Hotter loads are better?

[DRNewcomb]

You've not mentioned if you are FL or NS your cases.
FL sizing vs NS with the same case and load will display higher pressures when examining primers.

I bump the shoulder just enough to overcome any difficulty closing the bolt on the case. The cases gauge about maximum for .308 in my Forster case gauge. Necks are turned to ensure consistent tension. I use Bonanza BR dies with a .332" neck diameter.

 

[Eddie Harren]

308 brass very a lot in case capacity so watch your loading . Larry

So always fill them up 100%.

 

[Liven The Dream]

I have been shooting Varget in .308 Palma loads for years.
As stated above Varget from lot to lot is all over the place.
I weight sort my brass.
I try for 3010 FPS with 155gr. Bullets.
I have had Lots of Varget that have given me this at 45.5 gr., 45.8 gr. 46.0 gr., 46.3 gr. and 46.6.

Have Fun Shoot Well

 

[perry42]

Just remember that "hotter loads" decrease barrel life and some powders (mostly double base) can decrease barrel life significantly.

perry42

 

[MagnumManiac]

"Just remember that "hotter loads" decrease barrel life and some powders (mostly double base) can decrease barrel life significantly."

This is actually untrue, single base powders run far hotter than double base powders and burn throats faster.
I have halved my throat erosion in 300WM and 264WM by using double base powders.
Slow powders increase the rate of throat wear as the burn rate gets slower.

Cheers.

 

[RonAKA]

This is actually untrue, single base powders run far hotter than double base powders and burn throats faster.
I have halved my throat erosion in 300WM and 264WM by using double base powders.
Slow powders increase the rate of throat wear as the burn rate gets slower.

There would be some that do not agree with that line of thinking. There is a Barrel Life Calculator on this website that uses powder heat content and the weight of the powder to estimate the heat potential of the charge. There is a table of heat content values for the various powders. The double base VV 5XX powders have significantly more heat content and the somewhat reduced charge does not make up for the difference. I've done some comparisons on life estimated using say N160 compared to N560 and the N160 comes out ahead. Here is the table of powder heat content values.

 

[RemingtonAI]

Just for clarity, when we're saying "accuracy" above, I think you meant "precision". Precision is the relationship between the shots themselves, and of course accuracy is the relationship between the group and the intended target. The only reason why I point it out is that it can be confusing when trying to isolate factors that contribute to poor precision vs poor accuracy. Jesse

 

[Wjesswheel]

Just for clarity, when we're saying "accuracy" above, I think you meant "precision". Precision is the relationship between the shots themselves, and of course accuracy is the relationship between the group and the intended target. The only reason why I point it out is that it can be confusing when trying to isolate factors that contribute to poor precision vs poor accuracy. Jesse[/QUOTE

So if I am trying to shoot a 308 sized dot at 100 yards for score is that precision or accuracy?

 

[RonAKA]

Precision in shooting is small group size. Accuracy is how close you are to what you are aiming at. Those shooting for precision will sight their scope in to intentionally miss the aim point. You do not want to destroy your aim point and want the group to be offset from the aim point.

 

[RemingtonAI]

Well, if it were a single shot into a 308 sized hole for score I would assume it would require accuracy and the proximity to the center x would be the goal. If it were 5 shots scored on paper and the level of accuracy needed to be competitive was a single hole and the aim point was irrelevant, it would be sheer precision you would want. Guess it depends. Jesse

 

[Homerange]

Well, if it were a single shot into a 308 sized hole for score I would assume it would require accuracy and the proximity to the center x would be the goal. If it were 5 shots scored on paper and the level of accuracy needed to be competitive was a single hole and the aim point was irrelevant, it would be sheer precision you would want. Guess it depends. Jesse

Not at all. If I'm working up loads I don't give a brass razoo where they land on the target, I'm looking for a group, nothing else. When I've got my group, then I pull the POI to the POA.

 

[Joe R]

I noticed while chronographing some .308 loads with Varget behind a 168 g Nosler, that the hotter my loads got, the better the statistics looked. In fact, one of the loads with the best statistics is what I'd classify as too darned hot and had all the signs of over-pressure. I understand that loads that mostly fill the case are more accurate than those that are partially empty but I'm talking about ~2% (1 gn) between loads. Is this normal?

There are several factors that can lead to signs of over-pressure in spite. Your statement gives no data on which to base any judgement and everyone here seems to be taking guesses without adequate data. One possible cause is that you're not bumping the shoulder back enough. That can give you over-pressure results.

1. How much powder are you using?
2. What is your neck chamber diameter?
3. What is your loaded round diameter?
4. How do you measure to your lands?
   
5. If you're jumping, how much?
6. If you're not jumping, how much are you into the lands?
7. What kind of brass are you using?
8. How fast are your bullets going? And more...

You know the old GIGO... The more specific info you can give us about your rifle and reloading the more help we can offer you.

Kindest regards,

Joe

 

[RemingtonAI]

Not at all. If I'm working up loads I don't give a brass razoo where they land on the target, I'm looking for a group, nothing else. When I've got my group, then I pull the POI to the POA.

Right, because you are trying to evaluate your rifle/shooter/ammo level of precision, not accuracy. I guess that was my point, that when working up loads you are looking for precision, not accuracy. But of course, hitting targets at range requires accuracy and precision. So in order to help each other hit targets at range, especially when reloading is involved, it is important to be on the same page as far as terminology goes since they're both used as synonyms even though they relate to 2 very different aspects of hitting targets at range. Hope i didn't cause more confusion or come off as a stickler for terminology. Just reiterating what is in Brian Litz's book : Long Range Accuracy and Precision. Great book for those who haven't read it. His Weapon Employment Zone Analysis (WEZ) is great for evaluating a rifle/shooters probability for making impacts on various targets and ranges, and goes into great detail about the differences in evaluating precision vs accuracy and the different factors that contribute to each separately. Jesse

 

[DRNewcomb]

There are several factors that can lead to signs of over-pressure in spite. Your statement gives no data on which to base any judgement and everyone here seems to be taking guesses without adequate data. One possible cause is that you're not bumping the shoulder back enough. That can give you over-pressure results.

1. How much powder are you using?
2. What is your neck chamber diameter?
3. What is your loaded round diameter?
4. How do you measure to your lands?
   
5. If you're jumping, how much?
6. If you're not jumping, how much are you into the lands?
7. What kind of brass are you using?
8. How fast are your bullets going? And more...

You know the old GIGO... The more specific info you can give us about your rifle and reloading the more help we can offer you.

Kindest regards,

Joe

Joe,
1. Between 42 & 46 gns of Varget
2. For the life of me I can't find a freshly fired case to measure. It's a Winchester factory target Mod 70 bbl. I've never had the chamber cast.
3. .338" The necks are turned to .015" for concentricity and to obtain a moderately soft seating, not to obtain a particular loaded neck diameter.
4. With a bullet lightly seated in a resized case.
5. Should not be jumping.
6. Should be just touching.
7. Prepped LC 77 Match all from one lot.
8. ~2500 to 2818 fps. The ~2500 is because at 42 gns, velocity was all over the place.

Really, my question wasn't about dealing with over-pressure. Rather, I wanted to know if it was normal for SD & ES to drop with each increase in load up to and including "too hot". This is not a custom benchrest gun. It's my old match rifle I've adapter to shoot F-TR.

 

[Homerange]

Right, because you are trying to evaluate your rifle/shooter/ammo level of precision, not accuracy.

Correct.
And rather than dissect terminology we must attempt to be helpful within the context of the thread.
The OP is loading 308, a great calibre but only capable of so much in terms of long range work.
However it is capable of extremely fine accuracy in the right platform and in front of the right shoulder.

 

[Homerange]

Donald.
My best grouping loads are also Varget (ADI 2208) and reasonably hot too. In a 130 I shoot, highly compressed for a 6 fps spread.

 

[RemingtonAI]

I also use Varget for my .308 which has worked very well for me. In my rifle, i am using 43 gr. of Varget with a 178 g. AMAX and 43.5gr. for the 175 SMK. (with Lapua brass/#200 primers). Pretty standard loads but please do not try my data without working up, its just under hot in my chamber. Those are my "base numbers" and work well as is, but may slightly change +or - .2 depending on the time of year in order to get peak accuracy. Because of my short 16" barrel, speeds are not ideal for BC or wind, and may require slightly more elevation at range but are very precise get the job done well. Jesse