Pressure signs?

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  • Notalentbum

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    I know these are showing some pressure signs. The extrusion around the pin divot and some marking on the heel from the bolt face. Can any experienced eyes tell a "degree" of over pressure? These were loaded to a couple recipes I found on the net. They were supposed to approximate 168gr FGMM. One was 42gr Benchmark which is the max recommended load and the other was 42.8gr of 4064 which is well under max.
    Can having shot several of these cause damage to my rifle that's not obvious/visible?
    I noticed that these are really tough to resize, taking a lot more pressure than normal on the handle to cycle through.

    Matt

    One of these days I'll figure out how to post pictures so they show directly in the post!
     

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    Broom_jm

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    Maybe one of these days you'll also learn how to reload safely, by following a MANUAL and working up from a starting load?

    You probably didn't damage your gun, but if this is how you go about reloading, just give it time. Oh, and for your family's sake, make sure your life insurance is paid up.
     

    Leadeye

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    Reloading manuals have changed over the years, and so has powder. They are still a good place to start on a caliber like 308, odd calibers you can't find in a manual are the only place I go to the internet for info, and then proceed cautiously.
     

    Notalentbum

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    Maybe one of these days you'll also learn how to reload safely, by following a MANUAL and working up from a starting load?

    You probably didn't damage your gun, but if this is how you go about reloading, just give it time. Oh, and for your family's sake, make sure your life insurance is paid up.

    I do have a couple reloading manuals and the 4064 load was well within the ranges given. I was mildly concerned about the Benchmark load but I found that recipe repeated on several different sites. If I had a range in my backyard where I could easily work up loads, I could take my time and creep up on loads like this. As it is, the closest range is about an hours drive and their hours only allow me weekend shooting. Minimal opportunity to shoot leads to taking a little more aggressive approach.

    Matt
     

    M67

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    Were able to operate the bolt of your rifle to get the casings out or did you have to get a rod and tap to get the case to dislodge?

    Overpressured yeah, but nothing I'd have an "OMG" and freak out moment. Especially if your bolt unlocked without any extra effort.

    Did you accidentally seat the bullet too far down? What rifle do you have? Winchester primers?


    And are you 100% sure on the powder charge? Scale giving you fits, etc?
     

    Cameramonkey

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    I do have a couple reloading manuals and the 4064 load was well within the ranges given. I was mildly concerned about the Benchmark load but I found that recipe repeated on several different sites. If I had a range in my backyard where I could easily work up loads, I could take my time and creep up on loads like this. As it is, the closest range is about an hours drive and their hours only allow me weekend shooting. Minimal opportunity to shoot leads to taking a little more aggressive approach.

    Matt

    Maybe a range like Parabellum would let you setup a chrono just forward of the bench in your lane? While not optimal, a range where you can chrono your loads would help. It might require a quick 1 minute or less cease fire, but I dont see a range having a problem doing that twice. (once to place your chrono, another to retrieve it. If you get it setup and ready to go behind the line, moving it forward of the line will take just a moment)

    I feel for ya brother. My range is an hour away too. But if I need to do something quick and dirty, I suck it up and throw some bills at a local indoor range for an hour or so. $20 is worth the hassle of not driving 2 hours.

    here would be my plan of attack:
    Work up a half dozen loads of each recipe. Marked clearly in ziplocks.
    go to a local indoor range that can accomodate you and start with the low batch and work your way up, paying careful attention to each round. When you get to the point it doesnt look right via case issues or chrono issues, call it quits.

    While not ideal, a few extra bucks at a local range for a pre-planned session could be well worth it.

    Good luck and stay safe!
     

    K_W

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    My Ruger P95 pistol does the same thing with factory ammo. Some brands worse that others, but always the same bulge at the perimeter of the primer strike.
     

    sht4brnz

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    are you crimping the loads?
    potential reasons for showing pressure signs other than too much powder:
    too much crimp/neck tension can spike your start pressure,
    projectile is jammed in the lands because your coal is too long.
    Things to watch for:
    primer cratering is the first thing to show,
    higher pressures will be visible on your head stamp from your brass flowing into the ejector hole creating a shiny swipe mark, like oneshot was mentioning
     

    sloughfoot

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    The cratering and marking can also be a mechanical issue with the rifle. You don't say what you shot these out of. A .308 bolt gun? Perhaps a large chamber? Although what you posted is to be concerned about, the powder charges you used are not way out of the norm.

    If it was me, I would be inspecting the bolt face and firing pin hole diameter and firing some factory rounds with a careful inspection of the fired cases. Flattened primers concern me more than apparent cratered primers. I do not see flattened primers in your pics.

    I have one perfectly safe Mauser in 30.06 with a slightly large firing pin hole that produces primers that looks just like those you posted.

    One absolute however, you cannot ascertain the amount of over pressure by physical appearance.

    You have some work to do.....
     
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    oldpink

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    The bolt face ejector hole extrusion on the case head and the cratering are telltale signs of over-pressure loads.
    As already advised, back off your charge several grains.
    Also, do not try to salvage that brass, as it's already compromised.
    As for your rifle, it's almost certainly okay, but it won't be if you don't take measures to bring your loads down to safer levels and have a kaboom.
    I see that two of the cases are Lake City, so they're going to be thicker than ordinary Federal, Winchester, or Remington brass, which will boost your pressure levels.
    It's possible that the PMC brass is likewise thicker and causing higher pressures than expected.
     

    Woobie

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    Some of you guys are cracking me up. "Update life insurance" isn't very helpful, just alarmist. Hodgdon's website lists two different 168gn bullets with their Benchmark data.

    Barnes TTSX has 42.0gn listed as the max, and it is compressed. It generated 59,500 psi from their test barrel.

    Sierra 168 HPBT matchking was also 42.0gn, not compressed, and generating 49,300 cup (don't ask me why they used two separate standards)

    Now, we need to take into account that Hodgdon's insurance company wouldn't let them list some crazy nuclear load.



    With that being said, you never start at max. You don't know how much neck tension was used on the test load, you don't know how thick their necks were, the case capacity of the brass they used, the amount of leade in their barrel, and so on. You can load up various charges in a ladder test as part of your testing, and monitor your pressure signs between strings.

    My 700 has a large firing pin hole, and extrudes primers on loads under max. But as sloughfoot said, flattened primers are more telling in such a rifle.

    There has been some really good advice in here as well, so I won't repeat what's been said. I will just close by saying you have to be patient with reloading. I spent a year working up my .308 load, and several more months when I switched to TMK's. I just don't have that many opportunities to get to a range. You're going to have trips for testing bullets, trips for testing powders and charges, trips for testing neck tension, seating depth, all kinds of things. Don't rush it, enjoy the process.
     

    Broom_jm

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    What is safe in one rifle, with one set of components (primer, brass, charge, bullet) may not be safe in another rifle. Do you know how you find out if a given load recipe is safe in YOUR gun? You start low and work your way up to higher charge weights. I don't care if the range is 5 hours away and you can only go once a year. Convenience is not an excuse for unsafe reloading practices and one of the cardinal rules of reloading is to start low and work your way up.

    Hell, if you're that hard up for time to test properly, you're welcome to come down to my place and shoot. We'll put together 5 test loads and go shoot them at the 100 yard back yard target, then put together 5 more.

    I'm not sure why guys are mentioning pistol cartridges or asking if you used a large pistol primer. If you had, the damage (with a max charge) would be more dramatic.

    What kind of rifle are you firing these from? Do you have some factory rounds to compare the primers with? What primers did you use, exactly?

    As for the life insurance comment being alarmist, yer damn right it was...this guy should be alarmed! Something else I find alarming is the number of people saying that just because a given load recipe is not over MAX on a website means it will be safe in every firearm; that's simply not true and any experienced reloader knows it for a personal fact.

    Case in point: I had a 7RM with a very short throat. I sent it to my gunsmith and he said it looked like a leade was never cut, although couldn't explain how that was possible. You could not seat a 150gr bullet deep enough into a case for the ogive to not engage the rifling, without pushing the ogive past the mouth of the case. Even with the MIN charge weight, at the recommended seating depth, pressures were too high. IF I had been dumb enough to start at a published MAX charge, I may have had a kaboom.

    Every gun is different...be smart and work your way up. Reloading is something to get alarmed about, if you see evidence of a pressure excursion.
     
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    Notalentbum

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    Rifle is a Savage model 11VT. Primers are Winchester large rifle. I am questioning my scales to some degree. I've loaded quite a bit of the 4064 recipe and don't recall having any pressure signs before. I'll weigh a few projectiles tonight to check my scales.
    Only once or twice did I have to put any extra effort into the bolt handle to remove the case after firing and then it was just a smack on the bolt with my palm.
    I have considered using an indoor range but that won't tell me anything about accuracy which is what I'm looking at. These were supposed to be approximations of FGMM and this trip I was comparing them to FGMM. I shot 4 5 shot groups of FGMM, 2 groups of the 4064 recipe and 2 groups of the Benchmark recipe. Since it's such a drive, I take several rifles and spend 3-5 hours there. This particular trip I wasn't shooting all that great. Each group of the FGMM had a flyer pushing the group size up to around 2". Normally with this rifle I can hold sub 1" groups with occasional flyers pushing it up to about 1 1/4".
    I had previously done a ladder test with 4064 and at the time my best groups were at 43.0 and 43.2. The 4064 recipe was below this so I wasn't concerned with it. I'm pretty sure everything was the same components as when I did the ladder test. I don't recall any primer cratering or extractor markings back then. None of the FGMM I shot showed these pressure signs.
    I still have some of both loaded. I think I'll pull them apart a reweigh the charges.

    Matt
     

    Woobie

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    Sounds like a good plan. I wouldnt pull those down and check them until I had verified my scale though. But definitely try that.


    What kind of scale are you using? If you've shot this before with no pressure signs, you've got a new variable somewhere. And that's a good place to start.
     

    M67

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    Savages have notoriously tight chambers, maybe the OAL is the issue like another mentioned, it's too long for that particular chamber

    Winchester primers also tend to be softer, so they might show deformation quicker than CCI or another harder primer.

    As for the balance scale, I'd look into a digital
     
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