zeroing a nef 357 mag with 125g and 158g bullet

[jacks44mag]

I am trying to zero my nef 357 mag with a 125g and 158g bullet my reloading book said I can get  muzzle velocity of 1590 fps with 12.7g blue dot and 158g jhp and  muzzle velocity 1580 fpc with 7.2g of unique
On Hornady's Ballistics Resource and Calculator that if I zero both at 50 yards there would be only about .2
difference . well I zero the 158g but the 125g shoots 4 inches high. does anyone know why or what I can do to zero both

[gendoc]

must be pistol data ??
ain't but a few folks here had gud luck wifa 125gr bullet in the mag.

maybe i should say......i dunno !!!

i don't use either one of them powders

[Mac11700]

I am trying to zero my nef 357 mag with a 125g and 158g bullet my reloading book said I can get  muzzle velocity of 1590 fps with 12.7g blue dot and 158g jhp and  muzzle velocity 1580 fpc with 7.2g of unique
On Hornady's Ballistics Resource and Calculator that if I zero both at 50 yards there would be only about .2
difference . well I zero the 158g but the 125g shoots 4 inches high. does anyone know why or what I can do to zero both

Because nothing is definite when it comes to different rifles than the one that was tested to gain those results.There can always be a multitude of reasons,,from different lots of cases, powder,bullets..different conditions when shooting..different people shooting..The list is almost endless..One thing that is standing out about what you posted to me...did you chronograph these loads ? Do you know if you are getting the stated velocities..or are you just going by what the book recipe is calling for? While most book data is consistant with a lot of rifles,I've always found a few that would never come even close..

Mac

[mechanic]

Its a rare thing to have two different bullet weights to shoot to the same POI, but it's usually the heavier bullet that shoots high???  You might experiment some with the loads and get them close.  Thats something I've never really tried.  Best of luck though, and let us know how it comes out...would be good info to have.

[PawPaw]

The Alliant Reloader's Guide shows (for the .357 magnum with a 158 grain jacketed bullet), a max charge of 10.2 grains of Blue Dot.  Your load sounds to me like you're pushing the envelope a little bit.  Blue Dot isn't listed for a 125 grain bullet. 

I doubt you'll ever get both of those loads to shoot to the same POI.

I use L'il Gun in heavy loads with the .357 magnum and I'm getting about 1600 fps with a 180 grain flat-nosed, gas-checked lead bullet.

[trotterlg]

Problem is that if you push them the same speed the heavier bullet has more recoil than the light bullet and will shoot high.  The lighter bullet will shed speed faster and shoot lower.  This has to do with the muzzel rise when you fire.  A hotter load gererally shoots lower because it spends less time in the barrel so the muzzel hasn't risen as far as with the lighter load.  I think you need to chronograph the bullet speeds, I am betting you are getting nothing like what the load book says.  I think you will probably never get it perfect with any realistic load.  Larry

[knight0334]

You cant go by the book's velocities.   Its likely that the 125gr slug is going much faster than the 158gr at the muzzle..   Most book loads are for handgun length barrels, when you use a rifle length barrel velocities will go up.   The 125gr slug will most likely gain more velocity than the respective 158gr slug there for having less drop at standard ranges.   If you're shooting 50/100yrds with book quoted loads calibrated for handgun barrel lengths, you can probably figure in 300-500fps more for the 125gr and about 200-300fps for the 158gr.

The 158gr will usually have a better BC, but the sheer velocity that the lightweight slug will have will help it get further in less time - thus having less Galileo Drop(both objects fall to earth at the same velocity, hitting earth at the same time) in the same trap distance.  At 50-100 yard ranges, the velocity of the lighter bullet will factor more than the higher BC of the longer bullet.

Recoil doesn't usually effect first round trajectories.  The bullet is long gone and out the barrel before there is noticeable and measurable movement.  Recoil effects second and followup trajectories.

[jacks44mag]

Ok I know the muzzle velocity is for hand guns and will be differant with a rifle just trying to find a starting load close
The reloading book I have does show blue dot up to 13.7g so I'm still under max load this is a older book for 357mag only
I don't have any way to check muzzle velocity so I'm playing by ear.

[barm]

I know a guy who said he could get the 125's and 158's to hit with the same point of impact.  If I remember correctly the 125's were going about 200 fps less than the 158's to get the same point of impact.  I hope it helps.

[PawPaw]

my reloading book said I can get  muzzle velocity of 1590 fps with 12.7g blue dot and 158g jhp

Maybe I misunderstood your original post.  I went out and got some older loading data (Lee's Modern Reloading, 1996) and looked up the cartridge.  According to the tables in that older manual the max load for a 125 jhp and Blue Dot is 14.5 grains for a max velocity of 1795 fps.  That same table shows the max load for a 158 jhp to be 10.7 grains for a velocity of 1420 fps.

The most current data I can find from Alliant doesn't even show Blue Dot as an acceptable powder for the 125 jhp bullet in .357 magnum.  The current data shows that for a 158 jhp the max charge is 10.2 grains of Blue Dot for 1188 fps.

For a variety of reasons, powder and data changes over time.  This may be for product liability reasons, or it might be because the chemical composition of the powder has changed slightly.

I'm not going to tell you that you're in danger.  As a prudent handloader you know your equipment and your data.  There are times when I make an educated adjustment based on a long and knowledgeable experience with a particular set of data.  However, what was considered safe and effective 14 years ago may not be considered safe and effective today. 

[quickdtoo]

As Dennis stated, things change, Alliant had a warning on their website at one time on using Blue Dot with 125gr bullets in the 357.

I'm bringing this to the top due the warning on the Alliant website.

Tim

http://www.alliantpowder.com/safety/safetynotice.htm

Safety notice

Alliant Powder periodically reviews and tests their published reloading data to verify that our recommended recipes have not changed over time.
 
During the latest review Alliant Powder discovered that Alliant Powder's Blue DotŪ should not be used in the following applications:

Blue DotŪ should NOT be used in the 357 Magnum load using the 125 grain projectile (Blue DotŪ recipes with heavier bullet weights as specified in Alliant Powders Reloading Guide are acceptable for use).
Blue DotŪ should NOT be used in the 41 Magnum cartridge (all bullet weights).
Use of Blue DotŪ in the above cases may cause a high pressure situation that could cause property damage and serious personal injury.

We apologize for any inconvenience that this may cause and appreciate your understanding and cooperation in this matter.
 
 

And FWIW, many manuals list the 357mag in their rifle data, Hodgdon, Hornady and Lyman for example, barrel lengths between 16" and 20". 

Tim

[petemi]

Tim, That's some serious poop

Pete

[Hodr]

Gendoc
I load 38/357 to cat sneeze for plinking and goofing around with a 16" winchester trapper.  I go down to texas looking for hog I have good success with 125 grain Buffalo Bore.  2 or 3 sighting shots to refigure point of impact.  I don't really pull a trigger at anything over 50yds, but at that range the 125 grain holds up well, although it did take three on a large sow last trip.

blindhari

[jacks44mag]

Hay I like all your comments but I did state I was using UNIQUE powder for the 125g JHP and BLUE DOT for the 158g JHP 

Thanks for the safety tips

[gcrank1]

Why dont you try Unique for both and adjust the load(s), within safety, to see if you can get similar POIs?

[trotterlg]

Unless the only thing you will ever try to kill is paper at 100 yards this effort is doomed to failure.  You simply cannot get the same trajectory out of these two bullets no matter what you do.  Larry