Related to the Savage blow up thread, I want to present these photos of Savage bolts. Mind you that I'm not claiming any discredit to Savage nor am I blaming the bolt design for this event.

Merely pointing out something maybe we didn't all know.

This first photo is of the Savage .300 RUM bolt face. It's an attempt to create a CRF and IMO it's not a CRF at all as the extractor don't begin to capture the cartridge before the cartridge is released from the magazine.


This second photo is of a Savage bolt face in .300 Win Mag. Notice that it's entirely different.



Does this bring any opinions out?

WTF! Where did all the steel go? Are they only doing that on the RUM?

That didn't create the catastrophic pressure spike, but makes you wonder if the altered design maybe comprimised the overall strength of the action.

Check the dent in your head Pat, see if it looks like the top photo (sorry buddy, couldn't help myself )

FWIW, every action I've ever seen blown up was a CRF action.

quote:

Originally posted by Matt Norman:
WTF! Where did all the steel go? Are they only doing that on the RUM?

No, I have a 116 Safari in 375 h&h with the "CRF" bolt.

The full case head support of the post 64 Mod. 70 bolt was highly touted by Winchester as being a safer rifle. No doubt the design does give a bit more support to the case head, but personally, I am comfortable w/the CRF actions, none of which give full case head support. Then again, I don't believe in trying to push the envelope w/my handloads, either.

Regards,
hm

quote:

The full case head support of the post 64 Mod. 70 bolt was highly touted by Winchester as being a safer rifle.

IMO it is and substantially so. I'd never own a 22-250 or a 220 Swift on a CRF action or any other varmint or target caliber for that matter.

That is very interesting! I have had three Savages, and all are of the "better" design.

I will have to look at some of those at the gun store today to compare.

THAT is a very interesting picture Vapordog!
Kinda is funny that they would take case head support away from the round that ISN'T belted and develops higher pressures/velocities..
Matt, you see the hair under Vapors bolt pictures? THAT is MY hair... How did he get those photos... LOL...
IMHO, CRF is a nice feature, on a bolt action battle rifle, but for a "high powered" hunting rifle, I personally don't see the necessity... I would rather have the extra support around the case head, just in case (no pun intended)... How many times are we going to shoot at game while lying on our back or whatever awkward position that CRF would really be beneficial?
I put my friend on notice yesteray evening that I want to examine the parts of his "FrankenSavage" that blew up...
You know what else I discovered the other day, I barely missed another piece of "high velocity schrapnel" when this thing blew... I had my Tikka Whitetail hunter on by bench at the time of KABOOM. In putting that rifle back into the safe I noticed a 3/4"Lx1/2"Wx1/8"deep DENT in the nylon stock just behind the trigger on the left side of the grip... That piece of schrapnel couldn't have missed me by more than an inch or two... THAT woulda left a "mark"....
I hope it didn'tmess by scope adjustments up, because that rifle was still perfectly zeroed from last deer season (that was the only shot I got to fire before KABOOM)...
Farging Bastage......

Doesn't look to me like that modification would make any difference in the strength of the action. But it woulkd change gas-handling characteristics somewhat......

It has long been noted by several sources that the "belt" on belted magnums does nothing to increase the strength of the cartridge. In fact it has been thought by some to create a weaker cartridge. Most belted cartridges shoulder on the neck, and have enough slop around the belt to allow the brass to expand right in front of the belt more than it would if the cartridge wall had continuous support like unbelted designs do.
As far as case head support goes, if you look at a cartridge cut in half it can easily be seen that the only forces capable of causing the head to widen come from expansion of the primer pocket or a HUGE amount of rearward force. Other parts of the cartridge, and the action itself will fail long before the case head expands enough to come apart or tightly fill the ring on a push feed design. The ring does nothing to improve safety. As the head of the cartridge is never the failure point.

quote:

you see the hair under Vapors bolt pictures? THAT is MY hair... How did he get those photos..

Actually it's Springbok hide.

quote:

Doesn't look to me like that modification would make any difference in the strength of the action. But it woulkd change gas-handling characteristics somewhat......

El Deguello.....here's my take on this CRF safety issue.

It's no secret that the case is the weak link in the shooting system and it's a proven fact that under pressure the case can be forced into crevaces such as the extractor port or extruded into the ejector holes in push feed models. I have a .220 Swift case that was extruded that way.

When there is no support for the case head as is the case in the upper photo, the case head can actually be pushed under enough pressure out that cut and then rupture and the resultant enormous release of gas into the inner receiver ring.

I'm not at all convinced that the gas escape holes drilled into the receivers (Savage actually has one on each side of the receiver) is sufficient to handle this catastrophic release of gas. The pressure building in the much larger number of square inches of the inner receiver ring escalates the force to the breaking point of the steel and we get a "KABOOM" as it's said.

It's clear that we don't know what happened here but it's also clear to me that it takes a lot less of a "screw up with the reloading" to take apart a crf action than a properly made PF.

It's why Remington's front bolt ring is actually countersunk into the barrel. The barrel actually supports the bolt ring in case the forces actually bread the bolt in that ring.

Again, this is not to blame the design of the action for this mishap. It seems to be a severe screw up in the making of the ammo. We also have no info to say that the accident wouldn't have taken any action apart.....a Rem 700 or even a Weatherby Mark V

quote:

Other parts of the cartridge, and the action itself will fail long before the case head expands enough to come apart or tightly fill the ring on a push feed design. The ring does nothing to improve safety. As the head of the cartridge is never the failure point.

This is among the purest BULLSHIT I've ever read. It simply is not true.

quote:

Originally posted by vapodog:
This is among the purest BULLSHIT I've ever read. It simply is not true.

C'mon vapodog, tell us how you really feel!

All joking aside, while it is accepted that the full support of the PF bolts do give more support to the cartridge case, I am still comfortable with the CRF actions; after all they have been in use since the turn of the last century with relatively few issues.

I know, some have failed over the years, but most are traced back to extreme loads, obstructed bores, untrimmed case failing to release the bullet, etc. Even the majority of low number 03 Springfields that failed were attributed to the above mentioned causes, not poor heat treatment or design.

It is for this reason, I am still comfortable with the CRF design when used in conjunction with carefully crafted/sane reloads.

By the way, I'm sure you have basis for your choice of no 22-250 or 220 Swift on CRF actions. Is that due to the large overbore case or???

Regards,
hm

quote:

All joking aside, while it is accepted that the full support of the PF bolts do give more support to the cartridge case, I am still comfortable with the CRF actions; after all they have been in use since the turn of the last century with relatively few issues.

I know, some have failed over the years, but most are traced back to extreme loads, obstructed bores, untrimmed case failing to release the bullet, etc. Even the majority of low number 03 Springfields that failed were attributed to the above mentioned causes, not poor heat treatment or design.

It is for this reason, I am still comfortable with the CRF design when used in conjunction with carefully crafted/sane reloads.

By the way, I'm sure you have basis for your choice of no 22-250 or 220 Swift on CRF actions. Is that due to the large overbore case or???

There can be little disagreement here.....I have no axe to gring on the CRF design. If one is prudent handloading they're excellent guns. I have CRF in .300 win mag, .338 mag and .404 Jeffery and have no fear of them at all.

About the varmint rounds.....

It's my belief that these are the cartridges most commonly handloaded to the max and further they're reloaded many times as well. In my case I shoot .223, .22-250 more often than ten times the number of all the other cartridges I own together. Only because I reload them so often I'm more likely to let a long case sneak thru on me...or in other words I'm more likely to make a mistake with these than any other case as I only use new virgin brass for hunting with the big game guns.

I've loaded serious errors in the Remington 700 and also in the M-70 PF and both guns (and I) survived the incidents easily......no complaints except for the locked up actions. I have no idea what happened to any of these incidents....I can only suspect too long case got by me....I don't know.

I'm totally convinced that had I been using a crf, the action would have been destroyed.

quote:

Originally posted by vapodog:
I've loaded serious errors in the Remington 700 and also in the M-70 PF and both guns (and I) survived the incidents easily......no complaints except for the locked up actions. I have no idea what happened to any of these incidents....I can only suspect too long case got by me....I don't know.

I'm totally convinced that had I been using a crf, the action would have been destroyed.

Understand your reasoning now on the varmint cartridges. Was wondering what I missed.

I used to measure case length when reloading but ever since I discovered the Lee case trimmers, I now trim every case every time I reload it (it's so easy w/the Lee). Found it is quicker than measuring every time and trimming the long ones.

I've seen what a long neck can do to a case someone else overlooked and want no part of it!

Regards,
hm

Hey Vapodog, Any guess where robotek got his information? I'm guessing "denton"!

BTW, Nice flicks.

Though I'm sure glad we all have the choice between CRF and PF, and having used both quite a bit over the years, I still prefer the Remington and Weatherby PF designs for my use.

quote:

Originally posted by robotek:
It has long been noted by several sources that the "belt" on belted magnums does nothing to increase the strength of the cartridge. In fact it has been thought by some to create a weaker cartridge. Most belted cartridges shoulder on the neck, and have enough slop around the belt to allow the brass to expand right in front of the belt more than it would if the cartridge wall had continuous support like unbelted designs do.
As far as case head support goes, if you look at a cartridge cut in half it can easily be seen that the only forces capable of causing the head to widen come from expansion of the primer pocket or a HUGE amount of rearward force. Other parts of the cartridge, and the action itself will fail long before the case head expands enough to come apart or tightly fill the ring on a push feed design. The ring does nothing to improve safety. As the head of the cartridge is never the failure point.

Hey Robotek, If you don't want to experience what the other guy did(kaboom), I'd recommend you completely erase all that foolishness from within your head. Just went over it sentence-by-sentence and don't see anything even close to reality.

Some of the stuff is so nonsensical as to wonder how in the world you ever came up with such a complete and thorough lack of comprehension on cartridges.

quote:

...Most belted cartridges shoulder on the neck...

Looks like "denton speak" to me, cause it makes absolutely ZERO sense.

quote:

...the head of the cartridge is never the failure point.

Pitiful!
---

Nearly forgot...,Welcome Aboard Robotek!

Originally posted by vapodog:
Does this bring any opinions out?

Originally posted by vapodog:
This is among the purest BULLSHIT I've ever read. It simply is not true.


When you want to post a thread asking for opinions that’s what you should expect, even if they are not the same as yours. I gave my opinion based on experience building and shooting firearms along with an engineering degree. Vapodog’s well presented scientific evidence has convinced me that I am indeed wrong. I apologize to all of you.

Luckily I've never been present when something like this happened and I hope I never am. I've only been shown the results. I have formed my opinions based on what remained from the destruction I’ve seen when this type of thing happens. The facts are the first shot showed pressure signs and the second was difficult to chamber. Given that, the second shot never should have been fired. The actual cause may never be known as the evidence is mostly destroyed. I hope everyone recovers from this experience ok. My prayers go out to those involved.

quote:

Originally posted by robotek:
... I gave my opinion based on experience building and shooting firearms along with an engineering degree. ...

I'm not believing that at all. If it was true, the first robotek post would never have been made.

Most folks will find posting on "this Board" goes much better when you really are speaking from first-hand experience. Nothing at all wrong with "guessing or speculating" as long as that is stated within the post.

MY opinion has always been , the half push feed/half crf appraoch is a big mistake . You can't take a recessed bolt face type , cut out some of the steel , and expectto have the same good gas handling characteristics and casr head support you had before .

I don't quite buy the notion that a proper crf like a M-98 offers less head support . The cartridge actually sits much deeper in the barrel than an action with a recessed bolt face, with basically only the case rim protruding from the chamber .

The typical push feed has the rear end of the case actually hanging out of the chamber a bit . This is then suported by the reccessed bolt face , the belled out portion of the chamber(for the nose of the bolt) , and the receiver ring,,,,the so-called "three rings of steel".

BUT , when you remove a portion of one the "3 rings" as on the bastardized "crpf" like Savage AND Winchester is doing , what then is supporting the case head at the point where the bolt face recess has been removed ?

quote:

Robotek
I gave my opinion based on experience building and shooting firearms along with an engineering degree.

And how was the hunting there while you went to engineering school in Tijuana?

quote:

Originally posted by sdgunslinger:
MY opinion has always been , the half push feed/half crf appraoch is a big mistake . You can't take a recessed bolt face type , cut out some of the steel , and expectto have the same good gas handling characteristics and casr head support you had before .

I don't quite buy the notion that a proper crf like a M-98 offers less head support . The cartridge actually sits much deeper in the barrel than an action with a recessed bolt face, with basically only the case rim protruding from the chamber .

The typical push feed has the rear end of the case actually hanging out of the chamber a bit . This is then suported by the reccessed bolt face , the belled out portion of the chamber(for the nose of the bolt) , and the receiver ring,,,,the so-called "three rings of steel".

BUT , when you remove a portion of one the "3 rings" as on the bastardized "crpf" like Savage AND Winchester is doing , what then is supporting the case head at the point where the bolt face recess has been removed ?

Have a few of each (PF/CRF), one CRFP and this thread has piqued my curiosity. I pulled out a 98 Mauser chambered in 6mm Rem.; a Pre-64 Mod. 70 in 30-06; a post 64 (PF) Mod. 70 in 300 WM and a Savage 116 Safari in 375 h&h ("bastardized crfp")and measured the portion of case head protruding from the chamber. I am enlightened; they are all exactly the same. Only a few thousandths of an inch forward of the extractor groove of the case are exposed on all three types of actions.

Yes, the bolt ring on the PF Mod. 70 does enclose the case head, but the bolt tip on this rifle is not supported by a recess in the end of the barrel; it simply butts up against the flat end of the bbl.. I am told that the 700 Rem. does enclose the tip of the bolt in a groove turned in the end of the barrel but I do not own any Remingtons so could not check this out.

Any case head support lost to CRF actions is an acceped risk I am perfectly comfortable with as I am not one to push any envelopes. It is MHO that, with carefully prepared/sane handloads, the CRF and/or the CRFP is perfectly safe & acceptable.

Regards,
hm

quote:

It is MHO that, with carefully prepared/sane handloads, the CRF and/or the CRFP is perfectly safe & acceptable.

I doubt that any experienced reloader would disagree with that statement. Certainly not me nor anyone I know.

I kind of think the case was too long and a little of the neck was started into the lands. It would crimp the crap out of the bullet along with extra O.D. on the bullet.