Yes.
Primer's not dented enough to uniformly fire the primer.
Same thing with insufficient pin sticking out from bolt face or too much head clearance from cartridge to bolt face.
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Parts wear on bolt actions.
- Thread starter Polinese
- Start date
Primer's not dented enough to uniformly fire the primer.
Same thing with insufficient pin sticking out from bolt face or too much head clearance from cartridge to bolt face.
Lock time will fixed for a given spring force on the firing pin spring. Increases as the spring weakens.
A 25 pound spring force on a 2 ounce firing pin will have the pin moving about 17 fps at the end of a 1/4" travel to the primer.
Got the formula to calculate that from Unclenick but lost it.
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stagpanther
New member
So, translated to "normal mortals" language
that does mean the reduced impact force affects the efficacy of the primer ignition?Yes. You figured that out. Easy enough.So, translated to "normal mortals" language
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stagpanther
New member
It doesn't happen often, but sometimes I get lucky.
reynolds357
New member
Venture extractor does not reliably hold. In both my 270 WSM and my .204 Ruger, extractor quite regularly FTE. Pull bolt back, no brass. Get the rod out and tap. I guess If I did much more than plink with them,I would figure out what is actually wrong and fix them. (I know, dont many folks plink with 270 WSM)
If the extractor doesn't pull fired brass out of the chamber, the gun is BROKEN, and if under warranty, should be repaired by the maker. PERIOD.
usually easiest to just replace the extractor yourself, but you need to have a replacement. Even in the finest of arms, its is possible for the extractor to break and fail at any time. It SHOULD be good for tens of thousands of cycles but it might not be, and no one can tell you for certain if/when it will fail.
I got one of the semi auto Tommyguns, used. Gun looked new, clearly it had not been shot very much, The 3rd mag through it, the extractor broke, and it was done. I ordered a replacement. Actually 2 of them. Put one in the bolt, and the other in the buttrap as "on board spare" About a decade later, and a few thousand rounds without issue, I sent the gun to my son, because he asked for it. Its now several years later, and no issues.
in the early 70s I had a Remington 600 that got damaged due to an overload. Gunsmith fixed it, but it needed an extractor and none were available at the time, from Rem. Gunsmith made one. Worked fine until the gun was fired and then left the fired case in the chamber. Took about a month but the gunsmith got a Rem extractor and put it in. Rifle has been fine, ever since (I still have it).
In the early 80s Wife got a Savage 110CL .30-06 (on the advice of a friend, only time she didn't listen to me about guns...
) fired about half a box of shells and the extractor stopped working. Ordered one from Savage, took a month or so. I installed it and it worked. Gun was then sold, as the 06 was just too much gun for her. I've never seen a Mauser 98 extractor that was worn out, but I have seen some that were broken.
IF you want to keep your bolt gun running until the barrel is shot out (and beyond) get a spare extractor, and a set of all the springs to have on hand, jut in case.
I have worked on / replaced Mauser 98 extractors a few times. They were not broken, but just not holding onto the brass correctly. I don't own those guns, so I don't know whether they were worn by normal use, or their owners played gunsmith to improve something. Most of them just needed refitting, the rest needed replacement.
Refitting extractor is probably the 1st basic skill a smith should master.
-TL
Sent from my SM-N960U using Tapatalk
Refitting extractor is probably the 1st basic skill a smith should master.
-TL
Sent from my SM-N960U using Tapatalk
stagpanther
New member
I just bought a vanguard--which is essentially a Howa 1500 with a Weatherby barrel--and the bolt's extractor looks like a basic AR extractor. I haven't taken the bolt apart yet but disassembly looks pretty basic according to the owner's manual.
Stagpanther said:
As Bart already said, you have that right. It's actually a combination of the amount of energy in the firing pin strike and how the primer is seated that determines how rapidly the things light up. Start more of it burning on impact, then the rest goes faster.
Board member Hummer70, from his days at Aberdeen, said there are steel "cases", sort of like a headspace GO gauge with a square and flat bottomed primer pocket that accepts calibrated soft copper slugs. A firing pin with enough energy and length should indent the copper to a minimum depth of, IIRC, 0.030". This is how one determines if there is enough energy in a firing pin blow.
stagpanther
New member
Intuitively I thought it might be the case--I just wasn't sure how much. This would seem to suggest corollary issues of primer cup consistency, primer type, thickness, height etc.
stagpanther
New member
IIRC (which most of the time I don't) that .03 about matches the pin protrusion from an AR bolt breech face.
I think the 0.03" was a large primer number for a 7.62, but I may be remembering the number incorrectly. I'll have to look.
Primer seating becomes a factor. How firmly you seat primers affects how solid the resistance to the firing pin blow is. You don't want to use up the pin's energy seating the primer deeper.
This is from a declassified report:
It turns out from a report from Naval Ordnance at Indian Head from around that time, that reconsolidating to compress the priming compound by seating the primer about 0.003" beyond where its anvil first touches down on the floor of the primer pocket is about ideal, and produces the lowest velocity SD and most consistent reliability performance.
Primer seating becomes a factor. How firmly you seat primers affects how solid the resistance to the firing pin blow is. You don't want to use up the pin's energy seating the primer deeper.
This is from a declassified report:
It turns out from a report from Naval Ordnance at Indian Head from around that time, that reconsolidating to compress the priming compound by seating the primer about 0.003" beyond where its anvil first touches down on the floor of the primer pocket is about ideal, and produces the lowest velocity SD and most consistent reliability performance.
RaySendero
New member
This has been my experience also.
I'm still hunting with some deer rifles of the 1930s and 40s,
and never had triggers, safeties, firing pins, extractors or
anything besides the barrel to wear and break.
As matter of fact the only barrel wear problems I've had in hunting rifles were
quite sever erosion-corrosion before they effected accuracy to the point
that I had to replace them.
There are folks whose Winchester 70 actions still work 99% flawlessly after 2 to 3 thousand rounds per year across 40 years. New firing pin spring every year saves the remaining 1%.
Regarding Unclenick's good info ..... After measuring primers and pocket depths, it's easy to determine how deep primers need be seated below flush with case heads.
Regarding Unclenick's good info ..... After measuring primers and pocket depths, it's easy to determine how deep primers need be seated below flush with case heads.
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