Opinions on this sub-sonic Accurate Mold

[Spokerider]

Tom has drawn this mold design up for me, #36-240 B

http://www.accuratemolds.com/bullet_detail.php?bullet=36-240B-D.png

It's for a Uberti Baby Rolling block .357 mag that I have reamed to .357 max with a Manson reamer. To be used as a sub-sonic hunting round, point blank to 50m range. Cougar and black bear.

Calling on your expert opinons please......... do you see any apparent design issues, lube problems or issues, or instability issues with this design?

I NEED to keep the OAL short, so it feeds past the rolling blocks.....thus the short nose.

What can you tell me about the pros and cons of tumble lube design, as I've never tried it.

Thanks.

[Mk42gunner]

Spokerider,

I don't know about tumble lube, I have never had a TL mold. A lot of people like them, and have good luck with them; see Ranchdog's molds or Recluse's 45/45/10 lube.

It looks like you should have plenty of lube with that boolit.

With that meplat, it should hammer whatever you hit with it. Why subsonic?

I would like a thicker/ wider base band, I measured one from a Lyman 358429 HP that was .140", but the .09" might work just fine.

To check if you can feed it over the breechblock before ordering a mold; I would chuck a .358 boolit in a drill and use a file on it, then make a dummy round. no sense ordering a mold that the nose profile won't work for you.

As for stability, what is the twist in your barrel?

Robert

[Spokerider]

Thanks for the feedback.

Sub-sonic for rural areas I sometimes hunt.........wish to avoid the sonic crack.
Tom has matched the OAL of this design to what I currently shoot.......180gr cast performance WFN, and they feed fine, but just.

About the TL grooves......is there enough material there to adequately engage the rifling in the bore?

[GLL]

I would enjoy hearing more details about your rifle and see a few photos ! :) :) How did it shoot before your modification to MAX ?

I look forward to updates on its performance !

Jerry

[Spokerider]

I have quite a few threads on the research regarding pressures, safety issues and such posted on here and the GB forum, before rechambering it to the Rem Max.

It's a light, short 5lb carbine. If you've ever chased after hounds in the mountains......you'll appreciate the significance of these characteristics.

I have only ever shot it out to 50m, as my shots are all close in anyway. It shoots great, and with the peepsight, the sight-picture upon sholdering is instantaneous. From 38sp to .357 max, it can shoot them all.

[stubshaft]

Sub-sonic is fine but why do you want it so heavy? I've shot alot of hogs with the old 457130 running at about 750fps and that only weighs 152grs.

[longbow]

Spokerider"

Call it gut feel but your boolit design looks fine to me. I tend to agree with Mk42gunner on the base band though. I like a thick base band myself but yours is likely fine as is.

I have been thinking along similar lines to make a .44 mag "Whisper" based on this design scaled to 0.434":

http://guns.connect.fi/gow/QA7.html

Except I was thinking about changing to tumble lube grooves as you have. I have already modeled it in .45 cal and 0.434" (it is 406 grs. at 0.434")

What weight is your design?

Have you checked for required rifling twist to stabilize that length of boolit? That is about the only concern I would have.

Looks good to me.

Longbow

[nanuk]

I think the Uberti Baby RB's are 1/16" ROT

[Mk42gunner]

If it is in fact 1:16, I think I would shorten the boolit until it weighed no more than 220 grains, with the thicker base band. Read just about any thread about the .35 Whelen you will be busy for days reading about the best twist for .35 caliber barrels.

I can understand wanting a light carbine, I have followed dogs before.

Robert

[caseyboy]

Spokerider,

Not familiar with the 357Max but will it be sufficient to "drop" a treed tom? I have heard that they can be a handful if they hit the ground and are not dead yet. Have you given thought to a hollowpoint?

[Spokerider]

Sub-sonic is fine but why do you want it so heavy? I've shot alot of hogs with the old 457130 running at about 750fps and that only weighs 152grs.

Heavy = penetration. With a single shot, I want the first one to count.

This boolit is designed primarily for the ocassional mean black bear that is trying to kill my hounds. We have many, many black bears here, and seeing 15 in one day is not unheard of. Occasionally, a mean bear can be encountered and if all other methods of diversion fail to work, this mean bear needs to go to bear heaven.

[Spokerider]

Spokerider"

Call it gut feel but your boolit design looks fine to me. I tend to agree with Mk42gunner on the base band though. I like a thick base band myself but yours is likely fine as is.

I have been thinking along similar lines to make a .44 mag "Whisper" based on this design scaled to 0.434":

http://guns.connect.fi/gow/QA7.html

Except I was thinking about changing to tumble lube grooves as you have. I have already modeled it in .45 cal and 0.434" (it is 406 grs. at 0.434")

What weight is your design?

Have you checked for required rifling twist to stabilize that length of boolit? That is about the only concern I would have.

Looks good to me.

Longbow



Thanks for your input.
The design that I asked Tom to come up with, was for one that would utilize the heaviest boolit the 1 / 16 twist would stabilize. I *suggetsed* 240gr, and Tom drew it. The M. Man website has a program that matches bullit design and weight to bore twist, and 240gr was the heaviest weight boolit that a .358 1 / 16 twist would stabliize. Will it work?? Dunno....... That's kinda what I'm asking here.

Regarding the base........is there a risk of gas cutting past the .09 band?

[Spokerider]

If it is in fact 1:16, I think I would shorten the boolit until it weighed no more than 220 grains, with the thicker base band. Read just about any thread about the .35 Whelen you will be busy for days reading about the best twist for .35 caliber barrels.

I can understand wanting a light carbine, I have followed dogs before.

Robert

Thanks for the .35 Whelen suggestion. I'll look into the info.

[Norbrat]

Thanks for your input.
The design that I asked Tom to come up with, was for one that would utilize the heaviest boolit the 1 / 16 twist would stabilize. I *suggetsed* 240gr, and Tom drew it. The M. Man website has a program that matches bullit design and weight to bore twist, and 240gr was the heaviest weight boolit that a .358 1 / 16 twist would stabliize. Will it work?? Dunno....... That's kinda what I'm asking here.

Regarding the base........is there a risk of gas cutting past the .09 band?

Lots of the Lee TL designs have a very similar sized bottom band. I don't think you should have any trouble with it gas cutting, as long as you use a soft enough alloy and size it correctly for your barrel.

As for twist rate, as you are planning to use it as a low velocity, close range boolit, I wouldn't worry about it. It will probably work perfectly well.

I reckon go for it!

BTW, I've had good results using Trail Boss for low velocity loads.

[longbow]

Spokerider:

At the low velocities and so relatively low pressures you are likely to run (depends on powder choice some) I doubt gas cutting will be a problem if you have good fit of 0.001" to 0.002" over groove diameter.

I push my .44 mag PB boolits to full jacketed loads in an 1894 Marlin with no leading and little sign of gas cutting. Some recovered boolits show a little etching of the base band but accuracy is good and no leading.

It turns out I even scaled the Gunn design to 0.357" but had forgotten I did it and was in transition with software. I just loaded up a new version of the 3D software tonight and looked ~ sure enough I have the Gunn boolit scaled to both 0.434" & 0.357". Weight in 0.357" is 228 grs. so a little lighter than your design.

I will see if I can run your boolit length in a software program to determine recommended twist tomorrow. I can't recall the name of the software but it is downloadable from a British site and is supposed to be more sophisticated than the Greenhill formula. It is too late tonight.

So far it seems to provide "good" twist recommendations. Still confirming as best I can.

It seems to me that I have run the Gunn boolit design and came out to 1:14" for 0.357" but my memory is poor so I will check. Heck I didn't even remember I had modeled this in 0.357"!

Also, if I can trust my memory a bit it seems to me that a flat base boolit required less twist to stabilize than the boattail Gunn design ~ depending on velocity.

I will check tomorrow.

Longbow

[Spokerider]

I just found this Miller Stability Calculator
http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi

According to it, a 240gr bullet in a 1 / 16 twist is a go.

[longbow]

Sorry, I got sidetracked and didn't get to this tonight either.

The program I found is here:

http://www.stickledown.co.uk/ ~ WinGyro

I haven't had to to compare to Miller Stability and Greenhill yet.

The "advantage" of WinGyro is that it takes the nose length and boattail if any into account as well. Not sure how accurate results are but I have to assume pretty good considering the source.

Longbow

[Iowa Fox]

Spokerider, What powder are you planning to use for your sub-sonic loads?

[Spokerider]

Spokerider, What powder are you planning to use for your sub-sonic loads?

Well.......that's my next quest........never having loaded sub sonic before.

I have W231, HS6, Lil Gun on hand, as well as H110 for the 180gr loads I currently shoot. I'm wondering if any of these faster burning powders are acceptable?

[Spokerider]

[QUOTE=longbow;1539670]Sorry, I got sidetracked and didn't get to this tonight either.

The program I found is here:

http://www.stickledown.co.uk/ ~ WinGyro

I haven't had to to compare to Miller Stability and Greenhill yet.

The "advantage" of WinGyro is that it takes the nose length and boattail if any into account as well. Not sure how accurate results are but I have to assume pretty good considering the source.

Longbow[/QUO



I downloaded it and tried to run it, but it's not compatible with my windows.

[Norbrat]

Well.......that's my next quest........never having loaded sub sonic before.

I have W231, HS6, Lil Gun on hand, as well as H110 for the 180gr loads I currently shoot. I'm wondering if any of these faster burning powders are acceptable?

The faster, the better. Biggest issue is consistent burning with such a small amount of powder in a biggish case.

Don't use H110; isn't that the same as W296? That powder has a reputation of secondary explosion effect if used in small amounts in a large case.

I would use Trail Boss.

[grubbylabs]

I am loading a 270 grain RD 44 cal bullet with TL groves at 2,100fps without leading issues.

[Spokerider]

The faster, the better. Biggest issue is consistent burning with such a small amount of powder in a biggish case.

Don't use H110; isn't that the same as W296? That powder has a reputation of secondary explosion effect if used in small amounts in a large case.

I would use Trail Boss.

H110 is the same as W296.
I'll look into trail boss powder.

[jblee10]

I would certainly think 240 grains would penetrate a cat. I'm just curious. Why are you going subsonic? Have you put a can on a rolling block?

[Spokerider]

See my second post.........

No suppressors permitted in Canada.

[longbow]

Okay, I started to post then thought better of it as I am no expert here but have read some on reduced loads and preferred powders.

I had recently read and wanted to find again some info on reduced loads, powder burn rates and such. I found it here:

http://www.gmdr.com/lever/pistolpowi.htm

I am not sure what sort of loading density a .357 Max will be running with heavy boolits at subsonic velocity but I am betting something quite a bit less than a full case.

If so then the advice given by Norbrat is good. H110 and W296 are supposed to be used in a full case and not used for any sort of reduced load.

Also more info here though more for bottleneck cartridges but it seems similar fast pistol powders are recommended:

http://members.shaw.ca/cronhelm/DevelopSubsonic.html
http://members.shaw.ca/cronhelm/762ProjectRifle.html

Longbow

[Spokerider]

Longbow, thank for the links. The last two especially. I's going to take me a while to digest all of the info.

SEE or seconadry exposive effects is scary stuff!



I have figured out that a 44 special case has the same internal volume.......being 34 gr of water, as the Rem Max case, also 34 gr of water. There is load data available for the 44 Special with a 240gr boolit combo. Since I too will be shooting 240gr boolits, would this be a *safe* starting point for load info??

[felix]

That guy has been reading our board! ... felix