Excessive Reloading and Accuracy

RaptorAddict

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Oct 24, 2020
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I recently just finished off my first batch of 6.5CM with Peterson Brass. I took good care of the brass everytime I reloaded and got 12 reloads out of them. But I did notice that probably by the 8th relaod, now looking back, I wasn't hitting targets consistently out at 700 and beyond like I did before. I was fireforming my new brass yesterday, and it was was splashing low in the dirt out at 700. I assume could be new brass? I adjusted up to .3 mils and it was then on target. After that, I was hitting targets very consistently from 700 to 1000 with ease. Now, I was either just having a very good day, or my old casings were just getting so thin and worn, that the charges weren't consistent anymore after so many reloads. Could this be the case? Or was it just me all along? LOL!
 
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The MV anomaly for -3.0 mil error at 700 yards is ±500 fps...that's not from neck tension variance...

Possible explanations seem to be catasrophic component failure, or wrong dope dialed on the optic, etc. Basically, or something of that nature and not "predictable component deterioration" in line with normal use.

More likely...something is wrong in the data/observation...
 
The MV anomaly for -3.0 mil error at 700 yards is ±500 fps...that's not from neck tension variance...

Possible explanations seem to be catasrophic component failure, or wrong dope dialed on the optic, etc. Basically, or something of that nature and not "predictable component deterioration" in line with normal use.

More likely...something is wrong in the data/observation...
I’m gonna guess he meant .3 mils for That reason But maybe He’s having some sort of catastrophic issue and not realizing.
 
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Amazing how a “.” Can screw everything up in a conversation. Sorry about that guys. But I didn’t mentioned this is a Sako TRG I bought brand new in 2020. Got about 900 rounds down the pipe and it’s been solid. Just seemed strange I kept missing out at certain distances after the 8th, or 9th reloads. Still hit, but not as consistent as I did before. I can’t imagine it’s the rifle. The thing has been solid as can be. I let the barrel cool between every 10 rounds as well. So I don’t over heat it.
 
Virgin cases can have less velocity. As the first firing or two the brass expands more to fill chamber than it does on subsequent firings. 0.3mil at 700 may be a bit more than the velocity difference normally is with virgin and fired brass. But there's a plethora of other reasons that could add a tenth or two that aren't ammo related. So, could easily be things stacking on one another.

As far as being less consistent on the 8. 9, 10th, etc firing........you really don't have any info to support that or info that anyone can use to figure out why.

You mentioned its your first precision rifle and you have 900rnds on it. Which means it's a very good chance that a lot of your inconsistency is your fundamentals.
 
Virgin cases can have less velocity. As the first firing or two the brass expands more to fill chamber than it does on subsequent firings. 0.3mil at 700 may be a bit more than the velocity difference normally is with virgin and fired brass. But there's a plethora of other reasons that could add a tenth or two that aren't ammo related. So, could easily be things stacking on one another.

As far as being less consistent on the 8. 9, 10th, etc firing........you really don't have any info to support that or info that anyone can use to figure out why.

You mentioned its your first precision rifle and you have 900rnds on it. Which means it's a very good chance that a lot of your inconsistency is your fundamentals.
I’ll admit, I got a lot to learn still. Gonna be going through a course next month to get all these fundamentals cleared up. I’m the beginning, after my first reload, I chrono’ed to get a good SD. Then tried the muzzle velocity with the Kestrel. After that, it was smooth sailing. Now the range I go to does have funky wind spots, so it could be a factor. But noticing that after I dialed up 3 clicks, it was like I couldn’t miss. So I guess my real questions here is, should I be using a chrono more often and true up my MV more often? If not, then it was most likely me all along.
 
This was my first precision type rifle and I was learning everything along the way. Need to buy a chrono. I chono’ed in the beginning and that was it.
I’ve got one for sale in the PX.
 
Was the ambient temperature lower than when you zeroed the rifle?

10, 20, and 30 degrees colder may affect your propellant burn rate. If it's burning hotter your trajectory might be flatter, requiring an elevation correction. Cold may also cause your powder to burn slower with a longer pressure curve, again requiring an elevation change.
 
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You will get velocity and trajectory variations depending on conditions, I dont care how you load or what you do it will happen.
The conditions affect everything, the ammo the barrel and even the shooter. Its a big part of the game.

This is why you need to dope your rifle multiple times, record the conditions and then you can analyze the data and play with
your solver and see how close it matches.
 
I’ll admit, I got a lot to learn still. Gonna be going through a course next month to get all these fundamentals cleared up. I’m the beginning, after my first reload, I chrono’ed to get a good SD. Then tried the muzzle velocity with the Kestrel. After that, it was smooth sailing. Now the range I go to does have funky wind spots, so it could be a factor. But noticing that after I dialed up 3 clicks, it was like I couldn’t miss. So I guess my real questions here is, should I be using a chrono more often and true up my MV more often? If not, then it was most likely me all along.
Short answer is yes, get a chrono. As @Rio Precision Gunworks described, the first firing on new brass will have lower velocity. If you had a chrono you would have noticed that along with the low hits downrange.
 
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Was the ambient temperature lower than when you zeroed the rifle?

10, 20, and 30 degrees colder may affect your propellant burn rate. If it's burning hotter your trajectory might be flatter, requiring an elevation correction. Cold may also cause your powder to burn slower with a longer pressure curve, again requiring an elevation change.
I can see that then. Definitely a whole lot colder. Was wearing shorts when I initially got the SD. Yesterday I was bundled up. Lol!
 
I recently just finished off my first batch of 6.5CM with Peterson Brass. I took good care of the brass everytime I reloaded and got 12 reloads out of them. But I did notice that probably by the 8th relaod, now looking back, I wasn't hitting targets consistently out at 700 and beyond like I did before. I was fireforming my new brass yesterday, and it was was splashing low in the dirt out at 700. I assume could be new brass? I adjusted up to .3 mils and it was then on target. After that, I was hitting targets very consistently from 700 to 1000 with ease. Now, I was either just having a very good day, or my old casings were just getting so thin and worn, that the charges weren't consistent anymore after so many reloads. Could this be the case? Or was it just me all along? LOL!
When you get new lot of brass, there can be significant differences. Like neck tension could be much more than you set your other brass to (like, .003 - .005). Primer pocket depths could be a little different and certainly, case volumes are often different, as you can see in the pick below from Peterson Cartridge Co. These things will effect your results until you make adjustment accordingly after you've fire formed your cases.

Peterson Case specs.jpg
 
If you assume something like a 142 Sierra going 2700 fps, it only needs to change 75 fps to account for a .3 mil change at 700 yards.

If you don't keep close track of the brass hardness and the neck prep, and don't keep close track of the powder's water content, it is easy to be off by more than 75 fps. Start changing component batches, and all bets are off. Loose track of climate, and all bets are off.
 
Was the ambient temperature lower than when you zeroed the rifle?

10, 20, and 30 degrees colder may affect your propellant burn rate. If it's burning hotter your trajectory might be flatter, requiring an elevation correction. Cold may also cause your powder to burn slower with a longer pressure curve, again requiring an elevation change.
Not to mention the effect temp changes have on bullet drag.