|
|
Joined: Oct 2004
Posts: 4,340
Campfire Tracker
|
OP
Campfire Tracker
Joined: Oct 2004
Posts: 4,340 |
So, in the past weeks ive seen several posts where primers have pin holed and really cut up some bolt faces.
What I don't get is how come with a partial case head separation or even just plain normal shooting doesn't absolutely cut up the chamber walls? Obviously gotta be the amount of heat or time of burn but I just don't get the big damage on one hand and not the other? So...what forces are at play for the big diff?
Last edited by kraky111; 09/16/14.
|
|
|
|
|
Joined: Mar 2005
Posts: 4,999
Campfire Tracker
|
|
Campfire Tracker
Joined: Mar 2005
Posts: 4,999 |
Dunno. Have experience several of each and wondered that myself.
WAG: Case head separation is usually a longish crack whereas a when a primer blows through a pin hole, it creates an intense cutting gas jet that puts a nice little divot in the once pristine bolt face. The case head separation crack diffuses the escaping gas over more real estate so little to no gas cutting is done to the chamber wall.
|
|
|
|
|
Joined: Aug 2003
Posts: 17,491
Campfire Ranger
|
|
Campfire Ranger
Joined: Aug 2003
Posts: 17,491 |
Further, the primer does not "seal" around that area like the case around vents typically does during the brief highest pressure moment. Couple that with the fact that the primer's escaping gas has a relatively short path to follow to vent (firing pin) and it makes sense that a primer leak shows up in bolt face erosion.
Sometimes, the air you 'let in'matters less than the air you 'let out'.
|
|
|
|
|
Joined: May 2002
Posts: 9,538 Likes: 2
Campfire Outfitter
|
Campfire Outfitter
Joined: May 2002
Posts: 9,538 Likes: 2 |
Kraky, I've had some Winchester WLR primers develop pinholes in my Garand, eroding a brand-new 65-series bolt. The load was a typical Garand load, which is to say the pressure is reasonable.
I've sent two emails to Winchester, haven't heard a word back.
|
|
|
|
|
Joined: Nov 2011
Posts: 31,127 Likes: 5
Campfire 'Bwana
|
|
Campfire 'Bwana
Joined: Nov 2011
Posts: 31,127 Likes: 5 |
Winchester primers are soft. If you want to avoid punctures switch to CCI, they have a much harder cup.
You didn't use logic or reason to get into this opinion, I cannot use logic or reason to get you out of it.
You cannot over estimate the unimportance of nearly everything. John Maxwell
|
|
|
|
|
Joined: Mar 2005
Posts: 4,999
Campfire Tracker
|
|
Campfire Tracker
Joined: Mar 2005
Posts: 4,999 |
My two experiences with primer pinholeing have been with WLRM. The first I assumed was a chance occurrence. The second was my fault for not discontinuing using WLRM primers, albeit from different lots.
An Internet search seem to indicate that WLR/WLRM primers tend to populate the tales of woe more than others.
|
|
|
|
|
Joined: Apr 2009
Posts: 1,017
Campfire Regular
|
|
Campfire Regular
Joined: Apr 2009
Posts: 1,017 |
I've only had this happen with Winchester primers. I don't use them anymore. I used CCI's for 30 years and never had this happen.
|
|
|
|
|
Joined: May 2004
Posts: 10,877 Likes: 1
Campfire Outfitter
|
|
Campfire Outfitter
Joined: May 2004
Posts: 10,877 Likes: 1 |
|
|
|
|
|
Joined: Jun 2007
Posts: 24,674 Likes: 44
Campfire Ranger
|
|
Campfire Ranger
Joined: Jun 2007
Posts: 24,674 Likes: 44 |
Your best friend in this situation is a gap. It works the same as a cutting torch. I had some leaking on my 6mm and pin sized marks showed up on the bolt face. I had Dennis Olson mill a tiny groove around the affected area on the bolt face and that stopped any further damage.
Changing the primers, finding the cause is necessary too, but the small circle around the primer area is better than the pock marks...
|
|
|
|
|
Joined: May 2009
Posts: 656
Campfire Regular
|
|
Campfire Regular
Joined: May 2009
Posts: 656 |
If left alone, and no more primers pinhole, what will happen? I had 3 winchester primers pinhole out of 30 243 shells I loaded at one time. After reading this thread, I looked at the boltface. Sure enough, there are 3 tiny pits around where the edge of the primer sits. They don't look like much, should I take it to a gunsmith or something, or just shoot it and keep an eye on it. I already have some CCI primers. I put the winchesters at the back of the shelf. Are they good for anything now (low pressure loads or something) or should I throw them away?
|
|
|
|
|
Joined: Mar 2005
Posts: 4,999
Campfire Tracker
|
|
Campfire Tracker
Joined: Mar 2005
Posts: 4,999 |
If left alone, and no more primers pinhole, what will happen? I had 3 winchester primers pinhole out of 30 243 shells I loaded at one time. After reading this thread, I looked at the boltface. Sure enough, there are 3 tiny pits around where the edge of the primer sits. They don't look like much, should I take it to a gunsmith or something, or just shoot it and keep an eye on it. I already have some CCI primers. I put the winchesters at the back of the shelf. Are they good for anything now (low pressure loads or something) or should I throw them away? WIWD. Red flag the Win primers to be used only under hopeless desperation measures. Advice from several gunsmiths and very experienced HP shooters at my club is that the bolt face pitting is cosmetic. If you want to fix it, Do as Shrapnel suggest and have a very shallow groove milled to clean up the pitting. Alternatively, send the bolt to Gre-Tan to have the bolt face bushed. Another thread on bolt face pitting: https://www.24hourcampfire.com/ubbth...s/6562776/How_to_repair_pitted_bolt_face
|
|
|
|
|
Joined: Jun 2006
Posts: 10,084
Campfire Outfitter
|
|
Campfire Outfitter
Joined: Jun 2006
Posts: 10,084 |
Oddly enough I have never had a problem with Win Primers...
Go Figure
Snake
That which does not kill us makes us stronger
Friedrich Nietzsche
|
|
|
|
|
Joined: Jan 2001
Posts: 28,422 Likes: 6
Campfire Ranger
|
|
Campfire Ranger
Joined: Jan 2001
Posts: 28,422 Likes: 6 |
Only time I ever saw this was with a particular batch of Remington 9 1/2's in a .270. Two primers from one box had pin prick leaks right at the outer circumference and gouged divots in a very nice LH Model 70 bolt face.
If nothing else it gave me a new respect for the power of a directed stream of very hot gas under very high pressure.
BTW, I threw away that batch of primers.
Gunnery, gunnery, gunnery.
Hit the target, all else is twaddle!
|
|
|
|
|
Joined: May 2009
Posts: 656
Campfire Regular
|
|
Campfire Regular
Joined: May 2009
Posts: 656 |
[quote=fldoghunter]If left alone, and no more primers pinhole, what will happen? I had 3 winchester primers pinhole out of 30 243 shells I loaded at one time. After reading this thread, I looked at the boltface. Sure enough, there are 3 tiny pits around where the edge of the primer sits. They don't look like much, should I take it to a gunsmith or something, or just shoot it and keep an eye on it. I already have some CCI primers. I put the winchesters at the back of the shelf. Are they good for anything now (low pressure loads or something) or should I throw them away? WIWD. Red flag the Win primers to be used only under hopeless desperation measures. Advice from several gunsmiths and very experienced HP shooters at my club is that the bolt face pitting is cosmetic. If you want to fix it, Do as Shrapnel suggest and have a very shallow groove milled to clean up the pitting. Alternatively, send the bolt to Gre-Tan to have the bolt face bushed. Another thread on bolt face pitting: https://www.24hourcampfire.com/ubbth...s/6562776/How_to_repair_pitted_bolt_face Thanks for the reply. I will quit using win primers. If it's not going to hurt anything, it doesn't bother me. I had to really look to see it anyway
|
|
|
|
|
Joined: Aug 2003
Posts: 17,491
Campfire Ranger
|
|
Campfire Ranger
Joined: Aug 2003
Posts: 17,491 |
CCI 400s were the culprit when my 17 Rem had problems with pierced primers. Never had a large or small rifle or pistol primer let go.
Sometimes, the air you 'let in'matters less than the air you 'let out'.
|
|
|
|
|
Joined: Dec 2008
Posts: 555
Campfire Regular
|
|
Campfire Regular
Joined: Dec 2008
Posts: 555 |
almost always use win primers and never had an issue
go figure indeed
|
|
|
|
|
Joined: May 2008
Posts: 3,695 Likes: 1
Campfire Tracker
|
|
Campfire Tracker
Joined: May 2008
Posts: 3,695 Likes: 1 |
Same here, never had a problem with them.
|
|
|
|
|
Joined: May 2002
Posts: 9,538 Likes: 2
Campfire Outfitter
|
|
Campfire Outfitter
Joined: May 2002
Posts: 9,538 Likes: 2 |
Get some with the right lot number.
|
|
|
|
|
Joined: Dec 2002
Posts: 13,123 Likes: 2
Campfire Outfitter
|
|
Campfire Outfitter
Joined: Dec 2002
Posts: 13,123 Likes: 2 |
almost always use win primers and never had an issue
go figure indeed
I have used about every primer there is and quite a few WLR primer and some of the WLRM primers. Never had a visible pit from a primer. There must be a common denominator here somewhere.
NRA Benefactor Member
Those who live by the sword get shot by those who don't.
|
|
|
|
|
Joined: Jan 2005
Posts: 6,384 Likes: 5
Campfire Tracker
|
|
Campfire Tracker
Joined: Jan 2005
Posts: 6,384 Likes: 5 |
I have never had boltface pitting from Winchester primers but have had the issue with both small and large rifle primers by Federal. No! they were not high-pressure loads either just good middle of the road accuracy loads.
Anyone can turn out a bad batch of primers occasionally. Relegate the offending primers to low pressure loads or give them to someone you don't like.
drover
223 Rem, my favorite cartridge - you can't argue with truckloads of dead PD's and gophers.
24hourcampfire.com - The site where there is a problem for every solution.
|
|
|
|
|
544 members (1941USMC, 219 Wasp, 2500HD, 1lessdog, 1minute, 257robertsimp, 55 invisible),
2,436
guests, and
1,353
robots. |
|
Key:
Admin,
Global Mod,
Mod
|
|
|
Forums81
Topics1,193,897
Posts18,518,402
Members74,020
| |
Most Online11,491
Jul 7th, 2023
|
|
|
|
![[Linked Image from i.postimg.cc]](https://i.postimg.cc/63b8KsVp/DSCN4329.jpg)
