Over Pressure or Old Brass?

[warnera1102]

So I am working on a load development in my R700 using the 184 Bergers using 7977.The ladder load included a load at compressed 67.3 and one at 0.3gr above compressed load per the book ( reference the 180 ELDM). Now I am loaded these longer than the sammi specs at 0.010 jump.
What I didn't understand is that I had a hard bolt lift on the random chargers in the upper level. I had 1 at max charge of 67.6 compressed charger ( per book ) at 67.3 and one at below of 67.0.
Now the brass I'm using is hornady brass that has been full length sized several time, I did this because my low round count brass is loaded up.
Here is a picture of the back end, the 67.6 starts on the left. I'm wonder if the brass is just getting weak and is expanding more? I feel like I don't see any crazy pressure signs per the primers.

 

[Doom]

If you have hard bolt lift, you don’t need to look at primers. That is a sign of excessive pressure.

 

[warnera1102]

If you have hard bolt lift, you don’t need to look at primers. That is a sign of excessive pressure.

I guess what I didn't understand is why didn't every round at the velocity and charge have hard bolt lift? Only 1 round per 3 round group had it, the other 2 rounds felt fine.

 

[Milo 2.5]

Tell us how you accumulated the brass, buying all one lot of it, or multiple lots, or if by firing factory ammo. I say it could be case capacity issues.
I do not have the 184gr Berger in my QL, but 67gr for a 180 hybrid seems stiff. Ejector marks if brass is sized right for your chamber means pressure, no getting around that. Not really sure why you would need all your brass to have them to determine that you may be running hot.

I myself don't put much faith in Hodgdon data, but here is a 180 Berger vld for reference.

 

[warnera1102]

Tell us how you accumulated the brass, buying all one lot of it, or multiple lots, or if by firing factory ammo. I say it could be case capacity issues.
I do not have the 184gr Berger in my QL, but 67gr for a 180 hybrid seems stiff. Ejector marks if brass is sized right for your chamber means pressure, no getting around that. Not really sure why you would need all your brass to have them to determine that you may be running hot.

I myself don't put much faith in Hodgdon data, but here is a 180 Berger vld for reference.
View attachment 7592095

Thank you for the reply. That particular brass was from factory ammo, it's been reloaded several times.
What threw me off was the inconsistent hard bolt lift.I would assume if 1 round at a particular load caused hard bolt lift all the other rounds at the same load would do the same.

 

[Milo 2.5]

Thank you for the reply. That particular brass was from factory ammo, it's been reloaded several times.
What threw me off was the inconsistent hard bolt lift.I would assume if 1 round at a particular load caused hard bolt lift all the other rounds at the same load would do the same.

OK, let's say you are on the edge, your differences in brass is the issue. Separating them by case cap may help. Did you chrono, because things cannot look that good in that aspect.
I have been loading for 35 yrs and did the same shit last yr with Nosler 243 brass in a Tikka. Many different lots of ammo. I face palmed myself all the way to town after testing the shit show.
When I got to town, stopped at a LGS and bought some Sierra ammo, here is a group at 400 with it in 20 mph full value winds, 1-6 power scope. Way tighter than my fiasco at 100 yards.

 

[warnera1102]

Thank you. It's good to know i wasnt going crazy, I wasn't a fan of using that brass but I really want to try out these 184.
I had a few that the velocity didn't make sense based on the previous round.
I'ma try to find some better brass.

 

[Shooter71]

If the brass was fired in a different, larger chamber, and/or your die doesn’t size the base enough you’ll have hard bolt lift that mimics pressure.

 

[Foul Mike]

Is MV such an important factor to you,-- or accuracy,-- that you may be going with too much powder and wondering now why these problem crop up?
I never run compressed loads but do realize that may be the way to go with some combinations of components that are just fine, but on my 6.5/06 I am loaded down a bit to try and conserve the barrel for down the road and the Horn. BTHP Match bullets are still arounf 2960 MV. Fast enough for me and they shoot great to my standards, but you may want them to go over 3000.

I hate to think about the rounds down-range I shot that were too hot and the wear on the barrel and what is a couole of hundred FPS worth? and why?

 

[warnera1102]

Is MV such an important factor to you,-- or accuracy,-- that you may be going with too much powder and wondering now why these problem crop up?
I never run compressed loads but do realize that may be the way to go with some combinations of components that are just fine, but on my 6.5/06 I am loaded down a bit to try and conserve the barrel for down the road and the Horn. BTHP Match bullets are still arounf 2960 MV. Fast enough for me and they shoot great to my standards, but you may want them to go over 3000.

I hate to think about the rounds down-range I shot that were too hot and the wear on the barrel and what is a couole of hundred FPS worth? and why?

That's true.My goal is to push this between 1400 yards and a mile and from what I have seen at 1700 I'm getting 1100fps.
I was hoping to fine a node at the upper end of the velocity range, I like my 162 but I know the 184 will be alot more forgiving with wind.

 

[nutation]

If the brass was fired in a different, larger chamber, and/or your die doesn’t size the base enough you’ll have hard bolt lift that mimics pressure.

It seems like it would also be hard to close the bolt in this case.

 

[Milo 2.5]

It seems like it would also be hard to close the bolt in this case.

Not necessarily.

 

[warnera1102]

The brass was sized for my new chamber as I removed the removed the firing pin and tested the fitment proir to reloading.

 

[SporterII]

Carefully measure your case dimensions. If they vary by a thousand or even more that may need to be addressed. Not average but min. HS. Make sure there is at least .003 as this has been my observation with my getting a little sloppy. I also switched from fl to using a mandrel. Nice. .002 easier to hold.

 

[warnera1102]

So with the mandrel do you use the FL die to size the shoulder and body then switch to a mandrel die to resize the case mouth?

 

[sinister]

You're using Hornady brass. My experience with their particular alloying is, frankly, it sucks and gave me fits (especially in average, mid-range common .338 Lapua loads).

It frustrated me enough I lost patience with the brand and will use it only for practice and plinking ammo, not for serious use (target competition or hunting).

The heavy bolt handle lift is an indicator you're approaching the data's pressure limit warning (even though your primers are not flattening or smoke smudging-leaking). The slight cratering around the firing pin impact says you may or may not be seeing some flow (or, conversely, your firing pin hole is too large or your firing pin tip is narrow).

 

[SporterII]

Remove the expander. Get a dedicated primer removal die.
Clean a case , lubed and size .002 under. Check case mouth OD. This will tell you if you want to use your FL die. How much it works or overworks. Probably fine. I use my RCBS fl dies fine. Mandrel to yield a .002 expansion with your bullet seated.
It’s not much more investment.
no more snide remarks like “ guess we know who’s running pressure” comments.
may be your issue. May become otherwise helpful. I now hate that upstroke.

 

[918v]

You’re too close to the lands. That’s why you’re getting random pressure signs at max powder charge.

 

[sinister]

I loaded these longer than the sammi specs at 0.010 jump.

You’re too close to the lands. That’s why you’re getting random pressure signs at max powder charge.

With a little jump he shouldn't have too big a spike -- but he IS above published / compressed max (not that I haven't done it), and if you don't have data from others you have to do your own work-up -- which is what he's doing now.

OP, you didn't mention, but you are length-trimming your brass, correct?

For 1400- to mile-shots I'd be working on consistency and precision vice velocity. A little more bullet weight can make up for some velocity decay.

 

[warnera1102]

With a little jump he shouldn't have too big a spike -- but he IS above published / compressed max (not that I haven't done it), and if you don't have data from others you have to do your own work-up -- which is what he's doing now.

OP, you didn't mention, but you are length-trimming your brass, correct?

For 1400- to mile-shots I'd be working on consistency and precision vice velocity. A little more bullet weight can make up for some velocity decay.

I'm trimming the brass to sammi length.
I have some Remington and winchester brass laying around. I cannot find adg,norma or nosler brass.

 

[sinister]

7mm will take you to a mile, no prob -- just have to get the right bullet and charge.

My brother shoots a Winchester Laredo with a JP compensator. 175 Match Kings.

 

[NineHotel]

Do you have a case gauge? Do you measure how far back you are pushing the shoulder?

Factory chambers tend to run long on headspace. If you size to minimum dimensions, you can get what looks like pressure signs from the primer (flattening and cratering) even though the load may not be hot enough to cause the same signs under conditions where the brass isn't stretching .006" every time you fire it.

 

[warnera1102]

Do you have a case gauge? Do you measure how far back you are pushing the shoulder?

Factory chambers tend to run long on headspace. If you size to minimum dimensions, you can get what looks like pressure signs from the primer (flattening and cratering) even though the load may not be hot enough to cause the same signs under conditions where the brass isn't stretching .006" every time you fir

I use a hornady comparitor tool,i bump the shoulder back .002 when I resize. I think this answers your question.

 

[918v]

With a little jump he shouldn't have too big a spike -- but he IS above published / compressed max (not that I haven't done it), and if you don't have data from others you have to do your own work-up -- which is what he's doing now.

OP, you didn't mention, but you are length-trimming your brass, correct?

For 1400- to mile-shots I'd be working on consistency and precision vice velocity. A little more bullet weight can make up for some velocity decay.

He’s too close to the lands. If he doesn’t want random pressure problems he should do his ladder at lest .050” off

 

[Milo 2.5]

I'm trimming the brass to sammi length.
I have some Remington and winchester brass laying around. I cannot find adg,norma or nosler brass.

If you are going to try mix and match brass, which I hope you are not. At least do a case cap check on whatever brand you decide. You have received some solid advice here, wade through it.
If the intended use is to push the limits of the case, by all means find quality brass when you can and put it in service, your head will thank you.

 

[warnera1102]

If you are going to try mix and match brass, which I hope you are not. At least do a case cap check on whatever brand you decide. You have received some solid advice here, wade through it.
If the intended use is to push the limits of the case, by all means find quality brass when you can and put it in service, your head will thank you.

Thank you all. No i will not mix brass manufactures. Also now that i think about it I use the lee quick case trim, I wonder if that mandrel is effecting the case neck.

 

[Milo 2.5]

Also now that i think about it I use the lee quick case trim, I wonder if that mandrel is effecting the case neck.

That would be a separate issue from pressure or huge velocity spreads. Get your brass in order, find a safer charge and test.

 

[warnera1102]

That would be a separate issue from pressure or huge velocity spreads. Get your brass in order, find a safer charge and test.

How are you checking case capacity? I know this has got to be a dumb question.

 

[Milo 2.5]

How are you checking case capacity? I know this has got to be a dumb question.

Fill with water, leave spent primer in, easy to determine concave level of water, keep the same.
Another way would be to fill with a ball powder, need to zero empty case weight, then weigh when full.

 

[sinister]

OP, being as you seem to be pushing for maximum charge and velocity, how are your groups?

I'd rather win the small groups on-call / on-target class rather than the "Big Popeye biceps and forearm class" for working a bolt to get follow-on shots for whiffs just off-edge.

How does the rifle-ammo combo print using published loads? Have you software calculated down-range velocity and energy?

 

[warnera1102]

OP, being as you seem to be pushing for maximum charge and velocity, how are your groups?

I'd rather win the small groups on-call / on-target class rather than the "Big Popeye biceps and forearm class" for working a bolt to get follow-on shots for whiffs just off-edge.

How does the rifle-ammo combo print using published loads? Have you software calculated down-range velocity and energy?

Ill have to get the data from my ladder load tonight, but from what i remember the velocity spread didnt look good. Grouping was sub par compared to my 162gr eld load. The differnece between the 162 load was brass (older hornaday brass as stated ) and the bullet.

 

[918v]

The difference is due to the powder being on the slow side for the 162 and on the fast side for the 184

 

[warnera1102]

I thought about sorting over the Winchester brass or Remington Brass I have as they have only been shot 1 time (factory load). Find which one has enough consistant cases for another load development and try the best load from the previous 184gr development ( i think was 65.5gr) again.

 

[warnera1102]

Welp guy I got lucky and have 100 rounds of adg brass on the way!

 

[warnera1102]

Do y'all think I should get a mandrel for this new brass or just resize like normal?

 

[spife7980]

Running a mandrel through some lubed necks is never a bad idea.

 

[warnera1102]

Running a mandrel through some lubed necks is never a bad idea.

M looking at the Sinclair expanding mandrel, i figured the size would be 0.282 for a 7mm (0.284) but the show a 0.283?
I assume i am missing something.

 

[spife7980]

M looking at the Sinclair expanding mandrel, i figured the size would be 0.282 for a 7mm (0.284) but the show a 0.283?
I assume i am missing something.

“Expanding mandrel” is .001 below bullet diameter, “turning arbor” is .002 below bullet.

expander mandrel has just become slang for the general process.

get the dimension you need to accomplish what you are after, with variances in brass comes variances in outcomes.

 

[918v]

You use a 283 mandrel to get .002” neck tension because the brass springs back a little.

 

[Snuby642]

Using a mandrell has improved every load I do.

Do not hesitate on that one. Even if you fls with a standard die.

Just do it.

 

[warnera1102]

Running a mandrel through some lubed necks is never a bad idea.

So I just received my ADG brass and before I started to mess with it I tried to find a 7mm mandrel and die but I am not having alot of luck. Can I not just polish my RCBS expander to help with the resistance and still achieve the same neck tension?

 

[Milo 2.5]

So I just received my ADG brass and before I started to mess with it I tried to find a 7mm mandrel and die but I am not having alot of luck. Can I not just polish my RCBS expander to help with the resistance and still achieve the same neck tension?

Where did you look?
If you would return it, I can send you a .282" TiN and a die.

 

[spife7980]

So I just received my ADG brass and before I started to mess with it I tried to find a 7mm mandrel and die but I am not having alot of luck. Can I not just polish my RCBS expander to help with the resistance and still achieve the same neck tension?

You can try it, I would just load it if you dont have a mandrel.

 

[Milo 2.5]

You can try it, I would just load it if you dont have a mandrel.

Follow this advice, nothing to lose.

 

[warnera1102]

Where did you look?
If you would return it, I can send you a .282" TiN and a die.

Thank you, if this doesn't work I may take you up on that offer. I have a buddy coming down in a few weeks with his 300PRC, so I want to have my stuff together so maybe I can keep up with him.

 

[warnera1102]

So just an update.
I picked up some ADG brass and did small development with the 184gr bergers. I backed off the previous node I found with the hornady brass by 10% per ADG hoping to be within same node of 2800fps. What I found was a great velocity recording ( 2570,2573,2575) and a 0.5" group at 100 yards with no brass prep. This isnt the velocity I was looking for but this will let me shoot this weekend, hopefully with good results.

I did find a wilson mandrel, I will take the 50 rounds of the new 100 rounds of ADG brass, prep with the mandrel and see if I can find the higer end node at hopefully 2800fps.

 

[warnera1102]

Just an update I found a node at 2885 fps per my chorno on the 184 bergers with 66.5gr of 7977 but based on Strelok it maybe faster than that as i had to adjust the program to match the actual data. I got a chance to get some data our to 500 so far, hopefully I can get back out there and get data to 1000 yards.