Cratered and Flattened Primers

[gravelyctry]

Somebody mentioned earlier, and I haven’t seen a response, but are you trying to load 80 grain bullets at mag length?

 

[Nick Caprinolo]

Somebody mentioned earlier, and I haven’t seen a response, but are you trying to load 80 grain bullets at mag length?

No I loaded them with a lite touch to the lands, .010 and .020 off the lands.

 

[Walt Krafft]

What is the over all length at .010 off the lands? That will give us a better idea of the chambers freebore. I know you said it was chambered for 80 grain bullets. The oal will confirm that.

 

[Bill Norris]

Nick, this recently happened to me. New straight out of the box Mil Spec 5R .308 Rem 700 Stainless. Loaded New Lapua brass - Mild loads 150, 168, and 180 gr. Nosler BT at the Standard 2.800 OAL. When firing it and attempting to eject the spent brass - bolt lift a little tight and trying to pull the bolt back very hard like it is stuck. If I allow it to cool a few mins. somewhat easier but still far too much pressure had to be applied to get the bolt back. Once the brass is out if I put it back into the chamber and close the bolt again it is still hard to pull the bolt back. No other signs of pressure that I could see. I could put a new piece of (unfired) brass in the chamber and close the bolt and remove it and find a scarr on the brass head much like it had been fired with too much pressure. After consulting with my smith at OD Customs and Remington C S, I decided to have my smith re-barrel it. These things do happen that we can't explain is my point.

 

[fyrewall]

The bulge - just thinking of an event where some bullet speeding along at 3000 fps being pushed by some 50,000 psi (3 inches from muzzle) ran into a blob of incompressible liquid such as a blob of oil. I don't think the bullet would be compressed. What was the diameter of the bulge in respect to the barrel?. Barrel bulges are serious. Trued action is not going to help with a bulged barrel,

The rest of the stuff probably is caused by excessively hot loads, excessive head-space, & excessive space around firing pin in bolt face.

 

[chuckshooter]

I have had quite a few bad barrels in my life, the first one I will never forget. It was a just a stock Remington 223. after speaking to the Remington repair person on the phone, they told me to take it to a local shop and tell them that they were authorized to re-barrel the action and that Remington would pay. the owner of this shop proceeded to tell me how I had ruined the barrel by sticking something in to the muzzle and that he would not re barrel it. I of course had not done anything that he was accusing me of. I could not believe he was turning down work that Remington had already agreed to pay for. I walked out and shipped it to Remington. they replace the barreled action with a new one. I was able to talk directly to the person that had worked on the barrel and asked him if there was any way possible for me to have caused the damage to the barrel. his answer was "NO, it's just bad steel, it happens" That shop is still in business in my area, but it was then that I learned, just because they are a "reputable business" doesn't mean sh!t. the purpose of this story is, it's quite possible that you simply have a bad barrel and you aren't going to know why, no matter how many people tell you that you may have done something wrong.

 

[Texas10]

I'm shooting a 223 Criterion 8 twist, SAAMI chamber, 69 gr Lapua seated .005 into the lands, Varget, Fed brass. I found a node at 25.2 gr but was getting intermittent blanking of primers, and lots of cratering. Switched from CCI to 205M with some success, but eventually dropped to 24.6 gr node and had no blanking and less problems with compressed loads.

Unless your chamber is throated for 80 grs, you may be compressing the charge and perhaps not holding your seating depth, as I was with the above mentioned load. Is it possible you're CBTO is moving after seating? Have you checked loads 30 minutes after seating to verify CBTO has not changed?

As for the suspected bulge, a good micrometer should be able to verify it's existence.

I also have a factory 223 that blanked any ammo I put through it. I measured the firing pin tip and bolt head hole. There was .007 clearance and the firing pin did not meet Savages specs. I bought several new firing pins from Savage and cherry picked the best fit. Problem solved.

 

[fatelvis]

I sent my RPR bolt off to Gre-Tan smithing to have it bushed and turned. It totally eliminated any blanking or cratering with any sane loads. Two more of my rifles will be receiving this treatment shortly...

 

[ebb]

I don't know if it can happen with a rifle but my dad used to shoot a shotgun that belonged to my great uncle and it had bulged the barrel from snow. Guy at the range had a 20br with a custom barrel that bulged no one ever figured out why.

 

[MGYSGT]

I have shot 80 grainers of Hornady and Berger. My load exceeded 25 grains. With CCI 400 you can expect pierced primers at those loads. I switched to CCI 450 or BR-4 and the problem went away. As for the bulge, if your barrel is long enough, cut it off and recrown. You don't really need a very long barrel for 600 yards and below.

 

[Nick Caprinolo]

Yesterday I took the rifle to my gunsmith. He recommended the barrel be cut to 22 inches. It's in his hands now and I have every confidence in his work and ability.

Thank you all for your comments.