My 38S are slow and 357mags are fast

Guy’s

I need some help, I have only been reloading for 2 years and have been very happy with my results on paper down range and the deer in my freezer that I got with my hand loaded 357mag. But I thought maybe I could do better, I know I can do cheaper. So I just bought a Chrony Beta Master and after learning how to use it with my kids Nurf Gun I went to the range. Now my 380 and 9mm came in about 50ft/sec slower then I thought and that’s ok. But my 38 and 357mag is where I’m lost. I have a Ruger SP101 with a 2in Bbl. My 38 Spec averaged 470ft/sec, 430ft/sec slower than I was expecting. My 357mag averaged 1633ft/sec, 333 faster than expected and that has me real worried. My 38Spec receipt is 6.0gr Power Pistol, 125gr Berry HP, Federal 100 primer, and a COL 1.450. My 357mag is 14.9gr of 2400, 125gr Hornady HP-XTP, WSPM primer, and a COL of 1.590. I bought a Lee roll crimp die and crimp after seating. I do use a heavier crimp on the magnum than on the specials.

Also I might mention my 44 Spec averaged 50ft/sec faster and my 44Mag averaged 150ft/sec slower than expected.

A wise man on this forum of says to have more than just one book. I have the Hornady 7th, Speers 14th, and the Sierra's 5th Edition. I also referred to Alliant’s online Reloader Guide.

I have locked up the 357mag until I’m sure they are safe. I know you start low and work the round up but what do you base that on? I know Berry’s are cheap bullets and should not be used over 1200ft/sec so I use the Hornady on the Magnum’s. I would really appreciate any advice.

thanks,
Steve
:?:

My 44spc was way slow slow over the master beta, they were the 240gr lee cast. when i seated them deaper they where alot faster.
My 357 loads were just barley over 1100fps out of a 4" shooting a hot H110 load.
Them chronys!!!!!!

Sometimes the chrono raises more questions than it answers. You seem more like you are trying to figure out how you can best use a chrono in your own loading than have specific questions, so this is a general overview. When you read it, my idea is that it will give you a better idea of what a chrono can and can't do and you will have a better feeling for what to ask about.

There are a lot of variables involved, not just the components, but the interior finish of the barrels, the specific loading techniques used, etc. Cast bullets will have more MV than jacketed bullets of the same weight with all other variables unchanged. Lengthening OAL will lower pressure but not always MV; shortening OAL will raise both pressure and MV. Sometimes a very consistant load with regards to low ES and SD will pattern like a shotgun while another load with much higher numbers will produce very tight groups. Why? Who knows? It might be observable and repeatable, but it isn't always explainable.

Honestly, loading manuals are a general guide to produce safe ammo. Basically, they tell you: "If you keep your powder charge with a certain bullet weight in this range, nothing bad should happen". More important than the actual velocities of your loads, the chrono can tell you how consistant they are. This is not to say that a short range load with a very high SD isn't going to be very accurate, sometimes they are, but it is at longer ranges where those differences become an issue.

For your handguns, a chrono will tell you how your data source relates to the real world conditions with your specific guns. Do the different powders and bullets all run faster than listed so you clearly see that the gun itself is the deciding factor, or is there variation so the actual factors responsible for the differences are confused and unclear? It can also tell you if the velocities are way too high so you stop shooting and find out why.

With a rifle, those little numbers tell you a lot more. You can figure your bullet drop at long ranges much more accurately than trying to guess from the "book velocity" (Xgr of powder A with bullet B at OAL C is listed at velocity Y in the book, but your load is Y+123fps). You can now look up the bullet/vel in the table and KNOW how much it will drop at 200, 300, 400 yds. Loads with lower ES and SD are going to be more consistant as the ranges increase and will usually give you tighter groups.

For the average handgunner, unless you are tailoring loads for specific competitions like IPSC, a chrono isn't really going to give you a lot of important information. Other exceptions are when you are off the charts and using surplus powders or wildcat cartridges, but most reloaders don't don't do any of those things and just want to make themselves affordable ammo.

For a rifle shooter, a chrono makes more sense if you are doing load development, especially at longer ranges. Also when you want to wildcat or use surp powders, but again for most loaders, all they really need is accurate measured MV data to figure bullet drop with.

With my handguns, I usually just work up my loads for best accuracy with a powder/bullet combination, but I'm not interested in their velocities unless I want to shoot them beyond 50yds, so I honestly have no idea how fast most of my loads are.

With my rifles, I will check the MV after working up the most accurate loads at 100yds, especially if I want to shoot at longer ranges. But if it's a large game rifle that I will be shooting at 200yds or less, I do not usually bother. A nice tight group is what I'm after and a deer isn't going to notice a difference of a few hundred fps if my bullet placement is correct. BUT, the more accurate I need the load to be and the longer the range I want to use it at, the more important the chrono data is to me. I shoot several different wildcats and use a dozen different surp powders and I wouldn't want to be without one.

In the old days, chronos cost almost as much as new cars did and we figured out our MV's by measuring actual drop at 100, 200, 300,and 400yds and looking it up on the ballistic tables for that bullet to see what MV matched the drop measurements. It sure used up a lot of ammo.

My goal for the Chrony is 2 fold, if the velocity is consistent from batch to batch, any problems in grouping is coming from behind the gun and not in front of the hammer. The other is I have not started reloading rifle ammo YET! The outdoor range I go to is only 100yds and I know from experience if my 7mm Rem Mag is 2in high there I will be dead on at 200yds.

I guess my real reason for the post is to get some opines on if the 357mag is safe to shoot at that velocity? I still have 200rds left before I have to make more. Then when I make more, should I cut back on the power? I have probably shot 400-500 of these magnums with no problem. My grouping, I think is ok for a 2in Bbl but not nearly as good as my 44 with a 7 1/2in Bbl.

Thanks,

Sierra lists for 125gr bullet with 2400 a MAX of 19.0gr yielding a vel of 1500fps from a 6"bbl Colt Trooper. (I did not pick up on it because neither of my current revolvers likes 2400 - I had to look it up.) Even a really heavy crimp won't bump pressures and velocities that much.

Something does seem a bit odd and you have good cause for concern. These are possible causes in order of my opinion of probability: Overcharge, bad chrono, wrong case, wrong powder, contaminated powder

First, I would pull several rounds and double check the charge weights. That is the most likely possibility. I have had a similar problem when I did not properly zero my powder scale after moving it around, but I caught the mistake before shooting any of the rounds. The same thing could happen if the scale was set incorrectly and it went unnoticed.

If the charges weigh correctly, I would recheck velocities using a different chrono.

Are you using mag loads in .38spec cases? Probably not, but I figured I should ask as more than one newer loader has assumed there would be no problem.

Are you sure the powder was 2400? Could there have been a small amount of a different powder left in the measure by accident? Or could a different powder have been accidentally added to your can of 2400 when emptying the measure at a previous session? Examine the powder from the pulled rounds with a magnifier. We all try to be very careful not to get things mixed up, but we are all human and things happen.