.357 more accurate than 38sp out of a .357 carbine?

idek

New member
I have a .357 lever action, but I've mostly shot 38sp loads in it. However, since I could load .357 cases down to 38sp levels if i wanted, would I likely get better accuracy from downloaded .357s compared to 38sp since it would eliminate that extra little jump from the chamber to the rifling?
 
I'm going to take a stab at this; even though I'm no expert. Someone smarter than me may come along and supersede everything here:

The short answer is: I don't think it matters. For starters, both 38 Special and 357 Magnum are inherently accurate chamberings. I shoot a lot of 38 Special rounds through 357 Mag handguns. And I can tell you that they shoot straight. I don't see how it would be any different in a lever action rifle.
 
I know from shooting 44 mag and 45 Colt rifles that accuracy does not depend on reaching the lands. It is more dependent on roll crimp.
 
Thanks for the responses. I'll probably keep loading 38sp cases then, and reserve my .357 cases for actual .357 loads.
 
I get slightly better accuracy in my H&R single shot carbine with .357 brass, but the bullets are still nowhere near the lands.

For lever guns .357 brass usually cycles better, but it doesn't sound like you have a problem there. My Marlin did not like .38 brass.
 
I guess there is no way to tell about accuracy really, other than to try different ideas out and see what you get.

I agree with another contributor who suggests that a good roll crimp makes a difference, at least with cast bullets.

The reason I shoot 357's exclusively in a 357 lever gun is that I have experienced really stubborn fouling build up from shooting 38's, which are short for the chamber. Right at the 38 case mouth a ring of lead, lube, and carbon builds up in the chamber which I have never felt right about, and have had difficulty removing. Probably this same crud is in my leade or throat anyway, and not readily observable, but I run a brush through there from time to time in effort to keep this at bay.

I have read of a number of ways to remove this 38 crud, but I find it simpler to avoid it in the first instance by using the longer 357 brass, and finding a load my rifle likes.
 
Without trying it with your gun, you'll never know. Since handgun caliber carbines are short-range firearms, difference in accuracy between special and magnum cases may be so insignificant at 100 yards(1/2'') or less it won't really matter. Unlike with a rifle cartridge where that 1/2'' will equal two inches @ 500. I've found that while special loads(both .38 and .44) shoot accurately outta my carbines, when pushing the limits of their legitimate range, the magnum loads perform better. I see little difference in accuracy(from my carbines) when using magnum cases with special loads in either caliber.
 
...would I likely get better accuracy from downloaded .357s compared to 38sp since it would eliminate that extra little jump from the chamber to the rifling?
It has been my experience that it is true from S&W revolvers. However, others have reported no difference. I was so dissatisfied with the groups I was getting in .357 Mag.s using .38's, that I gave up on using .38 hand loads in them and just went with hand loads based on .357 cases. If you hand load for both .38 Spl. and .357 Magnum, there is no compelling reason to use .38 Spl. cases in a .357.
 
In a machine rest at 50 yards you should get better accuracy with the longer case and you prolly will. Shooting the gun on your hind feet you prolly can't tell the difference especially at close range.
 
I'll probably keep loading 38sp cases then, and reserve my .357 cases for actual .357 loads.

That is my recommendation.

I know it's getting out of scope from your original question, but I am of the school of thought that it is not a good idea to download 357 cases to 38 level performance. It's not dangerous. I just think that it lends itself to inconsistency. It's just rudimentary to not want a bunch of excess space inside the case; and 38/357 are rather cavernous as it is. Why exacerbate the condition? Excess space slows the burn rate, and reduces efficiency (more propellant needed to achieve the same performance, compared to a smaller case). None of this sits well with me.

There are loaders who say they do it without trouble. That's fair enough. But I choose not to.
 
In my Marlin 1894CS, loads put up in .357 brass are more accurate than those in .38 Special hulls. I've loaded a hellofa lot of cast bullets, gas checked in both types of brass using, Unique, 2400, Ac#9, 231, and Herco and the .357 brass is always better. Same with Hornady's 158 gr XTP, Remington's 158 gr JHP, and Sierra's 158 gr JHP, the .38 Special loads are never quite as accurate.

In magnum brass, that carbine is good for ~1" gps at 50 yds with either the cast bullet or Hornady's 158 gr XTP. At 100 yds, the Hornady is always a bit better than my cast, but not by much. Either will do 1-1/2" gps for the first three shots, using magnum brass, off a rest with a 2.5x scope mounted.

HTH's Rod
 
357 carbine

My Puma 357 rifle cycles 357's better but accuracy is a tossup.38's in it tickle instead of kick but at plinking ranges neither look to be more accurate than the other.
 
I think if you strapped the rifle down to a ransom somehow, you would find that the 357 would be indeed more accurate at 50 yards and over.

I am personally more accurate shooting .38 spl because of the lower recoil and more manageable control. but I believe with a proper bullet with a good BC would be more inherently accurate with the higher velocity of a .357 loading. but it's only as accurate as the shooter.

I am strictly speaking about velocity, this doesn't even mention the huge jump to the lands from a 357 chamber using a 38spl case. this can be easily remedied by using 357 brass with a 38 loading though. I doubt you or I will be

able to tell a difference between any configuration though, if not only that we would group better with 38 because it's an easy to shoot round. I think the debate could only be decided in a bolt action, scoped 357 rifle being shot from bags with an expert rifleman.

after writing the above, I scoured the webs for bolt ation 357 shoot-ots, very hard to find any extensive testing on the subject. I did find a couple articles on the ruger 77/357 bolt action, and it's tightest groups seemed to be from .357mag loadings, although nothing scientific about the testing.and very little info about the 38spl in general
http://www.gunblast.com/Ruger-M77-357.htm
http://www.alloutdoor.com/2013/08/27/ruger-77357-bolt-action-rifle-review-ultimate-survival-rifle/
http://www.americanrifleman.org/articles/2011/11/30/ruger-77357-rotary-magazine-rifle-review/
 
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I've spent a considerable amount of time working with just this scenario. I can tell you for a fact that 38spl will not shoot as well as 357 cases out of the rifle. There are a couple of reasons but primarily, the throat in the rifle can make all the difference in the world as to how well your rifle shoots. Having a long throat will cause problems from the bullet "jump" to the lands as well as the diameter of the throat. Cast bullets are especially effected by this. If gases get "around" the bullet before it enters the throat it will cause leading and will not obturate the bullet properly. The very best case is when the bullet is entering the lands before the base exits the case. Can this be measured...easily. Spend some time at the bench shooting both side by side with the same bullets and loads and you'll easily see the difference in group size. Do not use .357mag loads in 38spl cases. If you're simply shooting for fun and accurate groups, you can use 38spl loads in .357mag cases.
 
Differnce in accurracy? In theory, probably, but You'll never know the difference. Your load and component combination will be a far greater factor than which case you use.
 
I've spent a considerable amount of time working with just this scenario....fact
that 38spl will not shoot as well as 357 cases out of the rifle...the throat [jump]
This ^^^^ +1 ^^^^

Now if you seat the bullets way out (and can somehow still get a good crimp), you might be able to get away w/ 38SP cases.
(But why bother -- just get/use 357cases and be done with it)





(Unless, of course, you're just plinking at tin cans & mud turtles ≤ 25 yards. Then bang away. ;)
 
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