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atlatl
12-25-2011, 11:08 PM
I thought I might get the most well reasoned answer here, although it does not strictly pertain to cast bullet reloading. If I have a .357 revolver (S&W 340) and choose to reload 38 special brass to velocities approaching .357, using Unique, there should be no reason I can not use a lesser charge than specified for .357 loads safely in that gun. AS LONG AS I DON'T EXCEED 357 VELOCITIES USING THE SAME POWDER (Unique) THE PRESSURE SHOULD BE BELOW THOSE OF FULL 357 LOADS. Right??

Ben
12-25-2011, 11:17 PM
Not necessarily, ................

Putting lesser amounts of " 357 Mag. powder charges " into a 38 Spec. case which starts off with less boiler room than a 357 mag. case is comparing apples to oranges.

You're changing 2 variables at the same time, you're changing case capacity and powder charges, both at the same time. This could offer you a false sense of reloading safety. Better be real careful here...............

If you want to shoot some stiff ( but safe ) 38 Spec. loads in your 357 Mag. revolvers, you need to research 38/44 load data or better yet simply stick to 38 Special + P load data when using 38 Spec. brass.

If you choose to load 38/44 loads in 38 Spec. cases, once you assemble those loads, be DARN CERTAIN that those loads are fired in a 357 Mag. revolver ONLY.

See # 10 below :

http://castboolits.gunloads.com/showthread.php?t=53508

canyon-ghost
12-25-2011, 11:18 PM
Well, the pressure is why I think I'd choose to reload .357 brass to 38 special levels. But, true, you should be able to load hot .38 special for a .357 magnum. I've noticed with reduced loads that it isn't necessarily pressure but, heat and friction that want to cause problems.
Use a slower pistol powder and you should be fine, Unique would be good.

725
12-25-2011, 11:20 PM
Don't go messing around. Follow a good reload manual and don't go changing the loads. A .38 has a certain volume and .38 loads are made for the case size and bullet launched. .357's have a different case volume and the loads developed for the .357 case are just that. A hot .38 or a hot .38 +P is alot of whoop-###. Why don't you just get some .357 brass and load away? Don't over pressure the .38 case and think just because it's in a .357 revolver it will be OK. What would happen if some of those mega-.38"s found their way into a classic air weight or some lesser revolver?

454PB
12-25-2011, 11:24 PM
Well, yeah, kinda.

When you use .38 special brass in a .357 magnum, you effectively reduce the case capacity, which raises pressure. By reducing the amount of powder, you will reduce pressure and velocity. All you have to do is reduce it ENOUGH.

I'd suggest you use load data for .38 special, then increase the charge gradually until you begin to see signs of excessive pressure, or have reached the desired reduced velocity.

Unique would not be my powder of choice in this scenario, I'd use a slower burner.

Be cautious, you're not working with much case capacity to start with.

geargnasher
12-25-2011, 11:24 PM
Unless you are fully aware of and able to test the effect of the reduced volume of the shorter .38 Special brass, stick with published data. .357 Magnum brass is widely available for magnum loads, and .38 +P loads are more than good enough for all but the most serious shooting with a .357.

Gear

tuckerdog
12-25-2011, 11:28 PM
if i get what your driving at dont do it 38s are 38s just load 357 cases with 5.5 - 6 grn unique and 158 grn swc just my .02. I dont shoot 38s much in 357 revolvers other than training aids but a mod 15 smith is a good place to go with 5 grn of unique. my personal most accurate load in said revolver is 4.6 grn and rcbs 150 grn swc

beagle
12-25-2011, 11:28 PM
I'd stick to the data for 38 Special +P loads even though it's a .357 Magnum gun. Using .357 data in these short cases will run the pressures up and although in the past, many have done it, it only takes one weak case and you've ruined a good gun and maybe injured yourself or worse.

There is certainly enough data out there for .38 Special +P loads and older .38/44 loads to give you nice peppy loads if you want to use .38 cases.

If you want mag loads, get mag cases./beagle

sundog
12-25-2011, 11:29 PM
If your gun is chambered for .357, use .357 brass, and load accordingly.

Yes, you can shoot 38 spl. So be it. Don't try to make it something that it is not.

Le Loup Solitaire
12-26-2011, 12:43 AM
There is an old saying among old handloaders that goes, "357's make the best 38's". You can do fine with 357 brass and load it from 38 velocity up to whatever you would want from a 357. As such there is no question as to crowded air space, excess of pressure and the accuracy is good. So as others have commented, "why push the envelope?" LLS

Recluse
12-26-2011, 02:06 AM
The last incident I personally witnessed where case pressures were significantly increased beyond common sense cost the shooter his index and middle finger when his gun blew up--and his gun was a helluva lot stouter piece than that little Smith you're wanting to blow up.

Sorry, but I just do not get this kind of thinking.

LLS (post #10) offers the most saige, seasoned reasoning there is.

:coffee:

marvelshooter
12-26-2011, 08:20 AM
I remember reading Skeeter Skelton years ago in Shooting Times describing how he used to load for his then new .357 Smith and Wesson in .38 special cases when factory ammo and therefore cases for reloading were scarce. He simply loaded to the same OAL as a .357 round using the top lube groove for his crimp. He reasoned that the space under the bullet would be the same and not cause any problems. I have read all the posts in this thread and agree the wisest choice would be to use .357 brass for .357 loads but I also think Skeeter's method would be okay if none was handy.

Jim
12-26-2011, 08:30 AM
I got hold of a Ruger Single Six in .32 H&R mag. I set out to work up a very mild load using Lee .312-100-2Rs. I tried Unique, Bullseye and Red Dot. They all worked but I found the most accurate load I could come up with was with .32 H&R mag cases, not the .32 S&W longs. Boolit jump? I dunno, might be. All I know for sure is, each 'sweet spot' got better using the mag cases.

Bret4207
12-26-2011, 08:49 AM
I thought I might get the most well reasoned answer here, although it does not strictly pertain to cast bullet reloading. If I have a .357 revolver (S&W 340) and choose to reload 38 special brass to velocities approaching .357, using Unique (Wrong powder), there should be no reason I can not use a lesser charge than specified for .357 loads safely in that gun.(Don;t use 357 loads in 38 brass) AS LONG AS I DON'T EXCEED 357 VELOCITIES USING THE SAME POWDER (Unique) THE PRESSURE SHOULD BE BELOW THOSE OF FULL 357 LOADS. Right??

Wrong. The pressure curve of a given powder in one case will differ in a case with less capacity. That's reloading 101. If you want to bump 38 speeds up into the 38/44 or 357 area, you have to go slowly and carefully with the appropriate powder. I would suggest you do some more research before you go further. If I understand your thinking in the bold then let me warn you- you can exceed 357 pressures in a 38 Special using the wrong loads and never even approach 357 fps!

cajun shooter
12-26-2011, 08:56 AM
I can tell you that a very good friend of mine that is gone now had your same idea's. He loaded 357 loads in 38 spl. cases for a few reasons. One is that he was new to reloading as I had been his mentor and helped him put his equipment including his Lyman manual and he wanted hot loads to try in his new S&W 19.
We had a small range that was open to the public and went on Saturday mornings.
Tommy advised me that he had loaded some new rounds for his 19 that should be real eye openers.
I asked him what he did and he advised that he would just show me. Well as best I can remember is that there was a huge blast and I felt hot gases and shrapnel hit the left side of my face. I also saw this huge ball of yellow and red flames going in all directions.
When I was able to gain my senses and look in his direction, I saw the entire top strap appear to be in a huge arch over the cylinder area. The side of the cylinder facing me was gone and only had a flat appearance where the chambers once were.
Tommy's hand was bleeding as were the small areas around his shooting glasses.
He advised me that I was also bleeding from wounds on the left side of my face.
The revolver had to be opened with a hammer and wooden stake that was in my truck. We wanted to remove the remaining live rounds fearing they might go off.
This was the last time that he loaded any rounds that was not in the proper cases for the load. Best to use cases that are listed and not assume that it is safe to do it your way. Take Care and the Best of Luck to You David

trapper9260
12-26-2011, 09:46 AM
As for me this is what I do I shoot 38spl in my 357 mag jsut like I shoot 32 s&w long and 32 h&r mag in my 327 fed mag . What I do is this I use the brass that the gun is for and load it with what the brass is for .Like I load 357 with 357 data . sight in the gun and then I know I got the gun where it needs to be ,I do not go for the max on any of my loads. That way it is easy on the gun and the brass . it is easy enough to have brass split with out the max load . Then when I want to shoot 38spl in the 357 all i do is use the brass of a 38spl and use the data of 38spl but I start with the starting load and then test fire it and see if it shoots on target like it did on the 357 and if not I just add a little more powder at a time and I do not go fro the max . After it shoots the way it need to be sighted in the way the it should be then i stay that way . do not play with your sight on the gun just the powder I stay with in the data for that brass and that is it . you will have not as much power as what the gun is made for with a smaller case , but that is why you do it . to have more then one gun in one gun . So out of a 357mag you will have 2 guns in one , what I mean is you have a 357mag and a 38 spl. But do not shoot a 357 in a 38spl because the 38 spl is not made for the mag . and there is also anorther thing you need to know make sure you clean the gun before you shoot differnet brass then what the gun is made for like you just shot 38spl in your 357 clean your gun before you shoot 357 , or you will mess up your brass . I do the same with my 327 before I shoot a small brass like 32s&w long in the 327 . If you have any orther thing need to ask me let me know by PM . What it all comes down to is stick with what the brass is made for data and do not max and then you will be good and safe .I always stay away from the max loads . If I have the gun shoot the way I want why need the max load it is a waste of brass and powder .

ku4hx
12-26-2011, 09:51 AM
Load .38 Special level charges in .38 Special brass and load .357 Magnum charges in .357 Magnum cases. You can always load reduced charges in each to a point as specified in published and verified load manuals, but the only safe thing to do is have the head stamp be appropriate for the gun the cartridge is designed for.

What you load for yourself may be safe in your guns, but do you really want the liability of basically mislabeling ammunition?

atlatl
12-26-2011, 12:10 PM
I appreciate all the answers, I have been reloading for a long (20 years) time and have no desire to find the edge of safety. However, I want to use 38 special brass as I have alot of it and it ejects readily from the J frame whereas 357 does not due to length. Actually, 38/44 data is exactly what I want but none exists for the 135 gr Gold Dot bullet. My question is simply, as I have reliable .357 load data with Unique powder and I know the velocity that load will give in my gun, then if I load 38 special cases with the same bullet to the same velocity using the same powder (but a lesser charge) if the velocity is the same then the pressure (and safety) should be the same. Right? BTW I'm not even wanting to achieve 357 velocities, just alittle more than the Speer data gives the 38.

1Shirt
12-26-2011, 12:14 PM
Listen to Ben on this one! Load 38S to 38 limits and if you are shooting them in a 347, no reason why +P loads wouldn't be fine. Beyond that think you are pushing the envelope of logic.
1Shirt!:coffee:

mdi
12-26-2011, 01:46 PM
I appreciate all the answers, I have been reloading for a long (20 years) time and have no desire to find the edge of safety. However, I want to use 38 special brass as I have alot of it and it ejects readily from the J frame whereas 357 does not due to length. Actually, 38/44 data is exactly what I want but none exists for the 135 gr Gold Dot bullet. My question is simply, as I have reliable .357 load data with Unique powder and I know the velocity that load will give in my gun, then if I load 38 special cases with the same bullet to the same velocity using the same powder (but a lesser charge) if the velocity is the same then the pressure (and safety) should be the same. Right? BTW I'm not even wanting to achieve 357 velocities, just alittle more than the Speer data gives the 38.
Seems to be a lot of guessing going on here. Powder burning rates are not linear. As pressures increase (or decrease) the burn speed changes too. I may not know how to explain it but, with a certain case capacity a powder will burn at x speed whereas smaller capicity, higher pressure, powder may burn at xx speed, exponentially increasing pressure (?), or sumpin' like that.

My recommendation would be to load your 38 Spec brass to +P levels. If more velocity/energy is needed, go to a bigger gun that will eject 357 brass...

Recluse
12-26-2011, 02:18 PM
However, I want to use 38 special brass as I have alot of it and it ejects readily from the J frame whereas 357 does not due to length.

[smilie=b:

So you'd rather forego spending maybe $20 worth of new .357 Magnum brass to experiment with a $600 gun, all because the shorter brass is "easier to eject?"

[smilie=b:

I can't even believe I'm still reading this. Another one for India Lima.

:coffee:

tonyjones
12-26-2011, 02:33 PM
There is so much published, pressure tested load data available for .38 Special, .38 Special +P, .38/44 HD and .357 Magnum that I see NO NEED WHATSOEVER to interpolate load data in this instance. You have been given some excellent advice. Take it!

Regards,

Tony

geargnasher
12-26-2011, 05:50 PM
Clean the carbon rings out of the chambers, and trim your .357 Magnum brass to the proper length. If it's still tough to eject, reduce your loads, your gun is trying to tell you something and if you don't listen it will hurt you.

Gear

ku4hx
12-26-2011, 06:05 PM
RE: "However, I want to use 38 special brass as I have alot of it and it ejects readily from the J frame whereas 357 does not due to length."

I'm confused. How does case length enter into it? A long loose case will eject just as easily as a short loose case. If the .357 cases are sticking I'd assume either your sticking loads are over pressure of that part of each cylinder past the mouth of a .38 Special case is somehow rough or burred. Or maybe you need to trim the .357 cases back to nominal trim-to length. Are you using some kind of extra thick .357 Magnum brass?

In any case the gun is trying its best to tell you what's wrong.

EDK
12-26-2011, 06:15 PM
Skeeter loaded LYMAN 358156 seated to use the LOWER crimping groove in 38 special brass and WARM 38 loads in 357. IIRC he did not use full magnum loads.

The reasoning was that in the late 50s and through the 60s there was not a lot of 357 magnum brass available...police departments used 38 special for issue...and in a lot of cases, reloaded their own practice/qualification ammo. A LEO with a 357 revolver who carried it with magnum ammo was cutting edge...probably given some hard looks by "the old heads" in his department.

As the social unrest of the 60s/70s, Viet Nam war protests, etc. progressed, the politically correct law enforcement administrators got pretty paranoid about a gun with MAGNUM stamped on it or hollow point ammo...DUM DUMS. THEN in 1973, Clint Eastwood as DIRTY HARRY really stirred the pot!

Enough of the history lesson. 357 brass is cheap and readily available. Load 357 or lower loads in it. Load 38 brass with 38 loads. Anything else is likely to damage your gun or you...and if someone else gets hold of your "chilli peppers," the legal and financial problems will be traumatic. BESIDES which, I don't think you'd enjoy high end ammo in your snubby...whether it is proofed for it or not!

Remember Uncle Ed's laws for pistol shooters.

1. If they don't make carbide dies for it, forget it.
2. If you have to load it to maximum, you need a larger caliber.

You want to shoot magnums, get a S&W model 65 or some other K frame...an L-frame might not be a bad idea either. Well designed holsters and belts would carry a heavier...read more durable...revolver almost as well as your J frame.

:redneck::cbpour:

Tazman1602
12-26-2011, 06:20 PM
What Beagle said.............................

Art


I'd stick to the data for 38 Special +P loads even though it's a .357 Magnum gun. Using .357 data in these short cases will run the pressures up and although in the past, many have done it, it only takes one weak case and you've ruined a good gun and maybe injured yourself or worse.

There is certainly enough data out there for .38 Special +P loads and older .38/44 loads to give you nice peppy loads if you want to use .38 cases.

If you want mag loads, get mag cases./beagle

rbstern
12-26-2011, 06:28 PM
RE: "However, I want to use 38 special brass as I have alot of it and it ejects readily from the J frame whereas 357 does not due to length."

I'm confused. How does case length enter into it? A long loose case will eject just as easily as a short loose case. If the .357 cases are sticking I'd assume either your sticking loads are over pressure of that part of each cylinder past the mouth of a .38 Special case is somehow rough or burred. Or maybe you need to trim the .357 cases back to nominal trim-to length. Are you using some kind of extra thick .357 Magnum brass?

In any case the gun is trying its best to tell you what's wrong.

I think the issue he's referring to is the ejection rod length rather than case stickiness. The 357s don't come out as readily because the ejection rod on the j frame is very short, and the longer case compounds the problem.

ku4hx
12-26-2011, 06:34 PM
I think the issue he's referring to is the ejection rod length rather than case stickiness. The 357s don't come out as readily because the ejection rod on the j frame is very short, and the longer case compounds the problem.

Oh ok ... never had that particular problem. Well ....... now that I think more about it I may have many years ago. But I seem to recall pulling them one by one after the ejector did all it could. Unless this is a personal defense gun and you anticipate having to reload I'd opt for the finger tip pinch 'n pull solution.

Char-Gar
12-26-2011, 06:49 PM
If I understand what you want is to develop 38/44 loads for you J frame Smith using the 125 JHP and Unique, but have no data.

Now I would call that about 1,200 fps.

I have fired many, many 38/44 type loads (in 38 Special Cases) in a .357 magnum handgun with no issues as well as thousands of more shooters over the years.

Right now I loading 358156 HP (150 grain) over 7.5/AA5 for a velocity of 1,100 fps at a pressure of 24.6 CUP. This is well below any pressure that is going to get anybody in trouble in a .357 Magnum revolver or a heavy frame 38 like the Smith and Wesson Heavy Duty or Colt Single Action.

I have no experience with those itty bitty Smith J frames in 357 and don't want any. A friend offered to let me shoot his and I declined. Just too much recoil and blast for me to hit anything and I don't need a puberty test. You can have my share of them.

But if a fellow had a mind to do so, I don't see a reason why load with unique in a 38 Special case and a 125 JHP at a pressure below 25K CUP could not be developed and be plenty safe.

I certainly don't think a fellow should shoot for full snort 357 Magnum pressures (35K CUP)in a 38 Special case. I can find all kinds of reasons not to do that. But 25K CUP and what velocity that gives you, I would have no problems with.

If I have read your post correct this is about what you are looking for. I don't think you will be able to find such data in print but a fellow with a good reloading handloading program would be able to give you some pretty reliable numbers.

rsrocket1
12-26-2011, 08:05 PM
Here are some numbers:
in a .357 case
135g GD HP 1.590 COL; 0.280" seating depth
7.5g Unique 4" bbl
26.1 ksi (25% below SAAMI Max) 1136 fps

in a 38 Special Case:
everything else the same (0.280" seat depth)
31.4 ksi (12.9k above max for 38SP+P, 14.4ksi over max for 38SP)
1210fps. That's waaay over rated pressure for the case and right on the edge for .357 magnum pressures. Note the added pressure because of the smaller volume.

Would it blow up the gun? If the cases were at least as strong as those for .357, maybe not. Would I want to shoot these or be standing within 50 feet of you when you did? No.

I know that 5.0g Unique had been a lot of shooter's standard load and I loaded up 100 of these and found that they are good stout 38 +P rounds which give me 1000 fps with 158g LRN and LSWC's seated to 1.466". I have since figured these are generating about 24ksi and am no longer using this load. Even though it is well below 357 pressures, I figured "use 357 loads for 357 cases and 38 loads with 38 cases".

geargnasher
12-27-2011, 12:50 AM
Thanks or running the numbers, RSRocket1, they show exactly what we've been cautioning about.

Gear

Bret4207
12-27-2011, 09:53 AM
Alright, I understand what the OP is after. IMO, and it's worth just what you paid for it, you need to rethink your theory here a bit. The same powder with the same bullet at the same speed in a smaller case does NOT mean equal pressures. I'm not familiar with all the new age Smith model designations, but in a J frame the old stand by of 5-5.5 Unique and 150-160 boolit in 38 brass is simple and works. If you really want to use jacketed, lightweight bullets then start hunting the powder charts for a load giving high speed with low pressure in 38 brass with a similar weight bullet and go from there. I would also suggest you read up on pressure signs and warnings.

atlatl
12-27-2011, 02:46 PM
Here are some numbers:
in a .357 case
135g GD HP 1.590 COL; 0.280" seating depth
7.5g Unique 4" bbl
26.1 ksi (25% below SAAMI Max) 1136 fps

in a 38 Special Case:
everything else the same (0.280" seat depth)
31.4 ksi (12.9k above max for 38SP+P, 14.4ksi over max for 38SP)
1210fps. That's waaay over rated pressure for the case and right on the edge for .357 magnum pressures. Note the added pressure because of the smaller volume.

Would it blow up the gun? If the cases were at least as strong as those for .357, maybe not. Would I want to shoot these or be standing within 50 feet of you when you did? No.

I know that 5.0g Unique had been a lot of shooter's standard load and I loaded up 100 of these and found that they are good stout 38 +P rounds which give me 1000 fps with 158g LRN and LSWC's seated to 1.466". I have since figured these are generating about 24ksi and am no longer using this load. Even though it is well below 357 pressures, I figured "use 357 loads for 357 cases and 38 loads with 38 cases".

yes but I'm not suggesting to use the same amount of powder. I'm asking loaded at the same velocity (which would require less powder given there is less case capacity). If you have quick load or some thing similar - equalize the velocities and you will discover the pressures are similar. Should you want to do me a favor, try the 135 gr Speer with 6.2 gr of Unique in a 38 special case, I'm betting the pressure is less than full house 357 probably equivalent to 9mm Luger. Thanks, I did not intend for this thread to be a diatribe about safety or common sense but more a discussion of internal ballistics.

zxcvbob
12-27-2011, 03:12 PM
Here's a load that I shoot sometimes: .38 Special brass, 148 grain DEWC boolit @ 1.35" OAL, 7.0 grains of WSF powder (equivalent to about 6.5 grains of Unique.) Use at your own risk. Loaded to this length, the cartridges will not chamber in a .38 Special. I like it because I can switch the progressive press over to it from loading .38 Specials by only changing the powder and the seating die -- don't have to mess with the expander, the powder drop linkage, or the crimp die.

Papa smurf
12-27-2011, 03:55 PM
If I have learned anything in my 73 years its some folks have to learn on there own.
So you just sit back and watch and hope they dont hurt anyone else .----Papa Smurf

BOOM BOOM
12-27-2011, 04:14 PM
HI,
IFIRC the 38+p or 38 +p+ loads are in the velocity range of the 357 loads found in Lyman & Speer manuals.
These 38 loads are recommended to be only used in heavier revolvers.
I load more for accuracy nowadays rather than power/velocity.
Power is more for mag brass in my usage.:Fire::Fire:

9.3X62AL
12-27-2011, 04:52 PM
Not many of my 38 Special cases get loaded at "+P" levels any more. With plentiful 357 Magnum casings/cartridges ready at hand--and 2.5", 4", 6.5", and 7.5" barrelled revolvers in the safe, I am more apt to "tune" 357 Magnum loads to varying intensities than the 38s.

The question about extraction of fired cases shorter in length than the extractor rod on short-barrelled revolvers is a valid concern. The cases MUST release from the cylinder sidewalls, so pressures need moderating to accomplish that goal. My view is that boosting pressure of ammunition works at cross-purposes to the stated intent. My suggestion would be to load 357 cases to a pressure level of the old FBI load--158 lead HPs @ 900 FPS in a 4" 38 Special. My experience in the 2.5" Model 19 has been that mildly loaded 357 cases eject more readily than do hot-loaded 38s or 357s.

Bret4207
12-27-2011, 07:15 PM
yes but I'm not suggesting to use the same amount of powder. I'm asking loaded at the same velocity (which would require less powder given there is less case capacity). If you have quick load or some thing similar - equalize the velocities and you will discover the pressures are similar. Should you want to do me a favor, try the 135 gr Speer with 6.2 gr of Unique in a 38 special case, I'm betting the pressure is less than full house 357 probably equivalent to 9mm Luger. Thanks, I did not intend for this thread to be a diatribe about safety or common sense but more a discussion of internal ballistics.

If I follow you correctly, then the answer is still no, but it's a "depends on"/qualified sort of no. Making the assumption that in similar cases a given velocity with the same bullet will give SIMILAR pressure, or that at similar pressure you will get similar velocity. As I understand it, and you can find a lot of this info in the standard reloading manuals, it's not that simple. I've thought along the same lines myself because it seems like it makes sense. But you have to factor is the smaller combustion chamber and it's shape and the possibility that the internal case shape is quite different. You also have to factor in what that smaller combustion chamber does with that specific powder charge. Like I said earlier, you can go way past 357 pressure ( in this case) and never get the same speed. it's going to depend on the powder, the brass, etc. That's why I say read up on judging pressure or get some help with it because it's not always going to go like it seems it would. A lot of the time it does, but making assumptions has gotten me in trouble with things along the same lines as you want to do.

geargnasher
12-27-2011, 07:15 PM
yes but I'm not suggesting to use the same amount of powder. I'm asking loaded at the same velocity (which would require less powder given there is less case capacity). If you have quick load or some thing similar - equalize the velocities and you will discover the pressures are similar. Should you want to do me a favor, try the 135 gr Speer with 6.2 gr of Unique in a 38 special case, I'm betting the pressure is less than full house 357 probably equivalent to 9mm Luger. Thanks, I did not intend for this thread to be a diatribe about safety or common sense but more a discussion of internal ballistics.

Safety, common sense, and internal ballistics are very much interrelated. The part I highlighted in red bothers me very much about your understanding of what you're trying to do, and similar misconceptions you've put forth earlier on have concerned me and others from the beginning, that's why this has turned into a safety and common sense thread. Things related to internal ballistics are not as linear as they might first appear.

Gear

geargnasher
12-27-2011, 07:17 PM
If I follow you correctly, then the answer is still no, but it's a "depends on"/qualified sort of no. Making the assumption that in similar cases a given velocity with the same bullet will give SIMILAR pressure, or that at similar pressure you will get similar velocity. As I understand it, and you can find a lot of this info in the standard reloading manuals, it's not that simple. I've thought along the same lines myself because it seems like it makes sense. But you have to factor is the smaller combustion chamber and it's shape and the possibility that the internal case shape is quite different. You also have to factor in what that smaller combustion chamber does with that specific powder charge. Like I said earlier, you can go way past 357 pressure ( in this case) and never get the same speed. it's going to depend on the powder, the brass, etc. That's why I say read up on judging pressure or get some help with it because it's not always going to go like it seems it would. A lot of the time it does, but making assumptions has gotten me in trouble with things along the same lines as you want to do.

Ya beat me to it, Bret!


Gear