Mustang

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  16. #16
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    Decided to run the Jackets back through the Corbin 9mm to .308 die sizer. Same as if I had started with a new 9mm case; but it was much easier to cycle. Problem…. The skew returned to the bases of the jackets.

    Click image for larger version. 

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    It looks like trying to get a square base by placing the jacket where the old flash hole sits on top of the Corbin Bottom punch (small protruding tip into flash hole) is going to result in skews of the base even when I square the base after drawing the 9mm case into a .308 jacket blank. Some bases are dramatically skewed; others are minor amounts of skew.

    Thinking I will see if I can use the BTSniper "Square" bottom Punch and the Corbin .307 "Drawing" die combination to see if there is a possible solution. Completed Jackets from my BTSniper 5/16 Copper Tubing dies measure .3025" in diameter. This is too small for swaging bullets in the Corbin dies. (Corbins literature indicates a "Tight Fit" for 9mm to .308 Jackets - probably because of the massive amount of Brass that has to flow in the base of the jacket after being formed from 9mm Cases). I'll have to mix & match die sets to see if I can get Jackets from 9mm that have square, or squarish bases.
    Last edited by MUSTANG; 07-02-2018 at 06:04 PM.
    Mustang

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  17. #17
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    Quote Originally Posted by BlackoutBuilder View Post
    With shipping, using 5.7 Brass would be just a tad over $0.07 each. Right in the range of cost for Copper Jackets from 5/16" ACR tubing for myself. The 5.7 works for you; but is not the best option for myself as I can make jackets from 5/16" ACR tubing. Not even sure if I could make bullets from 5.7 in the die sets I have; that's another experiment for another day/week/month.

    With Sierra Match King 175 Grain .308's going for about $41.00 per 100 at local Sporting Good stores; rolling my own is definitely cost effective at $0.08 compared to $0.41 each. Making 147 grain .308 bullets out of 9mm cases is inviting if I can get to some level of accuracy as it can be quite a penny to take the son's, grandson's, granddaughter out to shoot the 03a3's, Garands, and M1a's. Currently they can go through a lot of rounds in the Ar-15 and bolt .223's without hitting the wallet to badly; would like to let them shoot the .308/7.72X51/30-06 rifles more.
    Mustang

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  18. #18
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    Cool, thank you for the breakdown, I appreciate it. I'm paying off a set that will do Cu tubing, and 5.7. Just wanted the options.

  19. #19
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    Mustang,

    Why not just draw the jackets down enough so they will fit in the core seat die. Then, use a punch that gets to the base of the "jacket" and seat it so the base is flat. The jacket can't grow because it's in the die it will ultimately end up in. If you really wanted to get fancy you could get him to make you a CS which is .001" smaller than normal with a rounded external punch. That would result in a jacket that was undersized, flat based and ready to use.

    I'm sure you could use it as is without the undersized core seat die. Just a thought.
    Zbench

  20. #20
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    Z-bench; your description is correct; and is what I am trying to achieve through a "Round-About" process using the three separate sets of dies. Trying to avoid spending another $200 to $250.

    The Corbin RBT die set does NOT have a core seating die like you are thinking. The Rebated Boat Tail die set has two dies (where a Flat Base Die Set has One die). There is the RBT #1; and the RBT #2 dies. RBT #1 is used for core seating and placing an angle (6º to 8º Boat Tail?) on the base. The bottom punch is used to eject the bullet being formed; and can not press the bottom of the forming base flat (the 9mm to .308 jacket has the skewed base, dramatic or slight). The RBT#2 bottom punch then puts the "Ring" for the Rebated Boat Tail on the forming bullet; it has a machined "Dish" in the bottom punch to form that RBT Base. (As does the punch for the base in the nose forming die). The RBT #1 die can not flatten the skewed base; and too much pressure on the RBT #2 could ruin the bottom punch as it try's to flow a huge amount of Brass to level it out - coupled with no place for the brass to flow too if the die were not set "Perfectly" - which could/would rupture the die or ruin the machined punch.

    A 2nd concern/thought is that inside of the 9mm to .308 Jacket the dome area is not centered and consistent in all sides/dimensions; couple with a flash hole not being exactly centered. This would result in the 9mm case not sitting exactly centered and balanced; resulting in a tilted case entering the Jacket making/draw die slightly to dramatically tilted and a skewed base. Flattening the base without addressing the inside shape would result in a flat base; but an out of center "Dome Area" - which would be an imbalanced bullet. My thinking anyway. If we took this "Possibly Unbalanced" jacket and core seated; we would simply have a flat based but unbalanced core seated jacket.

    The above description can not be addressed by my combination of die sets. I am working to se where I can go to get what visually appears to be a good bullet before spending primers and powders in testing. Adding the Corbin Flat Base core seating die may provide a means of getting a flat base. This is what nun2kute is doing in post #10; but he is not forming RBT bullets. If he is experiencing inaccuracy with the 9mm to .308 jacketed bullets; it is possible that the inside dome (and seated cores) are skewed inside the jacket; causing an imbalanced bullet. This is where I really wanted to go with the Threads Discussion and Input concerning finding an "Accurate" 9mm to .308 jacket conversion process.

    No one has posted a comment of having achieved "Accurate" bullets using this type of jacket; pictures I found in past postings and references all seem to point to a "Plinking/Survivalist" use of 9mm for jackets - close range only. I am thinking that an Additional "Specialized Die" is needed to allow reshaping the outside (skewed base) and the Inside of the dome area of the formed jacket in order to bring stall into alignment and "Balance".

    Other thoughts?
    Mustang

    "In the beginning... the patriot is a scarce man, and brave and hated and scorned. When his cause succeeds, the timid join him, for then it costs nothing to be a patriot." - Mark Twain.

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Abbreviations used in Reloading

BP Bronze Point IMR Improved Military Rifle PTD Pointed
BR Bench Rest M Magnum RN Round Nose
BT Boat Tail PL Power-Lokt SP Soft Point
C Compressed Charge PR Primer SPCL Soft Point "Core-Lokt"
HP Hollow Point PSPCL Pointed Soft Point "Core Lokt" C.O.L. Cartridge Overall Length
PSP Pointed Soft Point Spz Spitzer Point SBT Spitzer Boat Tail
LRN Lead Round Nose LWC Lead Wad Cutter LSWC Lead Semi Wad Cutter
GC Gas Check