Pet load test starting point

B

BJung

New member
I'm not keen on wasting powder and want to find a desired pet load as inexpensively and soon as possible.

In the beginning, I would load a progression of test loads from one end of the load table to the end and even beyond it. This ladder test gave me all my options.

Now, I am reading that the ideal MV for a particular cartridge such as the 7RM would be (for arguments sake 2800-2900fps for a certain bullet). Or a military rifle I have has a certain MV for its military issued rounds. I assume the rifle was designed for it. And so, shouldn't the ideal Node be somewhere there. And, if so, I make test loads +/- 0.3grains from where the load and MV is estimated to be from the load chart? I don't have to waste my time making test loads at the low end.
 
I load similar to what you're referring to. I would rather hit a velocity range and accuracy with as few rounds as possible. One issue with jumping to the middle however is that "the middle" with any particular powder might also be a max.

My grandson and I were loading for a 7mag a month or so back. We had 4 powders which are all good for the caliber and loading one of them at a time with starting loads and moving up. We had two down and the third blew primers at the second charge, only a half grain higher than the start load. If the brass was used I'd have blamed that, but we were using new cases for all loads.

I've had this happen before and its not something that I am fond of. The thing is when hand loading, all bets are off. Granted a manual might have 20 loads for different powders for a particular caliber, that don't always mean they will all be able to make the cut in every firearm.
 
Bench rest forums are rife with the shooter picking a bullet they WANT to shoot at a certain velocity. If it doesn't make that velocity, then it's scrap it, and rechamber for a bigger cartridge that will.
But they are pretty much shooting barrels from a limited number of manufacturers, and about the same contour. So when Pete screws a 6BR barrel on shooting 105gr MatchKings, his data isn't far off from Fred's data.

Hunting rifles are different.
There is vast differences on how the barrel is made, rather how it is rifled & stress relieved. How it attaches to the receiver. Just screwed in, vs barrel nut.
Barrel free floated, or pressure point in the forestock.
Is the chamber reamed on the tight end of specs, or the open (loose) end.

Just too many variables to assume any one thing.

Start low, work up.
 
Two Questions

Two Questions for what was said.

When the best load almost went Blam, were you loading within the published load chart? My plan is to load just under the max and work up.

The other is, if you have a similar model hunting rifle, couldn't the pet load be similar? I pulled out my old targets for my 7RM recently and compared the charge for the Nodes. They were identical to Ken Waters' pet loads using the same model rifle, bullet, and powder. This tells me that there is some sort of harmonics going on with for certain cartridges, especially when the components (as in the same model rifle then bullet components) are most similar.
 
Keep in mind that the barrel, powder and primer lot used to get the velocity and pressure data published are not the same as that you're going to use and get.

Testing a given load is the biggest variable. Will everyone shoot it in their rifle to the same accuracy level? In international long range Palma rifle matches, the same lot of ammo is issued to all competitors. Everyone doesn't shoot the same score and bullets the same velocity across all rifles. Those with the best quality rifles and proper marksmanship skills have the highest scores.

I'm not belittling those with less quality stuff or skills. Learn to shoot for accuracy against yourself. Match condition your mind then your body.
 
std7mag said:
Bench rest forums are rife with the shooter picking a bullet they WANT to shoot at a certain velocity. If it doesn't make that velocity, then it's scrap it, and rechamber for a bigger cartridge that will.
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Never heard of that. It's counterproductive because bigger cartridges for a given bullet are typically less accurate as well as harder to shoot precisely,

Please link me to an example. Thanks.
 
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A buddy'e method

When I started reloading I had a friend who would choose the bullet he wanted for his 7RM, then make test loads up to the Max until there were pressure signs. Then, he'd back off until he found his accuracy load.
 
A pet load I am trying to find is one that replicates the military round trajectory that comes close to the military sights on the rifle. This way I have reference points to work from. The only three things I have to work with is a bullet weight and same similar to the original and the closest powder to the original. Then I will load to the published MV. Any suggestions here?
 
burbank_jung said:
A pet load I am trying to find is one that replicates the military round trajectory that comes close to the military sights on the rifle. This way I have reference points to work from. The only three things I have to work with is a bullet weight and same similar to the original and the closest powder to the original. Then I will load to the published MV. Any suggestions here?
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Which specific military round?

They each have different trajectories.

USA military cartridge velocity specs are chronographed at 26 yards.
 
Just take the bullet you are planning on using and shop velocities on the powder sites. With some research you may find a powder that you have on the shelf or can obtain. Might find some other loaders that have already done your homework even.

I assume you know the velocity the military rifle load shoots from your rifle at a given temperature. Find a powder that gives you that velocity then do a load workup over a chrono to get the same velocity as the round you are trying to duplicate. Start low and shoot one or two rounds over a chrono to check for safety until you get to the desired velocity that matches the round. Then do a fine tuning with other factors such as primer choice, seating depth and neck tension to get a satisfactory group size, be safe
 
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military rifles under test

The first is a battlefield capture T99 Arisaka. I have 180gr Hornady RN and 150gr Hornady SP for this one.The powders I'm using is R15. 3031 might have been my second choice.

The second is a M96 Swedish Mauser. My primary test load for it is 160gr Hornady RN. I have a few Sierra 160SMP bullets left and will try those too, even though they were discontinued. My powders are R19 and R22.
 
IMHO, not a good idea. every gun and barrel is slightly different both in the chamber and barrel harmonics. That said I do cheat on occasion but only under certain circumstances, and i am not recommending it. If i have a gun that i have fully worked a load up in, same powder and bullet wt I will go half way down between stating and max rather than back to starting. From there i feel comfortable swapping primers and or bullets and working back up. if im working with a new powder or bullet weight I go back to the starting load.
 
Same

This sounds like what I do when I find a pet load that's beyond the manufacturers load data max load. I then start near the published max and work up. My T99 Arisaka's pet load is beyond the published max. I now look for an accuracy load near the documented MV.
 
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