38's in a .357 magnum rifle and the POI paradox


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R.W.Dale
March 25, 2010, 12:05 AM
Friends, Romans, 357 long gun shooters! I've gathered you here to have a discussion on if and how you've worked around the sighting and POI issues that result from shooting the two vastly different cartridges a 357 carbine can shoot.

Now in my case between two 357 long guns the difference in impact between 38's and 357's at 100yds is best expressed in FEET. With the 38's printing much much higher due to in bbl dwell time. We're talkin 1750fps 158grn loads for the magnum vs sub 1000fps loads for the special.

Thus far my only solution has been to consider both firearms as "one load" guns, particularly as one (the 357 rolling block) doesn't have enough elevation adjustment to even place 38's on a target board at 100"

IMO this is a dirty little pistol cal carbine secret that doesn't oft get discussed as it should. Folks like to point out how a 357 or a 44 carbine can shoot specials and how great that is, but they omit to mention that the gun will have to be completely resighted for each load in not only elevation but in some cases a bit of windage as well as with my marlin.

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lexjj
March 25, 2010, 12:29 AM
have you experimented with different bullet weights?

DPris
March 25, 2010, 12:33 AM
It can easily be solved by shooting .357s in .357 carbines. :)
Otherwise, of course you'll have diverging POIs.
Denis

R.W.Dale
March 26, 2010, 11:08 AM
anyone?

Jason_W
March 26, 2010, 11:12 AM
I have two williams peep sights for mine. Changing them depending upon load is pretty easy.

I don't shoot .38s out of it much anymore though. I have enough .357 mag brass so that I may as well just load .357 mag rounds down to the .38 spl level. I'm not sure, but I think doing this avoids some fowling problems that can occur when shooting specials.

bogus mcall
March 26, 2010, 11:53 AM
Krochus, in shooting my 44 mag marlin I have found that for practice and short range shooting, a light load of 7 gr tight group under a MB 240gr smasher shoots to poa @ 25yrds while 23 gr of H110 under 240gr XTP shoots poa @ 100yrds. Its just trial and error. I. Don't know of any short cuts. Oh, and by the way, the light loads hit about 3ft low at 100yrds.

farscott
March 26, 2010, 03:01 PM
I use two different sights in my Marlin 1894 to accomplish this. The factory "semi-buckhorn" sight is used for .38 Special loads, and the Marble peep sight is used for the .357 Magnum loads. To use the .38 Special, fold down the peep sight and flip up the factory rear blade. To shoot .357 Magnums, fold down the factory rear blade and flip up the Marble peep.

It works pretty well for me. I got the idea from switching between .22 LR and .22 CB loads in my Marlin 39AS and the resulting problems and from an article Francis Sell wrote about hunting with lever actions.

R.W.Dale
March 26, 2010, 03:56 PM
Some very innovative suggestions! Keep em coming

Cosmoline
March 26, 2010, 03:57 PM
I really like the three-leaf "safari" style sight systems. You can find them on gunbroker sometimes for standard dovetails.

Dynamite Rabbit
March 26, 2010, 04:01 PM
My understanding is that if you shoot .38s with a 180 grain bullet and about 4.4 grains of 231 you don't have to worry about where the bullet hits... :eek: :p

goon
March 26, 2010, 09:14 PM
In the 1894 Marlin I used to own it actually shot full power magnums and .38 Special handloads of reasonable power close enough at 50 yards that I could mostly hold dead on.

R.W.Dale
March 26, 2010, 09:16 PM
My understanding is that if you shoot .38s with a 180 grain bullet and about 4.4 grains of 231 you don't have to worry about where the bullet hits... :eek: :p
LOL but this only applies to the 1st shot. Subsequent bullet impacts become a big problem!

oldfool
March 26, 2010, 09:40 PM
depends on what your ambitions and expectations are, I guess

never yet saw a 38sp out of a 357 6" revolver that would hit same POI for same POA as a 357 out of a six inch revolver at 100 yards... nor a 22 rimfire either @50 vs 100, not out of any gun, short or long
(but mebbe I just haven't yet found the right gun yet, could be)

"windage and elevation" counts for most pistol cartridges out of most any gun, long or short, at 100 yards

if limit your ambitions to ~50 yards, only about a 1" difference out of most loads w/ carbine/rifle barrels 357 vs. 38sp
357s are prone to leave the muzzle a tad quicker than 38sp
but most pointy bullets shoot a bit flatter out of rifles than most non-pointy bullets

joneb
March 27, 2010, 01:14 PM
With the 38's printing much much higher due to in bbl dwell time.
have you experimented with different bullet weights?
I would load a 110gr.ish fast .38spl and a 180gr for .357 mag.

wcwhitey
March 27, 2010, 09:07 PM
In my case the only .357/.38 rifle I have is a Rossi SRC 16". The longest I have shot it is 50 yards. For me nail polish was the answer. Green for .38 (my reloads) and Red for .357 (my reloads). What I am saying is that all I have to do is adjust the rear sight to the appropriate notch on the ladder and I am good to go. POI is perfect for both. I don't think of the rifle as a target gun but with the color coding it is minute of coke can out to 50 yards no problem. Bill

R.W.Dale
March 27, 2010, 09:18 PM
I suppose I should add that my expectations for both firearms are pretty stringent. Which I'm pleased to say they're both exceeding. For example I was shooting the uberti rolling block at an 11" steel spinner at a range of 200m and making a fine showing might I add.

oldfool
March 28, 2010, 02:26 AM
I suppose I should add that my expectations for both firearms are pretty stringent. Which I'm pleased to say they're both exceeding. For example I was shooting the uberti rolling block at an 11" steel spinner at a range of 200m and making a fine showing might I add.
I dunno,
I don't think your accuracy expectations are at all unrealistic
3 moa (or better) isn't the least bit unrealistic with centerfire lever actions, some do quite a bit better
I guess I just didn't get the "surprise" factor re: trajectories of handgun cartridges (no matter how long the barrel), that's all
there never was any secret about it, much less a dirty little secret

some 45-70 guys shoot 1000 yard steel, some 30-30 guys kill whitetail at 300 yards, yet neither of those shoots all that fast-n-flat... much less with loadings of such disparate muzzle velocity as 38 vs 357
(those 45-70 guys often have really tall elevators on those peepers, because they expect to use them that way)
and you can get some really tall aftermarket elevator peep sights for most any lever action
(Marble's mebbe, I haven't looked for any such in too long now)

but 38/357s never have been touted as 200 yard hunting or target rifles, leastways that I know of (45-70s they ain't)
as some of the posters indicated, most of us shoot handgun cartridges at <100 yards, and within that context, elevation for zero just isn't all that radical... at 50, not enough to even bother with sight adjustment, just use a 6 o'clock hold instead of split center hold

if looking for fast-n-flat in a nice lever action, look at Browning BLRs, they do a bunch of fast pointy cartridges, and will hold their own with traditional bolt guns (because they "are" bolt guns)

R.W.Dale
March 28, 2010, 10:12 AM
as some of the posters indicated, most of us shoot handgun cartridges at <100 yards, and within that context, elevation for zero just isn't all that radical... at 50, not enough to even bother with sight adjustment, just use a 6 o'clock hold instead of split center hold

at 50yds with both my rifles fired from the bench the poi disparity is getting close to 2'

as to accuracy at 100m the rolling block is holding around 2moa with thr marlin not being tested much yet. Steel with a pistol cartridge carbine is just fun at longer ranges

WyrTwister
March 28, 2010, 11:59 AM
I have a Winny M 1892 that some one at some time converted to .357 Mag .

I have more .38 Special brass , than .357 brass .

I shoot a RNL ~ 150 grain bullet home cast from a Lee 6 Cavity mold . ( My pistol caliber lever guns seem to feed the RNL better than the SWC's I used to cast for wheel guns . )

I load about a 75% .357 pressure load ( either WC820 or AA # 9 ) in both kinds of brass .

The .357 brass gets the bullets seated & crimped at the last groove , closest to the nose of the bullet . The .38 brass gets the bullets seated and crimped one groove " longer " .

This makes the .38's ~ the same OAL as the .357's , with ~ the same internal case volume .

My Winny was set up to feed .357 OAL . Does not feed .38 OAL ammo very well .

So both the .357 and the .38 ammo is essentially interchangeable . And my S&W does not care either .

Just take a little additional care , when cleaning the chamber .

By the way , I do not own a .38 Special firearm . So , I am not concerned with having .38 ammo that is too hot for a .38 chambered gun .

God bless
Wyr

oldfool
March 28, 2010, 05:55 PM
at 50yds with both my rifles fired from the bench the poi disparity is getting close to 2'

as to accuracy at 100m the rolling block is holding around 2moa with thr marlin not being tested much yet. Steel with a pistol cartridge carbine is just fun at longer ranges
did not mean any above to be contentious, just honestly don't get it, and cannot think of any explanation for 2 feet elevation difference at 50 yards, same POA vs POI (sights untouched), 38 sp vs 357

I just shoot whatever "cheap (?)" off-shelf factory fodder I can find (don't reload), if it's "cheap", I buy it if/when lucky enough to find any, these days
ain't nothing special about mine, generic Marlin 1894 and LSI/Rossi '92, and they both shoot 38 vs 357 same difference at the ranges I am talking about, no matter whether using open sights or low power scope or red dot... ~ 1" difference at 50 yards IF/WHEN zeroed at 50 with either load, mebbe ~ 1 1/2" difference max
both will do ~3 moa with 38s, ~ 2 moa with 357s

if sighting same gun for a 200 yard zero on one cartridge, then switch cartridges, sights untouched, sure big difference expected.. but not supposing that was what you were saying

I am misinterpreting something, but somebody here ought to know what it is

R.W.Dale
March 28, 2010, 06:15 PM
did not mean any above to be contentious, just honestly don't get it, and cannot think of any explanation for 2 feet elevation difference at 50 yards, same POA vs POI (sights untouched), 38 sp vs 357

because you're thinking in terms of pure trajectory and external ballistics only.

Prolly the biggest factor coming into play is in bbl dwell time. Note the slower 38 are printing HIGHER than the 357's this is because the gun's has had a chance to move upward under recoil before the much much slower 38's can clear the muzzle. At 50yds the difference is the 38's hitting almost 2' high at 100 it's still over 3'

I just shoot whatever "cheap (?)" off-shelf factory fodder I can find (don't reload), if it's "cheap", I buy it

This is likely also a contributing factor with your experiencing. Factory .357 ammo particularly the cheap stuff isn't known for being the highest performing loads. Leading me to suspect your 38-357 velocity disparity is a lot less than my almost 1000FPS velocity difference

oldfool
March 28, 2010, 06:56 PM
"this is because the gun has had a chance to move upward under recoil before the much much slower 38's can clear the muzzle."

I dunno,
me "old shaky", I shoot for groups off a sandbag .. my barrel don't move enough to matter all that much, recoil/muzzle rise with 38sp is pert near zero, and hardly-more-than w/ 357
but it can't be your stance/hold/trigger, not doing 2 moa (with either/any load), no way, not suggesting any such

maybe it is barrel dwell time on 1750 fps vs 1000 fps, but I just ain't "been there done that", can't help

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