Unusual bolt repair.

[bobm]

A friend of mine had an over pressure round go off in his R700 SPS .22-250. The case head expanded well into the bolt face spaces. It was carefully pried out but tore a small chunk of the extractor capture ring off. However, the ejector plunger was badly hammered deep about .125 below the bolt face and stuck. The spring stem actually broke through the blind hole. Being forced well beyond the function zone, the roll pin shattered and made driving it out impossible.

I used a 1/16 carbide drill to get most of the roll pin out. The head of the plunger shank shows where the drill passed through. The spring shank breaking through was protruding enough for the firing pin to drive it flush with the shoulder. This made it easy to feel with a home made long punch to drive the whole ejector out.

The return spring was badly compressed and was replaced with a new one. I did not have a spare ejector but felt this minor new drill groove would not be a problem. A new roll pin finished up the reassembly. The rifle should function fine.

A combination of Teslong and Sony photos shows the story.

Bob M.

 

[bobm]

last photos

 

[Spike A]

A friend of mine had an over pressure round go off in his R700 SPS .22-250. The case head expanded well into the bolt face spaces. It was carefully pried out but tore a small chunk of the extractor capture ring off. However, the ejector plunger was badly hammered deep about .125 below the bolt face and stuck. The spring stem actually broke through the blind hole. Being forced well beyond the function zone, the roll pin shattered and made driving it out impossible.

I used a 1/16 carbide drill to get most of the roll pin out. The head of the plunger shank shows where the drill passed through. The spring shank breaking through was protruding enough for the firing pin to drive it flush with the shoulder. This made it easy to feel with a home made long punch to drive the whole ejector out.

The return spring was badly compressed and was replaced with a new one. I did not have a spare ejector but felt this minor new drill groove would not be a problem. A new roll pin finished up the reassembly. The rifle should function fine.

A combination of Teslong and Sony photos shows the story.

Bob M.

Hope your friend is ok, I’d say he got lucky … does he know what caused the over pressure?

 

[Walt Krafft]

I would be concerned the lugs or lug seats are compromised. To do what it did it was probably north of 100k psi.

 

[AlNyhus]

Nicely done repair.

 

[bobm]

Hope your friend is ok, I’d say he got lucky … does he know what caused the over pressure?

The owner sent me two pictures of his dilemma. He pried out the case. He was using an auto powder dispenser with a popular V propellant. His first three shots from a box of 50 were normal. #4 was the overload. A visual conformation would have seen more powder in this particular cartridge case.

I did not get to see the pried out case. He was going to disassemble the remaining rounds and check for any others that might weigh or look overcharged.

Close examination with the 10x loupe and the Teslong showed no impending damage to the lug root areas.

 

[AlNyhus]

If it made a person sleep better, the bolt handle could be TIG'd. Good time to optimize the camming, too.

 

[ricco1949]

I had a similar over pressure on a Rem 700, 20 VT load while prairie doggin' years ago. The primer blanked and I received a puff of gas and particles in my face. No injury......shooting glasses worked.

The case head expanded into the extractor groove and cold welded. I resisted the inclination to pry it loose sensing that the extractor rim would break like yours. I waited till I got home to machine it out on the mill.

The ejector was similarly driven in however the bolt lugs and abutments were in good order.

Since 18.0 g of CFE BLK fills the 20 VT case it appears that it could not have been an overload. I suspect it may have been a piece of unturned brass that slipped through the turning step.

After reading this thread I bore scoped the interior firing pin shoulder of the bolt and the ejector hole is completely through the shoulder.

Since it's a PD rifle, I will plug the ejector hole to prevent any future unabated gas release, bush the tip at same time, and thereafter manually extract each piece of brass.

I've since shot the rifle 1500-2000 rounds with and without the ejector installed. However I am now wary of another blanked primer and gas coming through the ejector hole unabated. It would still be blocked by the pin shoulder but a plug makes me feel better.

 

[bobm]

Thanks for sharing that similar story, ricco1949. Your plan to plug the hole is a good idea. It makes you wonder how thick the web of the blind hole is to be pierced like this.

With the right tooling it could be measured.

 

[ricco1949]

Since I last posted I above, I scoped 7 other Rem 700 bolts .....so 8 total. Out of the 8, 3 had the ejector hole exposed to the bolt interior.

One is from a friends rifle that has changed bolts so it's possible this bolt also was exposed to high pressure and gas release and one is mine mentioned in my post above.

However the 3rd one is from an unfired RR serial numbered 700. Only a semi circle of the ejector hole is exposed thus allowing the ejector to function.

So it appears that at least some ejector holes are drilled too deep from Remington.

The question remains ...does this present an increased risk of gas release in the case of a blanked primer or case head head separation?

 

[Walt Krafft]

I have examined over 100 recent Rem 700 actions and >90% have the hole breaking through. The ones that didn't had blueing solution trapped in the hole corroding the spring. I am deductiong from this that it is supposed to partially break through.

 

[ricco1949]

@Walt Krafft:

Thank you for the post. It gives some assurance that these actions do not pose additional gas release risk in case of a future blanked primer

 

[bobm]

I have examined over 100 recent Rem 700 actions and >90% have the hole breaking through. The ones that didn't had blueing solution trapped in the hole corroding the spring. I am deductiong from this that it is supposed to partially break through.

On the opposite side of the spectrum......I looked at my thirteen 700's all purchased new dating from the early 70's, mid years in between with the newest one made in '90. None were ever subjected to a case failure gas release. There was no drilled hole break through on any of them.

That little work endeavor took two hours but gave me an excuse to do some internal cleaning and fondle my 700's...

 

[ricco1949]

I'm still going to plug the hole in mine that goes nearly 100% through. There's very little metal left to capture the spring and extractor anyway.

I also found a very thin brass wafer about .100 in diameter attached to the interior hole opening when I scoped it. Apparently brass particles migrated up the hole and were peened by the firing pin on each firing.

 

[bobm]

This photo shows the bottom coil of the ejector spring in my "youngest" D prefix short action 700. The step depth measures .062 from the firing pin stop shoulder. Could that thin hard pin have punched through .062 softer bolt material? yes, it did including shearing the roll pin.

You gotta love the Teslong for stuff like this.

EDIT......in photos 0013 and 0014 the spring can be seen.

 

[AlNyhus]

If the hole is open at the back and you're not using the ejector, the hole should be plugged. Not doing so gives gas a way into the bolt which can damage the trigger as the f.p. assy. is forced rearward.

If it's broken through and you're using an ejector, a short plug at the bottom is also good insurance.

Good shootin' -Al

 

[ricco1949]

If the hole is open at the back and you're not using the ejector, the hole should be plugged. Not doing so gives gas a way into the bolt which can damage the trigger as the f.p. assy. is forced rearward.

If it's broken through and you're using an ejector, a short plug at the bottom is also good insurance.

Good shootin' -Al

Thanks for the tip Al.....when the primer blanked I was surprised that the Jewell trigger survived the ordeal without breaking. Now, knowing that the ejector broke through it seems even more unlikely.

 

[AlNyhus]

Thanks for the tip Al.....when the primer blanked I was surprised that the Jewell trigger survived the ordeal without breaking. Now, knowing that the ejector broke through it seems even more unlikely.

Big bullet to dodge. -Al

 

[Texas Solo]

Why not just replace the bolt head?

 

[ricco1949]

Why not just replace the bolt head?

They are Rem 700's.