Accuracy shooting .38 from .357 revolver

H

higgscharger

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Truth or myth:

When you shoot .38 from a .357, you get slightly worse accuracy than shooting a .38 from a natural .38 because the .38 is slightly smaller?
 
Probaby truth.
bullets same, cartridge length different. With the 38 there will bigger jump to forcing cone which will affect accuracy.
 
I was shooting a friend's S&W Model 19 last week, using my reloads. At seven yards, I looked at the target after three shots. No way could I miss the whole paper from that distance! Turns out they were in exactly one hole- not a ragged hole, not a clover leaf- one hole. I'd never done that before. I'll continue to shoot .38's from a .357 when I can, thank you very much.

Chuck
 
Theoretically the longer jump to the forcing cone might result in reduced accuracy, however it doesn't seem to be much of an issue.

If we eliminate the .357Magnum from the equation and think about the effect of bullet jump on accuracy in the .38Spl, it is instructive to remember that some of the most accurate .38Spl ammunition uses wadcutters which are seated flush with the top of the case--therefore resulting in a longer jump until the bullet bearing surface encounters rifling as compared to a more conventional rounded bullet.

But let's compare the two rounds to see just how much of a bullet jump difference there is.

It is a fact that the .357 Mag case is longer, however it's not longer to provide extra powder capacity, it's longer to prevent .357Mag rounds from being chambered in .38Spl cylinders. What that means is that while the cartridge cases differ in length by 0.135", the overall length of the two cartridges (bullet included) is typically very similar because there's no pressing reason to seat the .357Magnum bullet out to maximum length. In practice, the overall length of the two cartridges (as loaded) is essentially negligible. If you compare SAAMI maximum overall lengths for the two cartridges, there's only a 0.04" difference.

So, in practice, there's probably not really much difference at all in bullet jump.
 
I have 3 S&W revolvers I shoot .38s out of; a model 27, a 28 (both .357 Mags), and a K .38 Masterpiece. With 148 WC, I can't tell any difference out to 50 yards.
 
I would have to say "truth".

I have two 38s and four 357s. I learned long ago, for plinking, to use the correct brass for the given chamber. If you reload you can always use a 38 charge in your 357 reloads. My 357 revolvers are just as accurate as my 38s when follow this recipe. This also prevents a crud buildup in your 357 chambers.
 
Don't guess I was ever good enough to see a difference. That's also with a revolver capable with optics of shooting 1 1/2" to 2" 50 yard groups from a bench. I would say its more about the mix of parts used in the loads.

I have stopped in my old age stopped shooting 38 brass in my 357. Just as easy to load a lite load for 357 as in 38 brass.
 
There should not be any difference in accuracy as fas as you can tell.

Theoretically there might be a small decrease in accuracy but you won't be able to tell in every day use.
 
In actual use, I had a S&W that shot better with loads (all my shooting is with my handloads), in .357 cases (.38 equivalent), than using .38 Spl. cases. If others report the opposite result, it may be reasonable to conclude that it depends on the particular gun. Having seen the difference in that gun, my current practice is to use .357 cases in 357's, .38 cases in .38's. No good reason for me to do it any other way, not interested enough to spend time testing all my .357's to see.
 
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...while the cartridge cases differ in length by 0.135", the overall length of the two cartridges (bullet included) is typically very similar because there's no pressing reason to seat the .357Magnum bullet out to maximum length. In practice, the overall length of the two cartridges (as loaded) is essentially negligible. If you compare SAAMI maximum overall lengths for the two cartridges, there's only a 0.04" difference...
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In theory that is true. However, in practice I use the very same cast lead bullets in both, seated the same distance. So in my ammo, there is a 0.10 difference in the OAL.
 
There should not be any difference in accuracy as fas as you can tell.
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As Judge Judy would say: Should, Would, Could. Speculation. I would be more convinced by shooting tests. Speculation is worth what it costs.
 
As I understand it, the issue isn't so much the jump to the forcing cone but rather the jump to the cylinder throat. When fired from a .38 Special gun, the bullet enters the cylinder throat immediately as it leaves the case. This keeps the bullet properly aligned with the barrel thus causing the least deformation and contributing to best accuracy. When a .38 Special is fired from a .357 Magnum revolver, however, it has to pass through a section of oversized chamber before making it to the cylinder throat. This means that the bullet may not enter the cylinder throat perfectly straight and therefore might be slightly deformed leading to less that perfect accuracy.

Bear in mind, however, that these measurements are very small, that several other factors contribute to accuracy, and that any actual difference will likely be slight enough to go unnoticed by most shooters.
 
any actual difference will likely be slight enough to go unnoticed by most shooters.
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Especially those shooters who use only factory ammunition and shoot beer cans rather than test accuracy shooting groups, supported, from the bench to actually test the accuracy. To such shooters, just hitting the beer can or not is all that is important. There are shooters, then there are "shooters."
 
Years ago, a custom PPC pistol was made with a cylinder cut short enough to only accept 38 wadcutters. As I remember the forcing cone was extended to meet the end of the cylinder. I think the appeal was more that the lighter cylinder improved the double action pull rather than the increased accuracy. The combination never became widely popular. Looking at the actual 50 yards groups custom .357 revolvers have made with 38 wadcutters it is hard to see how there is much room for improvement.
 
dahermit said:
Especially those shooters who use only factory ammunition and shoot beer cans rather than test accuracy shooting groups, supported, from the bench to actually test the accuracy. To such shooters, just hitting the beer can or not is all that is important. There are shooters, then there are "shooters."
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Some of the top PPC shooters of yore chose Model 19 .357mags to shoot .38 target loads. As others mentioned, if there's a loss of accuracy just by virtue of the jump to the throat, it's relatively small. Other gun-specific things, like how well the throat stabilizes the bullet, chamber/barrel alignment, condition of the forcing cone, etc., all likely play a much bigger role.
 
In theory the .38 would be less accurate fired in the .367 chamber. In reality it isn't necessarily true. Based on my experience. If I was shooting Bullseye with a revolver, I buy a .38 instead of the .357, chances are there wouldn't be much difference but in a match you want every advantage you can get. For shooting IDPA I use a 586 with .38RN lead bullets. Shooting D/A it'll keep every shot on the head of the target at 25yds. I haven't tried it in a machine rest so I don't know how accurate it really is.
 
I have never noticed a consistent difference in accuracy between .38 spl and .357 magnum loads. Out of my S&W 19 .357 mag, the most accurate load is the old .38 wadcutter load from Winchester-Western. A verrrry close second is Double Tap's 125gr magnum load. Various other .38 and magnum loads are all over the place so you just have to find what works for your particular revolver.
 
I have fired many thousands of .38 wadcutters out of several .357 S&W revolvers and a few Colts and never noticed any difference in accuracy from the .357's. In fact, due to the lower recoil of the .38's, the guns may well have been MORE accurate with .38 as far as practical shooting is concerned (vs. Ransom rest shooting). I never tried loading .357 cases to .38 levels. I never saw any need to do that, but I did load .357 cases with 9mm FMJ bullets; they worked fine and were about as accurate as the others.

Jim
 
Dahermit-
I pity you if all you do is shoot paper. I have filing cabinets full of paper targets with chrono printouts attached. But when I want to have fun, 'reactive' targets are my first choice. I have introduced a number of first time shooters to the sport. I don't think many would have returned seeing their first groups on paper. Reactive targets give immediate feedback from misses, and reward hits with occasional theatrics that can amuse both the shooter and spectators. Grown men giggle when that beverage container sails 10' in the air.
 
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