A Brass Analysis by Pressure Signs

BFD

BFD

Hammer Time Executive member
@Schmo is a newcomer in the hand loading business and sent me some 708 brass to analyze via some brass measurements to align with pressure created per charge weight. Here it is:

Standard data:
Bullet: 118HHT
Brass: Nosler 7mm-08
Powder : Benchmark
Primer: Rem 9.5
Primer pocket new: .2075
Case web new: .4665
Barrel length: 22"
COAL: 2.810 crimped 1/8th turn on first PDR hill below ogive.

Observations: The primers of the 42 & 42.5gr loads decapped with a lot of resistance and good deal of pressure needed to push out the primers. I suspect this is due to the smaller .2075 pockets of the Nosler brass and the .2105 size of the Remington primers. I also noticed all primers, even with the very low pressure readings of the 42gr charge, were smeared flush to the case head and nearly to the primer pocket walls. I suspect Schmo's RCBS hand primer suffers the same problem as the one I had in that it isn't seating the primers deep enough in the pockets. I switched to the 21st Century hand primer with click adjust primer depth settings and all has been wonderful in that regard. All primers had a flat top to them, but none showed the hourglass of over pressure. That pancake top could hide that though.

Findings per Benchmark charge weights: (PPS = Primer Pocket Size, Web = diameter of pressure ring area just above extractor groove)

42 & 42.5gr
PPS: .2075
Web: .4665
MV: 2957fps/3000fps

43, 43.5, 44gr
PPS: .208
Web: .4665
MV: 3048fps/3054fps/3089fps

44.5 & 45gr
PPS: .2085
Web: .4675
MV: 3132fps/3169fps

45.5gr
PPS: .2085
Web: .468
MV: 3207fps

46gr
PPS: .209
Web: .469
MV: 3256

46.5gr
PPS: .2095
Web: .470
MV: 3298

*47gr
PPS: .223
Web: .4725
MV: 3302fps
*Blown primer, ejector circular divot with raised brass gouge.

Conclusions:
I think Benchmark in the 708 with 118HH is a conservative incremental pressuring powder. Seems predictable with the small & gradual pressure sign measurements. AFTER THE FACT analysis that is, like the one I outlined above. Visually, "just looking" at the case heads and primers, there is no real difference, bye the eye, visually between all the case heads and primers leading up to the nasty 47gr over pressure primer popper load. More support that the true read of pressure is by the primer pocket & web diameter growth. I think also the primer pocket growth of the two is the real indicator.

My recommendations to Schmo:
- Seat the primers deeper, even if that means putting a fired primer under the live primer to get it inserted deeper with RCBS. Or buy a 21st Cent hand primer.
- Group accuracy test the 43-44.5gr loads to see if anyone of the charge weights shoot better than others. Understanding the 44.5gr should be the highest charge weight loaded. 45gr had same brass measurements, but doesn't give a substantial velocity increase to risk pushing that weight.
- Agreed upon is the step to seat the case mouth into the first PDR valley, going .025ish deeper and testing same charge weight bracket.

My SWAG primer pocket longevity predictions upon growth from first firing: (Prior to primers not holding in case)
.0005 - 20+ loadings per case
.001 - 10 loadings per case
.0015-.002 - 3 to 5 loadings per case

With that potentially useless scale I just swagged, it's possible the metallurgy of the various brass manufacturers let one pocket enlarge .0015 and then hold there for longer than others. I'll need lots more observations on this. I've not been the best brass firings counter guy to date. I would just load them till a new primer would seat too easily, then mark and decap/save that primer on a better piece of brass. By measuring pockets I can forgo the brass prep steps only to find out it's a junk case at the end of the prep process.

This was a fun experiment and I plan to follow up with my own testing of Benchmark, 118HHT, in F.C 1X brass. I'll start with the 43-44.5 bracket where Shmo's loads seemed to be in the goldie locks zone of load development for hunting rounds.

Let me know what ya'll think!
 
I just finished gluein in the primers in a handful of 30-06 Lapua brass that I resized to 35 Whelen.

I'm going to run that pony till the sweat is dripping off of it. Hopefully I get three to five loadings out of them.

I'll go back in my hole
 
@BFD, thanks for looking at this for me. As you mentioned, there wasn’t much visible difference in case heads until the blown primer. Being new, this caused me to scratch me head. You were kind enough to let me send you the brass and inspect it, then give a nicely formatted report. I really appreciate it.
 
I have to second @Muddyboots in that I use the Sinclair PrimerPocket uniforming tool on ALL of my precision reloads before doing load development. This only needs to be done at the first loading, then a cleaning of the primer pocket afterwards.
 
BFD said:
Let me know what ya'll think!
Click to expand...
Love this test and work to document the findings.
I recently tested some new powders with pressure ladders and found some pressure and had to stop. Later when I went to resize the cases 5 of them had issues in the sizing die near the case web. Measuring case body diameters will be added to my routine as there were no visual differences.
 
Gday Brad
Nice tests but man that’s anal 🤣

& I’m going to come from this muppets position who dosent worry about that stuff anymore or the ones who really don’t understand what you’ve even relayed there as for a lot of new comers that’s just to hard to wrap one’s head around & honestly I don’t think they need to get wrapped up in all of that for now as learn the basics well first before one ventures into that stuff as watch the $ get spent & chase one’s tail is a often outcome

I mean no disrespect & value that data & I’ll explain why in a minute

But for now let’s look @ that data on velocity from schmo ( well done for compiling these as helps us all with the 118hht in the 7-08 )

Overall I don’t care to much on the velocity first off as I will toast a case in 2 shots if I get way better terminal results for hunting loads not practice loads ( extreme yes but I have done but don’t to much now as the hht has basically put that to bed & that’s even in my rums )
One maybe better served pushing the 45 or 46 gr loads for hunting ( I also don’t worry about nodes these days either) & put up with the reduced numbers of loadings per brass as how many is realistically used in hunting situation & that extra 150 /200 fps may be useful to a individual depending on the range they will most likely impact @

Eg
Hunter 1
Is a a 100 yard box shooter
So I’d take the higher velocity & forgo case life & aim for the 3200 MV load
As then impacts would be 3k plus ( I’m assuming figures haven’t checked)

Hunter 2
A one side of the field to tree line resulting in a most likely impact range of 300 yard impact
I’d take any of those loads from 42 to 46 gr & most likely settle in the middle @44 gr & fiddle with crimp if needed

As all impacts will be below the 2700 mark so you’ll not see any major differences in killings from 2400to 2650 ( assuming numbers not actual again )

just a bit to think about & may suite some others not so a individual thing

Now the data for the ones who don’t understand that information yet or don’t want to we can & should gain a extremely important piece of information off brads work
&
The most valuable information one can look @ is case life imo & do a comparison on one’s loads to the numbers of loads one gets before loose primer pockets occur & if your in that 2or 3 loads per piece of brass
( brass quality aside ) you’ve got high pressure loads & beware of it as things can go wrong if not careful here
If your in the 10 ish your good to go in a wide variety of conditions & if cost of brass dosent concern you one may stay there
20 you’ve doing very well

Side note
Now also in the mix here is annealing for the new to come to reloading & this can be one that a crimp can solve the issue /process of annealing as you’ll get away with non annealing for a fair while & if you combine that with your total number of loads per piece of brass it’s one that may not even be needed so the cost of a annealing may not even be worth it

sorry for derail so carry on

Cheers
 
Farleg said:
Gday Brad
Nice tests but man that’s anal 🤣

& I’m going to come from this muppets position who dosent worry about that stuff anymore or the ones who really don’t understand what you’ve even relayed there as for a lot of new comers that’s just to hard to wrap one’s head around & honestly I don’t think they need to get wrapped up in all of that for now as learn the basics well first before one ventures into that stuff as watch the $ get spent & chase one’s tail is a often outcome

I mean no disrespect & value that data & I’ll explain why in a minute

But for now let’s look @ that data on velocity from schmo ( well done for compiling these as helps us all with the 118hht in the 7-08 )

Overall I don’t care to much on the velocity first off as I will toast a case in 2 shots if I get way better terminal results for hunting loads not practice loads ( extreme yes but I have done but don’t to much now as the hht has basically put that to bed & that’s even in my rums )
One maybe better served pushing the 45 or 46 gr loads for hunting ( I also don’t worry about nodes these days either) & put up with the reduced numbers of loadings per brass as how many is realistically used in hunting situation & that extra 150 /200 fps may be useful to a individual depending on the range they will most likely impact @

Eg
Hunter 1
Is a a 100 yard box shooter
So I’d take the higher velocity & forgo case life & aim for the 3200 MV load
As then impacts would be 3k plus ( I’m assuming figures haven’t checked)

Hunter 2
A one side of the field to tree line resulting in a most likely impact range of 300 yard impact
I’d take any of those loads from 42 to 46 gr & most likely settle in the middle @44 gr & fiddle with crimp if needed

As all impacts will be below the 2700 mark so you’ll not see any major differences in killings from 2400to 2650 ( assuming numbers not actual again )

just a bit to think about & may suite some others not so a individual thing

Now the data for the ones who don’t understand that information yet or don’t want to we can & should gain a extremely important piece of information off brads work
&
The most valuable information one can look @ is case life imo & do a comparison on one’s loads to the numbers of loads one gets before loose primer pockets occur & if your in that 2or 3 loads per piece of brass
( brass quality aside ) you’ve got high pressure loads & beware of it as things can go wrong if not careful here
If your in the 10 ish your good to go in a wide variety of conditions & if cost of brass dosent concern you one may stay there
20 you’ve doing very well

Side note
Now also in the mix here is annealing for the new to come to reloading & this can be one that a crimp can solve the issue /process of annealing as you’ll get away with non annealing for a fair while & if you combine that with your total number of loads per piece of brass it’s one that may not even be needed so the cost of a annealing may not even be worth it

sorry for derail so carry on

Cheers
Click to expand...
It's always good to understand the rules before you bend or break them!
Every man is free to choose his own adventure in what he does. I personally think one should operate a system within it's performance specs. If more performance is wanted then step up to a bigger system capable of handling the performance as a norm and not as an exception. In this case, the answer is easy. 7RM, 7PRC, (Maybe even 708AI for another 100fps gain)
Keeping in the performance bracket of the 708 and reasonable pressures, Schmo has with the 44.5gr 3130fps hunting load, a 400yd gun with 2100fps impact velocity, and 300yds having 2320fps. (Fed ballistic calculator with 40F. 1000ft absl, BC G1 .340.)
Those hunting ranges provide what you declared to be your preferred minimal impact velocities of the HHT. (Keeping separate the absolute lowest to expect performance of 1700fps)

I think the biggest take away from the analysis is understanding where one wants to be in the dynamics of pressure/performance correlation. Obviously not everyone wants to play it safe, and they would rather push the ragged edge. (Go for it. Not my gun, equipment, money, or face) Others might have my opinion in that I'm not going to race a 250cc motorcycle at the points of blowing the engine just to keep up when I can hop up to the 500CC and keep a healthier operating machine.
 
Modoc said:
I have to second @Muddyboots in that I use the Sinclair PrimerPocket uniforming tool on ALL of my precision reloads before doing load development. This only needs to be done at the first loading, then a cleaning of the primer pocket afterwards.
Click to expand...
Good tool to keep in mind. In the case of the RCBS hand primer, it just doesn't seat the primers deep enough due to short stem length. When I switched to the 21st Century primer I've hit target depths in all the same brass.
 
BFD said:
It's always good to understand the rules before you bend or break them!
Every man is free to choose his own adventure in what he does. I personally think one should operate a system within it's performance specs. If more performance is wanted then step up to a bigger system capable of handling the performance as a norm and not as an exception. In this case, the answer is easy. 7RM, 7PRC, (Maybe even 708AI for another 100fps gain)
Keeping in the performance bracket of the 708 and reasonable pressures, Schmo has with the 44.5gr 3130fps hunting load, a 400yd gun with 2100fps impact velocity, and 300yds having 2320fps. (Fed ballistic calculator with 40F. 1000ft absl, BC G1 .340.)
Those hunting ranges provide what you declared to be your preferred minimal impact velocities of the HHT. (Keeping separate the absolute lowest to expect performance of 1700fps)

I think the biggest take away from the analysis is understanding where one wants to be in the dynamics of pressure/performance correlation. Obviously not everyone wants to play it safe, and they would rather push the ragged edge. (Go for it. Not my gun, equipment, money, or face) Others might have my opinion in that I'm not going to race a 250cc motorcycle at the points of blowing the engine just to keep up when I can hop up to the 500CC and keep a healthier operating machine.
Click to expand...
Gday Brad
Overall I agree I’m not trying to be argumentative for people to hopefully understand I want everyone to go home safe
On my first post I most likely didn’t relay that information correctly ( brain dead again ) as safety is paramount & why I like to see where limits are eg I have learnt to take temperatures to extremes as my old methods showed flaws so I had to up the level of temps testing due to what IFS becoming reality & id say I test some of my loads @ higher temps than most likely anyone here

Where I come from or tried to mainly is the cost of things these days & where I started all those years ago as didn’t have money to spend on , I’ll call them luxury items so basic equipment ( not cheap & nasty ) was all I could afford & from discussions with new comers to the sport I see some have these parameters in their budgets also & a new rifle may not be in their budget or wants & brass is often one overlooked as to give one the luxury of next level preformance ( I’m not saying unsafe but we can push the limits still safely eg use a first fired piece of brass ( a low pressure practice load ) then nominate those for hunting brass in schmo case the the 45.5 gr load & imo still be safe if he was a 100 yard box shooter ( I’d further test prior to using this on temp ) as that will be likely again 3000 plus impact
But now shift to your example above for schmo &
Thanks for the numbers & those are the ones I look @ the most & ea individual needs vary but why would you bother even doing a 45.5 gr load & the 44.5 gr load makes absolute sense imo & even the 44 wouldn’t worry me & still 500 capable
This is the hht line not the hh or like lines

Just trying to show the new comers not to get to worried on the lengths some of you guys go to & learn the basics first & foremost

Hope that message comes through clear but if not pull me up as safety is one we can’t be too careful with

Cheers
 
The study and breakdown is probably an advanced conversation might overwhelm some, not all. Id say an easy simple way to break this down for beginners is if their case body measures out of saami spec after firing it could be considered a sign of over pressure?

Eg: SAAMI max for 7-08 is .4703

BFD said:
46.5gr
PPS: .2095
Web: .470
MV: 3298

*47gr
PPS: .223
Web: .4725
MV: 3302fps
*Blown primer, ejector circular divot with raised brass gouge.
Click to expand...
 
Good points above!
OLD truisms for loading tell you don't exceed .001 expansion at the web (200 line on the brass drawing) for good brass life (and safety).
@BFD and others have clarified excellent ways to measure/detect over-pressure conditions by observing primers (beyond traditional approaches of flattening and cratering).
 
This data has been valuable to me so that I can evaluate brass from here on out when I do other load work ups. No worries, I didn’t get lost in his data lol. I’m a nerd when it comes to stuff like this. The info that’s boring to others I find interesting. I want all I can out of the 708, but not at unsafe pressure levels. As Brad said, if I need more performance than my 3100+ safe load, my 7 PRC is sitting on standby. My PRC is my main hunting rifle, this 708 is a little cheaper to shoot, longer barrel life, and mainly for coyotes and stuff where I don’t need the PRC.
 
Gday
Here’s one for everyone to chew over on brass & pressure levels

So we have a SAAMI spec of differences between different chamberings & let’s look @ 22-250 , 7-08 &308
All three have varying SAAMI specs 65,61&62 k respectively yet you can use the same brass for ea & the draw process on forming the brass is in the same batch just different forming dies used ( well is @ Bertrum )
So if one is to neck up or down the 7o8 brass as it’s the lowest rated does it all of a sudden become safe in the 308 &22-250 as in all reality of keeping with SAAMI 🤷‍♂️

So can we test that on the web measurement & primer pockets 🤷‍♂️

Now the next stage is we are seeing that Small rifle primer brass is being used instead of large so how does this relate to the SAAMI specs & pressure levels observed & those I’ve not done any tests or used so would be a interesting test to see & one I think will shock a few people if my assumptions are correct

Does anyone have a pressure trace system or able to get access to a pressure gauge rifle or what ever they are called

I’ll see what I can dig up from within part of that industry


Cheers
 
Ran the 118HHT with my components to compare to Schmo's data.
Schmo vs BFD
Bullet: 118HHT
Powder: Benchmark
Case: Nosler 7-08, H2O cap. 56gr. (Fed 308 necked to 7-08, H2O cap 53.5gr)
Primer: Rem 9.5 (WLR 2023 production)
Barrel: 22" (18")
MV:

43, 43.5, 44gr
PPS: .208 (.2105-.211)
Web: .4665 (.469-471)
MV: 3048fps/3054fps/3089fps (3107, 3152, 3153)

44.5
PPS: .2085 (.2115)
Web: .4675 (.4715)
MV: 3132fps (3235fps) *Stuck case in chamber. Mallet to open bolt.


Schmo's Nosler case capacity H20 (That's water) was a whopping 56gr!
My Fed brass came in at only 53.5gr H2O. I suspect this was the biggest contributor to my over pressure results.
I fired my rounds out an AR10 7-08 with the gas shut off for single shot as to reduce erroneous or false reads from the gas system on the brass. I then added 20fps per 1" barrel difference. (Schmo 22", BFD 18" = 4" difference = 80fps)

Schmo's bolt gun chamber, and pick of components with Benchmark is handling the pressures really good with the 118HHT. If Schmo discovers a tight shooting group with the 43-44.5gr charges I'd say leave it be and take advantage of Benchmark's great temp stability. If it doesn't group well, we discussed trying TAC, N135, and IMR3031 for some more velocity potential with same or even lower pressure. My groups with the 118HHT were not good and obviously blown big from over pressure. Load development will continue with reduced charges of Benchmark.
 
Last edited:
Fellas

I have a few questions and by all means do not want to be confrontational.

How are the primer Pockets being measured? Has there been any consideration in using pin gauges?

Is there going to be this same test conducted (How do I say it without being Pointed) using a premium harder higher quality brass? From my experience with Nosler it is extremely soft. I complained to Nosler about it years ago when working with a 7 mm Magnum. I have some federal premium 308 that has been loaded six or seven times and shows no signs of giving up soon. But this is a 308 Target load (42.0 IMR4895 175SMK)So that should be expected.

I'll go back to my hole now👍
 
A relative measurement for growth I use the opposing blades of the calipers with soft & even pressure applied while spinning the case. For an absolute measure for ad hoc "No-go gauge" one can measure the smooth end of the cheap Harbor Freight numbered drill bit kit. If the .211 bit slides in the pocket, there is the "no-go" test.
 
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