Blown out primers and pressure signs

[mikehill85]

Tap a fired case

Good idea. I shouldn't be too far off compared to a resized case, I'm only bumping the shoulder back a couple thou anyway.

 

[mikehill85]

Tap a fired case

So I was going to do that and I tried to insert a bullet into the neck of a fired case and realized I couldn't get it past the neck/shoulder junction of my brass. I have donuts in some of my brass. Any thought on the best way to get rid of them. IMHO it could be the cause of the random pressure problems.

 

[dellet]

So I was going to do that and I tried to insert a bullet into the neck of a fired case and realized I couldn't get it past the neck/shoulder junction of my brass. I have donuts in some of my brass. Any thought on the best way to get rid of them. IMHO it could be the cause of the random pressure problems.

Only way to get rid of them is to cut them out.

If your bullet will ride between the donut and lands, you don’t need to cut them out, just need to make sure of the placement.

But If you have some with and some without, tap one without.

Ultimately you will probably be turning necks.

Back to what I said earlier, “everything is within specs” is a bullshit answer. Between a hard jam on the bullets, and crimp on the base of the bullet, not to mention the probable short chamber, it’s a wonder all you had was a popped primer with a starting load near max.

 

[mikehill85]

Only way to get rid of them is to cut them out.

If your bullet will ride between the donut and lands, you don’t need to cut them out, just need to make sure of the placement.

But If you have some with and some without, tap one without.

Ultimately you will probably be turning necks.

Back to what I said earlier, “everything is within specs” is a bullshit answer. Between a hard jam on the bullets, and crimp on the base of the bullet, not to mention the probable short chamber, it’s a wonder all you had was a popped primer with a starting load near max.

Yes, I have some without and I also have bullets that I should be able to seat above the donut area (I'll check with the custom brass for the comparator). Either way, I should be able to test if the donuts are the problem.

I am honestly pretty surprised how well those last reloads shot (I averaged 0.45 MOA for 5-shot groups with the worst group being 0.59 MOA and the best being 0.23 MOA), given that the neck tension must be all over the place.

Anyway, it seems we are probably getting somewhere.

 

[precision1]

Hey Tikka actions are great for rebarrelling.lol


It's one of those things if it's not in my hands I can't help you.lol

I highly doubt donuts are your issue also your talking zero to nil pressure increase most times.imo

I briefly read through everything


I'm quick to turn a factory rifle into a poor man's custom in a hurry ......

 

[precision1]

If me or you can't follow reloading manuals and get results other than split cases necks early it's time to move on.you should be able to load to the manual/die Instructions and be fine except brass life.


Otherwise hello gunsmith or return to Tikka

 

[timeout]

I have read through the entire thread. It's very hard to know the cause sometimes without being there and measuring things. You have received mostly good info. I'm leaning towards donuts. Get some new brass and load incrementally increased charge loads to see if the problem goes away.

 

[mikehill85]

If me or you can't follow reloading manuals and get results other than split cases necks early it's time to move on.you should be able to load to the manual/die Instructions and be fine except brass life.


Otherwise hello gunsmith or return to Tikka

Where I live, I can't even find a gunsmith able/willing to check the headspace and Tikka only has a two year warranty which is expired. So yeah, neither of those is an option (at least until I can find a good gunsmith).

 

[mikehill85]

I have read through the entire thread. It's very hard to know the cause sometimes without being there and measuring things. You have received mostly good info. I'm leaning towards donuts. Get some new brass and load incrementally increased charge loads to see if the problem goes away.

Yeah, that's what I'm thinking. I may get SRP brass this time as well.

 

[J_idaho]

Did op ever figure this out. Was it the donuts. Or was it over sized flash holes?

 

[mikehill85]

Did op ever figure this out. Was it the donuts. Or was it over sized flash holes?

I haven't tested whether it was the donuts yet. I will give it a try this weekend. The large flash holes are definitely a byproduct of pressure, not the other way around. I checked for enlarged flash holes before my last session where I ended up with a popped primer. Before the primer popped the flash hole was a normal size.

 

[J_idaho]

I haven't tested whether it was the donuts yet. I will give it a try this weekend. The large flash holes are definitely a byproduct of pressure, not the other way around. I checked for enlarged flash holes before my last session where I ended up with a popped primer. Before the primer popped the flash hole was a normal size.

Have you tried neck Turning a few to eliminate its not coming from neck chamber contact. The only pressure problems I’ve seen was from reloads I left stored in high humid basement for period of time, carbon rings, over sized cases and not trimming brass. You mentioned being able to jam along ways. You also mentioned .002” neck tension those two things rarely go hand and hand. It sounds like you’re getting high neck tension randomly. Your sure your not putting a crimp when seating.

 

[mikehill85]

Have you tried neck Turning a few to eliminate its not coming from neck chamber contact. The only pressure problems I’ve seen was from reloads I left stored in high humid basement for period of time, carbon rings, over sized cases and not trimming brass. You mentioned being able to jam along ways. You also mentioned .002” neck tension those two things rarely go hand and hand. It sounds like you’re getting high neck tension randomly. Your sure your not putting a crimp when seating.

No, I don't have a neck turner. That would be a good thing to check though.
On "jamming" the bullets, I modified one of my fired cases to work with the Hornady OAL gauge and it actually showed that the lands were slightly further out than with a standard case you can buy from Hornady. So I definitely wasn't jamming into the rifling at any point. I was at least 0.020" off the lands.

Yesterday I tried shooting some loads with the bullets seated above the location of the donuts. I was shooing 140 grain Nosler RDFs and 140 grain Berger Hybrid Target bullets. I was able to go to the maximum charge for both without any pressure issues.

I checked my brass after and out of 35 pieces of brass only 2 of them had donuts. So it is looking like the donuts were probably the culprit.

 

[J_idaho]

No, I don't have a neck turner. That would be a good thing to check though.
On "jamming" the bullets, I modified one of my fired cases to work with the Hornady OAL gauge and it actually showed that the lands were slightly further out than with a standard case you can buy from Hornady. So I definitely wasn't jamming into the rifling at any point. I was at least 0.020" off the lands.

Yesterday I tried shooting some loads with the bullets seated above the location of the donuts. I was shooing 140 grain Nosler RDFs and 140 grain Berger Hybrid Target bullets. I was able to go to the maximum charge for both without any pressure issues.

I checked my brass after and out of 35 pieces of brass only 2 of them had donuts. So it is looking like the donuts were probably the culprit.

That’s good news.

 

[Webster]

Where I live, I can't even find a gunsmith able/willing to check the headspace and Tikka only has a two year warranty which is expired. So yeah, neither of those is an option (at least until I can find a good gunsmith).

Not an expert, but I would think that if the reamer was run in a little short or to long you could still size cases so they would work properly in your rifle. The gauge only determines if the chamber matches some SAAMI spec. It doesn't determine if the rifle if no good. It's a manufacturing tolerance to make the rifles since the factories have to have a spec for machining. Can you FL size the cases with 0.002" shoulder bump when it's needed and chamber a round? The go/no go gauge only checks for the distance from the case head to center of the shoulder distance. Nothing to do with chamber diameter. The gauge assumes the reamer is ground to proper diameter spec. and the variable is how far the machinist pushes the reamer in.

 

[mikehill85]

Not an expert, but I would think that if the reamer was run in a little short or to long you could still size cases so they would work properly in you rifle. The guage only determines if the chamber matches some SAAMi spec. It doesn't determine if the rifle if no good. It's a manufacturing tolerence to make the rifles since the factories have to have a spec for machining. Can you FL size the cases with 0.002" shoulder bump when it's needed and chamber a round?

Yes, this is what I am thinking too. Do you have a nearly microscope level of less volume for the cartridge to expand into if you are a few thou under SAAMI minimum headspace? Sure, you do. Should it make much of a difference/effectively any difference in the real world in terms of peak pressure? I doubt it.
I think the main issue with being short of SAAMI spec is that not all factory ammo is likely to chamber. That has never been an issue for me though.
I would add that I don't know how much I trust that go gauge. I ordered a different one from a reputable manufacturer and will be testing my headspace again when it arrives.

 

[Webster]

Yes, this is what I am thinking too. Do you have a nearly microscope level of less volume for the cartridge to expand into if you are a few thou under SAAMI minimum headspace? Sure, you do. Should it make much of a difference/effectively any difference in the real world in terms of peak pressure? I doubt it.
I think the main issue with being short of SAAMI spec is that not all factory ammo is likely to chamber. That has never been an issue for me though.
I would add that I don't know how much I trust that go gauge. I ordered a different one from a reputable manufacturer and will be testing my headspace again when it arrives.

I don't think you need any gauges. If you can size a case properly with the dies you have your OK. I read a while back on this website that someone had go/no go gauges from 3 manufacturers. They varied from each other by about 2-3 thou. A normal tolerance.

 

[mikehill85]

I don't think you need any gauges. If you can size a case properly with the dies you have your OK. I read a while back on this website that someone had go/no go gauges from 3 manufacturers. They varied from each other by about 2-3 thou. A normal tolerance.

Yeah, I probably don't. I just wanted to check for my own information. The other thing is that Tikka is manufactured in Europe, and it is likely to CIP standards (CIP is stamped right on the receiver actually), not SAAMI. The two standards rarely have exactly the same cartridge dimensions.

 

[DaveTooley]

Yeah, I probably don't. I just wanted to check for my own information. The other thing is that Tikka is manufactured in Europe, and it is likely to CIP standards (CIP is stamped right on the receiver actually), not SAAMI. The two standards rarely have exactly the same cartridge dimensions.

There are some very minor differences between SAAMI and CIP specifications but they are so small as to get lost in the noise and not anywhere that would cause problems.

 

[mikehill85]

There are some very minor differences between SAAMI and CIP specifications but they are so small as to get lost in the noise and not anywhere that would cause problems.

I'm not saying it would cause problems. I am saying it might make it so the go/no go gauges aren't interchangeable.