SAUM brass life?

[AlanF]

Thank you for all the replies.

It looks like the consensus is that 7SAUM brass life is far better than the .284W and at $160 for a box of brass that only last 8 - 10 firings at a mild 2730 ft/s, it may be worthwhile re-chambering my other barrels to the SAUM for better brass life and 200 ft/s more (still with a mild load for the cartridge).

I took my last .284W barrel out to 1900 rounds (without re-chambering) and in hindsight should have only gone to 1700ish MAX (probably even less) because that's where the accuracy was completely gone.

I'm sure a few 7SAUM barrels have been shot out by now, in general what is the competitive round count for a 7SAUM barrel before the need for a re-chamber?

Denis,

With my Shehane I can get 8 to 10 firings easily with 180s at velocities 2830 to 2860fps - its only when 2900fps is exceeded that primer pocket life shortens significantly. The standard 284 would run at very slightly higher pressure for the same velocity, but I'd suggest that there are other factors at play if 2730fps shortens brass life significantly. Also re barrel life, I won the Vic Queens in 2013 with a Krieger that was over 2000 rounds. Rod Davies has used some very ancient specimens at Queens shoots over the years. And ask Richard Braund how many rounds he gets out of his (probably > 3000!). So I'd suggest your 1700 round barrel was an exception - what brand was it?

Alan

[Matt P]

Thank you for all the replies.

It looks like the consensus is that 7SAUM brass life is far better than the .284W and at $160 for a box of brass that only last 8 - 10 firings at a mild 2730 ft/s, it may be worthwhile re-chambering my other barrels to the SAUM for better brass life and 200 ft/s more (still with a mild load for the cartridge).

I took my last .284W barrel out to 1900 rounds (without re-chambering) and in hindsight should have only gone to 1700ish MAX (probably even less) because that's where the accuracy was completely gone.

I'm sure a few 7SAUM barrels have been shot out by now, in general what is the competitive round count for a 7SAUM barrel before the need for a re-chamber?

Denis,

With my Shehane I can get 8 to 10 firings easily with 180s at velocities 2830 to 2860fps - its only when 2900fps is exceeded that primer pocket life shortens significantly. The standard 284 would run at very slightly higher pressure for the same velocity, but I'd suggest that there are other factors at play if 2730fps shortens brass life significantly. Also re barrel life, I won the Vic Queens in 2013 with a Krieger that was over 2000 rounds. Rod Davies has used some very ancient specimens at Queens shoots over the years. And ask Richard Braund how many rounds he gets out of his (probably > 3000!). So I'd suggest your 1700 round barrel was an exception - what brand was it?

Alan

Maybe you have a slow chrony or Alans is fast
In all seriousness I have had the same results as Denis, but I want to use 2209, I'm sure with a slower powder those velocities are achievable without destroying brass.
I'm getting about 2930 in my RSAUM using 55.8 of 2209 with 180 Hybrids and BR2's.
Matt P

[macguru]

I also want to use 2209
I'm getting about 2940fps in my RSAUM using 55.0g of 2209 with 180 Hybrids and BR2's.
I have reloaded a few cases 4 times and they still look perfect, in fact i expect they will last a lot longer than 8 firings....... but i have already ordered more just in case
Andrew

[AlanF]

Maybe you have a slow chrony or Alans is fast
In all seriousness I have had the same results as Denis, but I want to use 2209, I'm sure with a slower powder those velocities are achievable without destroying brass.

I rarely use 2209 with the 180s, so that could be the main reason for the difference Matt.

Just on the question of brass life, I look upon it as a consumable. With say 8 firings, that's about 20 cents per shot brass costs. Compare that with projectiles about 60 or 70 cents per shot, powder about 40 cents, barrel about 50 cents etc. Lets say you change from a 284 to a SAUM, and double your brass life for a saving of 10 cents per shot. But consider the effects on the other consumables. You'll need about 5 cents per shot more powder, and get maybe 10 to 20% less barrel life, costing about 7 cents a shot. So you're slightly ahead with the 284. Also, unless you anneal necks and clean inside cases, then using brass beyond 8 firings would be questionable anyway. So anyone who has or is considering a 284, I would strongly advise not to let the primer pocket issue put you off. It is a minor inconvenience.

[Brad Y]

And if the norma 284 cases being made now actually make it here and hold up a little better it may get better again. Hopefully that happens.

[pjifl]

I think it is sensible to think of cases as consumable. Case then is minor compared with other reloading components plus traveling costs.

Another way to look at is is to compare to barrel life.

For example, 200 cases shot 10 times each in a Saum would see off a barrel - just as an example.

Unfortunately, the real rub comes when one cannot obtain cases or there is a huge amount of work preparing cases - eg making them from another cartridge.
If it was not for this I would be quite willing to have a shorter case life.

It seems to me that many are deliberately trading case life for velocity in FTR to obtain performance.
No criticism - just the reality of the genre and required competition standard.
And, in general, 308 (even Palma) cases are much easier to obtain in Australia.

Peter Smith.

[AlanF]

And if the norma 284 cases being made now actually make it here and hold up a little better it may get better again. Hopefully that happens.

Did you mean norma or Norm ?

[BATattack]

Maybe you have a slow chrony or Alans is fast
In all seriousness I have had the same results as Denis, but I want to use 2209, I'm sure with a slower powder those velocities are achievable without destroying brass.

I rarely use 2209 with the 180s, so that could be the main reason for the difference Matt.

Just on the question of brass life, I look upon it as a consumable. With say 8 firings, that's about 20 cents per shot brass costs. Compare that with projectiles about 60 or 70 cents per shot, powder about 40 cents, barrel about 50 cents etc. Lets say you change from a 284 to a SAUM, and double your brass life for a saving of 10 cents per shot. But consider the effects on the other consumables. You'll need about 5 cents per shot more powder, and get maybe 10 to 20% less barrel life, costing about 7 cents a shot. So you're slightly ahead with the 284. Also, unless you anneal necks and clean inside cases, then using brass beyond 8 firings would be questionable anyway. So anyone who has or is considering a 284, I would strongly advise not to let the primer pocket issue put you off. It is a minor inconvenience.

totally agree with those words Alan. Also a lot of people forget to include their time and cost of components and barrel life to fire from some cases. It comes down to what you are willing to pay for ballistics.

[Brad Y]

And if the norma 284 cases being made now actually make it here and hold up a little better it may get better again. Hopefully that happens.

Did you mean norma or Norm ?

Did I say norma?

On another note, Ive ordered a shehane hydraulic form die, Wondering if a hydraulic form will cause even less pressure on the first firing.

[DenisA]

Alan I absolutely agree with looking at cases as a consumable. Maybe I need to chuck the 6BR (wont happen) so that I can't compare the idiosyncrasies of other cartridges to it. The 6BR's too good in so many ways.

It would be nice to get another 200ft/s from the 180's if the costs, barrel life and efforts are justified. I guess there's good reason for so many shooters moving to it.

It is good to break the cost down to reground ones self every now and then when brilliant new plans start manifesting in the mind. Cheers.

[AlanF]

...It would be nice to get another 200ft/s from the 180's if the costs, barrel life and efforts are justified. I guess there's good reason for so many shooters moving to it...

Denis,

In the current climate of energy limits and brass shortages, its quite surprising how many are changing from 284 to SAUM. But interesting that some SAUM users are going (or considering going) the other way ! I can't help feeling its just an excuse to get another gun in the cupboard !

I've always been reluctant to change calibres, so expect to stick with the Shehane. If I want to stoke the 180s up to 2950 then it will do it - with the costs being more powder, more recoil, more copper fouling (jacket damage), higher barrel temp, shorter barrel life, and as we're discussing here, reduced brass life. The only benefit is better ballistics, in particular less wind deflection. In my case there would be a 100 fps increase in muzzle velocity. BUT, my Excel simulation program says that the resulting ballistic improvement will increase a typical Queens aggregate score by just 1 point (plus a couple of Xes). That's when you ask yourself, with all the other difficulties that extra 100fps brings, maybe you would lose that point advantage (and more) because of loss of accuracy from things such as higher barrel temp, increased coppering, or even worse, a leaky primer. So 2850 fps will do me fine - the 100fps deficit to the SAUMs is rarely going to make a difference to the result. Same for the standard 284s at about 2820fps - ask Marty Lobert . For any new shooters who come to Rosedale and want to shoot the longs, I recommend the standard 284 without hesitation, because apart from expanding the Lapua necks, it is as easy as a 308 to get started with, yet gives virtually nothing away to anything else in terms of either accuracy or ballistics.

[pjifl]

This topic has been specifically about the SAUM so I did not mention that my workhorse rifle is a straight no neck turn 284 doing 2820 - exactly as Alan mentioned.

The SAUM interests me because it seems the best balanced of the larger cases known for superb accuracy but I intend to use the 284 far more often.

By the way - I cannot understand a 284 running at 2730 being hard on cases.

Peter Smith.

[DenisA]

By the way - I cannot understand a 284 running at 2730 being hard on cases.

Peter Smith.

G'day Peter,

Here's a link to an old thread of mine about my .284 brass life concerns.

viewtopic.php?f=5&t=4393&p=34993&hilit=.284+brass+life#p34993

What's changed since then is that I've dropped the MV to 2730 fps and doubled the brass life that mentioned in that thread. 4-5 firings v 8 - 10. With this later barrel, I've also gone to 50.1gn AR2209. My current MV has been measured with a Magnetospeed V3 which is giving results not too far off the Chronny Beta Master that I was using at the time. I still have the Chronny and have run it in conjunction with the V3.

I will say though that I'm still running that same batch number of brass as the free boxes that Lapua organised for me through NIOA were the same batch number.

I've come to terms with the life of the .284 brass, its no longer and issue for me. I'm just weighing up the pros and cons of .284W v's 7SAUM.

[BATattack]

I think probably half or more of the people building a SAUM just want to tick that box and say "yeah I had one of those!"

When I moved from 6.5 to 7mm there was a fork in the road and I wanted something different and at that time there were only about 2 SAUM's I knew of and only 1 that shot well. Now I've got all my brass, dies and reamers and figured out how to get the SAUM working I'd like to stick with the same caliber for the next few years but after that I might try a sea change

I've been beaten my 6mm 6.5s and straight 284s when using my saum so BC isn't the be all and end all. It's who's in the zone on the day.

Having my time again I'd probably look harder at the 284 and hope that the new Norma brass becomes more avaliable or just be content necking up the lapua or consider the 280ai.

[Gadget]

Hi Guy's
I have read this thread with interest, as some of you know I run my SAUM flat stick 180's @ 3100+ as I cannot go to Queens or other comps any more I will not bother to slow it down, the Match Rifle guys still have sensible energy limits so that's where I play now.

So to results, my first set of brass was toast after 8 to 10 firings I just could not get it out of the chamber it would stick so tight the base of the case would expand so much it was very hard to extract, the primer pockets were not a problem only brass expansion, I would F/L size every time and anneal every 2 firings and there was no sign of trouble until you just fired that one last shot with good results but when you tried to extract ( mallet time ) fortunately I run Barnard P's so a gentle tap with a rubber mallet and all sorted.
As for barrel life this one is at 1830 rounds and going strong its been pulled and inspected twice during it's life.

So to .284 or SAUM in todays climate of energy limits, I do not want to wind the horsepower of my SAUM down it's made for tossing 180 fast and it will do it all day long, so if I was starting again I think I would just go with a .284 or Sheehan to comply easily with energy limits, we have recently taken a club members .284 sorted a load and tuned it for him and he is now doing very will with it, including a 60/10 at Bendigo this is a very competitive round and I don't think you need anymore grunt in todays climate, but I will stick to a SAUM going Full Noise at 1200y it's way more fun.

Gadget