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Offline HHI-7420

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« on: July 11, 2004, 03:50:45 PM »
Harold Clark, I've been reading your posts about your ballistics program. I'm impressed. Now I've got a question.
I have a factory(TC) .35Rem. bbl. rechambered to .358JDJ. Playing around with Rel-7 I'm getting 1" groups  @ 100yds. using 47.0 grs. with a rem. clrn 200grs. My bbl. is 12-3/4" and non ported. How efficent is this load and can any improvement be made using this combination. Remember, rechambered TC bbl., not a custom. Thanks in advance.  Pat
By the way, I'm getting 2,245'/s ave. 10' from muzzle. Oal is 2.965".

Offline haroldclark

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358 JDJ
« Reply #1 on: July 11, 2004, 05:35:50 PM »
Sometimes, loads entered in the software give extreme pressures when dealing with the JDJ loadings.  I entered all data that you provided and the pressure was extreme, so I reduced the velocity to 2240 fps by reducing the amount of powder to 44.6 grains.  The pressure is still what I would consider too high, but this can be wrong.  I would consider checking your brass for pressure like extremely flattened primers and having to full length resize after firing a couple of times or only once.  Last week I was working with a guy that was using an AI 30-30 and my software showed very high pressures with his data too.

Assuming that this is a safe loading for the Contender, the following pressure ratio exists = 50001 with your load and 51,000 is the max allowed.  Most experts suggest not running your pressure over 48,000 PSI in a Contender.  Having blown two very fine firearms into oblivion, I heed the pressure warnings.

You will be getting 99.46% burn in the barrel and an efficiency of 26.9, which is very good.  The recoil is 25.9 foot pounds or equivilent to a 444 Marlin loading.

                       50 yds   100 yds  150 yds 200 yds  250 yds  
Velocity   fps.   2111.3   1981.0   1855.0   1736.0   1622.9  
Energy  ft.lbs.  1979.3   1742.7   1528.0   1338.2   1169.5


If you are getting 1" groups with this animal, I wouldn't mess with it.  
Let me know about your pressure signs, if any.  

Harold

Offline HHI-7420

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« Reply #2 on: July 12, 2004, 01:07:35 PM »
Harold Clark, thanks for the info. I wasn't getting but 2,243'/s in the first place. You say you dropped the vel. 3'/s by lowering the charge 2.4grs.? Maybe this is where we're going off. It has been a while since I shot any of this and if I remember correctly the cases dropped out and the primers looked ok. There was some smutting of the case body though(not sure what that means). JD shows up to 48.0grs. with a 220gr. slug. Also, in the 358jdj article in a past Handloader mag. showed 48.0grs. with a 200gr. Hawk slug. It would seem that I'm in the ballpark(I worked my way up to this point). I will load some more and double check again-may be a while though. Thanks again and post about this vel. question.  Pat

Offline haroldclark

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Loads for the 358 JDJ Cartridge
« Reply #3 on: July 22, 2004, 01:48:30 PM »
Pat, all I can say about your load of 47 grs. of Reloader 7 and a Remington 200 gr Round nose bullet with a cannelure is that this exceeds the pressure limits in my program.

The Maximum pressure allowed for the cartridge is 51,488 pounds per square inch and your load is running in the RED at 53,066 Pounds per square inch.

From your 12.75" barrel it will be approximately 2302 fps.  99.81% burn in the barrel with a 26.8% efficiency rating, which is very good.

I, personally, would be afraid to shoot that load in a Contender.  I don't have any other source for reloading data on the 358 JDJ cartridge.  It seems to me like you are trying to make Magnum 358 in a Contender and I don't think that is safe or wise.

I don't know what else to tell you.

Harold Clark

Offline HHI-7420

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358jdj
« Reply #4 on: July 23, 2004, 02:50:32 AM »
Harold, thanks again for rerunning the info. I'll heed your advice and back up 1gr. That should do it.  Pat

Offline KYODE

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« Reply #5 on: July 23, 2004, 03:23:19 AM »
how does that compare to SSK's....JDJ data?
i'm just wondering about how the ackley improved calibers, and JDJ improved calibers work in that program.
an improved case with 40 degree shoulders, and somewhat straighter case walls will grip the chamber better and provide much less breech thrust.
 :? ....still......maybe pressure is pressure....i just don't know :?  maybe it would depend on how well your primer pockets n such hold up after repeated firings.
my 30-30AI load of imr4198 and 130gr hornady ssp's showed excessive pressure in that program, but in my gun it is very accurate and everything looks fine. i took 2 deer with the load last season. more time will tell me something maybe. i'll have to see how well the brass holds up.

wildcats(to me).....are just that.....wild! :lol:

Offline HHI-7420

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358jdj
« Reply #6 on: July 24, 2004, 03:42:32 PM »
Kyode, I'm like you-I just don't know sometimes, even though I've been reloading for 45 yrs.(not as an experimentor), but as a hunter. I'm 1gr. less than JD shows for a 220gr. slug. I'm only seating 3/16" deep into the case neck, which is where I get my 2.965" oal. In the Handloader mag. story about the 358jdj they show 48gr for 200gr. slug. I also realize that I'm using a rechambered TC bbl. and not a custom one. I'm getting a lot of smutting of the case at higher loadings. At 47.5gr the shoulder of one case was caved in,. yet at 48.0gr. nothing happened except for a lot of smut on the case. Gonna call JD.  Pat

Offline haroldclark

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JDJ and AI cases
« Reply #7 on: July 25, 2004, 06:53:02 AM »
Does the software program take into account backward thrust and case wall grip to reduce it?

I don't know?  HHI's request for the info on a JDJ case is the second one that I have had.  In both cases, the pressures were extreme with the given load that was being used.

My software has the data for most of the JDJ cartridges.  I have not owned one although the 6.5JDJ is causing some brain chatter with me.

I have a shooting buddy that has the 7-30 Bullberry that is nothing more than an Ackley Improved case.  We have done serious experimenting with it.  He will start getting extraction difficulties and absolute flow on the primer (fills out the entire pocket to the case head.).  He had to load at 7-30 Waters loadings to avoid pressure.  Even at those lower pressures, he has to reisize the brass after every firing or he can't load most of them back into the chamber.  That is interesting.  We shoot 2 days a week for up to 6 hours each day.  I have a portable loading setup and I set up in the bathroom to avoid the wind.  We test right on the spot.

I, too, am in a quandry about my data and your JDJ Cartridges and I really don't have any other information.  However, after having destroyed three rifles over the past 30 years, I've played on the safe side.  Actually, none of them were from over loading with powder.

I have never seen any of JD Jones' loading data.  I can't imagine that his data would be improper.  He has been in the business for years.  I'l bet there have been some firearms meet their demise during his experimentations.

I have done a great deal of experimenting over the years, but as I say, I've never played with JDJ cartridges.

HHI,
I don't think one grain reduction is going to make a knat of a difference in your load.  I don't mean to sound like a doom day character, but I really hate it when a gun explodes.  I still have the wrap around sun glasses I was wearing when my Sako 308 went kaboom.  The glasses were nearly removed from my face and the right lense fell out.  There is a nast knick/cut in the frame above the right lense.

If It were me, I would prepare some ready to load cases that just need powder and a bullet seated in them.  Either take a powder measure and powder them at the range or take some other cases to hold given amounds of powder in a cartridge box and put a piece of foam over the top of the open case mouths, close the lid and take a press to seat the bullets as needed.

I frequently powder up 10 cases with starting loads and go up to as much powder as I want to try.  I fill a 50 round box with 5 different powder charges.  That way I can get right at it upon arrival at the range.  I can check for accuracy and check for pressure signs as I go.  If I get to a high pressure level with one or two rounds, then I don't have to pull bullets from the unused loadings.  I simply return the powder to the cannister.

You are getting velocities with your 358JDJ that should be suitable for Grizzley bears.  If it were me, I would reduce the loads down to 2100 fps and be safe.  2100 fps with a 200 gr 358 bullet should take anything we have in this country out to 200 yards, shouldn't it?

It has been nice chatting with you.

Offline HHI-7420

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« Reply #8 on: July 26, 2004, 02:05:50 PM »
Harold and Kyode, I called SSK and asked about all this. I was told that if I wasn't having any extraction problems or other signs of excessive pressures to stay where I was. The smutting was most likely due to lack of sufficient pressure to make the case expand against the cylinder wall. This was in lieu of the fact that I'm seating only halfway into the neck, where as they seat down to the shoulder. By the way they also said that their load info is about 25 yrs. old and powders do change. They advised Varget as probably the best nowadays(almost the same as AA-2520). This all has been something to think about.  Pat

Offline haroldclark

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« Reply #9 on: July 26, 2004, 03:44:55 PM »
I'm glad you talked to SSK people.  Apparently, my software does not handle the JDJ cartridges very well.  The software is based upon mathematical data along with the case capacities and etc.

I ran Varget just a few minute ago and with 52 grains and your 200 grain bullet, the case is 99.2% full and the velocity shows only 1633 fps.  Something is very wrong with this data.

I have used the software to compare with loading manual data and the comparisons are uncannily similar.

Harold

Offline HHI-7420

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« Reply #10 on: July 27, 2004, 11:03:13 AM »
Harold, if SSK is correct ( and I assume they are) about the powders, then it should produce around 2,300'/s. That is what I get with AA-2520 with no problems what so ever using 53.0grs.. Maybe it is just my oal.  Pat