Pressue Signs, your take on these cartridges

[Baron23]

HI guys - this is sort of a bit of a...oh, I don't know.....question with what I think is an obvious answer but given the potential criticality of over pressure hand loads and my absolute zero experience in evaluating brass for pressure signs, I thought I'd ask the forum.

This is once fired Hornady 6.5 cm brass with CCI BR-2 primers running H4350 (charge amount is shown in the pic) and Berger 140 gr Hybrid Targets.

To me, all of this brass looks fine. No extractor marks, no ejector indentation, no flow of primer cup material into firing pin hole, and while the primers are flatter than they were (well, they were fired), there is still radius on all of them.

I had zero bolt opening issues except a small increase in force needed for the one cartridge with the red arrow pointing to it. But this cartridge looks fine to me also (yeah, zero experience me! haha) and I know that when I sized all of this Hornady brass, there were a handful that I caught where the base was just a bit fat and really wouldn't seat fully in a Sheridan case gauge. Any that didn't, I set aside but that doesn't mean some didn't get through. So, without any other indications, it seems to me that this is most probably why on this one cartridge (and yes, with the highest charge in the ladder) the bolt was just a bit balky in opening.

But I'm all ears and completely willing to discount any thoughts of mine in favor of your far more vast experience.

See any pressure signs?

 

[KnowNothing256]

Heavy bolt lift is usually my go-to pressure sign because it happens early and has fewer potential causes than primer appearance (flattened/cratered), and if I really push it, an ejector mark. Only have these on ladders, then I back down for load selection.

Seems like you got a pressure sign, right where it would be, at the top charge weight. It's probably right at the edge of incipient pressure signs, since you didn't see others at similar charge weights, so you could choose to run there if you liked, but I'd find the next desirable spot down the ladder. I certainly wouldn't blindly attribute the heavy lift to a "fat" case that you didn't verify was in fact fat. If you truly wanna determine the cause, load up ten that are verified "skinny" and see if any of them show increased bolt lift force; I expect you'll see a few that do.

 

[Baron23]

Heavy bolt lift is usually my go-to pressure sign because it happens early and has fewer potential causes than primer appearance (flattened/cratered), and if I really push it, an ejector mark. Only have these on ladders, then I back down for load selection.

Seems like you got a pressure sign, right where it would be, at the top charge weight. It's probably right at the edge of incipient pressure signs, since you didn't see others at similar charge weights, so you could choose to run there if you liked, but I'd find the next desirable spot down the ladder. I certainly wouldn't blindly attribute the heavy lift to a "fat" case that you didn't verify was in fact fat. If you truly wanna determine the cause, load up ten that are verified "skinny" and see if any of them show increased bolt lift force; I expect you'll see a few that do.

Thanks!! And yes, I wasn't planning to run further at that top charge weight and I do appreciate your info about the sort of order where you see pressure signs...that being heavy bolt lift often first. Thank you.

By the by, the cartridge that gave me the bit of a heavy sign also was the fastest in that three shot set by 10 fps so 2870 mv.....not much higher, but if I was on the ragged edge there already, it may well not take much more than that to cause an issue.

I do really appreciate the reply.

 

[Deadman Pointers]

2850 is what I've been running at with 140s and H4350. You can always deprime and get a feel for whether the primer pockets are loose.

 

[Baron23]

2850 is what I've been running at with 140s and H4350. You can always deprime and get a feel for whether the primer pockets are loose.

Thank you. Great suggestion. Appreciate the reply

 

[parshal]

Heavy bolt lift is usually my go-to pressure sign because it happens early and has fewer potential causes than primer appearance (flattened/cratered), and if I really push it, an ejector mark.

I often get ejector marks long before I get heavy bolt lift. I don't think ejector marks, by themselves, are always indicative of excessive pressure. Probably higher pressure but not necessarily unsafe. Heavy bolt lift is excessive pressure and I will not run a charge that has any signs of bolt lift.

 

[KnowNothing256]

I often get ejector marks long before I get heavy bolt lift. I don't think ejector marks, by themselves, are always indicative of excessive pressure. Probably higher pressure but not necessarily unsafe. Heavy bolt lift is excessive pressure and I will not run a charge that has any signs of bolt lift.

Probably just depends on the cartridge and who knows what else, honestly. Loose primer pockets were proposed as a sign, but in my experience those are either inconsistent brass (looking at you, Hornady) or a cumulative effect over repeated firings.

I think really it’s about risk management and tolerance. We like to talk about overpressure rounds like going 0.5gr high on a 42gr load will send your bolt backwards through your cheekbone, but in the same convo folks will talk about their “warm” and “hot” loads that give them that little bit of extra speed at the expense of premature split necks, stuff bolt lifts, ejector swipes, etc. I think most people on SH agree that reliable function is preferred over an unreliable 40 FPS boost for our purposes, so we prefer to identify pressure signs then use them as the upper bound on load development. Seems like a solid approach to me.

Definitely good info that you see ejector evidence first tho; that’s why it’s good to be looking for all the signs as you increase charge weight.

 

[Choid]

It isn't a hard bolt lift until you need a mallet.

Seriously, everything looks good. You are on the right track, and there is so much data with 6.5C that as long as the velocities look like what the loads say they should, you likely have a "normal" barrel and will be fine in the normal range.

 

[Baron23]

It isn't a hard bolt lift until you need a mallet.

Seriously, everything looks good. You are on the right track, and there is so much data with 6.5C that as long as the velocities look like what the loads say they should, you likely have a "normal" barrel and will be fine in the normal range.

Thanks....yep, no mallet needed. Didn't even need to kick the bolt handle! haha

It was just a bit balky. Nothing major, but noticeable when opening. What is a bit interesting to me is that the load that had balky bolt lift was at 2870 fps and that is exactly where Berger factory loaded 140 gr Hybrid targets run in this barrel without ever a hiccup. So, it may have been a pressure sign or it may not. If I find that I want to at least try to run at that 42.1 range, then I will have to reload more than just three and see if I get any bolt lift signs or not.

I'm working on entering my MVs into the software that the fella here posted that will plot the Labradar series and pull the actually data out into a spreadsheet. Actually, I just started reading the manual (yeah, RTFM)

Then I will again prepare one of my dissertations on what I don't know about reloading (oh joy, bet you can't wait! haha) and ask for input on next step.....really, looking at MVs/ES/SD and groups, I think the next step is to zero in on a charge wgt range (or two), maybe drop to .1 gr between loads, and increase the number of cartridges in each and see if I can just settle on a powder charge.

Then comes seating depth and see what that does to groups....I'm pretty sure by that point, EVERYBODY will be sick of me and my novice, first time reloading, endless questions! haha

Take care.

 

[KnowNothing256]

What is a bit interesting to me is that the load that had balky bolt lift was at 2870 fps and that is exactly where Berger factory loaded 140 gr Hybrid targets run in this barrel without ever a hiccup. So, it may have been a pressure sign or it may not.

Ammo manufacturers often use powders that aren't publicly available which have different pressure curves than a given powder. Hell, even just switching powders that can be bought off the shelf can put you into pressure-sign territory at the same MV (a hyperbolically extreme example: trying to use a pistol powder to get 6.5CM factory ammo speeds). Unless Berger happens to tell you what powder they're running and it matches yours, this isn't a particularly meaningful comparison.

 

[Choid]

Thanks....yep, no mallet needed. Didn't even need to kick the bolt handle! haha

It was just a bit balky. Nothing major, but noticeable when opening. What is a bit interesting to me is that the load that had balky bolt lift was at 2870 fps and that is exactly where Berger factory loaded 140 gr Hybrid targets run in this barrel without ever a hiccup. So, it may have been a pressure sign or it may not. If I find that I want to at least try to run at that 42.1 range, then I will have to reload more than just three and see if I get any bolt lift signs or not.

I'm working on entering my MVs into the software that the fella here posted that will plot the Labradar series and pull the actually data out into a spreadsheet. Actually, I just started reading the manual (yeah, RTFM)

Then I will again prepare one of my dissertations on what I don't know about reloading (oh joy, bet you can't wait! haha) and ask for input on next step.....really, looking at MVs/ES/SD and groups, I think the next step is to zero in on a charge wgt range (or two), maybe drop to .1 gr between loads, and increase the number of cartridges in each and see if I can just settle on a powder charge.

Then comes seating depth and see what that does to groups....I'm pretty sure by that point, EVERYBODY will be sick of me and my novice, first time reloading, endless questions! haha

Take care.

For the record, I have enjoyed these threads. I can't wait for the bris.

 

[Baron23]

For the record, I have enjoyed these threads. I can't wait for the bris.

hahaha....how would like this old fuck trimming up your schmekel! hahaha

And notice the strict adherence to sterile procedure...no mask, no glove, but lots of beard hair! LOL

 

[Choid]

If he can make it look bigger...

 

[Baron23]

If he can make it look bigger...

No, that's not how it works! haha