Jump to content
Brian Enos's Forums... Maku mozo!
ArrDave

Out of curiosity, why is it most molds of 124/5 grains end up like a J

Recommended Posts

Seems like most bullet profiles offered at this weight end up adopting a JHP-esque or TC profile, i'm legitimately curious why there are not more 124 RN options?

Obviously the taller shoulders gives more surface area to engage rifling -> better accuracy but the other side is on short chambers not reamed they end up having to be loaded short, introducing feeding issues (potentially).

Is there a practical reason why molds are built that way? I don't know much about casting, so let it rip.

Edit: Asked another way by wgj3 below:

Lots of profile options with .45.

A good few options with TC, RNFP, and plain RN for .40.

Seems that many, if not most, .355 options have a profile most like the TC. Some have flatter points, some a little more rounded, but generally they all have a straight ogive and pronounced angular shoulder.

What is the history behind the lack of true RN bullet profiles in cast/coated 9mm options?

Edited by ArrDave

Share this post


Link to post
Share on other sites

casting bullets for 9mm is not common?

From what I can tell, you can get mold makers to cut any shape you want.

you have to live with an elevated price.

if you do a google search for

mold 9mm hollow point

you will find the custom makers.

about the molds.

the ease and reliability factors are high priorities for the product.

(the bullets themselves)

so the profiles are cut to create a bullet that can be tumble lubed

and fired without sizing and still expect reasonable accuracy from the pistol.

people have been casting for the .45 a good bit longer and

have a lot more opinions and options.

look for castboolits website a lot of info there

miranda

Share this post


Link to post
Share on other sites

Saying the profile is shorter and stubbier resembling a JHP moreso than a 124 RN. The one company that made a true RN profile now makes the JHP profile. Just curious why that is.

Share this post


Link to post
Share on other sites

Hi AarDave,

... you are talking about cast lead 9mm bullets that a company makes?

it is what sells?

miranda

Share this post


Link to post
Share on other sites

Lee makes a 6 cavity mold for 9mm that is a true round nose. Check them out.

Wife wouldn't go for that, she's at her limit with me just making cartridges, let alone projectiles!

Share this post


Link to post
Share on other sites

To answer what I think is the OP's question. No real difference in a RN or TC profile bullet as far as making the mould goes. Some complicated designs or lube grooves may make a bullet release from the mould more difficult, that is the only real consideration for bullet design.

Most commercial casting machines have a tapping system where the mold is physically tapped by the machine when the mould is open to make sure the bullet drops.

Share this post


Link to post
Share on other sites

Saying the profile is shorter and stubbier resembling a JHP moreso than a 124 RN. The one company that made a true RN profile now makes the JHP profile. Just curious why that is.

If you are referring to the old ACME 9mm RN bullet, after well over a million rounds the molds wore out. The custom mold maker they used to produce this bullet went out of business so to keep producing bullets they are now using an off the shelf mold until a maker can be located to reproduce the true round nose molds they were using. As far as I know they were making the only cast/coated copy of a jacketed round nose I have ever seen. As soon as a suitable set of molds can be found, they will make them again.

Share this post


Link to post
Share on other sites

Saying the profile is shorter and stubbier resembling a JHP moreso than a 124 RN. The one company that made a true RN profile now makes the JHP profile. Just curious why that is.

If you are referring to the old ACME 9mm RN bullet, after well over a million rounds the molds wore out. The custom mold maker they used to produce this bullet went out of business so to keep producing bullets they are now using an off the shelf mold until a maker can be located to reproduce the true round nose molds they were using. As far as I know they were making the only cast/coated copy of a jacketed round nose I have ever seen. As soon as a suitable set of molds can be found, they will make them again.

That's fantastic news, I much preferred the old profile. How did you find this out? I sent an email with a few questions regarding this but never got a reply.

Share this post


Link to post
Share on other sites

Saying the profile is shorter and stubbier resembling a JHP moreso than a 124 RN. The one company that made a true RN profile now makes the JHP profile. Just curious why that is.

If you are referring to the old ACME 9mm RN bullet, after well over a million rounds the molds wore out. The custom mold maker they used to produce this bullet went out of business so to keep producing bullets they are now using an off the shelf mold until a maker can be located to reproduce the true round nose molds they were using. As far as I know they were making the only cast/coated copy of a jacketed round nose I have ever seen. As soon as a suitable set of molds can be found, they will make them again.

I was curious if there was a reason in the casting that makes that mold more common, if there was a practical reason why that shape is more prevalent. The new ACME are laser accurate, I preferred the old one for a few small reasons (bigger bevel on the base, elongated profile easier to pinch)

Sent from an iDevice. Please forgive any grammatical or spelling errors. If the post doesn't make sense or is not amusing then it is technology's fault and most certainly not operator error.

Share this post


Link to post
Share on other sites

I'm still not sure that anyone has actually tried to answer the OP's question...

Lots of profile options with .45.

A good few options with TC, RNFP, and plain RN for .40.

Seems that many, if not most, .355 options have a profile most like the TC. Some have flatter points, some a little more rounded, but generally they all have a straight ogive and pronounced angular shoulder.

What is the history behind the lack of true RN bullet profiles in cast/coated 9mm options?

Edited by wgj3

Share this post


Link to post
Share on other sites

I'm still not sure that anyone has actually tried to answer the OP's question...

Lots of profile options with .45.

A good few options with TC, RNFP, and plain RN for .40.

Seems that many, if not most, .355 options have a profile most like the TC. Some have flatter points, some a little more rounded, but generally they all have a straight ogive and pronounced angular shoulder.

What is the history behind the lack of true RN bullet profiles in cast/coated 9mm options?

Updating my initial post, since you restated the question better than I initially asked it.

Share this post


Link to post
Share on other sites

I don't know how married you are to the 124/125 weight... but black bullets does make a 135 grain round nose coated bullet that flies well in most guns I've shot it through.

Being coated and not being 124 might be deal killers for you, just thought I'd mention it.

Edited by MemphisMechanic

Share this post


Link to post
Share on other sites

I only have one 125gn 9mm bullet mold and it's a regular RN, came from magma engineering.

Share this post


Link to post
Share on other sites

I only have one 125gn 9mm bullet mold and it's a regular RN, came from magma engineering.

How close to POI are you finding 135 to 124?

Sent from an iDevice. Please forgive any grammatical or spelling errors. If the post doesn't make sense or is not amusing then it is technology's fault and most certainly not operator error.

Share this post


Link to post
Share on other sites

Saying the profile is shorter and stubbier resembling a JHP moreso than a 124 RN. The one company that made a true RN profile now makes the JHP profile. Just curious why that is.

If you are referring to the old ACME 9mm RN bullet, after well over a million rounds the molds wore out. The custom mold maker they used to produce this bullet went out of business so to keep producing bullets they are now using an off the shelf mold until a maker can be located to reproduce the true round nose molds they were using. As far as I know they were making the only cast/coated copy of a jacketed round nose I have ever seen. As soon as a suitable set of molds can be found, they will make them again.

I was curious if there was a reason in the casting that makes that mold more common, if there was a practical reason why that shape is more prevalent. The new ACME are laser accurate, I preferred the old one for a few small reasons (bigger bevel on the base, elongated profile easier to pinch)

Sent from an iDevice. Please forgive any grammatical or spelling errors. If the post doesn't make sense or is not amusing then it is technology's fault and most certainly not operator error.

All my barrels have been reamed so I can still load the new style bullet out to the same length as the old one. I have found the new bullet to be more accurate in my guns. With the shorter nose you get more bearing surface because there is more bullet contacting the rifling rather than having the sharper nose riding down the barrel not touching anything on a free ride. The blunt nosed bullets won't load out to the longer OAL in CZ's but as you found they are more accurate. A jacketed bullet does not need a long bearing surface as the gilding metal is much stronger and holds the rifling better than the soft coated cast bullets.

Share this post


Link to post
Share on other sites

All my barrels have been reamed so I can still load the new style bullet out to the same length as the old one. I have found the new bullet to be more accurate in my guns. With the shorter nose you get more bearing surface because there is more bullet contacting the rifling rather than having the sharper nose riding down the barrel not touching anything on a free ride. The blunt nosed bullets won't load out to the longer OAL in CZ's but as you found they are more accurate. A jacketed bullet does not need a long bearing surface as the gilding metal is much stronger and holds the rifling better than the soft coated cast bullets.

That may very well be our answer.

Share this post


Link to post
Share on other sites

You all have me curious on the Acme bullet profile now as to which one I have. Can someone get an OAL measurement on the bullet itself between the old and new profile? When did this change happen? Getting ready to order more bullets from them and I will know at least to look out for this now.

Share this post


Link to post
Share on other sites

You all have me curious on the Acme bullet profile now as to which one I have. Can someone get an OAL measurement on the bullet itself between the old and new profile? When did this change happen? Getting ready to order more bullets from them and I will know at least to look out for this now.

I do not have my notebook handy, but the new profile is approx .02 shorter, IIRC .595 vs .575

Sent from an iDevice. Please forgive any grammatical or spelling errors. If the post doesn't make sense or is not amusing then it is technology's fault and most certainly not operator error.

Share this post


Link to post
Share on other sites

Just measured ten of the new profile, and they varied in length from .567 to .571 - so you might not be able to tell which one you have if the they're as close in length as ArrDave suggests. I have to seat it at 1.06 for my CZ. At that OAL, the seating depth is .259-ish, which is within a hundredth of an inch of few other bullets in that weight class that I load or have loaded in terms of seating depth, and within a hundredth of an inch of a few other bullets I load or have loaded in terms of OAL, AND AND AND even more importantly I've loaded this exact bullet at 1.06 and it works functions just fine at that OAL in my CZ.

So, basically, the new profile works just fine. Don't get hung up on the short OAL. This bullet is not too short to feed properly, and it's not seated so deep as to cause problems there.

Share this post


Link to post
Share on other sites

Just measured ten of the new profile, and they varied in length from .567 to .571 - so you might not be able to tell which one you have if the they're as close in length as ArrDave suggests. I have to seat it at 1.06 for my CZ. At that OAL, the seating depth is .259-ish, which is within a hundredth of an inch of few other bullets in that weight class that I load or have loaded in terms of seating depth, and within a hundredth of an inch of a few other bullets I load or have loaded in terms of OAL, AND AND AND even more importantly I've loaded this exact bullet at 1.06 and it works functions just fine at that OAL in my CZ.

So, basically, the new profile works just fine. Don't get hung up on the short OAL. This bullet is not too short to feed properly, and it's not seated so deep as to cause problems there.

Yeah, the new profile is super accurate. Even with Titegroup and a pro auto disk measure on the smallest setting I didn't experience any over pressure issues, got it chrono'd and it was doing 130-131 PF out of a 4.6" gun.

Share this post


Link to post
Share on other sites

Just because you can get short enough to cause feeding problems doesn't mean that relatively shorter than max puts you in danger of feeding problems. If the concern is "short OAL" causing feeding problems, I would ask who is having feeding problems? My CZ has eaten I don't know how many thousands of bullets of various profiles and manufacture in the 1.06-1.07 OAL range without a hiccup. That's a normal OAL for me.

Share this post


Link to post
Share on other sites

I went from 1.112 with the old profile to 1.067 with the new profile in my Cz. My only concern is the higher possibility of compressed loads with some powders. I do not have any of the old profile left to compare to. I have not shot them yet to compare but the old style were the best coated bullet I have used.

Share this post


Link to post
Share on other sites

I went from 1.112 with the old profile to 1.067 with the new profile in my Cz. My only concern is the higher possibility of compressed loads with some powders.

A few things:

  • Record all the bullet dimensions and data you can think of. You don't ever again want to be in a position of "I don't have any of the older ones to compare to."
  • Old profile is .594 in length. New profile .574. At your OALs, that's seating depths of .232 vs .257. So you're looking at 25/1000ths of an inch difference, or 2.5/100ths, depending on how you brain likes ratios. ;) So almost nothing.
  • However deep you think your 124/125 bullet is, there are people loading 147 grain bullets even deeper.
  • Finally, why are you worried about compressed loads? It does not mean it's dangerous. It DOES mean that you're going to get more consistency in how the powder column sits in the case from cartridge to cartridge, which is going to increase consistency of burn, which often leads to more precise loads. Compressed loads are often THE most accurate loads. Now, if you're using a type of powder that will break and fragment under strong compression, and you severely compress it to the point that it crunches, you are increasing the surface area of the powder relative to its mass, which increases burn rate, and THEN you might have a problem, but that's not a likely situation in 9mm.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...