want to drive a 250 gr .357 to 1000 fps with H110, BD, or 4198; mag or max case?

[Whiterabbit]

hi guys,

Load data is real thin for a 250 or even 300 grain bullet in a 357 mag or 357 max case, particularly at 1000 FPS. I want to use Blue Dot ideally, but H110 or 4198 is OK too.

Do any of you guys know how much I would need to drive the bullet to 1000 fps? I can measure it out and determine what case I need after that. I just don't know approx how much blue dot I need to drive a 250 grain 357 cal bullet to 1000 fps in a straightwall cartridge. Or H110. Or 4198.

I need to hit the ballpark out of the gate because I don't like loading H110 except at 100% case capacity so I will cut the cases to length if needed. This is a purpose-specific application.

Any help?

[17nut]

Well the RCBS .358-250gr bullet is 1" long and to keep max it seats .7" into the case. Now thats a teeny tiny powder space you have left there!
6 grains of Blue Dot is 100% filling (31kpsi) and you need a min. of 17" barrel to get you past 1000fps om that mouse fart load.

I fear that you need to use pixie dust for the 300gr bullet since it will take up all your powder space.

[paul h]

Can't help with what velocity you'll get as you didn't give your barrel length. If you can find published data with barrel length, reduce velocity by 25 fps per inch of barrel and you should be close.

As much as I like H-110 as a magnum handgun propellent, my experience in the 357 max with 200 gr cast produced huge velocity swings and poor accuracy, so I would advise against using it with the 250's. It might work fine or it might be really weird, I wouldn't chance it.

Google led me to some loads for 255 gr cast http://www.reloadammo.com/357max.htm

As a ballpark when you increase bullet weight by 10%, max powder charges tend to drop by 5%, or if bullet weight increases by 20%, top charges drop by about 10%. This doesn't work in instances where the heavier bullet drastically decreases the powder volume.

Looking at the data, H-110 likely won't produce subsonic loads so you'll need to choose a powder that is friendly with being downloaded or go with a slower powder. Extrapolating the 220 gr data, 2400 might be the ticket.

[rundownbear]

That is like loading a 300 BO. Heavy bullet subsonic loads but trying to do it with less that 1/23 the powder capacity. Not sure that's an achievable goal.

[DougGuy]

Seriously? Use a caliber/cartridge that starts with a 4. Problem solved.

[Outpost75]

Don't know what you are shooting this out of, BUT loading in .38 Special brass with Accurate 36-245D, at Ctg. OAL 1.65" using a compressed caseful of RL7, about 12 grains, in a break-open, single-shot rifle with 16" twist, quiet, subsonic and accurate.

Attachment 181814

[Whiterabbit]

No OAL limitation. Single shot gun style. I can use as large or as small a case and OAL I want, but it will be a rimless design so I can't just ream to max and cut the case as desired and go with it. Thus the need for "research". Barrel length is undefined, but will be "short". extrapolating 25 fps per inch is a reasonable recommendation.

As much as I like H-110 as a magnum handgun propellent, my experience in the 357 max with 200 gr cast produced huge velocity swings and poor accuracy, so I would advise against using it with the 250's. It might work fine or it might be really weird, I wouldn't chance it.

Looking at the data, H-110 likely won't produce subsonic loads so you'll need to choose a powder that is friendly with being downloaded or go with a slower powder. Extrapolating the 220 gr data, 2400 might be the ticket.

Done. H110 is out. Though I can go up and down in case capacity as needed to ensure no downloading, but frankly you are right. The sensitivity of it means it's not likely I'll be able to nail the geometry I need with (lets be honest) as little information or limits I'm suggesting in this thread.

So that leaves ideally bluedot, maybe 4198. Looks like bluedot would be fairly compact, and 4198 fairly bulky. Any of you guys use bluedot for heavy-for-cal 357/38? decent powder to use? or should I focus on a 4198 type powder?

[NoAngel]

Have you met the .358 Winchester? You guys should really introduce yourselves to one another.
It'll give you everything you're looking for and MUCH more.

[Whiterabbit]

That is like loading a 300 BO. Heavy bullet subsonic loads but trying to do it with less that 1/23 the powder capacity. Not sure that's an achievable goal.

You basically nailed it. Looking to duplicate 300BO performance, very roughly speaking, but with a 357 cal bullet. The OAL is unlimited thus the powder capacity is not limited either. Barrel will be short, and the case can be customized for length, but it needs to be rimless straightwall. If I could use a rim then it would be easy: use the 357 max case and cut down as needed once 1000 fps was achieved with the desired powder so the mouth met the crimp groove at 100% case fill. But since I need the mouth for headspace I have to make an educated guess up front as to my case volume needs. Knowing it's an educated guess at best anyways due to not having a defined barrel length.

Thus I consult the experts here on CB.

[runfiverun]

the maximum will do it.
1680 or slower would be more advisable.
I use AA-2230.[used 1680 data to get started]
I haven't chronoed the 250 in my revolver but it's probably fairly close to the 1-k you want.

[dverna]

A 7.62x39 case necked up to .357 could be one option.

Don Verna

[Hamish]

Whiterabbit,

1K should be pretty easy in the Magnum case. My hunting load with the 360-230 Thor is 14.4 gr. 2400@1450 fps. This is a Contender load.

245 gr@1K sounds a lot like the old bowling pin match loads,,,,,

Since you are saying rimless I am assuming you're thinking of using .223 brass. Been kicking around the idea of doing a full length .357 Super Max rimless for awhile myself.

[ironhead7544]

You might be able to use the 351 WSL case for your wildcat. There was also a 35 WSL cartridge that I heard will fit into the 357 Magnum chamber.

[rond]

35 Remington and Unique.

[P Flados]

You mentioned rimmless. This makes me think you want to try using 5.56 / 233 brass. On a couple of similar threads, I have promoted a gun that will fire either a rimmed or rimless versions of the DW 360. The most recent being:


http://castboolits.gunloads.com/show...-about-357-MAX

The length makes for an "easy" cutoff conversion of 223 / 5.56 cases.

Being only a little longer that a std 357 mag lets you use std 357 mags provided you have enough bullet extending from the case to avoid bullet shaving concerns at the sharp step that a rimless case would headspace on.

The extra case capacity plus the ability to drive to a higher pressure(say 5.56 pressure, 55000 psi) allows you to drive a DW rimless pretty hard with no risk that your ammo would find its way into a"wimpy" 357 magnum gun. The resultant performance would probably be pretty close to 357 max performance at “book” values given the SAAMI 40,000 psi limit for the max.

There is a downside to the concept. Although cutting down 5.56 is easy,the base of a seated bullet is probably going to get into the region where the thickness of 5.56 brass is very inconsistent. I say this based on my experience with converting 223 & 5.56 to 327 magnum(a lot more work than this conversion). The thickness issue can be dealt with several ways. A loose chamber and case neck turning are obvious choices but they are not so good for most folks. The other choice that is probably not really all that bad is just cut off a lot of brass and toss some fraction with thicker case walls.

As for powder, you seem to want a real heavy bullet. This means you probably will get good results going just slower than H110. My choice would be H 4227.

[Wayne Dobbs]

Don't know what you are shooting this out of, BUT loading in .38 Special brass with Accurate 36-245D, at Ctg. OAL 1.65" using a compressed caseful of RL7, about 12 grains, in a break-open, single-shot rifle with 16" twist, quiet, subsonic and accurate.

Attachment 181814

I can think of several applications for that load.

[Outpost75]

I can think of several applications for that load.

1:40 tin/lead from Roto Metals.

4198 will also "work" with a "compressed, nominal case full."

.38 Special brass is cheap and plentiful.

Penetration is astounding!

[NoAngel]

35 Remington and Unique.

This too, but the .358 is easier to make brass for.

[paul h]

For what he wants to do, I think the 38 sp or 357 mag will be just about the right case capacity, assuming an action that can handle at least 40 kpsi. Ideally you could have someone run a quickload calculation. Note that quickload doesn't seem to work as well with straightwall cases, but it under estimates pressures so that's a good thing. And if you're having someone run a quickload calc, for giggles see if you can where you want with unique or another medium rate powder. No reason to go with a slower powder if you can get what you want with a smaller dose of a faster powder and keep pressures where you want them.

If one is looking to build the ideal suppressed round it will have the smallest possible case capacity, and use the fastest possible powder. The goal is a small charge of fast powder and the lowest possible pressure at the muzzle and smallest possible volume of gas.

Certainly it is easy to use a host of existing cartridges downloaded, but they are less than ideal. Also large cases downloaded tend to have less than the best accuracy.

Running a small case at medium to high pressure should be the ideal in terms of accuracy and minimal report or most effective suppressed.

[P Flados]

You basically nailed it. Looking to duplicate 300BO performance, very roughly speaking, but with a 357 cal bullet. The OAL is unlimited thus the powder capacity is not limited either. Barrel will be short, and the case can be customized for length, but it needs to be rimless straightwall. If I could use a rim then it would be easy: use the 357 max case and cut down as needed once 1000 fps was achieved with the desired powder so the mouth met the crimp groove at 100% case fill. But since I need the mouth for headspace I have to make an educated guess up front as to my case volume needs. Knowing it's an educated guess at best anyways due to not having a defined barrel length.

Thus I consult the experts here on CB.

I took another look at the above.

You basic idea about starting with a 357 max length case and trimming back is not impossible if you can find a surrogate gun to experiment with. For example, I have a TC 14" maximum. For testing, the cases do not even need to be cut, just change the bullet seating depth. However, gun to gun details makes this much less than perfect.

If you want perfect, make sure you build effort gives you access to a chamber reamer that will do the longest you may want. However, just start out with the gun only cut for the shortest length you would be ok with. Make up a few short cases and test. If you can not get what you want, then just cut a little deeper, make up a few more short cases and test again.

If you pick one or two powders in the H4227 to H4198 range, You should be OK with starting loads that have a small (say 1/16") gap between the base of the bullet and top of the powder and then increase powder up to no gap (100% density). Going slightly compressed may also be OK, but about the time you start compressing more than a little, there would be no reason to not just increase the case length.