Cratered and Flattened Primers

[Nick Caprinolo]

Having trouble with primers cratering and flattened. Powder charge is 2 grains less that max. Loading for .223 Remington, in a 700 action. Loading 80 gr Berger bullets with 23 gr of Varget. Hodgdons manual says max load is 25 grs. I am using Lapua virgin brass. This is a new build, with only 75 rounds fired through it. I also fired 20 rounds of Norma factory ammo with the same results.

I think I read somewhere that this could be caused by a firing pin problem. Can anyone point me in the right direction.

To compound my dilemma, while cleaning the barrel today, I noticed a bulge at about three inches from the muzzle. I could feel it as I ran a patch in it. Looking closely I could see a slight thickening on the outside. It was not there earlier in the week when I cleaned it but the primers were still looking like it was a powder overcharge. I am meticulous with my powder charges so I know that is not the cause of any of this.

Nick

 

[1911nut]

The Berger manual says 22.2g of Varget is max.

Could be that or firing pin spring or bolt needs to be bushed.

Don’t know about the barrel, left a patch in it?

 

[BenPerfected]

Having trouble with primers cratering and flattened. Powder charge is 2 grains less that max. Loading for .223 Remington, in a 700 action. Loading 80 gr Berger bullets with 23 gr of Varget. Hodgdons manual says max load is 25 grs. I am using Lapua virgin brass. This is a new build, with only 75 rounds fired through it. I also fired 20 rounds of Norma factory ammo with the same results.

I think I read somewhere that this could be caused by a firing pin problem. Can anyone point me in the right direction.

To compound my dilemma, while cleaning the barrel today, I noticed a bulge at about three inches from the muzzle. I could feel it as I ran a patch in it. Looking closely I could see a slight thickening on the outside. It was not there earlier in the week when I cleaned it but the primers were still looking like it was a powder overcharge. I am meticulous with my powder charges so I know that is not the cause of any of this.

Nick

Are you shooting a factory barrel or a custom? Might be time to talk with a gunsmith.
Ben

 

[Walt Krafft]

What is your loaded round length? Loading the 80 grain and heavier at magazine length will greatly increase pressure.

 

[Nick Caprinolo]

This is a custom build. Barrel from a first line barrel maker and chambered by a first line smith. Remington 700 trued action. Bolt was trued but no other work on it. I started with a light jam and worked back to .020 off lands. At this point it likes .010 off lands.

Just scoped the barrel and where the bulge is the inside of the barrel is totally black. The rest of the barrel is clean as a whistle. Have no idea how the bulge got there. All rounds fired properly and the load was below maximum by 2 whole grains. The chamber was cut to use 75 to 80 grain bullets.

 

[Bc'z]

Hogdens load data is a recipe with guidelines, case, primer, and a specific bullet.
How many of your components match that recipe?
I'm gonna guess and say none.
Lapua and norma brass are of heavier construction probably having less internal volume than the brass listed in hogdens recipe. This can cause pressure to rise.
Now look at bullet bearing surface, more bearing surface will cause more preasure.
These are just my thoughts on probable causes.
Now I'm thinking about you barrel...
Did all your shots make it to the target?
Thinking out loud here

 

[243winxb]

CCI 400 primers flow early, if using them? But loading 2 grs under max , primers should not look like high pressure.

Bolts from 2008, 2010, Some had a bevel on the pin hole. Looked like high pressure , but was not.

Bluge, strange.

 

[Bill K]

Just because Hodgdon shows a max load ( or any other manual) does not mean that, that load is safe in YOUR rifle. Start with the starting load and work up till you rifle and conditions show that you are reaching max. Often you will find your's will start showing pressure before you reach the listed max load. Safe and sane is the way to work, in your rifle and the conditions i.e. temp, etc your are shooting at.

 

[mike a]

A BULGE!!! If you really really have a bulge I would absolutely not fire another round. Like it's been said, maybe a patch got let in there. Maybe your fault maybe a bad piece of steel. Either way don't risk injury. Contact the maker and send in in. Mike

 

[Dusty Stevens]

Send it back

 

[BDman]

Bulge generally indicates an obstruction at some time. Stuck bullet, patch, fluid or mud in it and fired. Three inches from muzzle would not be from an over pressure cartridge. My .02.

 

[Nick Caprinolo]

As I said, There were no irregularities while I was shooting. All bullets were accounted for as I examined the targets closely trying to find the right distance from the lands.

Because of the stellar reputation of the barrel maker, I am sure they will offer a replacement. Of course I will still have to eat the cost of chambering and crowning the barrel.

The twenty factory rounds I fired were Norma with 55 gr bullets. These should never show a primer problem.

This is not my first rodeo. I have went through the process of breaking in and fine tuning a load many, many times. this is the first time I have experienced this problem, with the exception of loading a known hot load.

I do not attribute the barrel bulge to an over loaded cartridge. this is the kind of thing you would see if there was an obstruction in the barrel, which I am sure there was not.

Also todays temperature never reached 55 degrees so heat was not a problem and I always let the barrel cool between groups.

It seems to em that I read that this can be caused by the firing pin. Not sure if the cause is a pin too thin. I have read that on some occasions the hole has to have a bushing inserted. I just am not sure why.

 

[fyrewall]

Sounds like all sorts of problems:

Firing pin hole in bolt face too large - crater
Excessive Pressures - crater
Flattened primers - excessive head space
Flattened primers - excessive pressure
Bulge - obstruction in bore

GO TO GUN SMITH - printed words without inspection are not sufficient

While working as a gofer for a well known gunsmith I saw some of this stuff.

 

[1911nut]

“It seems to em that I read that this can be caused by the firing pin. Not sure if the cause is a pin too thin. I have read that on some occasions the hole has to have a bushing inserted. I just am not sure why.”

A weak spring or small fp relative to the hole in the bolt can allow the primer metal to flow into the bolt hole causing the crater. More worse with hot loads.

You need a new barrel and if I was shootin Bergers I’d get the Berger reloading manual.

 

[Nick Caprinolo]

I will certainly be getting a new barrel. That is a no brainer. AS far as the berger book is concerned, it is always notoriously light with powder charges. That still does not explain why factory loaded ammunition shows the same primer problems. My gunsmith will be examining the rifle first thing this week. Monday I will contact the barrel manufacturer for a replacement. I am confident there was nothing in the barrel as I always run a nylon brush through the action and barrel after I use a patch. Further since this is a new barrel, I scoped it after cleaning the last time I shot it.

 

[lawman29]

Slug the barrel

 

[D-4297]

For the sake of discussion ; let's assume that your load is within reason , and you're getting cratered primers . The usual culprit is to much wear in the carrier , or F/P bushing . It can be from wear , or just a error in manufacturing Q.C. . New doesn't mean perfect . It only means new . Stuff happens .

We all think the tip of our firing pin has a perfectly concentric radius on it . They start out that way , but can develop a tipped nose , chip , or just get pushed out of round from use . The tip didn't get fully hardened . So...you pull the trigger , the spring does it's job , and BANG . The F/P hits the primer , and as it is pushing into the case , it is also moving sideways , due to excessive clearance in the f/p bushing , causing the cup to tear slightly , allowing the burn blowback thru the cup . The tip of the F/P may even have developed a slight bend in the tip from a loose bushing .

Check the diameter of the F/P , and the bushing , or carrier . As far as the barrel , I agree that the mfg. is the best solution .

 

[Rsadams]

Didn't see which primer but as said previously the CCI standered small rifle will flatten at below max charge.... I have flattened them way under max charge.... The bulge though is a no-go and needs to be inspected and the reason found out....

 

[Pawnee Bill]

Cratering=Firing Pin hole too big. Have firing pin bushed. Problem go away.

 

[Nick Caprinolo]

Didn't see which primer but as said previously the CCI standered small rifle will flatten at below max charge.... I have flattened them way under max charge.... The bulge though is a no-go and needs to be inspected and the reason found out....

Yep, I was using CCI primers.