DPMS LR308T odd brass dynamic going on - Page 2

Wildalaska · July 2, 2007, 05:01 PM

Quote:

When the info. arrives, I will post the official Remington information.

Well we are the Alaska repair center for remington (going on 12 years plus) and we see a cratered primer, it goes back

WildthatshwytheyhavelegalcounselireckonAlaska

kirbythegunsmith · July 6, 2007, 11:29 PM

Here are pictures direct from the cases that were personally sent to me from the Manager of Product Service and Law Enforcement Training at Remington Arms, Ilion NY, a 25 year veteran of Remington services.

These have been represented as having a normal primer mark for Remington 7400 Model Rifles.

3 cases fired in 3 different 7400 rifles, and all exhibit the "crater" mark from the firing pin hole chamfer present on the bolt face.

This is not something done to other rifles, but evidently just the semi-loaders, and not just at Remington.

These are the 3 cases, and the minor primer craters are very similar to the ones I previously posted from a 7400 at my shop.

This is a sample case from a brand new AK74 5.45mm, and there is a crater look to that primer.

This is a close look at one of the primers from the 7400 here. The tip dent is 1.2mm (about .047), and the total crater rim is 2mm, about .079. The firing pin hole is about .058". I think that what we have is a plastic-type flow of the primer cup into the chamfer, and a small amount of re-flow of the firing pin dent mark back into the firing pin hole. (Can you see that little crease in the crater between 4 and 6 o'clock?) During application of EXCESS pressure from stiff reloads, etc., that might be a place for failure, but at what level does a primer fail in such a tiny spot? 70,000? 80,000? About the same level that would cause a blow-out in a bolt-action?

Here is primer re-flow in shotgun primer firing pin dents that may make the principle easier to see, but just happens to occur right in the deep center section.

I wanted to show another case expansion situation that is of normal appearance. These 7mm Mag. cases are from a Browning BAR, and the expansion marks just in front of the belt should not be cause for concern.

I noticed that nobody spotted the situation that I commented about in my 6/23 post here. Look at the first picture in that post, and see if you spot an anomaly.

I expect to have a special situation to post here for seeing extreme pressure signs, and of course with some descriptive pictures.

[email protected]

Wildalaska · July 7, 2007, 03:12 AM

Well we are the Alaska repair center for remington (going on 12 years plus) and we see a cratered primer, it goes back

Its Remingtons call to make, not ours.

And I shot a 7400 a few days ago and it exhibited no cratering of primers...none

WildsoletsgoroundandroundAlaska

velocette · July 7, 2007, 08:01 AM

??

kirbythegunsmith · July 8, 2007, 02:58 AM

Give that man a ceegar.

One primer is backed out slightly, see?

The manager at Remington says that they have a form letter that they send to shooters, etc. that think that they have a problem with cratering of primers in their gun.
Right now, Remington is having their yearly shutdown for major machine maintenance, etc., but he is supposed to get me a copy as soon as he can.

I already believe him when he says that this is a typical condition to have a tiny chamfer on the new 7400's.

Perhaps you (WA) were shooting an older gun from prior to this minor design change.

Regardless of what I say or think, if the line personnel at Remington don't consider this minor chamfer/crater mimic to be of any concern to them (as long as we are talking MINOR, not YIKES) then I won't waste money and time on shipping in a gun with that condition.
You can avail yourself, like I did, and ask the personnel that you deal with where you could send samples of cases and/or e-mail pictures (like I have already been doing) so the response time and/or cost can be minimized.

Then, like you say (and I concur) the factory can be the one to shoulder the burden of decision and liability in questionable cases. Once they have given their decision, you can feel covered or whitewashed, as the case may be.

Here are the predecessor cases from the primers pictured in the last post showing a "re-flow" in the central part of the primer dent. These punctured primers mixed in these samples were an unpleasant discovery.

These were from the same time but had not punctured, but did exhibit signs of a rough firing pin tip in the center of the dents. Notice that top primer?

Why do you suppose that one shell failed to fire, and show such a minor firing pin mark, considering there were similar shells with punctured primers from the same session?

During the session with the .410 that made the previous examples, I had also shot another, a Stevens single shot.

Notice the re-flow on these primer dents. Now that's re-flow, ain't it?

This shotgun has the rebounding hammer, so the firing pin has no pressure exerted to hold it extended for more than a micro-second. The pin hole is large enough to allow some opportunitistic reforming under pressure. There is not a large clearance between the pin and hole, as shown.

I will have more interesting pictures for the next posting.

Will anyone have any guesses of why there was a failure to fire in with the punctures?

Are there any comments about the pictures in the previous posting, such as the AK74 crater, the 7 mag. case expansion marks, or the firing pin dent measurement/commentary?

[email protected]

Wildalaska · July 8, 2007, 11:51 AM

Quote:

Perhaps you (WA) were shooting an older gun from prior to this minor design change.

No Kirby. It was "brand new". It was not extracting. We fixed that.

FOLKS...if you see cratered problems in your (STANDARD FACTORY) rifle SHOOTING FACTORY AMMO in any rifle, stop shooting. Take it to a reputable gunsmith or a service center.

Period.

WildastotherestiwillspeaktoremingtonpersonallyandyouallKNOWwhoiamasopposedtonetanonymityAlaska

kirbythegunsmith · July 29, 2007, 12:46 PM

I had promised to post the info. from Remington when received, but had been waiting for the Remington summer annual shutdown to complete, so sorry for the delay.
I will also post a few relevant pictures next posting.

NOTE: I was still wondering if anyone had any input on why (in the 07/08 posting) the one batch of shells that included primer dents with firing pin scarring showing also had one shell that failed to fire. Who can discern the problem that occurred that time? That cylinder load had one shell puncture a primer, and that one failure to fire, all in one batch of 5 shells. Who gets the prize this time? Pictures of the fault and cure are upcoming.

Here is the letter straight from the top man in the repair etc., the supervisor that I referenced earlier in my other posts.

That is the official word from Remington.

Fred said that one of his people knew WildAlaska and had a good working relationship, so no disrespect is intended in any way, shape, or form.

[email protected]

I have more posts at
www.thehighroad.org
and
www.shotgunworld.com

Wildalaska · July 29, 2007, 01:40 PM

Notice the word "if" in their letter.....

Folks here is the important "if"......if you have any rifle that craters primers on a factory load, stop shooting and bring same to a gunsmith right away.

Period.

Wildansomeonelsewilldetermine"if"itisnormalAlaska

Gee Kirby thanks for vouching for us :barf:

James K · July 29, 2007, 02:11 PM

This thread is now so far off the original question and so confused, that I hesitate to jump in, but if I understood correctly, the original problem was what appeared to be stretched cases on one side only. If that is the situation, the most likely cause is a bolt face cut at an angle, because the bolt head was not set up correctly for end milling. That is pretty easily checked but the rifle should be sent to the factory for a fix.

Note that a rifle with an angled bolt face can show perfect headspace, since the gauges will read from the "high" point of the bolt face. If you want to check, use some Dykem blue on the bolt face and then run the gauges.

Jim

July 6, 2007, 11:29 PM	#27
kirbythegunsmith Member Join Date: February 15, 2007 Posts: 75	Details from Remington Here are pictures direct from the cases that were personally sent to me from the Manager of Product Service and Law Enforcement Training at Remington Arms, Ilion NY, a 25 year veteran of Remington services. These have been represented as having a normal primer mark for Remington 7400 Model Rifles. 3 cases fired in 3 different 7400 rifles, and all exhibit the "crater" mark from the firing pin hole chamfer present on the bolt face. This is not something done to other rifles, but evidently just the semi-loaders, and not just at Remington. These are the 3 cases, and the minor primer craters are very similar to the ones I previously posted from a 7400 at my shop. This is a sample case from a brand new AK74 5.45mm, and there is a crater look to that primer. This is a close look at one of the primers from the 7400 here. The tip dent is 1.2mm (about .047), and the total crater rim is 2mm, about .079. The firing pin hole is about .058". I think that what we have is a plastic-type flow of the primer cup into the chamfer, and a small amount of re-flow of the firing pin dent mark back into the firing pin hole. (Can you see that little crease in the crater between 4 and 6 o'clock?) During application of EXCESS pressure from stiff reloads, etc., that might be a place for failure, but at what level does a primer fail in such a tiny spot? 70,000? 80,000? About the same level that would cause a blow-out in a bolt-action? Here is primer re-flow in shotgun primer firing pin dents that may make the principle easier to see, but just happens to occur right in the deep center section. I wanted to show another case expansion situation that is of normal appearance. These 7mm Mag. cases are from a Browning BAR, and the expansion marks just in front of the belt should not be cause for concern. I noticed that nobody spotted the situation that I commented about in my 6/23 post here. Look at the first picture in that post, and see if you spot an anomaly. I expect to have a special situation to post here for seeing extreme pressure signs, and of course with some descriptive pictures. [email protected]

July 7, 2007, 08:01 AM	#29
velocette Senior Member Join Date: May 25, 2007 Location: South Florida Posts: 924	Kirby, are the primers backed out on those "anomalys? ??

July 8, 2007, 02:58 AM	#30
kirbythegunsmith Member Join Date: February 15, 2007 Posts: 75	Details Give that man a ceegar. One primer is backed out slightly, see? The manager at Remington says that they have a form letter that they send to shooters, etc. that think that they have a problem with cratering of primers in their gun. Right now, Remington is having their yearly shutdown for major machine maintenance, etc., but he is supposed to get me a copy as soon as he can. I already believe him when he says that this is a typical condition to have a tiny chamfer on the new 7400's. Perhaps you (WA) were shooting an older gun from prior to this minor design change. Regardless of what I say or think, if the line personnel at Remington don't consider this minor chamfer/crater mimic to be of any concern to them (as long as we are talking MINOR, not YIKES) then I won't waste money and time on shipping in a gun with that condition. You can avail yourself, like I did, and ask the personnel that you deal with where you could send samples of cases and/or e-mail pictures (like I have already been doing) so the response time and/or cost can be minimized. Then, like you say (and I concur) the factory can be the one to shoulder the burden of decision and liability in questionable cases. Once they have given their decision, you can feel covered or whitewashed, as the case may be. Here are the predecessor cases from the primers pictured in the last post showing a "re-flow" in the central part of the primer dent. These punctured primers mixed in these samples were an unpleasant discovery. These were from the same time but had not punctured, but did exhibit signs of a rough firing pin tip in the center of the dents. Notice that top primer? Why do you suppose that one shell failed to fire, and show such a minor firing pin mark, considering there were similar shells with punctured primers from the same session? During the session with the .410 that made the previous examples, I had also shot another, a Stevens single shot. Notice the re-flow on these primer dents. Now that's re-flow, ain't it? This shotgun has the rebounding hammer, so the firing pin has no pressure exerted to hold it extended for more than a micro-second. The pin hole is large enough to allow some opportunitistic reforming under pressure. There is not a large clearance between the pin and hole, as shown. I will have more interesting pictures for the next posting. Will anyone have any guesses of why there was a failure to fire in with the punctures? Are there any comments about the pictures in the previous posting, such as the AK74 crater, the 7 mag. case expansion marks, or the firing pin dent measurement/commentary? [email protected]

July 29, 2007, 12:46 PM	#32
kirbythegunsmith Member Join Date: February 15, 2007 Posts: 75	Remington Details I had promised to post the info. from Remington when received, but had been waiting for the Remington summer annual shutdown to complete, so sorry for the delay. I will also post a few relevant pictures next posting. NOTE: I was still wondering if anyone had any input on why (in the 07/08 posting) the one batch of shells that included primer dents with firing pin scarring showing also had one shell that failed to fire. Who can discern the problem that occurred that time? That cylinder load had one shell puncture a primer, and that one failure to fire, all in one batch of 5 shells. Who gets the prize this time? Pictures of the fault and cure are upcoming. Here is the letter straight from the top man in the repair etc., the supervisor that I referenced earlier in my other posts. That is the official word from Remington. Fred said that one of his people knew WildAlaska and had a good working relationship, so no disrespect is intended in any way, shape, or form. [email protected] I have more posts at www.thehighroad.org and www.shotgunworld.com

July 7, 2007, 03:12 AM	#28
Wildalaska Junior member Join Date: November 25, 2002 Location: In my own little weird world in Anchorage, Alaska Posts: 14,172	Well we are the Alaska repair center for remington (going on 12 years plus) and we see a cratered primer, it goes back Its Remingtons call to make, not ours. And I shot a 7400 a few days ago and it exhibited no cratering of primers...none WildsoletsgoroundandroundAlaska

July 29, 2007, 01:40 PM	#33
Wildalaska Junior member Join Date: November 25, 2002 Location: In my own little weird world in Anchorage, Alaska Posts: 14,172	Notice the word "if" in their letter..... Folks here is the important "if"......if you have any rifle that craters primers on a factory load, stop shooting and bring same to a gunsmith right away. Period. Wildansomeonelsewilldetermine"if"itisnormalAlaska Gee Kirby thanks for vouching for us :barf:

July 29, 2007, 02:11 PM	#34
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	This thread is now so far off the original question and so confused, that I hesitate to jump in, but if I understood correctly, the original problem was what appeared to be stretched cases on one side only. If that is the situation, the most likely cause is a bolt face cut at an angle, because the bolt head was not set up correctly for end milling. That is pretty easily checked but the rifle should be sent to the factory for a fix. Note that a rifle with an angled bolt face can show perfect headspace, since the gauges will read from the "high" point of the bolt face. If you want to check, use some Dykem blue on the bolt face and then run the gauges. Jim