Safety Warning for Berger 77 grain OTM Tactical Factory Loaded Ammunition

Molon

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This is a safety warning pertaining to Berger’s factory loaded ammunition.



Berger 223 Remington

77 grain OTM Tactical

Part # 65-23030

Lot # P002745-1




beger_kaboom_box-2018309.jpg






berger_kaboom_lot_number-2018317.jpg






While firing this ammunition from one of my Krieger barreled, semi-automatic, precision AR-15s, I experienced an uncharacteristic amount of recoil and muzzle blast. This occurred with the second round fired from the magazine and there were two bullet holes in the target, so there was no type of bore obstruction involved. (This AR-15 has functioned flawlessly for over one thousand rounds and has produced ½ MOA 10-shot groups at 100 yards.)



The action failed to cycle after firing this second round from the magazine and the trigger was dead. No amount pulling/pounding on the charging handle was able to free-up the bolt carrier group. As stated above, there were two bullet holes in the target so there was no type of bore instruction involved.



At home, I had to use a mallet and a Delrin rod to pound the bolt, carrier and case out of the barrel extension/upper receiver. Prior to pounding out the bolt carrier group, I took a quick look in the bore with a cheap borescope. It was clearly visible that the brass case (Lapua) was still tightly sealed to the walls of the chamber.






berger_kaboom_borescope-2018316.jpg






Upon examining the spent case, it was clearly visible that the primer pocket was greatly expanded and there was a large amount ejector and extractor brass-flow. The primer fell out of the bolt face when the case was removed with the pounding-out of the bolt carrier group.



berger_kaboom_03-2018310.jpg






The was a large “belt” of expanded brass just above the extractor groove. This belt had a diameter of 0.414” at the at the broadest section. The case was split on either side of the extractor brass flow. The case rim was split at the ejector brass flow.





berger_kaboom_05-2018312.jpg








berger_kaboom_07-2018314.jpg






berger_kaboom_06-2018313.jpg










I have not yet conducted a damage assessment of my AR15. A link to this thread has been sent to Berger and I’ll post their reply when I receive it. Until such time, I urge anyone who has also purchased this ammunition not to use it.


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This Krieger barrel has a 223 Remington chamber with a 1:9" twist. This barrel was purchased directly from Krieger Barrels, Inc. and was chambered by them. I've fired over a thousand trouble-free rounds through this barrel. The box label for this Berger ammunition clearly states that this is 223 Remington ammunition.

Using a bullet pulled from this lot of ammunition, I determined the cartridge overall length that would be necessary for the bullet to be seated to the lands of this barrel. That distance was 2.322" and since the factory loaded ammunition was loaded to magazine length, the bullet was nowhere near the lands of my barrel.






sinclair_seating_dpeth_gauge_02_resized-1378837.jpg




Shortly before shooting this Berger factory loaded ammunition, I fired a 10-shot group of factory loaded Sierra Prairie Enemy 55 grain BlitzKings. That group had an extreme spread of 0.72 MOA.



sierra_prairie_enemy_10_shot_group_at_10-2020487.jpg
















berger_kaboom_casehead_letters_01-2021963.jpg




The blown case has a weight of 99.0 grains. The neck diameter of this case is 0.254”. The diameter of the “belt” above the extractor groove is 0.414” at the broadest section.

The diameter of the case rim across the extractor and ejector brass flow is 0.423” and the diameter of the case rim rotated to 90 degrees of that position is 0.382”. The primer pocket has a diameter of approximately 0.222” at the broadest section.

I pulled-down 20 of the unfired cartridges from this lot of ammunition. Here’s the compiled data.




berger_factory_ammunition_data_sheet_02_-2025493.jpg




You can see a larger view of the above data sheet here. (or just click on the pic above.)



Pulled-down powder from this Berger ammunition.


berger_pull_down_powder-2020583.jpg





Pulled-down powder charge weights . . .




sample_standard_deviaiton_of_powder_char-2026901.jpg




I pulled-down a couple more rounds after compiling the above data and found a round with a charge of 23.6 grains. The puts the powder charge variation at 1.8 grains.



powder_charge_graph_003-2062310.jpg





28.6 grains of this pulled-down powder filled a randomly selected pulled-down case to the case mouth. The longest cartridge overall length that I measured from this lot of factory loaded ammunition was 2.262". I was able to load 26.0 grains of the pulled-down powder into a pulled-down case and seat a pulled-down bullet to a cartridge overall length of 2.262".





This ammunition is a heavily compressed load, so bullet set-back is highly improbable. Since it was a compressed load, I was unable to use my custom K&M compression gauge to obtain an accurate measure of neck tension, however, it required quite a bit of force to pull the bullets from the cases using a press-mounted, collet bullet-puller. Also, using the custom K&M compression gauge, I applied 90 pounds of force to one of the factory-loaded cartridges that had a cartridge overall length of 2.253". After applying the 90 pounds of force, I again measured the COAL. It was still 2.253".





Pulled-down case weights . . .


sample_standard_deviaiton_of_case_weight-2026909.jpg



The case weights past the plus one standard deviation are the heaviest Lapua Match cases that I've ever seen. (Legacy"standard" Lapua cases did weigh more.)






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Could you post a full length photo of this case and an unfired case side by side?

berger_kaboom_fired_case_next_to_unfired-2020446.jpg



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@Molon
Can a bullet, and when pressing its tip against a firm surface be easily moved further into the case ?



No. This ammunition is a heavily compressed load, so bullet set-back is highly improbable. Since it was a compressed load, I was unable to use my custom K&M compression gauge to obtain an accurate measure of neck tension, however, it required quite a bit of force to pull the bullets from the cases using a press-mounted, collet bullet-puller. Also, using the custom K&M compression gauge, I applied 90 pounds of force to one of the factory-loaded cartridges that had a cartridge overall length of 2.253". After applying the 90 pounds of force, I again measured the COAL. It was still 2.253".





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...........wonder if it's N140?


Berger pulled-down powder . . .

berger_pull_down_powder-2020583.jpg




VihtaVuori N140 . . .

vihta_vuori_n140-2021597.jpg











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It takes well over 70,000psi to make lesser brass flow into the ejector pocket like that, as well as make the primer pocket go from a circular shape to an egg. Primers will often blow at 70ksi, but the case head might not have anywhere near that much eschar/soot.

I agree with 357max, that if this wasn’t Lapua brass, we’d be looking at case head separation and a blown ejector at a minimum.

My guess is that this was anywhere from 75-90ksi, maybe more.


How much pressure does it take for the letters on the case-head to engrave into the face of the bolt?:)


berger_engraved_bolt_face_02-2021962.jpg




I flipped the image of the bolt for easier comparison to the blown case-head.

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Did the weapon fire out of battery?

that’s my guess.


As stated in my original post, I had to pound the bolt, carrier and fired case out of the barrel extension/upper receiver. The round did not fire out-of-battery.


The pic below shows the orientation of the locking-lugs on the barrel extension when the rifle is in the normal firing position. Note that the top locking-lug is exactly at the 12 o’clock position. You can also see that it is aligned with the index pin, which is at top-dead-center.






barrel_extension_01-2002127.jpg








In the next pic, we see the orientation of the locking-lugs on the bolt when the bolt-carrier group has completely unlocked.





bolt_rotated_to_completely_unlocked_posi-2002129.jpg








When the bolt has rotated completely into battery, the first locking-lug clockwise of the extractor (when looking directly at the bolt-face) will be in the 12 o’clock position. At this point it is physically impossible to have an out-of-battery discharge.







bolt_rotated_to_completely_in_battery_po-2002128.jpg










Now, let’s look at the position of the firing pin when the bolt has first rotated completely into battery. With the bolt still in the same position as in the picture above and completely in battery, you can push the firing pin as far forward as it will go (or hit it with the hammer or have the hammer follow the bolt into battery) and the firing pin will not have even started to protrude from the face of the bolt. It is physically impossible for the firing pin to come into contact with the primer before the bolt is completely in battery.





tip_of_firing_pin_when_bolt_is_completel-2002133.jpg






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What chamber is your Krieger?

This Krieger barrel has a 223 Remington chamber with a 1:9" twist. This barrel was purchased directly from Krieger Barrels, Inc. and was chambered by them. I've fired over a thousand trouble-free rounds through this barrel. The box label for this Berger ammunition clearly states that this is 223 Remington ammunition. Using a bullet pulled from this lot of ammunition, the cartridge overall length was 2.322" with this bullet seated to the lands of this barrel.

Shortly before shooting this Berger factory loaded ammunition, I fired a 10-shot group of factory loaded Sierra Prairie Enemy 55 grain BlitzKings. That group had an extreme spread of 0.72 MOA.



-----------------------------------------------------------------------------------------------------------------------------------------------------


What you're seeing with the belt is excessive pressure inside the case ballooning the web in the space between the bolt and breech face and chamber chamfer.
Yup.



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@Molon - I would love to see one of your macro shots of the case head fired without issue? Did have even a hint of pressure indication?
The above request is not to question you in anyway, but for the benefit of anyone reading this.


berged_fired_case_head_01-2024078.jpg



Did Berger ask for the blown case back to help with their investigation?

No.



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Aren't those bullets seated long or something?

This Berger factory loaded ammunition is loaded to magazine length. The longest rounds that I sampled are 2.262"; that's a jump of approximately 0.060" to the lands in this Krieger barrel.

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I did not see any specs on barrel.

Post #18.

Thicker necks in a smaller/tighter throat would create pressure

The case neck does not extend into the throat of the chamber.

Try to drop a bullet back into a fired case, if you can. If a bullet does not drop free or with very little resistance into a fired case.....prob a part of the issue, along with it is a bit warm of a load to begin with.


berger_pin_gauge_case_mouth_01_resized-2021964.jpg



...


2nd, a faster twist rate with heavier bullets can show pressure sooner.

This barrel has a 1:9" twist.


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What does the neck measure fired - unfired?

The fired case neck measured 0.254"

The unfired, factory loaded Berger rounds had neck diameters running 0.2505" to 0.252".



Have you shot Lapua through this Krieger before?


On numerous occasions.


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A little carbon ring would be magnified badly by the Lapua brass.

There is no carbon ring in this barrel.


. . . but I'd like to see tight neck fit ruled out.

See the measurements in post #22.


Assuming you'll be running the remaining unfired rounds across your scale to see if anything obvious shows up.

That's the plan.

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Any chrono data on the Berger lot/ammo samples?

No.


How much Berger ammo have you previously put thru the rifle ?

This is the first time I've used Berger factory loaded ammunition.

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I still think you should look at barrel reamer specs vs loaded ammo. The PTG reamer spec for the neck is .252. Most Lapua and other high end brass is .015 on neck wall thickness. That equals a .254 loaded diameter (.015 neck x2 plus .224 bullet diameter). It should be a .250 loaded diameter for it to run right. I have seen this many times.

Post #22

The fired case neck measured 0.254"

The unfired, factory loaded Berger rounds had neck diameters running 0.2505" to 0.252".



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@Molon do you have a way to measure distance to the lands/jam in your rifle?


Using a bullet pulled from this lot of ammunition, the cartridge overall length was 2.322" with this bullet seated to the lands of this barrel.


.

Have you shot this particular load from Berger in this rifle before?

No.

and lastly, it’s now summer and hot, possible the box of ammo was sitting in the sun/trunk of a car before it went through the rifle?

No.

Do a bunch of shooting and let the runs sit in the chamber a while?

Negative.


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Yeah I have some of that lot too. It's all been completely fine in my 223 Wylde. Bolt gun. Both lots 1 and 3


The Krieger barrel that this incident occurred with has a true 223 Remington chamber.


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Hmmmm. Of course, the ammo is 223 Rem ammo. It isn't. "223wylde". So that's not an excuse, but Id think that figures into it. What do you think?

223 Wylde chambers can safely fire 5.56mm pressure rounds.


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Update

Berger has reached out to me and offered to replace this ammunition. They also said ".We have had a couple of these reports. But it dosent seem an issue with all of this ammunition."

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Update:

Berger is sending me a call-tag for the unfired rounds. Berger also stated, "there has been a change in this load between the lot that you have and the lot that we are sending you. The new load was developed in a standard SAAMI 223 Remington chamber."

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.....
 
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eastexsteve

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It's been my experience that factory ammo loaded with a Berger bullet - whether by Berger or Federal - is usually a rather warm load. I have a case right now of FGMM with Berger 185gr in 308win that is noticeably hotter than any of Federals other offerings in this caliber. They don't extract hard, but they leave extractor marks and start to flatten primers. I'm always very careful when I shoot Berger or Federal ammo with Berger bullets to make sure I scrub the chamber good and run a dry patch down the barrel, and make sure the bolt face is spotless.

I don't own a chronograph, but I fired this particular .308 round through a friends unit from my 24" barrel bolt gun. One round through a cold barrel produced 2622 mv at 10 feet. That's cooking.
 
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Ledzep

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    Did the weapon fire out of battery?

    that’s my guess.

    Doubtful. Out of battery firings usually obliterate the case. Separate the head at least.

    What you're seeing with the belt is excessive pressure inside the case ballooning the web in the space between the bolt and breech face and chamber chamfer. The window between "fine" and a total rupture.
     
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    eastexsteve

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    Giving it more thought, that's .223 Remington ammo which should be operating at a lower pressure than 5.56 NATO. A 5.56 AR15 should have no problem with this round. Out of curiosity, is your barrel chambered for .223, 5.56, or 223 Wylde?
     
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    357Max

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    What does the neck measure fired - unfired?

    Have you shot Lapua through this Krieger before?
     

    Molon

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    Did the weapon fire out of battery?

    that’s my guess.


    As stated in my original post, I had to pound the bolt, carrier and fired case out of the barrel extension/upper receiver. The round did not fire out-of-battery.


    The pic below shows the orientation of the locking-lugs on the barrel extension when the rifle is in the normal firing position. Note that the top locking-lug is exactly at the 12 o’clock position. You can also see that it is aligned with the index pin, which is at top-dead-center.





    barrel_extension_01-2002127.jpg








    In the next pic, we see the orientation of the locking-lugs on the bolt when the bolt-carrier group has completely unlocked.





    bolt_rotated_to_completely_unlocked_posi-2002129.jpg








    When the bolt has rotated completely into battery, the first locking-lug clockwise of the extractor (when looking directly at the bolt-face) will be in the 12 o’clock position. At this point it is physically impossible to have an out-of-battery discharge.







    bolt_rotated_to_completely_in_battery_po-2002128.jpg










    Now, let’s look at the position of the firing pin when the bolt has first rotated completely into battery. With the bolt still in the same position as in the picture above and completely in battery, you can push the firing pin as far forward as it will go (or hit it with the hammer or have the hammer follow the bolt into battery) and the firing pin will not have even started to protrude from the face of the bolt. It is physically impossible for the firing pin to come into contact with the primer before the bolt is completely in battery.





    tip_of_firing_pin_when_bolt_is_completel-2002133.jpg










     

    Molon

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    What chamber is your Krieger?

    This Krieger barrel has a 223 Remington chamber with a 1:9" twist. This barrel was purchased directly from Krieger Barrels, Inc. and was chambered by them. I've fired over a thousand trouble-free rounds through this barrel. The box label for this Berger ammunition clearly states that this is 223 Remington ammunition.

    Shortly before shooting this Berger factory loaded ammunition, I fired a 10-shot group of factory loaded Sierra Prairie Enemy 55 grain BlitzKings. That group had an extreme spread of 0.72 MOA.

    sierra_prairie_enemy_10_shot_group_at_10-2020487.jpg



    ...
     
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    357Max

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    Lapua case necks are thicker by about .001 per side. A little carbon ring would be magnified badly by the Lapua brass.
    Especially if it was a tight match chamber for LC brass.

    It just looks like straight up overcharge but I'd like to see tight neck fit ruled out.

    Assuming you'll be running the remaining unfired rounds across your scale to see if anything obvious shows up.
     

    ma smith

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    Any chrono data on the Berger lot/ammo samples?

    What range was your paper target (during malfunction)?

    For what ammo (eg 77gr) is your rifle zero'd?

    How much Berger ammo have you previously put thru the rifle ?
     

    Molon

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    Molon

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    357Max

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    There is no carbon ring in this barrel.




    See the measurements in post #22.




    That's the plan.


    ...
    Yep sure looks like a straight up overcharge.

    Berger I'm sure is using VV powder...........wonder if it's N140?

    If I recall correctly this ammo is new for 2021 & just so happens Blue Caller reloading has 30 boxes in stock.

    Thanks for posting & hopefully it didn't do major damage to your rifle. Anything but Lapua brass & I have no doubt the outcome would have been worse.
    That case couldn't get any closer to completely letting go!
     
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    Mk32784

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    Could be a undercharge to... powder is set off all at once vs burning though the stack.
     
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    357Max

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    I've run a lot of Berger factory ammo in 6.5 Creedmoor & it definitely is on the hot side (140 Hybrids going 2900 from a 24" barrel).
    That said it's never given me pressure signs.

    This had to be an oddball charge. I wonder if a freak primer that had a bunch of extra compound could cause this?
     

    ma smith

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    Last time I checked there are two ways to measure (estinate) FPS,
    chrono or variance to known dope.
     

    Downtown

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    An overcharge of that magnitude should show on a scale quite obviously, right? Very curious if you'll find another one in what you have. Though if it was at all common, surely it would show up with other customers.
     

    LRRPF52

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    It takes well over 70,000psi to make lesser brass flow into the ejector pocket like that, as well as make the primer pocket go from a circular shape to an egg. Primers will often blow at 70ksi, but the case head might not have anywhere near that much eschar/soot.

    I agree with 357max, that if this wasn’t Lapua brass, we’d be looking at case head separation and a blown ejector at a minimum.

    My guess is that this was anywhere from 75-90ksi, maybe more.

    372e6d57-ecad-44e2-9eef-33ff0f4075d9_zpsgy9rgeau.jpg
     

    Downtown

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    Frightening that a factory round would be overcharged that much. I'm looking forward to what Berger says, especially considering the meticulous data that Molon usually gathers.
     

    eastexsteve

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    I stated earlier here, as did someone else, Berger is hot ammo. And, I also found that Federal loaded with Berger bullets is hot ammo. It shoots really well for me, but I'm very careful when I use that stuff. But, what you have there looks like more than just a one grain overcharge. I would find a reloading scale and bullet puller and go from there.

    If you look at the pics you posted of the cases, between the rim and big unsupported bulge it looks like it almost separated right there. It's hard to believe it's still in one piece.
     
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    Downtown

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    I would think that's such an overcharge that it wouldn't be necessary to pull bullets. Probably just weighing loaded rounds would find a heavy one.
     

    BuildingConceptsllc

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    Wow. I have a bunch of this ammo and just got more. Ive shot it a lot but only in my bolt gun. It is pretty hot ammo and it shoots ridiculously well in my bolt gun. Kind of scary with that much pressure...
     

    bfoosh006

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    @Molon

    I am curious... what is the neck tension like on the remaining rounds ?

    Can a bullet, and when pressing its tip against a firm surface be easily moved further into the case ?

    I am not suggesting bullet setback is the culprit in this case... but I am curious.
     
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    Molon

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    @Molon
    Can a bullet, and when pressing its tip against a firm surface be easily moved further into the case ?



    No. However, this is a heavily compressed load so it is not possible to obtain an accurate bullet pull/push reading on my custom K+M compression gauge. Pulling bullets from the factory loaded rounds did require a significant amount of force to pull the bullet out of the case using a press-mounted collet bullet-puller.


    compression_gauge_03-2021600.jpg



    ...
     
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    Gwain

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    I did not see any specs on barrel. My guess is - Lapua brass is thicker all around. Thicker necks in a smaller/tighter throat would create pressure due to bullet not releasing, being held in case until pressure actually forces it out. Try to drop a bullet back into a fired case, if you can. If a bullet does not drop free or with very little resistance into a fired case.....prob a part of the issue, along with it is a bit warm of a load to begin with.

    2nd, a faster twist rate with heavier bullets can show pressure sooner. So there could be multiple things adding to this.
     

    whatsupdoc

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    I did not think it was possible to over/under charge a cartridge using modern commercial loading equipment.
    I was under the impression that every cases powder charge height was checked.