C.U.P for 124g-2R 9mm Using Unique???

[SlowSmokeN]

Never cased a boolit before and want to make sure I get off on the right foot. I pick up some range lead and smelted it into ingots.

My next step is to get is test for BHN so I know if I need to go up or down on the number.

Problem is I cant find the C.U.P. using 124g-2R 9mm. It is the Lee 6 cavity. I have searched hours already through this forum, but cant find anything.

What BNH am I looking for. Looking to load Unique @4.0-4.3g using the 124g round nose lee mold.

Thanks for the help

[Forrest r]

That light load should put you in the 20,000 CUP range.

[SlowSmokeN]

If Optimum BHN = CUP / (1422 x .90)
than 20,000/1279.8 = 15.62
So I want to be 16-20 BNH? (not sure why I rounded to 20, seemed good)

[uscra112]

Almost impossible to judge pressure until the seating depth is a known parameter.

[SlowSmokeN]

The Lyman 49th shows
125 JHP 1.075 OAL
120 (#2 alloy) 1.065

With the 124g cast boolit, I was going to go with 1.075 OAL.

There is so much importance placed on the BHN, so I am trying to get a good start before actually casting them.

I will also be slugging my barrel.

What are your thoughts of where my BHN should be?

[Harter66]

I'm shooting the LEE TL356-124TC . I don't recall what it chrono'd but the load at 4 gr of Unique is abou as high as I would want to go . It is begining to "crater" the primers in my HP9 which likes them as cast,but seated to the ogive. I shoot WDWW,but have shot ACWW as well w/no issue.

[Houndog]

I like that boolet cast of wheel weights with 2% added Tin, water dropped, sized to .357-.358 depending on which gun, seated to 1.080, and loaded over 4.5 Unique in random headstamped cases. This combination has worked well in 5 different 9MM pistols.

USE AT YOUR OWN RISK!

[FirstBrit]

The Lyman 49th shows
125 JHP 1.075 OAL
120 (#2 alloy) 1.065

With the 124g cast boolit, I was going to go with 1.075 OAL.

There is so much importance placed on the BHN, so I am trying to get a good start before actually casting them.

I will also be slugging my barrel.

What are your thoughts of where my BHN should be?

I just ran your data on my QuickLoad programme. With 4,3 gr. Unigue you will have a powder fill of about 110% ( i.e. compressed load) if the case volume of your particular brass are identical with SAAMI standards. With 4,0 gr. your powder fill would be just a tad over 100%. Regarding pressure QuickLoad only give figures in PSI or Bar. With 4,3 gr. Unique the average pressue would be about 29k. PSI which is getting close to max. with 4,0gr. you will be down by 24k. PSI or thereabouts. If your bullet weights out of the mould are in fact higher than 124 gr. this of course will also have an adverse effect on pressure. An extra 4 gr. in bullet weight would add about another 700 PSI to Pmax.
IMHO these results would require an alloy hardness of about 16 BHN. You might get away with 14 BHN since the Unique powder is not a real fast burner in terms of handgun powders. Also if your brim full case volumes are slightly higher than SAAMI Standard of 13,3 gr. H²O then pressures will be slightly lower. By about 1k. PSI if similar to my PMC/Magtech brass ( 13,6 gr. H²O)

Best regards,

Adrian - Germany.

[runfiverun]

here's the scientific old school method.
step by step even.
pick a lower starting load.
make some boolits from the largest batch of the alloy you have or can make.
go try them.
make adjustments, stuff like...
you know: up/down the powder charge, water drop the alloy,add another coat of alox, add some shot to the alloy.
keep some notes.
then make the final adjustment to what you have workin for you, by loading and shooting.
repeat for other guns.
get more lead,get more brass.

bhn isn't everything, that whole 1422 thing,it's an approximation of what should be close that whole math thing is for the plastic flex state of lead [pretty good info if you are gonna swage it]
anything from 10-15 bhn should be plenty good for what you want to do.

[SlowSmokeN]

I just ran your data on my QuickLoad programme. With 4,3 gr. Unigue you will have a powder fill of about 110% ( i.e. compressed load) if the case volume of your particular brass are identical with SAAMI standards. With 4,0 gr. your powder fill would be just a tad over 100%. Regarding pressure QuickLoad only give figures in PSI or Bar. With 4,3 gr. Unique the average pressue would be about 29k. PSI which is getting close to max. with 4,0gr. you will be down by 24k. PSI or thereabouts. If your bullet weights out of the mould are in fact higher than 124 gr. this of course will also have an adverse effect on pressure. An extra 4 gr. in bullet weight would add about another 700 PSI to Pmax.
IMHO these results would require an alloy hardness of about 16 BHN. You might get away with 14 BHN since the Unique powder is not a real fast burner in terms of handgun powders. Also if your brim full case volumes are slightly higher than SAAMI Standard of 13,3 gr. H²O then pressures will be slightly lower. By about 1k. PSI if similar to my PMC/Magtech brass ( 13,6 gr. H²O)

Best regards,

Adrian - Germany.


I am having a hard time finding loading info for this bullet using Unique. With your program, what is the rage (minimum - maximum) of powder to use. Would really like to start at the bottom range

[Bret4207]

You will be a lot better off listening to Runfiverun and starting with the basics rather than thinking some formula is going to give you the perfect alloy. It won't. There IS a lot of importance placed on Bhn, but it's almost entirely from the people selling bullets with a high Bhn that are trying sell more of them by saying a high Bhn is better (it's not) and by people who simply don't understand that Bhn is way down the list of importance in cast shooting. Bhn is a relative number, no more, no less. You'll be far better served forgetting all that krap for a while until you get the basics down and doing a whole lot of reading here. You'll find Bhn is a tool, but it's not the most important tool or the best tool or the only tool.

[Old Caster]

I will have to say that too high of a Bhn is more often a problem than too low. I was told that in 1965 when casting bullets for the AMU in the army and it took forever for me to finally admit it was true. I read so many books that thought the hardest was the best and I thought that the AMU shot their bullets so slow (725fps) that they were only talking about target bullet . I think the reason so many commercial bullets are hard is because they look better after being shipped and banged around plus the mindset is there and is hard to change. It was for me for sure.

[SlowSmokeN]

I have been reading this site for hours and hours days on end. I have smelted and made muffins.

The next step is to cast a boolit. Just want to make sure I start on the right foot.

As one person has as is tag line" it is all a guessing game until you pull the trigger". Once you pull the trigger it is to late if you didn't do your homework .

[Bret4207]

Well, you're a long way to shooting your first cast boolits yet then, aren't you? For now work on making as close to perfect boolits as you can. And I'll give you some hints for the next questions you'll be asking- no your mould isn't clean enough, yes you need to flux more, no you don't need to smoke the mould, yes a bigger sprue puddle will help, no you aren't going fast enough- stop looking at the fresh cast boolits and fill the mould, it's too cool.

[MtGun44]

Don't waste so much time thinking about BHN, it is a relatively unimportant variable for
most pistol applications.

FIT is what you need to worry about primarily and combustion chamber volume. The 9mm
has a TINY combustion chamber (volume under the boolit inside the case), so seating the
boolit deeper or using the same LOA with a longer boolit will put the base deeper and
with ALL ELSE BEING THE SAME run the pressures way up, esp in the 9mm. Most 9mms
need .357 or .358 diameter to work well. Look at the sticky in the handgun section on
setting up for a new 9mm, it walks you through the process and the thought process.

You want to start LOW and work up to account for errors in this area. One member is
currently posting pix of blown cases and has damaged two guns with the 9mm and Clays
powder, which has a VERY rapid pressure rise curve, and based on his results (I think he
may have had boolits push back into the case during feeding or recoil and dramatically
reduce the combustion chamber volume) Clays may be a bit of a questionable powder
choice for 9mm. Of course, maybe TG or BE would have reacted the same.

Make sure that you cannot push a boolit into the case with max effort by holding a
sample cartidge and pushing the boolit against a hard surface.

Bill

[SlowSmokeN]

Thank you, Bill, found the sticky. Looks I am starting with a boolit that demands a little more attention.

The good part is, it will transfer over to other rounds I do in the future.

Ryan

[popper]

Slug the barrel, cast some bullets, make dummys and see what fits and cycles good. See how much crimp you can use that allows chambering, feeds well and prevents set-back. Then you can worry about the powder and BHN. Unique is good, just doon't use compressed loads.

[SlowSmokeN]

Slug the barrel, cast some bullets, make dummys and see what fits and cycles good. See how much crimp you can use that allows chambering, feeds well and prevents set-back. Then you can worry about the powder and BHN. Unique is good, just doon't use compressed loads.

Thanks, getting my barrel slugged next Monday. Hopping to get my muffins from smelted range lead tested also.