Primer Puncture

Phantom30 · July 22, 2019

Granted this was a rabbit hole exercise. May objective was to see if there was a chance any of my Powder Coasted Cast bullet would stand up to this pounding and produce reasonable long range accuracy.

Phantom30 · July 22, 2019

I was too slow on my edit to fix the spelling above

•Granted this was a rabbit hole exercise. My objective was to see if there was a chance any of my Powder Coated Cast bullet designs would stand up to this pounding and produce reasonable long range accuracy in AR class 6mm or 6.5mm Creedmoors.

•IMHO before the magazine feed lips releases the casing or the shoulder has reached the feed ramp, the bullet tip in Creedmoors has already contacted the feed ramp and or counter bore. The force is significant enough to have an impact on bullet symmetry and resultant accuracy.

98Z5V · July 23, 2019

Those Hornady 147 ELDs are all I use in the .260 Rem. Nothing else.

Those are handloads, yes? Factory ammo won't have brass that color. You have a crimp issue, right off the bat, if your COAL is longer during extraction, than what you set them at when you loaded them. You definitely need more crimp. Second would be a chamber issue, if it's hanging up that ogive, enough to pull the projectile further from the case than what you set it at (that's aside from the crimp issue).

Judging from the lack of a circular ring around the ogive, what's setting them longer is chambering them from a magazine, BCG locked to the rear, and using the bolt release to chamber the round. That would be almost an identical effect as using them in an inertia bullet puller... Because of the need for more crimp...

Edited July 23, 2019 by 98Z5V

98Z5V · July 23, 2019

11 hours ago, Phantom30 said:

I sent these to Hornady back then....Thanks.. for your concern...Well they now offer A-tip

In this pic series, it clear that there's zero crimp on any of those, and you fed the ammo the way I suspected. Zero crimp on a semi is a pretty big issue, as you've just seen.

Two important take-aways from this: Hot loads, if you keep going hotter and hotter - you're gonna end up puncturing primers. And, you have to crimp your loads if they're gonna be used in a semi-auto firearm. You have to crimp them pretty damn good in a lever gun, too, and the reason should be obvious. I'm just sayin'...

Edited July 23, 2019 by 98Z5V

Phantom30 · July 23, 2019

The ELD tests were dummy loads no primer no powder. Just a way to examine what was gong on with the tips. Yes crimping is important in an auto-feeder. The casings were new Hornady. The zero crimp became evident early so the next ones were crimped with the standard Lee Crimp die. Maybe the crimp was not strong enough but since these were just test items, the crimp was interesting but secondary to what was going on with the tips.

As an aside a strong crimp has the potential to strip the coating from my objective powder coated round which is where my interest really was before this tip issue arose.

As for your comment about the utility of the 147gr Hornady ELD Match, bullet that's very true in a bolt gun, as you can see I love ELDs in my 6mm Creedmoor. I have some 6mm A-Tips that just can in and awaiting their 153gr 6.5mms, expensive but they really should get out there. Hancock's 1960s history will repeat itself it they start making them with rebated boat tails, and doing that would reaffirm what CORBAN has been selling for years. Tubbs has been selling his RBT closed tip 6mm bullets for some time and they work well.

Edited July 23, 2019 by Phantom30
spelling

Phantom30 · July 23, 2019

The chambering tip deformation is not devastating or catastrophic but it exists. The next attachments were zoomed in on the original pictures so I could provide the clearest examples. If you are hunting especially out east where 150 yards is a typical shot then no big deal, but if you are out west making a 1,000 yard shot it is going to open up the group. Can I prove it with target examples. No but aerodynamics says asymmetry will cause variations in the ballistic trajectory. That's all I am saying tip deformation from auto feeder chambering exists and it is bullet type dependent. It may not be as dramatic with an ELD round but a Hornady White Tail will be screwed up.

Phantom30 · July 23, 2019

The effects are there the magnitude of the meaning depends on the type bullet.

jtallen83 · July 23, 2019

Is this a one off event with this particular caliber and rifle or does it happen in all AR rifles in all calibers? I have not seen this the few times I have used those bullets in a factory load, 308 or 223, maybe I didn't look close enough?

98Z5V · July 24, 2019

2 hours ago, Phantom30 said:

but if you are out west making a 1,000 yard shot it is going to open up the group.

You're purely speaking hypothetical, with zero practical to back that up. My guns aren't damaging the ELD-M tips when they chamber rounds.

I can tell you this - My .260 Rem AR only gets fed Hornady 147gr ELD-Ms. Only. My Grendels only get fed Hornady 123gr ELD-Ms. Only. They don't have any issues whatsoever with "groups opening up" at 850 yards. No issues. I'll get a good 1k set up and bring the targets.

Phantom30 · July 24, 2019

3 hours ago, jtallen83 said:

Is this a one off event with this particular caliber and rifle or does it happen in all AR rifles in all calibers? I have not seen this the few times I have used those bullets in a factory load, 308 or 223, maybe I didn't look close enough?

I consider this a Creedmoor issue. My suspected villain is the distance between the casing shoulder and the bullet tip, which is larger than the barrel extension face to counter bore. 6mm is more suspect because it will drop down further onto the ramp and I believe increase the chances of finding the counter bore. My 6mm counter bore has copper stains aligned with the feed ramps so it appears to be a potential source of chambering impacts. (Hornady Black BTHP) I know this is a system design weakness because my 1st 6mm Creedmoor AR, the barrel maker left out the counter bore. Jammed every time, round compression. After he put the counter bore in, it works fine but the stains are evidence of the counter bores necessity.

The 6.5mm ARs have stains on the feed ramps and counter bore. The stains are largely caused by the S&B FMJ ammo ogive scraping but not damaging the rounded tip. However with enough force you could end with a seating alignment when it hits the lands. Cocking the round slightly in the casing.

If you look at the Hornady White Tail Target the impacts are all over. That soft lead tip will obturate at 7KPSI which apparently it is getting when the tip hits the ramp or counter bore. Enough to get all over a 7" target at 100 yards. So That round would not be good for hunting in a 308AR, at least in a Creedmoor format. All these rounds are factory loads I have been showing. Only the Tip drill ELDs were partial hand loaded.

Does this apply to all AR rifles. Don't know but why does my bolt gun shoot under a dime and my AR squeak under a quarter with the same caliber and ammo?

98Z5V · July 24, 2019

21 minutes ago, Phantom30 said:

If you look at the Hornady White Tail Target the impacts are all over. That soft lead tip will obturate at 7KPSI which apparently it is getting when the tip hits the ramp or counter bore. Enough to get all over a 7" target at 100 yards. So That round would not be good for hunting in a 308AR, at least in a Creedmoor format. All these rounds are factory loads I have been showing. Only the Tip drill ELDs were partial hand loaded.

Does this apply to all AR rifles. Don't know but why does my bolt gun shoot under a dime and my AR squeak under a quarter with the same caliber and ammo?

Hornady White Tail is all SOFT POINT, loaded with their Interlock projectile. Either RN, SP, BTSP. All of it. Have you never seen the warnings about soft point ammo in AR-type semi-auto platforms, and possible feeding problems?...

Pics of your bolt gun under a dime would be nice, group count is important. Show me that's happening with a 10-rd group. :thumbup:

I'd still like to see you address what's happening with my 850-yard shots, and why it's not opening up like crazy, since my ELD-M tips have to be damaged from loading through an AR-type platform...

Edited July 24, 2019 by 98Z5V

98Z5V · July 24, 2019

On 7/20/2019 at 3:08 PM, Phantom30 said:

Oak Standard AR-10, rifle length.

On 7/20/2019 at 3:21 PM, 98Z5V said:

Who is Oak Standard? Rifle gas in a 22" barrel is already more dwell time, so your pressures are already up.

On 7/20/2019 at 3:34 PM, Phantom30 said:

Oak Armament. IL

Standard AR-10 gas tube

Rifle Length

On 7/20/2019 at 3:46 PM, 98Z5V said:

WHITE Oak Armament, you mean?...

Please address this while you're at it. :thumbup:

Phantom30 · July 24, 2019

All of my Creedmoor ARs have White Oak Armament gas Tubes. The one in question is an AR-10 rifle length tube.

The picture below is the only one I have available which addresses your request. But it is only 6 count not 10.

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98Z5V · July 24, 2019

Wow - you are some piece of work. Just to you know, it's not "Oak" or "Oak Armament." It's White Oak Armament.

Not that we've solved that, with you eluding to all kinds of things, ...

WHO MADE YOUR BARREL? WHAT BRAND IS IT?

You misdirect, provide useless information, then try your smoke and mirrors... It's almost like "you don't really WANT a solution" - you just want to post up a whole bunch of shiit that doesn't even pertain to what you asked. The deeper you go, the deeper we get, the more BS comes out of you, and even more misdirection...

98Z5V · July 24, 2019

5 hours ago, Phantom30 said:

The effects are there the magnitude of the meaning depends on the type bullet.

Here's a PERFECT example of what I'm talking about, right in my last post. Misdirection and BS...

You have UNCRIMPED handloads, right there. That's not "not enough crimp..." There's ZERO crimp on those. You already stated, in all your charts earlier how you're loading these - BCG locked back, chambering them with the bolt release.

The only reason they didn't come out of those cases further, it because the projectiles hit the rifling lands, and that's the marks you're seeing on them. Look at that Blue Monster you have up there - that thing BURIED itself in your rifling lands...

98Z5V · July 24, 2019

3 hours ago, 98Z5V said:

You're purely speaking hypothetical, with zero practical to back that up. My guns aren't damaging the ELD-M tips when they chamber rounds.

I can tell you this - My .260 Rem AR only gets fed Hornady 147gr ELD-Ms. Only. My Grendels only get fed Hornady 123gr ELD-Ms. Only. They don't have any issues whatsoever with "groups opening up" at 850 yards. No issues. I'll get a good 1k set up and bring the targets.

If this is SO bad to shoot these ELD-Ms through an AR platform, and the tips all deform when you chamber them, @Phantom30, then why isn't is affecting my 850-yard downrange performance on those guns I stated above?...

98Z5V · July 24, 2019

10 minutes ago, 98Z5V said:

WHO MADE YOUR BARREL? WHAT BRAND IS IT?...

@Phantom30, please, please, please... answer that one, too... :thumbup:

Phantom30 · July 24, 2019

The 22" and 24" 6.5 Creedmoor barrels were purchased from Primary Arms made by Bear Creek Arsenal, fluted SS, !:8 twist

The 24" 6mm Creedmoor was made by Apache Arms.

survivalshop · July 24, 2019

I would say that any loaded ammo or Dummy Round will get marks on them from feeding & even more from Extracting them complete , always . The Tips are probably hitting , as you theorized , the Fat Cartridge Body & skinny Long Bullets of the 6MM family of Bullets seem like they should feed with out much trouble , but the geometry lends itself to push the Bullet tip up when feeding . Some Bullets/Brands do it & some don't . I know of some that have altered their Feed Ramp area , to help , of course do this at your own risk , because it will not take much to go too far & cause other issues .

I know some that use exposed Lead tip Hunting Bullets in Semi auto feeders with no issues , AR's are a little harder on the Bullet Tip area & its why I don't use them , it only will takes one of those Tips or large enough piece to shear off & feed into the Chamber with the live round , to show its not a good idea to use them. Not to mention a piece falling into the FCG .

Ravenworks · July 24, 2019

I've been using bonded soft tip rounds such as Ranger-T and Gold Dot and never noticed a decline in accuracy.

Then again I'm only using them in the 100 to 400 yard range.

Cliff R · July 24, 2019

Not sure if any of this helps with the topic at hand, but a few things come to mind reading following this thread.

A good crimp is essential in any auto loading platform. Just make sure the doesn't happen just a fuzz-nut before the bullet seating operation. This can and will bulge the cases just a tad, which may cause feeding issues and near impossible ejection if you try to unload without firing the round. Unlike a bolt gun full length resizing is pretty much required with auto loading weapons, even if you only own one in a particular caliber and plan on shooting all your hand loads in it. Another advantage to the bolt guns besides being able to neck size only you can also push the bullets out further for less "jump" into the rifling. You'd be surprised the little things you can do here to improve accuracy.

So right from the start our auto loading AR platform weapons have a few things working against them in the accuracy department, but that does not mean that you still can't get them to shoot excellent groups. From what I've found since moving from bolt guns to auto loaders, I have to work a little harder to get them to group well. The only exception to that is my 450 Bushmaster. Whatever Hornady and Bushmaster did with that marriage, they did it right. IF the shooter isn't punching out one jagged hole at 100 yards....it is NOT the weapon!

I don't have a single AR platform weapon here that doesn't scratch the case and bullet to some degree, just goes with the territory.

I frequently and quite successfully shoot pointed soft point Sierra 150 grain bullets in all of my 308-AR's. They are actually extremely accurate despite the fast twist, but they can and will get beat up and tips smished up a bit if you find yourself unloading them without firing the round........Cliff

Phantom30 · July 25, 2019

Thanks for the advise. Like I mentioned earlier I believe that bullet tip issues are a Creedmoor problem. I have not noticed any problems with M1A or FALs in 308W. Most of the accuracy responses I have gotten here have been about other calibers. No one that I know of here has discussed their accuracy experience with a Creedmoor. I got into this fur ball because I had primer punch issues. I still have to positively confirm the same lot numbers in the same case of ammo. And I have to Chrono the S&B rounds and confirm the 142 and 147 grs for comparison at 1600. Since I have extended my stay here I might be able to work that in. So until I have that data CU.. Thanks again for being helpful

I was asked earlier about my barrels and I timed out on my edit to here is the full response

OK for Creedmoor types there are 22" and 24" 6.5 Creedmoor barrels which were purchased from Primary Arms made by Bear Creek Arsenal, fluted SS, 1:8 twist, 6G, rifle length gas system. The 24" 6mm Creedmoor was made by Apache Arms, from Excalibur 5R 1:7 blank, it also has a DMPS 308 barrel extension, rifle +2 gas system. These 3 are the AR barrels. Bolts guns are Ruger Precision 6mm Creedmoor, Ruger Predator 6mm Creedmoor and Ruger Predator 6.5 Creedmoor.

Edited July 25, 2019 by Phantom30
spelling

98Z5V · July 25, 2019

1 hour ago, Phantom30 said:

No one that I know of here has discussed their accuracy experience with a Creedmoor.

I've clearly discussed my experience with .260 Remington, with is the virtual twin to 6.5 Creedmoor, yet you ignore that, completely. Completely.

I can't get you to answer anything, unless I directly call you out on this BS exercise you're engaging in. So tell me, @Phantom30,how do my Hornady 147 ELD-Ms survive in my .260 Remington, and why am I not seeing the wild group-spreading that you "theorize" at 850 yards?... :popcorn: