Reloading Lead for the 10mm

[sqlbullet]

Part of the trick is getting a fast enough cadence that your mold doesn't cool down while you gawk at your purty boolits.  I have seen lots of new casters do this.  They open the mold and look at the bullets in the mold.  Then they drop them out of the mold and examine the wrinkly bullets of a first cast for 45 seconds to a minute.

Then they repeat, not realizing that all the heat gained from the pour was lost while they looked at their not so prized bullets and wondered over the wrinkles.

Cast 100 bullets as fast as the sprues cool, then examine our results.  Chances are 80 or more will be perfect.

[The_Shadow]

My Lyman pot has a mold shelf on the top edge of the pot to allow preheating of the mold as the alloy melts, when the alloy is read, so to is the mold!  Some people use a small hot plate to pre heat their molds~ 

[Caneman]

i gawk at the boolits while i wait for the sprue to cool... it's your fault shadow you tempted me with casting boolits , now i am finishing up a pid for my Lee drip-o-matic to set a more consistent temp... first 3 casting sessions have been ladle pour with a propane burner, fun to learn how to do this technique...

i talked to Tom at accurate molds (email, anyway), and he designed a 220gr boolit for the 10mm, check it out its the Accurate Bullet Design 40-220B (may get his one next month, if the wife doesn't find out!), the purpose if this load would be a "bear load" for woods use:

http://accuratemolds.com/bullet_detail.php?bullet=40-220B-D.png

[The_Shadow]

 Caneman writes!

it's your fault shadow you tempted me with casting boolits

Well...I'm not sorry and I'm quite sure you won't be either!

I use a small vise grip to add weight to the drip-o-matic stem, it let's me twist it some also to help re seat.

That's a heavy bullet, I see it is being made with a bevel base...that helps with seating but if it were a gas check base that would help with driving it at upper speeds.  Getting checks adds to the cost and time.  If the base was cut straight it would be heavier still...

The length will take up powder space so the load will require adjustments as not to raise pressures too much.

Nice bullet design no the less!

[Caneman]

Caneman writes!

it's your fault shadow you tempted me with casting boolits

Well...I'm not sorry and I'm quite sure you won't be either!

I use a small vise grip to add weight to the drip-o-matic stem, it let's me twist it some also to help re seat.

That's a heavy bullet, I see it is being made with a bevel base...that helps with seating but if it were a gas check base that would help with driving it at upper speeds.  Getting checks adds to the cost and time.  If the base was cut straight it would be heavier still...

The length will take up powder space so the load will require adjustments as not to raise pressures too much.

Nice bullet design no the less!

the new Lee 4-20 now has a hevier metal handle   

Tom said he beveled the base so it wouldn't deform the case as much due to it being seated lower... this boolit will probably move at around 1050 ~ 1100 fps as a first guess, you think a gas check would be needed for this lower velocity (if sized properly)?  I can see this load starting at about 6.0gr of LS and loving up from there...

[The_Shadow]

If sized properly and not deformed by too much crimp it should do well.  Did he give a total length?  I see the 0.6495" number on the page but is it longer than that?    The Hornady 200XTP is 0.682"

The Underwood pull-down showed their's as; Length 0.7360"/ Dia. 0.401"/ Meplat 0.280": Hard Cast 220gr. HC actual weight 219.0 grains and he was pushing them with 800X @ 1200 fps...the one I tested left leading pretty bad in my S&W1006...

[Caneman]

that drawing is a little confusing, but if you start at the base and find each up arrow it delineates the OAL up to that point, so the bullet OAL length is 0.700 as shown by the top most up arrow...

wonder if that Underwood bullet was a little undersized for your barrel, that is the problem with off the shelf lead as they have to offer one size fits all and it may not do well with your gun...

my 10 slugged out at 0.400, so I can get this mold made at 0.403 and size it to 0.402...

you think i can water quench these boolits and make them more like hardcast?

don't think i would want to push this load to 1200 fps, i would think that 1100 fps would be plenty...

[The_Shadow]

The Underwood pull-down was measured at 0.4010", don't really know why it left so much lead in the barrel either.
I didn't get that with my own cast bullets...

[Yondering]

That bullet would be a lot better for the 10mm if that bevel section was removed from the mold (making the bullet shorter by that much), probably end up about 215gr? Looks like it would be a pretty good bullet with that modification.

Leading comes from pressure as much as velocity. Every full-pressure 10mm or 40 S&W cast bullet I've recovered shows signs of gas cutting at the base, if it doesn't have a gas check, regardless of size or hardness. Larger diameter and harder does cut down on the gas cutting, but does not eliminate it. I'm using thin aluminum discs (cut from soda cans) sized over the plain base, to eliminate this. Leading and gas cutting are completely eliminated, and long range accuracy is improved as a result. I made my own tool, but PatMarlin on castboolits sells a plain base .40 checkmaker that works very well.

[Caneman]

That bullet would be a lot better for the 10mm if that bevel section was removed from the mold (making the bullet shorter by that much), probably end up about 215gr? Looks like it would be a pretty good bullet with that modification.

Leading comes from pressure as much as velocity. Every full-pressure 10mm or 40 S&W cast bullet I've recovered shows signs of gas cutting at the base, if it doesn't have a gas check, regardless of size or hardness. Larger diameter and harder does cut down on the gas cutting, but does not eliminate it. I'm using thin aluminum discs (cut from soda cans) sized over the plain base, to eliminate this. Leading and gas cutting are completely eliminated, and long range accuracy is improved as a result. I made my own tool, but PatMarlin on castboolits sells a plain base .40 checkmaker that works very well.

that looks like a good tool, for $84 not bad since it is probably a lifetime investiment

[Caneman]

i had a discussion with Tom again of Accurate Molds... he can make this 220gr as a flat base, but was concerned that it wouldn't chamber... it did a test, seating a 200gr boolit the same depth inside the case as the 220gr, tapered the rim to 0.4195 and it dropped right it the chamber... i see the benefit of having a plain base boolit, being able to use a gas check with PatMarlin gas check die for plain base boolits, or being able to not us a gc with just the plain base... more to come

[475/480]

I have a 215gr WFNGC from mountainmolds.com that measures .660" with GC attached, Bullet weight is 208gr + GC 8gr = 216gr. I am thinking of getting a true heavyweight bullet in the 220 or 230 gr class that will be PB.


Sean

[Yondering]

Caneman, one of the main problems with a bevel base bullet is trying to lube them. In a normal RCBS/Lyman style luber-sizer, the bevel base causes lube to get under the bullet base, and makes a big mess. It's almost impossible to lube them cleanly, without finding some way to seal off that bevel from the lube. (I have used styrofoam sheet and shotgun wad petals with some success, when necessary.) I think this is the biggest reason many casters prefer plain base, IMO.

Tom's concern about chambering that bullet is valid, in some makes of brass, but most brass you'll find now should be OK. I shoot a 220gr cast bullet that's about that long, and using mixed brass, once in a while I get one that bulges around the base and won't chamber. This also causes the base to get rounded off, usually not evenly, so it's not good for accuracy. Just choose your brass, and it should be OK.

I do like that bullet design. One thing I'd recommend is a small step-down at the front driving band, where it transitions to the nose. A step down to .398" or so is adequate, and ensures a consistent band length after sizing. Some bullets will drop a little larger than others, depending on mold and alloy temp, and alloy itself, and sometimes they won't be sized perfectly concentric. All of these can cause uneven front band lengths, which can sometimes cause issues with seating and throat engagement.

[The_Shadow]

Yondering I agree with most all of what you are stating, However I don't like and step down for semiauto as in the (Semi Wad Cutter) except that necessary for cutting clean holes on paper targets.  I like the smooth transition back into the bullet's shoulders.
I understand the principle you refer to because using the RCBS or Lyman sizers they can deform that section.  Using the STAR sizer this doesn't happen because the are sized nose first as they are pushed thru on their base, and I find my bullets to be more uniform from stem to stern!

That is one reason why I move away from the RCBS sizer lubricator for my semiauto bullets also the STAR sizer is much faster for the task!
http://www.magmaengineering.com/component/banners/click/14/

[Yondering]

Shadow, I hear what you're saying, but a small step-down like I'm talking about doesn't affect feeding in a semi-auto at all; we're only talking about a .003-.005" step, not a semi wadcutter shoulder. The brass itself makes more of a shoulder on the loaded round than what I'm referring to.

In fact, a small step like this is even more necessary in a semi-auto, IMO, to avoid potential out of battery issues.

Both bullet styles in this pic have a step like I'm talking about, at the front driving band. When sized, it's just barely enough of a step to feel.