Catastrophic Bolt Damage on my FNSPR

chops_are_in

chops_are_in

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Full Member
Minuteman
Feb 4, 2005
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New Castle, Colorado
www.lancewood.com
#1
Right off the bat I want everyone to know this post is not meant to be critical of FN in any way. I just want you guys to see what happened this past Saturday to my FNSPR in .300WSM.

As you can see from the photos below, the right bolt lug and part of the bolt face sheared away. This happened on round 2,015 through the rifle. The rifle had been shooting great for the past several years with never a problem. It's my favorite match rifle, and I'm just sick to my stomach.

th_BoltLugExtractor-12192009.jpg


th_BoltFace-Closeup01-12192009.jpg


th_BoltRightLug-Closeup01-12192009.jpg


th_BoltRightLug-Closeup02-12192009.jpg


There were no signs of excess pressure... no ruptured primer or ejector marks in the casehead. I was able to retrieve the case intact from the chamber once I got the pieces of the bolt out of the way.

I contacted FN this morning via phone, and I will be sending the rifle in for warranty service.

I have never seen or heard of anything like this happening to a modern bolt rifle in my 30+ years of shooting.

I'm thinking it must have been a flaw in the bolt. Do you guys have any ideas?

Matt
 
#5
Re: Catastrophic Bolt Damage on my FNSPR

Ask FN if they will provide you the RCFA (Root Cause Failure Analysis) information on that fracture.

It could be many things, differential hardening, stress fracture, manufacturing defect in the metal (not FN), work hardened from machine working the bolt, etc.
 
#6
Re: Catastrophic Bolt Damage on my FNSPR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shooter65</div><div class="ubbcode-body">Hard to beat the durability of a 700 action.
Glad you did not get hurt. </div></div>


Not wanting to come across the wrong way, but I have seen many failures with the 700 platform, but few with the pre 64 Winchester design.

I have had a bit of experience with both for comparison, and between the 700 and the Winny, I now prefer the Winny for several reasons.

YMMV
 
#7
Re: Catastrophic Bolt Damage on my FNSPR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Fighthard</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: shooter65</div><div class="ubbcode-body">Hard to beat the durability of a 700 action.
Glad you did not get hurt. </div></div>


Not wanting to come across the wrong way, but I have seen many failures with the 700 platform, but few with the pre 64 Winchester design.

I have had a bit of experience with both for comparison, and between the 700 and the Winny, I now prefer the Winny for several reasons.

YMMV </div></div>

Pretty tactful I'd say Fighthard.
 
#8
Re: Catastrophic Bolt Damage on my FNSPR

Glad you are OK! What happened with the bolt? Did it move, jump or anything, was it easy to remove? The fact that the case was not damaged is new to me. I've only heard of older military rifles, specifically the swedish mauser getting a lug striped. Your ordeal makes me question the term "modern bolt action" Hope FN does it right for you, those rifles are expensive.
 
#12
Re: Catastrophic Bolt Damage on my FNSPR

Sheesh, that sucks !
Are there any beach marks at the propagation site ?
Glad you are allright, I assume.

However, I don't think you will be out of commision because of that.

Well atleast maybe someone else will have a chance at the next match
grin.gif
 
#14
Re: Catastrophic Bolt Damage on my FNSPR

Looks like porosity or crystallization.
Doesn't look like there was much deformation before the fracture. That's somewhat troubling.

Chops,

Can you tell if the lugs were bearing evenly, prior to this? If not, the asymmetrical lug load would contribute to this.
 
#15
Re: Catastrophic Bolt Damage on my FNSPR

I'm sure glad everything held together too. There was nothing to abnormal about the shot fired when the bolt sheared. No bolt movement of any kind. I didn't notice a thing until I went to lift the bolt handle and it was a little stiff. I had to force it a bit to get the bolt to rotate, and then slide the extractor forward from its recess so I could withdraw the bolt itself.

An expensive proposition, yes... This rifle is part of a complete package put together by Mr. Hunter at FN in June of 2004. I wanted an exact copy of what FH was marketing to FBI HRT, and it cost me $5,400.

Ahhh yes... New ammo or reloads... that was the first question FN asked when I called on the phone. There isn't any real match ammo factory loaded for the .300WSM, so the answer to that is simple. I was shooting my match ammo loaded in Winchester cases with 67.0gr of Reloader-19 under a 210SMK seated 0.072" off the lands. I know that's a big jump, but the rifle liked it that way. This is the max suggested load given to me by Sierra when I called about reloading the 210SMK in the .300WSM. It has proven to be safe and reliable in both my FN and my friends custom Savage 12 LRPV, also in .300WSM.

Does anyone with experience in metallurgy have any insight into the color patterns in and around the area of the fracture?
 
#16
Re: Catastrophic Bolt Damage on my FNSPR

buffybuster,

The best I can tell the rear surface of the lugs have worn evenly, but it makes sense that that right lug must have been carrying more than its share of the load.

The bolt has never received any other attention than what it received at the factory. It's been mirror smooth since day one, so I never felt the need to have it lapped or trued.

Matt
 
#19
#20
Re: Catastrophic Bolt Damage on my FNSPR

Keep us informed. It makes sence that one lug might have been loading more than the other. Maybe the mating lug in the reciever will give a clue.
 
#21
Re: Catastrophic Bolt Damage on my FNSPR

I believe the color difference that you are refering to is the heat treating process.

The match is the 2nd, already !
I had better get my stuff together.
That .243 is going to be pretty slick, is Danny's getting along to ?
 
#22
Re: Catastrophic Bolt Damage on my FNSPR


1. Defect in heat treating? Indicated by the color, and close to the surface, appearing to be in the location of defect #4.

2. Differential heat treatment? Appears not to be uniform along the length of the bolt and is under the lug area.

3. Matches the heat treatment defect in #2.

4. Possible defect in raw material, crystallization or deposit, opposite from the side of #2 and appears to match the area of #1 and is close to the surface of the bolt.

Combined,the defect on one side and the imperfect heat treating on the other, both occurring under the high stress area of the lug, may be the cause of a failure of this type. Just my opinion though.

I would really like to see what FN says.


51u88.jpg
 
#23
Re: Catastrophic Bolt Damage on my FNSPR

Wirehand,

That color difference is the heat treatment, but I don't know enough about what I'm looking at to determine if there are any clues to the failure.

Danny's McGowen 1-7" .22-250 barrel for the Savage won't be here in time, so he's falling back to his Kimber 84M Longmaster VT in .22-250 for January's varmint caliber match. It's nice to have so many clubs in the bag.

Supersubes,

Thanks for posting the links on bolt thrust and shear strength. After reading through what Dan Lilja has written about bolt thrust and case head diameter, it go me thinking.

Mr. Lilja mentions in his writings that under normal circumstances, in a dry chamber, the expanding walls of the brass case will absorb up to half of the bolt thrust forces through friction against the walls of the chamber... But if the case is oily this advantage is lost. Far more bolt thrust would be transferred directly to the bolt face and transmitted as shear force against the lugs. Now, my cases weren't oily, but the barrel on my SPR is chrome lined... I assume the chamber is fully chromed as well. The .300WSM is a 60K PSI class cartridge with a large diameter inside the case head to multiply bolt thrust well over what would be present in a .308 case head diameter. I wonder what effect a freshly cleaned chromed chamber would have on a brass case's ability to absorb bolt thrust through friction. Hmmmm...

This combination certainly wouldn't be considered a design weakness in a healthy action, but if there was a flaw in the bolt face it might make it more likely to shear.

BOLTRIPPER,

I generally consider the lottery a tax on people who are bad at math, but given the circumstances and your advice I tried a $5 lotto game this morning... apparently my luck has passed
grin.gif
.

You guys have a great day,

Matt
 
#25
Re: Catastrophic Bolt Damage on my FNSPR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">Fighthard, nice post. Interesting analysis. I'm also curious as to what FN will say. </div></div>

There're not going to say anything. There're going to replace his bolt and keep whatever info they find to themselves period.
 
#26
Re: Catastrophic Bolt Damage on my FNSPR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body">There're not going to say anything.</div></div>I'm afraid that you may be abolutely correct.

It looks like a clean break.
 
#27
Re: Catastrophic Bolt Damage on my FNSPR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">Fighthard, nice post. Interesting analysis. I'm also curious as to what FN will say. </div></div>

There're not going to say anything. There're going to replace his bolt and keep whatever info they find to themselves period. </div></div>
You are right. Business is business, and we are just regular civilians.
 
#28
Re: Catastrophic Bolt Damage on my FNSPR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body">There're not going to say anything.</div></div>I'm afraid that you may be abolutely correct.

It looks like a clean break. </div></div>

you are 100% correct there.

First I was drawn to the "black dot" (#4) on the lug. In that I am not familiar with how these bolts are manufactured (cast, forged, machined...etc) it is at best speculation. Similar to a sand pile model if #4 is a impurity in the metal then the failure would seem reasonable.
 
#29
Re: Catastrophic Bolt Damage on my FNSPR

Chops,

Looks like the lug that sheared was the bottom lug. If so, can you see how the bottom lug abutment looks like and was the feedramp machined or notched in anyway to weaken the abutment.

OR

Perhaps the top abutment stretched and the bottom held fast, overloading the bottom lug.

Really interested on what FN has to say, if they will admit anything.
 
#30
Re: Catastrophic Bolt Damage on my FNSPR

I'm glad to read that you are in the condition to discuss the repair instead of in hospital with a hole in your head. That would not have been a happy X-mas for you. I've experienced a 700 with a hot primer/bad load, moisture in chamber, overpressue, whatever the hell it was. Bent the firing pin- who knows what can happen. But eye protection isn't a bad idea.
 
#31
Re: Catastrophic Bolt Damage on my FNSPR

Thanks for taking the time to analyze the photos of the bolt, Fighthard.

I don't expect to get anything from FN but a repaired rifle. I'll try to make direct contact with the gunsmith reviewing the rifle once it's in their system. I'm going to ship it out Monday.

buffybuster,

Here's a few closeups of the chamber and feed ramp. The feed ramp is factory stock with no notching.

ChamberView-Closeup01-12242009.jpg


ChamberView-Closeup02-12242009.jpg


Merry Christmas!
 
#32
Re: Catastrophic Bolt Damage on my FNSPR

goning to mske it hard to keep my eye on the target when i get mine in a stock glad you still have both your eyes good luck with getting it fix dont worry about the first shots after you get it back probaly just FLENCHING!!!!!!!!!!!
 
#34
Re: Catastrophic Bolt Damage on my FNSPR

I can't make many assumptions on the bolt based on the pictures, but knowing that tensile and tear (shear) strength are inversely proportional, one could conclude a small crack in the material propagated along the flat surface to cause the failure.

The root cause could be a material defect, fluctuation in the heat-treat process, or something as simple as worn tooling during machining. I also wouldn't rule out a dimensional issue in the chamber placing disproportionate stress on a section of the bolt lug.

If this is something FN has encountered before, they may already have isolated te root cause. If not, I wouldn't count on them sending a failure analysis, as they may be as clueless as you. "One-off" defects can leave you scratching your head, as sample sizes of one give nothing for statistical analysis.
 
#35
Re: Catastrophic Bolt Damage on my FNSPR

"First I was drawn to the "black dot" (#4) on the lug. In that I am not familiar with how these bolts are manufactured (cast, forged, machined...etc) it is at best speculation. Similar to a sand pile model if #4 is a impurity in the metal then the failure would seem reasonable."

From what I understand, the bolt is Investment cast and heat treated.
 
#38
Re: Catastrophic Bolt Damage on my FNSPR

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: HateCA</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">Fighthard, nice post. Interesting analysis. I'm also curious as to what FN will say. </div></div>

There're not going to say anything. There're going to replace his bolt and keep whatever info they find to themselves period. </div></div>

+1, bet your ass, they'll just blame YOUR handload, and keep the failure analysis report under close supervision.Those pictures are quite disturbing-even without formal metallurgy training.

Thank God, you are able to post this problem and not having a neurosurgeon patching up your brain.

Those Dan Lilja articles have ignited many a shit storm on this forum throughout the years. ie.The conversion of a LA R700 to chamber the 338LM, an over 68K cartridge. There is no kill like overkill when talking about action strength.

That is some scary shit. It just wasn't your time to "leave the range".

 
#39
Re: Catastrophic Bolt Damage on my FNSPR

through racing and building cars, i've seen lots of broken cast metal, and in what i've seen with breaks that look like this, the outer darker area has been broken or cracked for some time and the lighter colored area in the center is the fresh break that finally failed due to the longstanding broken area.
again these are my observations from experience in other areas, take it for what its worth

either way..glad you're ok
 
#40
Re: Catastrophic Bolt Damage on my FNSPR

Im not an expert on metals by any means but the cross sections of your broken pieces look like some of the MIM pieces Ive had broken on an M1A. It would be a bit disconcerting to me if a bolt would be made of MIM if that is the case. Again I have no idea, its just an observation.
 
#41
Re: Catastrophic Bolt Damage on my FNSPR

WOW Glad you are still good to go. Did you notice that chip of metal missing by the feed ramp? Was that there before your bolt failed or was it damaged as a result of the bolt, you can see it really good on the bottom pic , across from what looks like a burr on the feed ramp?

Respectfully submitted
 
#42
Re: Catastrophic Bolt Damage on my FNSPR

Wow, look at that bolt! 300wsm too........hummmmmmmm... Looks like a real clean break on the bolt face, that's interesting. Porosity, maybe a little slag, can't really tell from this angle, it does look like the heat treating was not uniform.

I have a FN 300wsm, I hope my bolt holds together...oh....if I had a bolt that is...
frown.gif


Good luck with this. Keep us up to date. Mine is still sitting at FN, slowly rusting away.....slowly rusting away.....
 
#46
Re: Catastrophic Bolt Damage on my FNSPR

I wonder if the rest of the FN bolt is as hard as the bolt handle? It is harder to get a bolt knob put on the FN bolt because of the metal hardness. If this is the case would that mean that the metal may be more brittle?
I've heard of the rem bolt handles snapping due to their softness but the forces applied in those cases may not be the same as those applied to this broken lug I don't believe. Or maybe they would be comparible?
Too bad my pops wasn't still around. He would be just the guy to answer this.
Looks like a one off to me as I haven't heard of others like this or with winny's.
 
#47
Re: Catastrophic Bolt Damage on my FNSPR

Well guys, I received a letter from FNH USA, Inc. Customer Service today, and its not what I was expecting...

Props to Lt. Arclight for calling it... It's a bill for $343.00 to repair the bolt assembly!

I have 20-days to send in the repair approval form and my money or they will return the rifle as-is.

I called Allan at their Customer Service number this morning, and he told me they had evaluated the rifle and determined that the damage was caused by "bad ammunition, meaning excessive pressure".

I explained to Allan that I did not agree with their conclusion... that I had carefully detailed the load I was using in my letter that shipped with the rifle, that the load was recommended to me by one of the Sierra Bulletsmiths, it was not over-pressure, and that I weighed every charge to within 0.1 grain on a Lyman DPS1200 digital scale.

Allan repeated himself in mono-tone...

Damn, was I naive to believe in that lifetime warranty.

I don't want to cut off my nose to spite my face at this point.

What do you think?

Chops
 
#48
Re: Catastrophic Bolt Damage on my FNSPR

I would make a nice blog and also put those pictures and your story on every single firearms board there is. And then, send the a nice letter with the sites on it.

Bad press = alot of lost business.

The metal looks like porosity to me. That is just my informal analysis from years of inspecting our heatsinks coming from vendors from all over the world. During the last commodity rise, I was getting heat sinks that had metal parts that were not even fully melted when forming our casting....literally bolts and garbage in the heatsink.
 
#50
Re: Catastrophic Bolt Damage on my FNSPR

This is what many say are the dangers with the old Mausers, usually blamed on hot loads.....guess what,....many were made by FN.

FN should be happy your face is intact, and there is not a injury/liablity suit, and I would figure, they would be happy to fix it for you...another rifle to cross off my "maybe I should venture away from perfection to try" list.

Pierce Engineering, or a great many other smiths, would fix it for free, and thouroughly appologize for the issue to begin with...thats what a lifetime warranty is about. No limited bullshit. That is an expensive out of the box rifle.

BTW, I bet if you were LE or if it were an issue rifle, they would take right good care of you.
 
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