- This topic is empty.
-
Topic
-
Ranch Dog
Okay guys, I’m finished with the design work on my three 30 caliber short necked cartridges; the 300 Savage, 308 Win, and 7.62×39.
These cartridge represents a bit of a challenge in cast bullet design, that being the need to contain the body within the case neck and then balancing the center of pressure with the center of gravity while retaining a usable bullet length. My focus has been on using these bullets in modern bolt action rifles. The reason I’ve focused on these actions is because of the demand they place on the bullet fitting all the detailed features of the chamber cut. The details of the chamber cut in these rifles are very consistent and are capable of being verified during manufacture with go/no-go gauges. Fitting the bullet to the chamber features is important if the for the bullet is to survive at the cartridge designed pressure and velocities. If we are not going to push all of these we might as well just shoot a 30-30 Win. Of course, your bullet alloy and it’s treatment is just as important if not more so. I can get the design right, but you have to control the product at the drop.
The first and last have updated features and the 308 Win is a new design. Here they are in line with each for a comparison; the TLC310-165-RF for the 300 Savage, the TLC310-180-RF for the 308 Win, and the TLC313-150-RF for the 7.62×39
My original TLC310-150-RF for the 300 Savage was a 150-grain bullet and I tried to get around the intracacies of the chamber cut of this cartridge with a simple tangent ogive. Like all three of these offerings the chamber is just too complex for a simple design to provide a good fit.
The new design considers the needs of the step, freebore, freebore leade, and leade cut into the SAAMI chamber while at the same time confining the bullet body within the case neck.
I also wanted to see a longer bullet nose to improve feed from the magazine, no matter the design of that magazine. A chamber impression from my Savage 110 was used to verify that this manufacture does cut to the SAAMI specification.
One thing that I started to do as a standard when designing a bullet is defining the case length with any design in that the case neck is so important. To accomplish this I use the Lee Case Length Gauge/Trimmer minus .005″ to establish this length. These trimmers are easy to check using your calipers by measuring from the base that meets the cutter to the pin. These trimmers should measure at the SAAMI trim length when checked. When a case is trimmed, deburred, and chamfered it should be at the maximum SAAMI trim length minus .005″. Any shorter and the timer should be discarded and a new trimmer purchased. Keep this standard in mind if you use a adjustable trimmer.
Another item that I have incorporated into my design work since establishing a case length, is to design a bullet that provides a set cartridge overall length. These lengths are defined to the .005″.
This is an orignal design based on what the 300 Sav and 7.62X39 have taught me about critical dimension chambers but I have little doubt that it will not but prove to be great critter getter!
The exact same features that were present in the 300 Savage are present in the 308 Win. Like the TLC310-165-RF, top band is used to fit the step, and freebore, and freebore leade, and then a tapered bore rider is used to address the leade.
A chamber impression of my Mossberg 800A verified the SAAMI dimensions used to in the cartridge design.
The base of the bullet matches the base of the case neck using the same brass standard that was mentioned as well as establishing a cartridge overall length.
This final design is what brought me to the short necks and has taught me the most about bullet design. There is no doubt that the 7.62×39 has become my favorite cartridge. As a fellow that tromps the brush of my South Texas ranch, I know that this cartridge is capable of meeting the needs of a life time of feral hog and whitetail hunting. I have more rifles in this cartridge now than I do in any other cartridge that I shoot and as a lever nut, that is saying a lot.
Like the 300 Savage, this isn’t my first rodeo and the same lessons learned about a simple tangent ogive apply. These ogives may work for leverguns but they don’t allow a modern bolt gun be all it is capable of being.
Top band and a very short tapered bore rider (.015″) is used to match the critical components of the chamber.
The chamber has been verified against my Savage 10 FCM, Ruger Mini-30, and Zastava M85 (my favorite light rifle). I have sidelined the 10 FCM until I have a chance to fire lap the barrel. In this Savage the freebore leade tapers to a .308″ groove and .300″ bore. I’m going to try to lap it out to .310″/.302″ or get rid of it.
The magazine feed from my bolt guns is slick as a whistle and once I dressed the forward edge of my Mini-30 magazine, the same can be said.
The 7.62×39 is a great compact cartridge especially when used in a bolt gun like the Zastava M85 Mini-Mauser. If you have ever wanted a Savage 340 or Remington 788 chambered in 30-30 Win for cast bullet hunting, you would love this combination!
This has been the longest cast bullet project I’ve attempted, several hundred hours of sweating the small details, but I believe it will pay off in the performance you see out the barrel. I have much more information available to include loading data but it has been a long day.
Swede has my shop drawings and will be doing his work to give you the options you like to see in any of my designs. We should have the group buys up tomorrow. Let’s get this going, I have a bunch of rifles that need bullets!
-
Replies
-
SwedeNelson
Have group buy’s started
300 Savage
http://noebulletmolds.com/smf/index.php/topic,589.0.html
308 Win
http://noebulletmolds.com/smf/index.php/topic,588.0.html
7.62×39
http://noebulletmolds.com/smf/index.php/topic,587.0.htmlThanks for the interest
Bullet maker, maker
Al Nelsonmikehupp
daveridenour
Michael,
I have been looking at various 7.62x39mm CIP mould designs for some time. I also have a “weakness” for HP designs as well. What I need, however, will also have to feed and function reliably from the magazine of a gas operated semi-auto. Have you tried your design to see if it will function in semi-autos without doing any modification to feed ramps, etc?
Thanks,
Dave
markpissos
I really like the 308 shortneck designed bullet! I have reloaded for over 40+ years but I am fairly new to casting and definitely a fan of the RD molds. I do have a question though: Up until now, I have been resizing and using Ben’s Red as my lube of choice, but how would this bullet fair using that lube? Please excuse my ignorance, but an inquiring mind would like to have some advice from those in the know. I would really like to try this bullet in my single shot 308 Win.
Thanks,
Mark.
Michael,
I have been looking at various 7.62x39mm CIP mould designs for some time. I also have a “weakness” for HP designs as well. What I need, however, will also have to feed and function reliably from the magazine of a gas operated semi-auto. Have you tried your design to see if it will function in semi-autos without doing any modification to feed ramps, etc?
Thanks,
Dave
Dave, I’m shooting the bullet, the one that Lee cut, out of my Ruger Mini-30. I’ve had to do two things. The first is trim the brass back because Lee got the bore rider wrong but I don’t expect that to be an issue here at NOE. The second thing I did was dress the upper, leading edge surface of my magazines. The Ruger product is rough so I smoothed it. Going out to shoot a bunch in a few minutes.
I really like the 308 shortneck designed bullet! I have reloaded for over 40+ years but I am fairly new to casting and definitely a fan of the RD molds. I do have a question though: Up until now, I have been resizing and using Ben’s Red as my lube of choice, but how would this bullet fair using that lube? Please excuse my ignorance, but an inquiring mind would like to have some advice from those in the know. I would really like to try this bullet in my single shot 308 Win.
Thanks,
MarkI really don’t know about the lube Mark as all I use is liquid Alox. I purchase my lube in bulk from White Label lube
.
Michael,
I have been looking at various 7.62x39mm CIP mould designs for some time. I also have a “weakness” for HP designs as well. What I need, however, will also have to feed and function reliably from the magazine of a gas operated semi-auto. Have you tried your design to see if it will function in semi-autos without doing any modification to feed ramps, etc?
Thanks,
Dave
Dave, I’m shooting the bullet, the one that Lee cut, out of my Ruger Mini-30. I’ve had to do two things. The first is trim the brass back because Lee got the bore rider wrong but I don’t expect that to be an issue here at NOE. The second thing I did was dress the upper, leading edge surface of my magazines. The Ruger product is rough so I smoothed it. Going out to shoot a bunch in a few minutes.
…
Michael,
Thanks. I don’t mind modifying the feed lips on some mags, but I don’t want to have to modify the guns themselves. I would really like to hear how the bullet works in your Mini 30.
Dave
Thanks. I don’t mind modifying the feed lips on some mags, but I don’t want to have to modify the guns themselves. I would really like to hear how the bullet works in your Mini 30.
I shucks them out the barrel as fast as I can tap the trigger from the reset. The Mini-30 is not a target rifle but it can hold its own. I have 100% hits on a 6″ gong at 50 yards and about 85% on the same size gong at 100%.
My original TLC313-150-RF bullet is the only cast bullet I’ve shot in the rifle and it definitely does not shoot as well as the 152-grain jacketed. The reason for it is that it has a short chamber, it wasn’t cut completely to the SAAMI spec. I have to seat the bullet deep, trim the brass neck very short, but then the base of the bullet is extending into the case. With all this, the bullet isn’t a match. Not the bullets problem as it fits my SAAMI cut chamber rifles well, its Ruger’s lack of attention to detail. The chamber is over a 1/2″ short.
Here is what the short cartridge looks like against the way it should look.
I have had failure to feeds with the factory 152-grain offerings and now I know why. What needs to be done with this rifle is the chamber needs to be finished with a reamer. The bad thing is that the barrel will need to be removed for the the work. I thought about sending it back to Ruger, but I suspect for some grand reason they cut them that way on purpose. The return shipping would be more than renting a reamer and at least I know I will get it right. The step will end of being a bit long but in the grand scheme of things with the remainder of the up front stuff being right it will not matter. With the better bullet fit, this should make this rifle’s MOA more competitive with my other rifles.After making the chamber impression, I stripped the rifle completely down to clean it and prep it for the barrel removal. I haven’t done the complete stripping since the installation of the Mini Scout Mount. Once I could get the bolt closed with my cast bullets, the shortened cartridge, I never had any feed problems so I didn’t worry about the plumbing. What I found is that it looks like the Alox is keeping things lubed quite well. All the parts and pipe cleaners run through the holes had the Alox reside (grease) on them. Shooting off the trigger reset, the Mini-30 does hammer them out.
I suspect you are only asking about the feed but I wanted to hit on the chamber issues as it is important for everyone to understand that all three of these offers are cut to a specific, the SAAMI chamber. The bullets also have a lot a detail to them, if you are casting with straight wheel weights you will probably not see the needed definition. Add 2% tin to your mix and the differences will stand out.
I thought that I would add a few pictures of my Mini-30 as I really do like the rifle and didn’t want the negative issues with it to go with out the positive. It is a 5454 Tactical rifle with the Mini-Scout Mount III on it. The scope is a Weaver K4 Classic using Weaver QD rings. It is sighted in with both the scope and peep, more of a ghost ring. I don’t hesitate a second to pull the scope on and off in the field as my hunting demands.
Despite the issues I noted, it is the night time killer of hogs…
It had a very busy first year, just a sampling of its handy work!
Oh, I also added a cat to the hit list…
Michael,
Thank you for your reply. That’s all I needed to know. It looks like I need to try one of your moulds too. Great info and pix too.
BTW. I really like your rig. I have a Marlin 1895G, and the Leupold 2x scout scope with the heavy duplex reticle. It works great for the hilly, woodsy, brushy areas around where I live.
Thanks again,
Dave
keithsharp
Mike Bambauer
Could you also design target/hunting bullet for 308 that would compete with the 30XCB, It would only require a more pointed nose maybe.
It is not something that I would be interested but I went ahead and made it a spire point and ran the cartridge overall length out to 2.800″. I did not do the chamber overlay as the bore rider and top band did not change.
The only thing that I see is that the CG & CP has moved out to a 4% difference. All of my designs contain the two points within 2.5%. Using the simple Green Hill formula, the bullet with a 1:12 twist is stable down to 1129 FPS. With 1:10, 378 FPS. The design software that I use has a more complex calculation and it suggests that the bullet is very stable in flight.
Hello Michael,
I have one of your TLC310-180-RF .308 molds on order along with the 7.62X39 mold..
I am wondering what are your favorite powders for the .308 mold assuming you have a proto-type bullet to work up load data..
ThanksNo prototype bullet for the TLC310-180-RF so I’m we are all in the same boat with the design. Late next week, I will have generated load data sheets for all three designs. Here is my plan with what I will shoot based on Hodgdon powders.
Using my Lyman #2 with the #8 shot added, water quenched, I will shoot it at 42.0 KPSI, 48.0 KPSI. I’ve had no issues with the alloy issues at 48.0 KPSI with the 300 Savage and 7.62×39 prototypes. The next jump to the Maximum Nomial Pressure might take a change to my 50/50 ww/linotype. I’m using that alloy with the Rossi R92 454 Casull and it has done very well on whitetails and feral hogs so it will be interesting to see what it does with all three of the 30 caliber short necks.
mikehupp
georgehajduk
I’m in for the 300 Savage & 7.62×39 molds.
SwedeNelson
williamquiles
daveridenour
markpissos
keithsharp
Mike Bambauer- You must be logged in to reply to this topic.