Brass predicament…

[Bater]

Have a 243AI build that will be done this winter. Only probably I’m having is sourcing 243SRP brass. Peterson is the only quality brass manufacture that makes it as far as I know, and nobody has any in stock. I will continue to look for it but if I can’t find it what would be next best in your opinion? I run Alpha 260 SRP in my 260AI and it is phenomenal, just don’t know what issues I might run into necking it down to 243. I’d like to stay away from turning if it all possible.

Lapua LRP 243
Peterson LRP 243
Lapua SRP 260
Alpha SRP 260

What would you do?

 

[wind gypsy]

I'd get LRP brass before necking down 260 brass. I typically get lapua when available but not sure how lapua and peterson 243 brass compare. I'd bet lapua has a little more capacity.

 

[mlevimadden]

What is the purpose of your build?

Personally, I'd rather avoid necking down brass and would prefer a LRP with the case capacity of a 243AI if it's going to see cold weather use for a field/hunting rifle.

 

[Bater]

I'd get LRP brass before necking down 260 brass. I typically get lapua when available but not sure how lapua and peterson 243 brass compare. I'd bet lapua has a little more capacity.

Yeah I agree. I have a couple boxes of virgin Peterson 243 LRP and not sure if I want to pick up some Lapua LRP instead. Capacity differences doesn’t matter to me, primer pocket longevity is what I care about. Anybody have experience between Peterson/Lapua for primer pocket durability?

 

[Bater]

What is the purpose of your build?

Personally, I'd rather avoid necking down brass and would prefer a LRP with the case capacity of a 243AI if it's going to see cold weather use for a field/hunting rifle.

Just a backpack hunting mountain rifle for deer/bears here in the west. It will see plenty of freezing temperatures, but my 260AI (Alpha SRP) with CCI 450’s / H4350 has zero ignition issues in temperatures well below zero.

 

[wpeach1912]

I don’t think you’ll see any difference between large and small rifle primers. Do you anneal and have tight chambers? Unless you’re trying to turn your 243ai into a 6UM, you’ll probably crack necks or get case head separation before primer pockets wear out. I’d just get 500 pieces of lapua LRP brass and call it good

 

[wind gypsy]

I’d just get 500 pieces of lapua LRP brass and call it good

That's half a barrel life in fire forming

 

[wind gypsy]

Just a backpack hunting mountain rifle for deer/bears here in the west. It will see plenty of freezing temperatures, but my 260AI (Alpha SRP) with CCI 450’s / H4350 has zero ignition issues in temperatures well below zero.

On the ignition front, i'd be more worried about it with different (ball, double based) powders. I'm not an expert on it other than I know I've had hang fires with factory berger 6 Creedmoor SRP ammo in cold weather. I also recall hearing recently on a podcast with a primer/powder guru that undetectable hangfires happen and people never know because they are so incredibly short, but the milliseconds that ignition is further delayed also increases opportunity for POI displacement before the bullet is out of the barrel.

 

[RockAndSage]

primer pocket longevity is what I care about

OP, honestly, this seems like a case of over-thinking it. Most guys will burn out their barrels long before they blow out a primer pocket.

Also, primer pockets can be fixed.

 

[Bater]

I don’t think you’ll see any difference between large and small rifle primers. Do you anneal and have tight chambers? Unless you’re trying to turn your 243ai into a 6UM, you’ll probably crack necks or get case head separation before primer pockets wear out. I’d just get 500 pieces of lapua LRP brass and call it good

Yeah I AMP every time before FL sizing. Yikes 500 pieces would last me five barrels! I’ve usually been good with 100 pieces of quality brass per barrel. My Alpha SRP 260AI is now on its 17th firing and the pockets are TIGHT. When you say that you don’t think I would notice a difference, are you talking about the durability of the SRP/LRP pockets?

 

[Bater]

OP, honestly, this seems like a case of over-thinking it. Most guys will burn out their barrels long before they blow out a primer pocket.

Also, primer pockets can be fixed

Well I’ve lost pockets in 5 or 6 firing with lesser brass, so it’s definitely a concern.

 

[Bater]

I guess it comes down to this then. Has anybody seen a primer pocket durability difference between Peterson/Lapua LRP standard bolt face brass?

 

[wyosam]

Yeah I agree. I have a couple boxes of virgin Peterson 243 LRP and not sure if I want to pick up some Lapua LRP instead. Capacity differences doesn’t matter to me, primer pocket longevity is what I care about. Anybody have experience between Peterson/Lapua for primer pocket durability?

If you’re wrecking primer pickets in either, you should just be shooting a larger case. The fps difference between wrecking brass and having it last pretty much forever is meaningless in the real world.


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[BRTreedogs]

Well I’ve lost pockets in 5 or 6 firing with lesser brass, so it’s definitely a concern.

Is 5 firings just not enough for you because you’re fire forming AI?

 

[HandgunHTR]

If you are getting loose primers in “lesser brass”, then you are still over-pressure.

If you use premium brass, whether LRP or SRP, you can still go slightly over-pressure and be ok.

 

[pods8 (Rugged Stitching)]

I feel like the SAW cartridges (obviously running over pressure) have folks leaning on SRP brass to hide pressure.

 

[Bater]

Is 5 firings just not enough for you because you’re fire forming AI?

I don’t understand your question. The primer pockets that I’ve wrecked in five firings were with cheap brass like Nosler and Hornady. I’m not referencing the current Peterson or Lapua. You would have to be running something super hot and nearly unsafe to destroy quality primer pockets in five shots.

 

[BRTreedogs]

I don’t understand your question. The primer pockets that I’ve wrecked in five firings were with cheap brass like Nosler and Hornady. I’m not referencing the current Peterson or Lapua. You would have to be running something super hot and nearly unsafe to destroy quality primer pockets in five shots.

I’m saying 5 firings is plenty for me.

I’ll just buy new brass after 5 if needed.


I don’t understand why you need 20 firings unless it’s to avoid fire forming.

 

[Bater]

I feel like the SAW cartridges (obviously running over pressure) have folks leaning on SRP brass to hide pressure.

Yeah I think you’re right. It’s amazing what kind of pressure you can run with SRP. With my 6GT and 260AI using SRP I had to start looking for other less obvious signs than the standard primer criteria that we are used to.

 

[TaperPin]

Going from .264” to .243” is so small it wouldn’t make a difference even in a minimum no-turn neck chamber (edit: always check with gunsmith on the reamer used in case it was designed only work with certain brands). Have you run a piece of 260 brass through your 243 dies and measured the neck thickness? You couldn’t ask for a better case, other than the head stamp won’t say 243.