EXTRAPOLATING FOR REDUCED LOADS?

[mgatc]

Re-read the section in Lees' manual pertaining to the effects on pressure and velocity by reducing the charge in 1% increments. (Chapter 9 - A 1% reduction in charge equals a 2.5% reduction in pressure and a .9% reduction in velocity)

I wanted to load .357mags with berrys 125gn and Unique powder but the velocity was too high.

Berrys instructions say to load using the middle to lower end of the jacketed data and not to exceed 1200fps.

Page 552 of the Lees manual shows 125 grain jacketed bullet with Unique powder at 8.7gn to start and 9.6 not to exceed.

I tested the theory using the NEVER EXCEED load and then began reducing the load by 1% at a time until it matched the START LOAD. I did the same thing with the velocity using a .9% reduction as suggested and it was withing 7fps of the published velocity.

I continued to extrapolate this formula until the velocity dropped below 1200fps at 7.1gn of powder. I even continued beyond this point to a velocity of 1044fps at 6.2gn of Unique. Lee suggests this can be done safely down to a third of the published load.

Is my understanding correct? Can I safely use this formula to determine a reduced load below that which is published? What else should I be aware of?

m

[carver]

I'm not up to date on this, but why not try another powder? I personally use the loads posted in the manuals. If the powder I have on hand won't get me what I want, then I just buy a different powder that will. My reasoning is that if the reduced load is what I want, then I will probably be shooting quite a bit of ammo with this load.

[BillM]

Berry's plated bullets? Use lead bullet data. Berry's bullets are
soft lead, with a VERY thin copper plating. You can push them a little
faster than plain lead, but not much. Most jacketed data is way too
fast.

FWIW, watch your crimp. Overcrimping berry's bullets will cut the plating
and accuracy will be suffer.

Personally I prefer a good cast lead bullet, usually moly coated. Works fine
for light loads and lots cheaper than Berry's.

[JLA]

you have essentially put a mid range .38 special load in a .357 mag case, which it is safe to do...

DISCLAIMER!!!-It is not safe to stuff .357 magnum loads in a .38 special case!!!

[mgatc]

Originally Posted by JLA

DISCLAIMER!!!-It is not safe to stuff .357 magnum loads in a .38 special case!!!

I tossed all of my .38 cases when I began handloading to avoid the potential of loading a magnum round in a sub mag case.

Does anyone on the forum use this method to create reduced loads?

[steve4102]

Lee data is nothing more than a copy of others data. In the case of your 357Mag I believe it is Speer/Alliant data.

Lyman 48 lists the following.
357 Magnum
125gr Hornady JHP
1.590 OAL
Unique, Start-7.0gr-990fps---Max-9.7gr-1358fps

[steve4102]

Originally Posted by mgatc

Does anyone on the forum use this method to create reduced loads?

I do not. I don't like to go below published Min except with H-4895 in rifle rounds.

[JLA]

I personally would go the route carver mentioned and use a powder that yields lower velocities. Trailboss comes to mind. and itll do it with a full case of powder so you get good load density and a light recoiling load, whats not to love about that???

[noylj]

Yes. Best powders for reduced loads (because they have been so used for decades) are Unique and Bullseye. As you go to lower velocities, you should move to Bullseye.
The only "problems" are going so low that you stick a bullet in the bore. Going down to about 700fps is no problem.

[mgatc]

As long as get the rounds below 1200fps I should be ok with the Berrys'.

I'm showing 1202fps with 7.2 gn of Unique down to 1044fps with 6.2. I had planned to stay within these parameters.

Trying to ensure that my calculations were in the ball park

[JLA]

Originally Posted by mgatc

As long as get the rounds below 1200fps I should be ok with the Berrys'.

I'm showing 1202fps with 7.2 gn of Unique down to 1044fps with 6.2. I had planned to stay within these parameters.

Trying to ensure that my calculations were in the ball park

go smack between the 2. it should be cruisin along at about 1125, which is a decent plinkin load. itll still level steel plates and wont recoil your hands off...

[woolleyworm]

Originally Posted by mgatc

Page 552 of the Lees manual shows 125 grain jacketed bullet with Unique powder at 8.7gn to start and 9.6 not to exceed.

I tested the theory using the NEVER EXCEED load and then began reducing the load by 1% at a time until it matched the START LOAD. I did the same thing with the velocity using a .9% reduction as suggested and it was withing 7fps of the published velocity.

I continued to extrapolate this formula until the velocity dropped below 1200fps at 7.1gn of powder. I even continued beyond this point to a velocity of 1044fps at 6.2gn of Unique. Lee suggests this can be done safely down to a third of the published load.

Is my understanding correct? Can I safely use this formula to determine a reduced load below that which is published? What else should I be aware of?

m

I'm trying to take this from step one here; Is this a load that you have worked up before, or a new load? Are you're saying that you STARTED your load development from 9.6gn and worked backwards??

A published MIN load is just that, if you go below that, then youre into a range which isn't published as safe " by that reference, be it Lee, Hornady, etc "

I will read the Lee manual tonight to see the exact section that you're talking about as far as the 1/3 issue. "Lee suggests this can be done safely down to a third of the published load." There's a reason that they publish min loads; while I agree that there are "safeties and cushion" within the published data, I wouldn't go off of "suggestions", go by Exact and what is published unless you have a true NEED to experiement outside a lab/testing environment.

[mgatc]

WW,

Not sure where to start.

I have not ever used other than a published load.

Published loads for the bullet/Powder combo that I want to use exceed the recommended velocity for the bullets. (Berry's 125gn copper plated).

So yes, I am trying to create a load that will safely utilize the berry's bullets and Unique powder. To do this, I am applying the precepts in Chapter 9 (See first post) of Lee's reloading Manual.

I have not, as of yet, actually loaded any shells using this theory. I posted my question here to see if anyone can confirm that this theory is valid and usable. If so, then, did I apply it correctly to arrive at a safe recipe.

m

[noylj]

My manuals show a 'recommended starting load' but not a 'minimum safe load.' I think someone is reading more into the 'starting load' than actually exists.
It is a load that should be safe in all guns in good shape and properly chambered for that cartridge to act as a start load. Not that a lighter load is NOT SAFE.
Likewise, I sure hope the poster didn't actually start at the max load and work down.

[mgatc]

I have gone back and re-read all of these posts and realized that I my wording may have led to some confusion.

When I posted that I had started at the "never to exceed" load and worked down, I was referring to the extrapolation formula - not actually loading rounds this way!

[woolleyworm]

Originally Posted by mgatc

I have gone back and re-read all of these posts and realized that I my wording may have led to some confusion.

When I posted that I had started at the "never to exceed" load and worked down, I was referring to the extrapolation formula - not actually loading rounds this way!

That's all the clarification I was lookin for. I just wanted to make sure I had a clear picture of what you are trying to do. I didn't have a chance to read the Lee manual last night, I will try again tonight.