Lapua Palma 308 Brass with small primer

[taka]

Just wondering a couple of things with this brass

1. Has anyone experienced the misfire or hangfire drama when in cool or cold weather (mentioned on Salazars web site)

2. the small flash hole (about 60 thou) - anyone tried reaming the flash hole to 62 or 65 thou, just wondering if the flash hole would be better the same or similar size as the 223 cartridge. Or best to leave alone....

I started thinking about this when I got decapper pin stuck (65 thou) in a cartridge, and then started measuring things (I had assumed that the flash holes would be similar size to 223 cartridge flash hole)

Steve

[Matt P]

Steve
I tried the Palma brass with little success to point I sent it back and got the normal 308 brass.
Matt P

[johnk]

I've been using them for a while with no issues, but I still have AR2206. I didn't change the flash hole; I just spun my ejector pins down to the right size.

[IanP]

Just wondering a couple of things with this brass

1. Has anyone experienced the misfire or hangfire drama when in cool or cold weather (mentioned on Salazars web site)

2. the small flash hole (about 60 thou) - anyone tried reaming the flash hole to 62 or 65 thou, just wondering if the flash hole would be better the same or similar size as the 223 cartridge. Or best to leave alone....

I started thinking about this when I got decapper pin stuck (65 thou) in a cartridge, and then started measuring things (I had assumed that the flash holes would be similar size to 223 cartridge flash hole)

Steve

I am using them with 2208 powder and CCI 450 (magnum) primers. So far so good, excellent accuracy even when fireforming.

It would seem your worries are pretty much unfounded despite what German says in his blog. Bryan Litz markets a precision brand of 308W ammo and guess what cases he is using!

If you are using Redding dies swap the decapping pin over for the skinny BR pin. Sinclair Int sell universal de-priming dies that come with both size pins. I swapped the decapping rod over in my Wilson 308W neck sizing die with one from my 6.5x47L (small dia pin) die.

Dont modify the case and keep using them with your fave powder and only believe what you find to be true about hangfires etc. Always knockers comment the sky will fall when things change. The best facts are gained from discussing it with others using them, thats whats good about forums!

Ian

[bartman007]

Ian,

In regard to performance of the new case over the old, have you seen any significant speed differences?

I have been running the older Lapua cases for some time, and can't really fault them.

Does having a smaller primer pocket give you the advantage of a stronger case, that allows you to put more powder in and increase the pressure?

I currently use 2208 and have found a sweet spot at 45.6 grains, so was wondering how much powder you are squeezing in to the new case.

Regards,

Bartman

[IanP]

Ian,

In regard to performance of the new case over the old, have you seen any significant speed differences?

I have been running the older Lapua cases for some time, and can't really fault them.

Does having a smaller primer pocket give you the advantage of a stronger case, that allows you to put more powder in and increase the pressure?

I currently use 2208 and have found a sweet spot at 45.6 grains, so was wondering how much powder you are squeezing in to the new case.

Regards,

Bartman

I cant provide years of experience reloading 308W but you can venture over to the usrifleteams website and have a read here for yourself: http://www.usrifleteams.com/lrforum/ind ... opic=13711

It would appear from those using both cases for long periods that hangfires dont happen with the Lapua Palma brass. It seems the consensus is that the smaller primer does produce a slight reduction in case pressure thru ignition providing a rounder, less abrupt pressure curve.

Match rifle shooters love the Palma cases because they last much longer launching the heavy projectiles which punish standard cases.

It seems you get a few fps less with the small primer brass but also gain less ES and better SD. The overall opinion is that if your happy with the performance and accuracy provided by the standard brass then there is no good reason to change.

One final thought if you do venture across to the usrifleteams site (like many do from here) ask what the USA team are using and why Lapua would make a small primer 308W case available for sale if it did not provide some benefit.

I'm using a load recommended to me from jcinsa which is a lightly compressed load of 46.0gr of 2208. This is used in a Barnard action with a 30", 12T, 5R Krieger barrel. Always work your way up to forum suggested loads!


Ian

[bartman007]

Ian,

Interesting link. They all had a bit to say about the small and large primers.

I think I'll stay with the large for now.

It seems that 46grains is the time that primer pockets begin to stretch. Maybe a sign that should be heeded

I don't see 3 reloads as being an economical use of brass. I did however like the comment made about various diameters of primer being related to brand. So in the event you get loose pockets, you could change primer manufacturer and keep using the brass a little longer! Good for those that have given their brass a hard time.

Regards,

Bartman

[Matt P]

Just wondering a couple of things with this brass

1. Has anyone experienced the misfire or hangfire drama when in cool or cold weather (mentioned on Salazars web site)

2. the small flash hole (about 60 thou) - anyone tried reaming the flash hole to 62 or 65 thou, just wondering if the flash hole would be better the same or similar size as the 223 cartridge. Or best to leave alone....

I started thinking about this when I got decapper pin stuck (65 thou) in a cartridge, and then started measuring things (I had assumed that the flash holes would be similar size to 223 cartridge flash hole)

Steve

I am using them with 2208 powder and CCI 450 (magnum) primers. So far so good, excellent accuracy even when fireforming.

It would seem your worries are pretty much unfounded despite what German says in his blog. Bryan Litz markets a precision brand of 308W ammo and guess what cases he is using!

If you are using Redding dies swap the decapping pin over for the skinny BR pin. Sinclair Int sell universal de-priming dies that come with both size pins. I swapped the decapping rod over in my Wilson 308W neck sizing die with one from my 6.5x47L (small dia pin) die.

Dont modify the case and keep using them with your fave powder and only believe what you find to be true about hangfires etc. Always knockers comment the sky will fall when things change. The best facts are gained from discussing it with others using them, thats whats good about forums!

Ian

Ian
The OP asked a question which I answered that I had issues with to the point of sending it back for refund, actual experience. You are correct about one thing don't beleive everything you read just because Litz uses doesn't mean it's better than the standard case, maybe it's just marketing hype.

Matt P

[IanP]

You are correct about one thing don't beleive everything you read just because Litz uses doesn't mean it's better than the standard case, maybe it's just marketing hype.
Matt P

Matt, I dont think Bryan Litz is big on hype! He is big on facts and he has the ability to provide an understanding of ballistics for shooters without them needing a degree in maths.

It wasn't marketing hype that beat the Australian team in Queensland just recently. It was Bryan Litz winning overall and team USA beating the Aussies. Guess what cases the USA boys were using!

Ian

[Matt P]

You are correct about one thing don't beleive everything you read just because Litz uses doesn't mean it's better than the standard case, maybe it's just marketing hype.
Matt P

Matt, I dont think Bryan Litz is big on hype! He is big on facts on he has the ability to provide an understanding of ballistics without needing a degree in maths.

It wasn't marketing hype that beat the Australian team in Queensland just recently. It was Bryan Litz winning overall and team USA beating the Aussies. Guess what cases the USA boys were using!

Ian

Yep if the Aussies used those cases they would have won !!!
No matter what the text book warriors say, some combination just don't work.
Matt P

[IanP]

Yep if the Aussies used those cases they would have won !!!
No matter what the text book warriors say, some combination just don't work.
Matt P

My point was Matt, that the yanks won using a case that has more going for it than just hype, as you suggested.

I dont try to put shooters off buying a box of palma cases, I suggest they should try them out and make their own judgement. Litz knows how to test bullets and accuracy and the world is following his lead using G7 BCs I dont think he would waste his time selling quality ammo in cases that dont perform.

Maybe you know better ?

Ian

[M12LRPV]

... the world is following his lead using G7 BCs ...

A question...

How does the use of a G7 BC against a set of G7 data tables compare to Sierra's velocity based multiple G1 BC's against a set G1 data tables???

[AlanF]

How does the use of a G7 BC against a set of G7 data tables compare to Sierra's velocity based multiple G1 BC's against a set G1 data tables???

Using the G7 system, the BC of a typical target projectile can be accurately described with a single number, whereas to get the same accuracy with G1 calculations, you need a multitude of BCs and velocity thresholds (as Sierra provides). And most ballistics programs don't cater for the Sierra type figures anyway. So the answer to your question is that G7 is simpler, and there is at least one free program (Berger Ballistics) available to use it.

Another important advantage is that with G7 you can work backwards from your own observed "come-ups" and velocities to determine an accurate G7 BC, whereas it would be much more complex (practically impossible?) to derive Sierra type BCs and velocities from field data.

Alan

[M12LRPV]

Sorry. It was a loaded question on my part.

I have a ballistics program that handles sierra style velocity based BC's and have used it to back calc multiple G1 BC's for a projectile that originally had one G1 BC based on trajectory info. I wrote it myself.


The real answer to my question is... There is no practical difference apart from one being a single number.

The other reality is of course that the variance between a G7 BC calculation and even a single G1 BC calculation can often be lost in the users estimate of the atmospheric conditions under which the calculation is performed.

In a practical sense it render's G7 BC's little more than a gimmick.

For the vast majority of boat tail projectiles, G5 is a more accurate model than G7. If it was that important to be publishing BC's for the the best fitting model then a company would be publishing G5 BC's instead of G7 BC's

I think someone was trying to make a point about G7 BC's though. Do we know what that point was?

[IanP]

Sorry. It was a loaded question on my part.

I have a ballistics program that handles sierra style velocity based BC's and have used it to back calc multiple G1 BC's for a projectile that originally had one G1 BC based on trajectory info. I wrote it myself.


The real answer to my question is... There is no practical difference apart from one being a single number.

The other reality is of course that the variance between a G7 BC calculation and even a single G1 BC calculation can often be lost in the users estimate of the atmospheric conditions under which the calculation is performed.

In a practical sense it render's G7 BC's little more than a gimmick.

For the vast majority of boat tail projectiles, G5 is a more accurate model than G7. If it was that important to be publishing BC's for the the best fitting model then a company would be publishing G5 BC's instead of G7 BC's

I think someone was trying to make a point about G7 BC's though. Do we know what that point was?

I look forward to reading your next book on ballistics and in particular to the peer reviews by your fellow ballisticians.

Ian