What would you do?

[codym]

I got a custom 280 AI a while back. The gun was built on a rem 700 action, and was never fired by the seller and only fired by the builder to test function. I receive the rifle and attempt to fireform some barnes 280 Rem brass. Four rounds, four miss fires. Talk to the smith that built the gun, he wants me to try more ammo, I tell him I think the gun should fire this ammo. Send the gun in to him. He puts a new firing pin spring in and re-sets headspace which he charges me for plus shipping both ways, but whatever as long as the gun is right. I get it back and load up 30 round in 280 ai nosler brass, BR2 primers, H4831 and hornady eldm's at the lands. I also have the other 16 factory loaded 280 barnes. Go out and shoot 8 of the factory 280 rem rounds and about half of the 280 ai loads, no problem. Next time out I FL size 10 more rounds plus my leftover loaded 280 AI rounds from the trip before. Everying is going well until the last few rounds and I get a miss fire. Very good dent in the primer just no bang.... hmm toss it thinking it's a one off. Run home ultra sonic clean, neck size and load 40 more rounds with the same components. This time I get miss fires about ever 6th round and had miss fires and one hang fire on 5 out of the last 7 rounds. It seems like I can almost feel a difference when I close the bolt on a dud round but not exactly sure how to describe it. I will also mention the miss fires seemed to increase the harder I run the bolt home. When I got home I pulled the bullet and powder and put a new BR2 primer in case, it fired. I'm lost with what to do here. I went from never having had a miss fire in a bolt gun to now having a rifle with a dozen or more in less than 75 rounds. My question at this point is should I try to mess with different primers, sizing, bullet seating depth, or some other suggestion. I have a feeling that there is still a head space issue but the smith has had 2 cracks at it so far and it's still not right. Also kind of ****es me off I got charged for the "repair" in the first place. Any suggestion is appreciated please let me know if theres something I'm missing.

 

[Barrelnut]

I would try some Federal primers. They have a softer cup than CCI primers.

 

[just country]

morning, u said the bolt feels different when u get a miss fire?
could b a problem with the cocking procedure inside the bolt-with
the firing pin. have u lubricated the inside of the bolt-firing
in area? justme gbot tum

 

[codym]

I have some gmm215' s I can try.


I haven't lubed the bolt at all. It feels sort of mushy, not solid. I don't know if that makes any sense.

 

[MagnumManiac]

To check head clearance is quite simple.
Take a primed case, fire it and measure the primer protrusion.
Also check firing pin protrusion by de-cocking the firing pin and measure how far it sticks out. It should be no less than .045" and no more than .065".
Others have differing opinions on this, but that is where I have never had misfires or pierced primers.

With an AI chamber, on the parent case there should be a negative headspace situation. The shoulder/neck juncture should be .003"-.005" LONGER than the chamber.
It has been established that Nosler messed up when they submitted their 280AI to SAAMI, they forgot to use a negative headspace it appears.

Cheers.

 

[L.Sherm]

Look at the cocking ramp has it been ground on?

 

[codym]

To check head clearance is quite simple.
Take a primed case, fire it and measure the primer protrusion.
Also check firing pin protrusion by de-cocking the firing pin and measure how far it sticks out. It should be no less than .045" and no more than .065".
Others have differing opinions on this, but that is where I have never had misfires or pierced primers.

With an AI chamber, on the parent case there should be a negative headspace situation. The shoulder/neck juncture should be .003"-.005" LONGER than the chamber.
It has been established that Nosler messed up when they submitted their 280AI to SAAMI, they forgot to use a negative headspace it appears.

Cheers.

So are you sticking something into the depression left in the primer then measuring that way? I've never done what you are talking about

 

[MagnumManiac]

So are you sticking something into the depression left in the primer then measuring that way? I've never done what you are talking about

No, it is 2 separate measurements.
Firstly, fire a primed case only, then with a depth mic, verniers or straight metal rule, measure from the case head to the top of the primer.
The other measurement of the firing pin is with the firing pin in the unlocked fired position. You do this by turning the cocking piece clockwise and unlock the bolt.
Measure from the boltface to the top of the firing pin.
A good set of digital verniers are adequate for these measurements.

Cheers.

 

[HARPERC]

No idea Cody. But: Stupid stuff, what temps are you shooting in. Have you looked at degreasing the bolt. Are you neck, or FL resizing. Change primers for sure, and how are you seating them. Any idea what spring, and pin you're using.

 

[WildRose]

I got a custom 280 AI a while back. The gun was built on a rem 700 action, and was never fired by the seller and only fired by the builder to test function. I receive the rifle and attempt to fireform some barnes 280 Rem brass. Four rounds, four miss fires. Talk to the smith that built the gun, he wants me to try more ammo, I tell him I think the gun should fire this ammo. Send the gun in to him. He puts a new firing pin spring in and re-sets headspace which he charges me for plus shipping both ways, but whatever as long as the gun is right. I get it back and load up 30 round in 280 ai nosler brass, BR2 primers, H4831 and hornady eldm's at the lands. I also have the other 16 factory loaded 280 barnes. Go out and shoot 8 of the factory 280 rem rounds and about half of the 280 ai loads, no problem. Next time out I FL size 10 more rounds plus my leftover loaded 280 AI rounds from the trip before. Everying is going well until the last few rounds and I get a miss fire. Very good dent in the primer just no bang.... hmm toss it thinking it's a one off. Run home ultra sonic clean, neck size and load 40 more rounds with the same components. This time I get miss fires about ever 6th round and had miss fires and one hang fire on 5 out of the last 7 rounds. It seems like I can almost feel a difference when I close the bolt on a dud round but not exactly sure how to describe it. I will also mention the miss fires seemed to increase the harder I run the bolt home. When I got home I pulled the bullet and powder and put a new BR2 primer in case, it fired. I'm lost with what to do here. I went from never having had a miss fire in a bolt gun to now having a rifle with a dozen or more in less than 75 rounds. My question at this point is should I try to mess with different primers, sizing, bullet seating depth, or some other suggestion. I have a feeling that there is still a head space issue but the smith has had 2 cracks at it so far and it's still not right. Also kind of ----es me off I got charged for the "repair" in the first place. Any suggestion is appreciated please let me know if theres something I'm missing.

My first thought is that you need to back off just a hair on your resizing die. Try that and see if it doesn't solve the problem.

If you have a neck size only die I would try that and see what you get as a result. It sounds to me that your chamber may be cut a few thousandths too deep at the body/shoulder junction.

 

[WildRose]

I have some gmm215' s I can try.


I haven't lubed the bolt at all. It feels sort of mushy, not solid. I don't know if that makes any sense.

Just curious, how tight is the firing pin inn the firing pin hole? Just a little bit of drag between them could have a serious impact on how much pressure the pin is exerting on the firing pin and how deep the firing pin is punching.

 

[Alibiiv]

I got a custom 280 AI a while back. The gun was built on a rem 700 action, and was never fired by the seller and only fired by the builder to test function. I receive the rifle and attempt to fireform some barnes 280 Rem brass. Four rounds, four miss fires. Talk to the smith that built the gun, he wants me to try more ammo, I tell him I think the gun should fire this ammo. Send the gun in to him. He puts a new firing pin spring in and re-sets headspace which he charges me for plus shipping both ways, but whatever as long as the gun is right. I get it back and load up 30 round in 280 ai nosler brass, BR2 primers, H4831 and hornady eldm's at the lands. I also have the other 16 factory loaded 280 barnes. Go out and shoot 8 of the factory 280 rem rounds and about half of the 280 ai loads, no problem. Next time out I FL size 10 more rounds plus my leftover loaded 280 AI rounds from the trip before. Everying is going well until the last few rounds and I get a miss fire. Very good dent in the primer just no bang.... hmm toss it thinking it's a one off. Run home ultra sonic clean, neck size and load 40 more rounds with the same components. This time I get miss fires about ever 6th round and had miss fires and one hang fire on 5 out of the last 7 rounds. It seems like I can almost feel a difference when I close the bolt on a dud round but not exactly sure how to describe it. I will also mention the miss fires seemed to increase the harder I run the bolt home. When I got home I pulled the bullet and powder and put a new BR2 primer in case, it fired. I'm lost with what to do here. I went from never having had a miss fire in a bolt gun to now having a rifle with a dozen or more in less than 75 rounds. My question at this point is should I try to mess with different primers, sizing, bullet seating depth, or some other suggestion. I have a feeling that there is still a head space issue but the smith has had 2 cracks at it so far and it's still not right. Also kind of ----es me off I got charged for the "repair" in the first place. Any suggestion is appreciated please let me know if theres something I'm missing.

Just curious about which .280 Ackley Improved that you have? Is it the SAAMI, Nosler .280Ai or is it the .280 Ackley Improved (Wildcat, 40 degree)? There's like a .014 thousandths difference between the two cartridges. I encountered this dilemma as many others have when discussing this caliber and their differences. Do you have the proper dies for your rifle's particular caliber; SAAMI chamber or Wildcat 40 degree caliber? I am not sure about if this kind of a mismatch will cause your problems, however I believe that it is worth checking in to. You might want to ask the gunsmith, who made the build, if "he knows" what chamber and headspace gauges he used to make the build. The .280 Ackley Improved (Nosler), or is the rifle chambered for the original .280 Ackley Improved, 40 degree chamber.

If your rifle build has the original .280 Ackley Improved, Wildcat 40 degree, your chamber is done with the same reamer, only the chamber is drilled .014 thousandths deeper than the .280 AI SAAMI. If you have a set of SAAMI dies they are going to size your brass, including the shoulder, .014 thousandths shorter than the original .280AI Wildcat 40 degree shoulder. With that said, and "if" you have the .280 AI Wildcat, 40 degree chamber in your rifle and you are using the original, .280 Ackley Improve SAAMI dies, your brass is going to be too short by .014 thousands, this includes the datum point from the base to the shoulder of your brass. If there's enough firing pin protrusion, you could still be getting some rounds to go off, which could be causing the sporadic discharges of your rifle. IMHO. Whew I hope that I wrote this properly and that this all makes sense to you. If someone else would like to chime in on this post it would be helpful also.

 

[Alibiiv]

From the Redding Reloading Equipment:
Tech Line & Tips (FAQs)
280 Ackley Improved vs. 280 Rem. Improved 40 Degree
The SAAMI spec cartridge carries the approved name of " 280 Ackley Improved " .
The older wildcat has several names including 280 Ackley Improved 40°, 280 Rem Improved 40°, 280 Imp 40°, 280 Ackley, 280 Rem Imp, and more.
The SAAMI spec 280 Ackley Improved chamber is .014 inches shorter at the datum line headspace dimension than the traditionally accepted wildcat chamber spec as previously produced.
Our current production dies are for chambers that are cut to the SAAMI specification and are stamped "280 Ackley Imp".
Any Redding dies made before 2011 are stamped " 280 Rem Imp 40° " and are built to the originally accepted wildcat specs.
These older dies will not bump the shoulder of cases for a SAAMI chamber. In other words, the old dies are too deep for the current SAAMI chamber.
Redding makes a Competition shellholder that is .014 deeper than the standard #1 shellholder so the owner of a wildcat chamber can use the current SAAMI spec dies for safe resizing.

Failing to use this shellholder or to back the die away from a standard shellholder by a minimum of 0.014" will result in too much shoulder bump which may create an unsafe, excessive headspace condition when fired in a traditionally dimensioned wildcat chamber.

To find the die part numbers for a current production SAAMI spec. rifle, please download our current catalog as a .pdf from www.redding-reloading.com.
You will find these dies listed in Series C and Category II. Limited quantities of the traditional wildcat dies which are marked " 280 Rem Imp 40° " are available at Custom Series Die prices.

 

[LoneTraveler]

Did you chronograph the loads? Has the primers backed out of the cases on firing? The best indicator of excessive head space, Or die adjustment problem.
If you have only neck sized the cases and they are not firing. Something in the bolt may be causing the problem.
Take the bolt apart, Check if there is some scrap of metal loose in the firing pin front section. Clean the whole firing pin channel. Carefully insert the firing pin in from the front of the bolt and see if it slides in an out smooth. There is a possibility the tip of the firing pin is bent and dragging, Check for shiney or scratched areas on side of tip.
Check under the bolt handle where it closes in the action and stock. Make sure the bolt is going down so the firing pin is not dragging in the cocking slot on the back of the bolt. If the bolt handle has been replaced any metal removed off the under side, And the bolt rotating and dragging down the side of the cocking notch by rotating to far.
It could be a bad lot of primers. Hard cup or incomplete compound.
Good Luck in finding the problem and a cure.