First time reloading: 7mm08

Hey team,

I'm new to reloading and could use some help and advice.

Over the last year I've slowly been gearing up and collecting components getting ready to reload. Late last week I finally loaded and fired my first loads!

Long story short is that I'm worried that I'm missing pressure signs so I'm looking for feedback and advice as I don't want to screw this up!


If it helps, I'm loading for my Christensen Arms Ridgeline in 7mm08 with 1:9" twist and 24" barrel + suppressor.

My components for reloading are:
- Hornady once fired brass
- Hornady 162gr ELD-M projectiles
- IMR 4064 powder
- CCI 250 LR mag primers (I had no luck getting any CCI 200s, so these had to do!)

COAL of 2.837" (mag fit, just)
CBTO of 2.143"

I wanted to start conservatively, so I started with a pressure test ladder from 37gr upwards in 0.5gr increments, hoping to get to book max of about 39.5gr. After reading a lot where people suggested loading a few grains over book max I loaded up to 42gr, just in case, never expecting to fire the last few loads. I loaded a single load for each charge weight. I looked through my reloading manual (Lyman), online Hogdgon load data, Hornady load data and estimates from Gordons Reloading Tool (GRT) and jotted down my expected velocities at each charge weight. My sourced all seemed to agree that 39.5gr was book max so my expectations were set accordingly.

My original goal with reloading was to learn something new, have fun, and I really wanted to throw the 162gr ELD-Ms at a shade over 2600fps which I should be able to do at a shade over 39gr.


I had a chronograph for the day and it was about 20C and sunny day at the range, so I felt like I had everything ready to go. :)

I started by firing three Hornady Precision Hunter 150gr ELD-X factory loads and verifying the claimed 2770fps on the box. The three readings from the chrono were 2749, 2771 and 2795—quite a spread but gave me confidence to continue.

After that I worked up the courage to fire my first load @ 37gr. Success! It went the right kind of bang and the velocity was about what I expected, maybe a little higher. Each time a load was fired I noted the velocity and checked each case for pressure signs. Each load showed a very, very small change in the "cratering" around the firing pin on the primers, nothing substantially different from the factory Hornady loads I fired first though, and I didn't really notice any other changes. At 39.5gr I had a clear ejector mark on the case and almost stopped, but I decided to fire the 40gr load just to confirm I was getting close to my limit. I expected to see the same extractor mark again, at which time I would have stopped, but there was no mark on the case at 40gr... so I continued on all the way up to 42gr!!! I was carefully trying to detect a stiffer bolt lift, but there was no noticeable change here either, and I checked each case pretty carefully before firing the next load. I did see some of the velocities jump around with 40.5gr being slower than 40.0gr and 42gr being slower than 41.5gr, but seeing as I only fired a single round I have no idea about es so I don't know if these are valid data points or not...

At 42.0gr I am 2.5gr over book max and velocity is creeping up towards 2800fps so I really need to make sure I'm not being stupid—please help!



The questions playing in my mind are:
- Am I way over pressure and flirting with disaster?
- Even if 42gr is "safe", is it giving my brass and rifle a bloody hard time which will end in more cost and affect reliability of the rifle or my loads?
- I know I can easily get my original target velocity, so should I stick close to book max at 39.5gr, knowing I'm being really very safe, and just work on nodes around there?
- Do I have a bit further I could push my loads safely?
- Did I go about this process all wrong?


My plan right now is to start looking for a velocity node. This time I'll load 3 at each charge weight, working my down from 42gr in 0.3gr increments or so and looking for a stable velocity node but I want to double check before I choose my charge weight max.

Here's photos of the case heads at each charge weight, one of the factory Hornady Precision Hunter loads and my velocity notes from the day:
https://drive.google.com/drive/folde...0C?usp=sharing



What do you think?

I don't load for 7mm-08, but the fact you are up to nearly 200fps faster than listed maximum velocities suggests pressure will also be well over maximum.

Quote:

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Originally Posted by Cigar

I don't load for 7mm-08, but the fact you are up to nearly 200fps faster than listed maximum velocities suggests pressure will also be well over maximum.

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What he said. Pressure signs generally won’t show until you’re way over pressure or something else is wrong. Velocity is a much better indicator.

Keep going over MAX and ignoring the books and you won't be reloading long.

Big 7mm08 and 162gr fan.
I'd drop back and find an accuracy node just around or below book max.
I'd be doing a ladder test to find your node looking at rungs on the target and flat spots with velocity on the chrono, then do a setting depth test on the middle rung to find my load.
Normally get a decent hunting/ field shoot load within 20 rounds this way
Then it give you plenty of leeway for temperature variations, give decent brass life and accuracy.

I ran an 18inch 7mm08 for along time.
Mostly using the 162gr Amax/ eld m @2530fps with 2208.

Would regularly take goats and fallow past 500meters and longest kill at 602 meters.
Personally, I'd be dropping my load right back, especially as a beginner reloader

@raspy I just plugged your numbers into GRT for 42gr, the velocity matches your actual pretty well, but predicted pressure is nearly 78,000psi, max allowable pressure is 60,000.
Things could turn very bad very quick, you are probably lucky it hasn't already. I wouldn't be surprised if your brass is trashed already, it's probably safest to bin the fired cases from the higher loads.

I realise I'm opening myself up to flack for posting this thread, so appreciate the restraint so far. :oh noes:


My intention wasn't to achieve 7mmRM performance out of my 7mm-08, but because the pressure signs I was looking for never eventuated I pressed on as carefully as I thought I could.

I did some initial loading on my last 7mm08 with a friend who's an experienced reloader and we got to a shade under 40gr of IMR4064 with a similar projectile (actually the older, translucent tipped 162gr ELD-M which were giving me a different CBTO by about 0.003" for the same COL, but that's by the by) and started to see a step up of primer cratering and some clear, small ejector marks so we pulled pin. I was trying to do the same here... though this time I was doing it on my own.

It sounds like I should count my lucky stars that I didn't have a failure on those higher loads and back right off back down to be under max pressure and work for an accurate node under that? I'm happy to discard the brass from the higher loads as I would rather be on the safe side—would you advise getting rid of all the brass from over max pressure then?

Really appreciate the advice so far @Cigar and @lau lau!

Quote:

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Originally Posted by raspy

I realise I'm opening myself up to flack for posting this thread, so appreciate the restraint so far. :oh noes:


My intention wasn't to achieve 7mmRM performance out of my 7mm-08, but because the pressure signs I was looking for never eventuated I pressed on as carefully as I thought I could.

I did some initial loading on my last 7mm08 with a friend who's an experienced reloader and we got to a shade under 40gr of IMR4064 with a similar projectile (actually the older, translucent tipped 162gr ELD-M which were giving me a different CBTO by about 0.003" for the same COL, but that's by the by) and started to see a step up of primer cratering and some clear, small ejector marks so we pulled pin. I was trying to do the same here... though this time I was doing it on my own.

It sounds like I should count my lucky stars that I didn't have a failure on those higher loads and back right off back down to be under max pressure and work for an accurate node under that? I'm happy to discard the brass from the higher loads as I would rather be on the safe side—would you advise getting rid of all the brass from over max pressure then?

Really appreciate the advice so far @Cigar and @lau lau!

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Agree with the advice of others above, my suggestion would be to get alongside your friend or another reloader in your area to learn everything you can - you'll learn plenty more on your own later, but you need to do it safely.
Personally - I've always loaded conservatively as I'm seeking accuracy & good hunting results (rather than velocity).

Quote:

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Originally Posted by raspy

I realise I'm opening myself up to flack for posting this thread, so appreciate the restraint so far. :oh noes:


My intention wasn't to achieve 7mmRM performance out of my 7mm-08, but because the pressure signs I was looking for never eventuated I pressed on as carefully as I thought I could.

I did some initial loading on my last 7mm08 with a friend who's an experienced reloader and we got to a shade under 40gr of IMR4064 with a similar projectile (actually the older, translucent tipped 162gr ELD-M which were giving me a different CBTO by about 0.003" for the same COL, but that's by the by) and started to see a step up of primer cratering and some clear, small ejector marks so we pulled pin. I was trying to do the same here... though this time I was doing it on my own.

It sounds like I should count my lucky stars that I didn't have a failure on those higher loads and back right off back down to be under max pressure and work for an accurate node under that? I'm happy to discard the brass from the higher loads as I would rather be on the safe side—would you advise getting rid of all the brass from over max pressure then?

Really appreciate the advice so far @Cigar and @lau lau!

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Greetings @raspy,
First things first don't beat yourself up on your handloading to date. I tried some fairly hot loads early on as well. As far as the brass from your hot loads I would let the primer pockets tell you if they are fit for use. If a new primer seats with some resistance then they should be OK. There is an awful lot to learn and some of the stuff you will see on line and on Utube is unhelpful or downright dangerous. The first item to learn is that looking at primers is worthless for estimating pressure. Many on the Forum will disagree with that but there are just too many variables for reliable results. A shiny ejector mark indicates way too much pressure and the lack of one does not indicate safe pressure either. The Hodgdons data for the 7mm-08 is pretty good and loads I have chronographed are close to predicted once barrel length and powder charge have been allowed for. The need to change CBTO for different batches of the same projectile is well known. I think that your decision to retreat back to the book max or lower loads is wise. You might wish to consider dropping back to a lighter projectile if you want to increase velocity, That 150 grain Hornady ELDX looks like a good match for the 7mm-08 and I might even try them in my 7mm SAUM when they become available again. Finally the 7mm-08 does not require endlsee testing to get a decent load, Pick one from the loads you have tried and go with that for the present. You can still experiment but it is March tomorrow and you need loads for the next few months,
Regards Grandpamac.

I've been running a similar combination in my 7/08 for almost 10 years now.

A sprinkle of 2208 with a 162gr Amax gives me 2640fps in a long action 20" T3. Probably on the warmer side, but hey. Absolutely devastating on animals.

Velocity is not a measure of pressure , all it tells you is how fast the projectile is going and yes chronographs Lie . Pressure signs can show with both over and under loaded ammunition , which can be confusing as there are other things which can make you think there is to much pressure .
Your powder is on the fast side , for the projectile , and the projectile is on the heavy sidefor the calibre which isn't bad . But a rule to use is for any given calibre is that fast powder for light projectiles and slower for heavy . Most likely your load is not going as fast as the chronograph has told you and with no signs of pressure you are still safe at 42gr , reloading manuals are only a guide not an absolute because idiots love blaming someone else for their cockups .
Personally I would use the next slower powder , but your choice will still work , although at 42 you are at pretty much max for gain with out pressure problems , and I would do a pressure ladder test again to see if you are getting false velocity readings as I suspect.

Quote:

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Originally Posted by Tankd

Velocity is not a measure of pressure , but it is an indication of pressure. More velocity requires more pressure. You can play around with different powders to get a bit more velocity for the same pressure, but this is largely small differences..all it tells you is how fast the projectile is going and yes chronographs Lie Yes, chronographs can be wrong but with at least 11 readings in the expected range I wouldn't be calling it wrong in this case without a very good reason . Pressure signs can show with both over and under loaded ammunition , which can be confusing as there are other things which can make you think there is to much pressure .
Your powder is on the fast side , for the projectile , and the projectile is on the heavy sidefor the calibre which isn't bad . But a rule to use is for any given calibre is that fast powder for light projectiles and slower for heavy . Most likely your load is not going as fast as the chronograph has told you and with no signs of pressure there were pressure signs at 39.5gr, and with magnum primers signs might not show up as well you are still safe at 42gr , reloading manuals are only a guide not an absolute because idiots love blaming someone else for their cockups .
Personally I would use the next slower powder , but your choice will still work , although at 42 you are at pretty much max for gain with out pressure problems , and I would do a pressure ladder test again to see if you are getting false velocity readings as I suspect.

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With pressures possibly 30% above max, a lot of caution is good idea.

Agree with grandpamac.. primers will tell you state of brass. I can anneal them for you which will probably help but won't restore stretched primer pockets (before you size and prime!).

I'd do a ladder test say 37.4 to 39gn in 0.2 gn increments and chronograph. If you are not sure about the chrony you can chrony with my LabRadar at my place. Look for a flat spot and load a few at the weight before the speed dropped off. I have often found this will give a very good SD and then seating depth can be played with for accuracy if needed. Happy to help.

Thanks for all the feedback and ideas—as well as generous offers!

I think working more on load development is going to have to wait for a little while now as I've got some hunting to do and thankfully I have enough precision hunter to see me through for a while :)

The goods news is that I'm very confident I can get a load with the performance I was looking for originally with the components I have. I'm going to back right off to a more sensible upper bound and load up to it in small increments under it as my next step

Will post again when I have my next set of questions :D