Min load in one manual is max in another??

TargetNorth

TargetNorth

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Hi Guys
I'm reloading
190gr Hornady BTSP
Varget
.308 Winchester
Tikka lite. I think a 22" barrel.

Here is the data that is confusing:

Hodgdon: (http ://data.hodgdon.com/cartridge_load.asp)
41.0 - 44.0 (Compressed at 44)

Lee: (Modern Reloading Second Edition, Page 431, 190 grain jacketed bullet)
41.0 - 44.0

Hornady: (7th Edition Hornady Handbook of Cartridge Reloading, Page 450, 190 grain BTSP)
31.3 - 40.9

So right next to each other:
41-44C
41-44
31.3-40.9

The problem is the max of one is the min of the other.

I took this load out today, loaded up 41, 41.5, 42, 42.5, 43, 43.5, 44 grains of varget, 5 of each. I am teaching a friend the basics of reloading, and had brought out the Hornady book to show pressures, speed (was chronying loads), etc. We look in the Hornady book and sure enough, the 41 grains was over the maximum. I was sure I had loaded right (I had loaded 41 before in the same gun) but we fired that 41 grain, and the primer was fairly flat and the velocity was 2500, in the maximum zone according to the manual. Wasted trip to the range as we obviously didn't shoot any of the others, and now I'll have to unload them.

What gives? Anyone have any ideas why this is? Have you guys seen this before? I essentially was getting pressure signs with a load that shows as minimum in two manuals.

Thanks,
Barry
 
The rule is "Start low and work up." You did, and found that the start load was Max (or more). This happens.

Each rifle is different, assuming your bulets were not seated too close to rifling.

The various bullet compnaies base their results on THEIR rifles, not yours. The published MAx load does not mean it is safe in all guns. I have seen Start loads that were too hot in a rifle.
 
TargetNorth said:
I was sure I had loaded right (I had loaded 41 before in the same gun) but we fired that 41 grain, and the primer was fairly flat and the velocity was 2500, in the maximum zone according to the manual.
Click to expand...

In my so far limited experience, the Hornady loads are typically much milder than other manuals and have shot as such in the rifles I have loaded for.

Why wouldn't you try a couple of the next loads if somewhat flattened primers were your only signs of pressure? Although, since you were seeing velocities at the upper end of the book range you could just stop there and call it a day.

Ganderite is very correct, max loads vary significantly between rifles and it seems yours is giving max load pressure signs and velocities with a less than book max charge. That's the way it goes some days.

Mark
 
^^^
I too have noticed that Hornady seems to low-ball their load data. I don't know if it's a liability thing or if they don't want you getting the same performance as their factory loaded ammo lol
 
mmattockx said:
Why wouldn't you try a couple of the next loads if somewhat flattened primers were your only signs of pressure? Although, since you were seeing velocities at the upper end of the book range you could just stop there and call it a day.
Click to expand...

It definitely crossed my mind to keep shooting, but as I am still newish to reloading, I didn't want to have a moment that I regretted. Better to come home, check up on CGN, check other manuals to make sure I wasn't making a mistake, and live to tell the tale...

What other indications are there are pressure? If the primers are flattening out (I was using Federal primers, which other posts on here have indicated flatten under mid-pressure loads, so are not good indicators of high pressure) I can't use them as a sign. Do I just check the velocity numbers? I don't know what the limit is that damages the gun, or worse.

Thanks for the comments,
Barry
 
TargetNorth said:
What other indications are there are pressure? If the primers are flattening out (I was using Federal primers, which other posts on here have indicated flatten under mid-pressure loads, so are not good indicators of high pressure) I can't use them as a sign. Do I just check the velocity numbers? I don't know what the limit is that damages the gun, or worse.
Click to expand...

Difficult bolt lift and/or extraction are signs as well. Flat primers along with tough bolt lift would definitely indicate time to stop.

Since you loaded in 0.5gr increments, I would have tried at least the next two loads, up to 1.0gr over the first one. Pressure signs do not come on in 0.5gr, so you could have tried them to see if you get progressively more warning signs or if things stay steady.

The chronograph is a good indicator, too. If you are seeing pressure signs and the velocity numbers are way up there, that also indicates you are getting to the top loads. Often, more powder will not give more velocity at some point and this is also a good place to stop.

Mark
 
When I was looking for loads for my 300 win mag, I looked at 7 different manuals that were on the counter at WSS. I started low, and worked up. The load my gun is happiest with is actually below the starting load in one book. If I went with just that book, I'd have given up on my bullet and powder combo and tried somthing else. Start at the lowest you can find and work up from there.
 
Min load in one manual is max in another??

Yup.

The other thing is companies lowering their loads as time goes and they get more lawyerized.

Take the 300 win mag for instance...

There used to be manuals showing 75.0 gr of IMR 4350 and 180gr bullets for a 300 win mag for example...now I can't find one (and I've got about six manuals) with a load over 71.0gr, and some stop at 69.0.

Want a real shocker? Check out Nosler's reloading data on their web site!!!! They are sickenly downloaded! NONE of their 180gr loadings for 300 win mag are even getting 3000 fps! Actually their 300 win mag, 180gr data looks a little like 30-06, 180gr data from thirty years ago...back when publishers had 300 win mags pushing 3200 fps with 180's. PS - Nosler's reloading data for 30-06, 180gr bullets maxes out at 2675 fps on their web site right now...seems to be thirty years ago everybody knew a 30-06 could push 180's to 2800...and that's without all the advances in powder in the last while...

What I do when getting into a new cartridge is check out several sources and basically do an averaging of all sources and go from there.

You've got to watch barrel lengths that they test with too. I thought my Sierra manual had fairly slow speeds for 338 win mag until I noticed they had a 21" test barrel. WTF? How many 338 win mags are there out there with 21" barrels?
 
I just went through this exact issue myself. You can see my trials and headaches in this thread:

http://www.canadiangunnutz.com/forum/showthread.php?t=508134

was ready to use my reloading manuals as kindling!!

My best powder charge was below minimum in some books giving above max load velocities. There were many variables although, but it does show how difficult finding consistent data is.
 
I found the loads in the Hornady book to be a little light compared to other sources. For .308 I got the best accuracy when I was almost at max or slightly above their data.

FYI, I am loading same 190gr Hornady BTSP with Varget and they worked best for me with 39.5-40.5 gr of powder.

A few difference Hornday 180 gr bullets were most accurate with 43-44 gr of Varget.
 
Bear in mind that all bullets are not the same nor are the rifles they are shot in. Hornady's data is probably specific to the bullet you were actually using. Other sources you looked at may not be and may be arrived at based on a flat based bullet with less surface bearing area and less intrusion in the powder space. It's another reason why loads are worked up rather than just arrived at based on a different source.
 
I use a chronograph when working up a load. I stop when I hit the velocity for a max load even if the powder charge is lower than the maximum listed in the manual.
Keep in mind that the guns used by the powder and bullet companies have different tolerances than yours. Keep in mind as well that powder can vary from lot to lot. Some lots will be faster (hotter) than others or produce more pressure for the same velocity.
Brass can also make a difference. Thick brass with less capacity will start showing pressure sooner than will brass with a slightly larger internal capacity. This is a win as I have found that usually this means a bit more velocity with less powder.
 
Adding more confusion

Some velocities in manuals are taken from a sporting rifle shooting the pressure guns loads. e.g. mininium chamber and bore as compared to a loose factory. So if you use a chrony max,as I do,the data is pretty useless to you.

But do the work up thing with a chrony. Those rebuilts are cheap enough.I was always,yeh,yeh,until I got a surprise with a 30-06 shooting H4350 and a 180gr bonded cup and core. This is a very very common loading,and considered damm near mistake proof.I had started low and worked up. Well,my velocities went crazy with signs of spiking, and well below max. This was my 7th 30-06 I have loaded for. The fellow that sold it,complained of the kick. I can imagine,220 factory loads were likely Weatherby fast ! I found a load using a more lineral powder, IMR-4350,and I get to use less of it.
 
Try worrying less about how close you are to the maximum, and more about how accurate the load is.
That's not to say you can go over max, but that you will likely find your most accurate load is a bit below max.
Just don't be one of those guys that has to have a maximum load at all cost, every smidgen of velocity etc. It's accuracy that really counts.
 
John Y Cannuck said:
Try worrying less about how close you are to the maximum, and more about how accurate the load is.
That's not to say you can go over max, but that you will likely find your most accurate load is a bit below max.
Just don't be one of those guys that has to have a maximum load at all cost, every smidgen of velocity etc. It's accuracy that really counts.
Click to expand...

This is true, but there is often a very accurate node up near max pressure levels. Losing 50fps to gain 1MOA is a very worthwhile trade off and the animal or paper won't be able to tell the difference.

Have a read through this article for the approach used by some precision shooters, it is a good way to work through the problem:

http://www.longrangehunting.com/articles/precision-reloading.php

Mark
 
John Y Cannuck said:
Try worrying less about how close you are to the maximum, and more about how accurate the load is.
That's not to say you can go over max, but that you will likely find your most accurate load is a bit below max.
Just don't be one of those guys that has to have a maximum load at all cost, every smidgen of velocity etc. It's accuracy that really counts.
Click to expand...

That is absolutely true - I use the manual velocity as an upper limit but my goal is an accurate load. My 30-6 likes 150 grain bullets at 2750. My .303 likes 200 grain cast bullets at 1450. Both give humane kills and the 200 grain cast will shoot the length of a mule deer (along the spine with the bullet ending up under the hide in the neck) on a "texas heart shot". Both can be loaded hotter but I like the accuracy at those lvelocities.
The point where I stop adding powder is the point where the groups are smallest.
 
I definitely am most interested in accuracy. The only benefit I can see from more velocity is less drop... and as I won't really shoot beyond 300m the drop is easy to calculate and easy to adapt to. Even IF I were to shoot at a slightly lower velocity, the .308 has lots of power (IMHO) for moose.

Actually, I should say the thing I'm most interested in is not blowing my self up while reloading. Second is accuracy. :)

Thanks for all your replies, this is very interesting.
 
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