Load development or not?

[Maurygold]

Primers can make all difference. For example . . .

I picked up some Remington 9.5's for a really good deal and thought I'd just use them for fireforming some brass. Out of curiosity, since I've never used them before, I loaded up 25 rounds just to see if the velocity difference (if any) due to reports of them being hotter than Fed's and CCI's. Criminy! Average velocity was higher than what I normally get by ~20fps, but it was the inconsistency the floored me. For the 25 rounds I got an SD of 33 fps and and ES of 97fps. What the . . .??? I've never had loads do that poorly, even though I wasn't using my best brass. Then I loaded up 10 rounds of my best loads that work really well, where I typically get mid single digit SD's, but the only difference being the Remington primers. Velocity was still ~20 fps faster than normal and the SD was 14.2 and the ES was 41. The Remington primers I've got SUCK! I guess I'll still use them for fireforming though.

A few weeks ago I got some .308 Alpha brass and decided to fire form them. I loaded up 10 with my favorite load using CCI400's just to find their case volumes. Out of the 10 I got 3 pierced primers. That too is a first for me. Apparently the larger flash holes that Alpha brass has puts more pressure of the thinner 400's cups. Followed up with CCI 450's in 10 more and they performed well, giving me 5.3 SD and a 16 ES, and . . . the two 5 round groups were at .435". Because those 10 did so well, I loaded up the 80 remaining cases with the same load. Yesterday, 80 rounds fired and chronoed with an SD of 6.2 and an ES of 29.

Choosing the right or wrong primers can make a difference.

I didn’t say ignore primers. Actually if you followed my advice you would have had zero problems and arrived at the same end.

Like I said: Magnum fed or cci always seated to max depth.

 

[XP1K]

@MaurygoId, alright, I got out a few minutes ago with your reccomended 78gr of h1000 in Norma brass lit by a 215m. 020" off the lands overall length was 3.718", 2.935" base to ogive.

When I prepped cases last night every piece of brass came out of the die at .305" inside the neck. I think it has a .311" bushing in it. At .305-.3055" I didn't even bother with running a mandrel through them. I tend to like a hair more neck tension myself. But, for the sake of trying it, I'm about to run three pieces through the mandrel and see what effect it has. After running a mandrel through them they're at .306-.3065"

So far this is where we're at. 78 was a little warm. Left some pretty good ejector marks so I backed off to 77. Sd came down and it tightened up a bit. Almost loaded and shot it again but sd was high anyway so I abandoned ship. Pretty sure I blew #2 as my rifle twisted in my hand when the shot broke. Poor form on my part. #3 went through #1.

On to 76.5, group had a nice shape to it the way it worked out, but I think there's more to be had. Going to see what that ec tuner is all about. But that's a topic for a different thread.

clockwise from the bottom, 78, 77, 76.5, three shots each.

 

[XP1K]

Holy cow batman! Could the mandrel make all the difference ? 76.5 just turned out an sd of 2.8. Only three shots though.

 

[straightshooter1]

Holy cow batman! Could the mandrel make all the difference ? 76.5 just turned out an sd of 2.8. Only three shots though.

It's not the mandrel. Like you said . . . it's "only three shots". Though, a particular neck tension can make a difference. Now you'll have to test again to verity.

 

[XP1K]

It's not the mandrel. Like you said . . . it's "only three shots". Though, a particular neck tension can make a difference. Now you'll have to test again to verity.

Yeah so, without the mandrel treatment sd was 7.7, awesome, good enough for me. Reloaded nine more just like them. Not so Bueno.

three in that one on the right.

I'm out of prepped brass so that's all for today.

 

[Rocketmandb]

Primers can make all the difference. For example . . .

Just a few weeks ago, I picked up some Remington 9.5's for a really good deal and thought I'd just use them for fireforming some brass. Out of curiosity, since I've never used them before, I loaded up 25 rounds just to see if the velocity difference (if any) due to reports of them being hotter than Fed's and CCI's. Criminy! Average velocity was higher than what I normally get by ~20fps, but it was the inconsistency the floored me. For the 25 rounds I got an SD of 33 fps and and ES of 97fps. What the . . .??? I've never had loads do that poorly, even though I wasn't using my best brass. Then I loaded up 10 rounds of my best loads that work really well, where I typically get mid single digit SD's, but the only difference being the Remington primers. Velocity was still ~20 fps faster than normal and the SD was 14.2 and the ES was 41. The Remington primers I've got SUCK! I guess I'll still use them for fireforming though.

Also few weeks ago I got some .308 Alpha brass and decided to fire form them. I loaded up 10 with my favorite load using CCI400's just to find their case volumes. Out of the 10 I got 3 pierced primers. That too is a first for me. Apparently the larger flash holes that Alpha brass has puts more pressure of the thinner 400's cups. Followed up with CCI 450's in 10 more and they performed well, giving me 5.3 SD and a 16 ES, and . . . the two 5 round groups were at .435" (at 100 yds). Because those 10 did so well, I loaded up the 80 remaining cases with the same load. Yesterday, 80 rounds fired and chronoed with an SD of 6.2 and an ES of 29.

Choosing the right or wrong primers can make a difference.

Lots to unpack here, and, coincidentally, part of a video I'm doing voiceover for as I write this.

To talk the key points in what you wrote:
- You tried a different primer to see if they are hotter than others.
- They were inconsistent - high ES/SD
- In another scenario, you got pierced primers trying a new brass (Alpha) that has larger flash holes

Let's talk the primer difference thing.
- It is quite possible that the Rem 9.5s are just that crappy compared to CCIs, though I doubt that's the case - those numbers are atrocious.
- More likely, the Rems are indeed "hotter" than the others you've tried, which means they are igniting the powder more quickly, which will force everything to peak pressure sooner, which increases burn rate of the powder, which in turn drives up pressure more, etc.
- It is likely the reason your numbers went to hell. Your velocity changed just a little bit, but, more importantly, the new primers drove your peak pressure to hit significantly earlier. This changes how your bullet accelerates (quicker), how it engages the lands (sooner and harder), and the pressure behind it as it does so.

I would bet that if you did some load development (gasp!) with perhaps a slower-burning powder and those hotter Rem 9.5 primers, maybe even some seating depth change, you'd find a load that works pretty well.

 

[Rocketmandb]

If it works for you, then by all means, keep your process. I used to do essentially the same thing, until more testing made me realize that there was no real velocity "nodes". Or at least they didn't really exist like the ladder would make you believe.

I'm now in the camp that there aren't velocity nodes perse, but rather pressure profiles that work (or don't) for a given bullet/neck tension/seating depth. Change the pressure profile and you get different results. This explains why you can get great results, as an example, with something like H1000 in a 300 PRC, but change to RL33 charged to attain the same velocity, and results go to crap.

This also helps explain the differences I'm seeing in all the testing I'm doing around effective neck tension (primarily neck lubes) - more to come next Friday, by the way, as I head out again with my 300 PRC to do even more validation (or refutation) that neck lube matters.

 

[straightshooter1]

Lots to unpack here, and, coincidentally, part of a video I'm doing voiceover for as I write this.

To talk the key points in what you wrote:
- You tried a different primer to see if they are hotter than others.
- They were inconsistent - high ES/SD
- In another scenario, you got pierced primers trying a new brass (Alpha) that has larger flash holes

Let's talk the primer difference thing.
- It is quite possible that the Rem 9.5s are just that crappy compared to CCIs, though I doubt that's the case - those numbers are atrocious.
- More likely, the Rems are indeed "hotter" than the others you've tried, which means they are igniting the powder more quickly, which will force everything to peak pressure sooner, which increases burn rate of the powder, which in turn drives up pressure more, etc.
- It is likely the reason your numbers went to hell. Your velocity changed just a little bit, but, more importantly, the new primers drove your peak pressure to hit significantly earlier. This changes how your bullet accelerates (quicker), how it engages the lands (sooner and harder), and the pressure behind it as it does so.

I would bet that if you did some load development (gasp!) with perhaps a slower-burning powder and those hotter Rem 9.5 primers, maybe even some seating depth change, you'd find a load that works pretty well.

There's no doubt that the Rem 9.5's are "hotter" than any other's I've used (maybe even the magnums I've used). And yes, I feel sure I can get some improvement with with load development. It's just that I've never had such poor results from any previous loads that were not "developed", even when I used scales that didn't weigh powder near a accurately as I do now. Since those results, I have tried a couple other powders and charges in some good brass and still, at best, only get SD's in the mid teens and ES's accordingly.

The CCI-450's are working really well in the Alpha brass with the load that works well in the Lapua brass and CCI-400's. Tomorrow, I'm doing a little more testing out of some curiosity to see how the larger flash hole works on a few Peterson brass (same case volumes) with the 450's. Yes, I enlarged the flash holes on the Peterson brass.