primer cratering

S

Shadow9mm

New member
So I zeroed my new rifle, at TC Compass in 30-06. I started working through a batch of hand loads and noticed primer cratering with the starting loads. started with 47g of varget over a 150g hornady interlock. i looked back at the factory loads i had zeroed with and they were all cratered as well. federal power shock 150g, federal fustion 150g, and remington core lokt 220g. the three together are the factory loads, the ones in the box are my hand loads. friend sait it might be a too long firing pin? I contacted TC, waiting for an answer from them.
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Looks semi safe to me.

Common thing when there's too much clearance from the firing pin tip to its hole in the bolt face. Good inspectors firing proof loads at the factory will see that problem then send the rifle back to production to be fixed.

Good gunsmiths can hard chrome plate that pin tip to a .001" clearance. Had that done to a Winchester 70 back in 1967.
 
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You might want to look at the face of the bolt to see if it might be a bit too large or might have been chamfered. I have a Remington 700 BDL what will produce a cratered primer even with light 5.0 gr. Unique cast bullet loads designed for plinking. When I inspected the bolt face using a magnifying glass, I saw the the hole had been slightly chamfer, for whatever reason I have no clue. May the hole had a burr and they tried to clean it up. I've run some seriously stiff hunting loads through that rifle and I've never had a problem. Naturally YMMV.
Paul B.
 
Paul B. said:
You might want to look at the face of the bolt to see if it might be a bit too large or might have been chamfered. I have a Remington 700 BDL what will produce a cratered primer even with light 5.0 gr. Unique cast bullet loads designed for plinking. When I inspected the bolt face using a magnifying glass, I saw the the hole had been slightly chamfer, for whatever reason I have no clue. May the hole had a burr and they tried to clean it up. I've run some seriously stiff hunting loads through that rifle and I've never had a problem. Naturally YMMV.
Paul B.
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Paul B. you are a geinus! Managed to get a picture, needed more light to see it but I think you got it dead on! Thank you! Sent an e-mail to double check with TC to make sure it is supposed to be this way but I don’t think I will have to send her in!
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Have that pin bushed. Looks like a hot dog in a hallway by those primer marks. Having a bolt bushed is usually not much more than 100 bucks.
 
got an update from Thompson Center. they do no chamfer their firing pin holes, they said it is an issue, and I do need to send it in. bummed but at least they are taking care of it..
 
I got the rifle back, The notes are not particularly clear but it looks like they replaced the bolt. Had a bunch of packing grease around the ejector.

Notes from TC were as follows

"Performed Services: Evaluate / Repair
Repair Bolt
Passed Range Testing"
 
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