Gunsmithing 700 blow up, is the action still good?

[Jim the Plumber]

Got to look at a Rem 700 in 7mm mag that had the last 8" of barrel split in twwner thought it was mud that caused the obstruction. Bolt looks good, opens and closes as if nothing has happened. Lugs and receiver lugs look fine, no galling or apparent set back. From this discription, is the action any good?
Thanks
Jim

 

[HotIce]

Re: 700 blow up, is the action still good?

PICs?

 

[border_reiver]

Re: 700 blow up, is the action still good?

magnaflux bolt head and receiver at lug abutment..

 

[Victor N TN]

Re: 700 blow up, is the action still good?

Or order a new bolt.

 

[Travis S]

Re: 700 blow up, is the action still good?

Take it to a good smith.

 

[flyboy]

Re: 700 blow up, is the action still good?

probably fine but needs to be looked at by someone thats qualified.

 

[Greg Langelius *]

Re: 700 blow up, is the action still good?

MTBF.

Mean Time Between Failures is an engineering term that assigns an average failure probability based upon conventional cycles under conventional conditions.

When one presents the system with an insult, a cycle that far exceeds conventional conditions, it consumes a large helping of presumed safe remaining number of cycles.

I'd say that the MTBF on that action just took a significant dive.

If ther's any way to gracefully avoid employing that action in a firearm you or someone you love will be using; I'd take it.

Greg

 

[Downzero]

Re: 700 blow up, is the action still good?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">MTBF.

Mean Time Between Failures is an engineering term that assigns an average failure probability based upon conventional cycles under conventional conditions.

When one presents the system with an insult, a cycle that far exceeds conventional conditions, it consumes a large helping of presumed safe remaining number of cycles.

I'd say that the MTBF on that action just took a significant dive.

If ther's any way to gracefully avoid employing that action in a firearm you or someone you love will be using; I'd take it.

Greg </div></div>

Statistical analysis doesn't tell you anything about one instance. The probability of an observation taking any value in a distribution is zero.

I'd inspect the action, expecting to screw a new barrel on it and go to town.

 

[Phil1]

Re: 700 blow up, is the action still good?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">MTBF.

Mean Time Between Failures is an engineering term that assigns an average failure probability based upon conventional cycles under conventional conditions.

When one presents the system with an insult, a cycle that far exceeds conventional conditions, it consumes a large helping of presumed safe remaining number of cycles.

I'd say that the MTBF on that action just took a significant dive.

If ther's any way to gracefully avoid employing that action in a firearm you or someone you love will be using; I'd take it.

Greg </div></div>

Statistical analysis doesn't tell you anything about one instance. The probability of an observation taking any value in a distribution is zero.

I'd inspect the action, expecting to screw a new barrel on it and go to town. </div></div>

+1

 

[Tangodown911]

Re: 700 blow up, is the action still good?

Bring it to a smith.

 

[Terry Cross]

Re: 700 blow up, is the action still good?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: __JR__</div><div class="ubbcode-body">magnaflux bolt head and receiver at lug abutment.. </div></div>

+1000

Bringing it to a good smith or a bad smith will not tell anybody if there are any fractures or structural compromises in the lugs or lug seats.

Eyeballing it, even with the Hubble, will not tell anyone what is going on.

Do what JR said and send it out for a MagnaFlux.

TC

 

[BLAWTON]

Re: 700 blow up, is the action still good?

Headspace is a good indicator of how the pressures effect the action. If it didnt move you should be fine. I would check the lug to action surfaces with a small lapping job. If they still meet up square you should be fine. Runout across bolt face is another good check along with any type of gauling on the metal is not a good sign.

Just got a barreled action back that someone loading 130 grains of rl-15 instead of rl-25. The results were not good. I couldn't even beat the recoil lug off the barrel. But the action survived. The headspace moved about .01" and the od on the tenon grew .01 as well. All that needed done was re facing the bolt and action and everything looked GTG. There was no stress fractures as well which i supprised a little. M-F is a must as well to check for fractures!

 

[el gordo2]

Re: 700 blow up, is the action still good?

To bad it's not a M70 action, they are much easier to decern if they are usable or not.

 

[Tomcat088]

Re: 700 blow up, is the action still good?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: el gordo2</div><div class="ubbcode-body">To bad it's not a M70 action, they are much easier to decern if they are usable or not.

</div></div>

DAMN! Glad I wasn't behind that one. Hope the person that was is alright, lol.

 

[TDR911]

Re: 700 blow up, is the action still good?

el gordo2,

Now that is some scary shit to have your hand on when it goes off. Whats the story behind it and it failure??

I do not think this one will pass the magna flux test??

 

[el gordo2]

Re: 700 blow up, is the action still good?

Belongs to a friend of mine. It was a 270 Win of his and he told me his father handloaded for. He was very fortinate to walk away from that with only some minor cuts on his left arm and face.

Only thing I know for certain is that is was a handload that did that. Nothing agaisntWinchester or any make of action as mistakes can happen with all of them.

I keep the pictures around to remind me that while shooting and handloading are fun, it can potentialy become very dangerous.

 

[sandwarrior]

Re: 700 blow up, is the action still good?

El gordo,

YOOOUUUCCHH!!

Glad he only came away with some 'minor' cuts. The cramps in his a$$ must've painful too for a while I bet. I think one big problem I've seen with handloading isn't that the loads run way over. It's the one in front of the one that blew up that was a squib...and left a bullet in the barrel. I never blew one one up but I've had a few squibs.

 

[mexicanmatch]

Re: 700 blow up, is the action still good?

that's why you carry extra pants with you. Sure glad the shooter was ok.

 

[BLAWTON]

Re: 700 blow up, is the action still good?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sandwarrior</div><div class="ubbcode-body">El gordo,

YOOOUUUCCHH!!

Glad he only came away with some 'minor' cuts. The cramps in his a$$ must've painful too for a while I bet. I think one big problem I've seen with handloading isn't that the loads run way over. It's the one in front of the one that blew up that was a squib...and left a bullet in the barrel. I never blew one one up but I've had a few squibs. </div></div>

Getting powders mixed up is prob the biggest problem i can think of.

Ask eddybo....

 

[border_reiver]

Re: 700 blow up, is the action still good?

Out at our private range about 10-11 year ago now, Dad was sighting my uncle's 270 WM Remmy 721 for deer season. He'd just zeroed the 308 BLR, put it away, had the bolt rifle in bull bag..single loading, gets shot on paper, then stays behind rifle reaches for the next round, into action, bolt locked, i had the target in spotting scope standing behind him.

BOOOOOOOOOOOOOOOOOMMMMMMM, ppppfffffffffffffttt!!! He says I'm blind, son of a, I said take your shooting glasses off..they were filled with smoke..his cheeks were bleeding and his chair was about 6" further back from the bench than when he started. I looked down at the bench, looked at him, wagged my finger..You just shot a 308 round thru a 270, didn't you. That would explain it he says. Might have been the longest 270 bullet ever shot I says..Hunter barrel, CM, no splits, stock was fine..

Took it to work, pulled the barrel, bolt head was destroyed so threw that in the bin. Magnaflux the action, looked a-ok. Got a 700 bolt for magnum BF, chambered a 300 win mag custom lighter varmint barrel, more of a magnum sporter, screwed it on, threw it in an HS varmint stock, bedded in. Load tested, ran high pressure loads on purpose at various points, ran about 150 rounds thru. Took it back, uncle came to pick up rifle, said here you go..This'll work better for them Montana elk anyway. Every one of his mule deer and elk since 1998 has been taken with that rifle..GTG. But I did check it out thoroughly beforehand.

JR

 

[9H_Cracka]

Re: 700 blow up, is the action still good?

Another good reason to shoot the 280 instead of the 270. I put a 308 round down one of those with no problems at all! 12" low at 200 yards still woulda been a dead elk.

 

[Kaisersose]

Re: 700 blow up, is the action still good?

Not a Remington looks like a Browning abolt. Makes you think.

http://www.youtube.com/watch?v=rRKP1OkR1fA&feature=related

 

[eddybo]

Re: 700 blow up, is the action still good?

Hell yes putting the wrong powder in one can cause problems...lol I still have not gotten the recoil lug off that barrel tennon. It now has a .003 press fit. I feel for the person that used rl 15 rather than 25, but bet the 8208 I used instead of WC872 created more pressure. Thank goodness it was a Lawton action rather than a winchester. The one pictured above is scary.

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: NotAGuru ⊕</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: sandwarrior</div><div class="ubbcode-body">El gordo,

YOOOUUUCCHH!!

Glad he only came away with some 'minor' cuts. The cramps in his a$$ must've painful too for a while I bet. I think one big problem I've seen with handloading isn't that the loads run way over. It's the one in front of the one that blew up that was a squib...and left a bullet in the barrel. I never blew one one up but I've had a few squibs. </div></div>

Getting powders mixed up is prob the biggest problem i can think of.

Ask eddybo.... </div></div>

 

[bohem]

Re: 700 blow up, is the action still good?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Downzero</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Greg Langelius *</div><div class="ubbcode-body">MTBF.

Mean Time Between Failures is an engineering term that assigns an average failure probability based upon conventional cycles under conventional conditions.

When one presents the system with an insult, a cycle that far exceeds conventional conditions, it consumes a large helping of presumed safe remaining number of cycles.

I'd say that the MTBF on that action just took a significant dive.

If ther's any way to gracefully avoid employing that action in a firearm you or someone you love will be using; I'd take it.

Greg </div></div>

Statistical analysis doesn't tell you anything about one instance. The probability of an observation taking any value in a distribution is zero.

I'd inspect the action, expecting to screw a new barrel on it and go to town. </div></div>

Actually, statistical analysis based upon metallic failure theories tells you quite a bit about it. The rainflow diagram built around this failure would be a good thing to work up.

I would re-use it IF and ONLY IF the action and bolt are taken to a good NDT shop and inspected for cracks via Mag Flux AND X-Ray. The receiver also needs to be measured for setback of the lugs and straightness. If you can't detect a setback, but they're not straight, then I'd toss it.

The straightness is assuming that the action was true to begin with. The most important thing to do is NDT it with the two methods I mentioned above.

 

[former naval person]

Re: 700 blow up, is the action still good?

One other mitigating factor that hasn't been mentioned, is that he barrel pressure sixteen inches down the bore will be quite a bit lower than chamber pressure, reducing the load on the bolt and lugs.
The other failures to think were caused at the chamber end where pressures are high. I don't have Quick Load, bu just for giggles, one of you guys might run a QuickLoad prediction for pressures 8 inches back from the muzzle. JMHO

 

[sandwarrior]

Re: 700 blow up, is the action still good?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Jim the Plumber</div><div class="ubbcode-body">Got to look at a Rem 700 in 7mm mag that had the last 8" of barrel split in twwner thought it was mud that caused the obstruction. Bolt looks good, opens and closes as if nothing has happened. Lugs and receiver lugs look fine, no galling or apparent set back. From this discription, is the action any good?
Thanks
Jim</div></div>

In this case it's pretty clear that there was an obstruction in the barrel. I think the same thing in the video that [email protected] provided us.

However, being a multiple reloader (many calibers and many powders) I could see where using the wrong powder can become an issue. I've had to dump a few hoppers of powder that I didn't empty when I got done and didn't remember what I last put in there. It probably gets worse now that a lot of the traditional powders are now short cut and coated. You can't tell the difference between a new slow powder vs. a fast old style powder.

 

[CaptLink]

Re: 700 blow up, is the action still good?

If you are able to pull the barrel from the action and physically examine the bolt seats then the action may be OK you must also check where the bolt handle locks into the action and the lugs on the bolt you are looking for cracks or distortion.Magnaflux is a way to check for cracks or you may soak the whole disassembled action in gasoline then wipe it dry the gas will creep out of the cracks.Use common sense when using gas.Your barrel is probably shot but it can be used for other things hope this will help you Pat

 

[DAVETOOLEY]

Re: 700 blow up, is the action still good?

Jim

You told us about the barrel. What about the brass and bolt lift after the Oh Shit moment? That will give us some indication of the load on the bolt face thus the lugs. The brass is the weakest link in the chain. A picture of the case head would help. Remingtons are really tough. If casehead expansion didn't wreck the bolt nose and extractor your friend should be in good shape.