I'm now shooting my new Surgeon 6.5x47 Lapua; a case which uses small rifle primers. Fired just over 100 rds yesterday while running pressure/ladder tests. No primers are flatened; most have slightly, not alot, cratered faces. If I run 10 rounds, increasing .4 gr each round, I see slight ejector marks on some cases 7 through 10. Not all, and barely perceptible. No hard bolt lift. No out of norm velocity increases or an actual velocity decrease which can indicate top or too high pressure.

I've seen high pressure before buth this is a bit different.

Anybody with lots of experience with sm primed cases?

Alan

quote:

Originally posted by GSSP:
Anybody with lots of experience with sm primed cases? ...

Yes.

Velocity doesn't mean spit when it comes to Pressure. As long as you refuse to use CHE & PRE you will never know anything worthwhile about the Pressure - except for how long the Primer Pockets remain snug at a specific Load.

So, you can Load at a specific level, shoot, reload, shoot, reload, etc., and see how long the Primer Pockets stay snug. Or, you could use CHE & PRE and know what is going on immediately after each shot.

Keep fighting it though.

ejector marks show your at maximum IMO.

Hot Core,

I agree. I've used CHE & PRE in developing NATO spec MK 262 loads for my AR. What sort of expansion numbers do you think I want to stop at? I'd know what numbers to look for in a small case/small primer but this is a large case/small primer and the brass surrounding the primer is obviously thicker and I figure it will affect the numbers.

Alan

quote:

Originally posted by GSSP:
Hot Core,

I agree. I've used CHE & PRE in developing NATO spec MK 262 loads for my AR. What sort of expansion numbers do you think I want to stop at? I'd know what numbers to look for in a small case/small primer but this is a large case/small primer and the brass surrounding the primer is obviously thicker and I figure it will affect the numbers.

Alan

Kind of late now, you need to take a measurment with the brass unfired as a base then compare after fireing.
I don`t think primer size has any bearing on "how much" head expansion is OK or too much. Most figures I`ve seen claim 0.0005" is the max. I`d stop if you find any expansion and call it good myself. 0.0005" leaves no room for the guy with the micrometer to error.

quote:

Originally posted by GSSP:
I'm now shooting my new Surgeon 6.5x47 Lapua; a case which uses small rifle primers. Fired just over 100 rds yesterday while running pressure/ladder tests. No primers are flatened; most have slightly, not alot, cratered faces. If I run 10 rounds, increasing .4 gr each round, I see slight ejector marks on some cases 7 through 10. Not all, and barely perceptible. No hard bolt lift. No out of norm velocity increases or an actual velocity decrease which can indicate top or too high pressure.

I've seen high pressure before buth this is a bit different.

Anybody with lots of experience with sm primed cases?

Alan

here a deal on factory ammo for the 6.5x47 Laupa

"Factory 6.5x47 Lapua loads shoot the 139-grain Lapua Scenar at 2690 fps, the 123-grain Scenar at 2790 fps, or the 108-grain Scenar at 2950 fps."

Have you checked on 6br site and see what those guys are getting for load/velocity that might be a good place to start.

If your at the top end of your loads and getting marks I'd back down some.

Good for you.

I use the same numbers for all Cases which can be found in the CHE & PRE Instructions. I realize there should be a minor difference, but it just complicates the process to have different Values for each size case.

I'd also recommend you do the CHE measurements(for the First reading) using "once-fired" cases, as mentioned in Speer #12 page 55.

I'm not aware of any Factory Ammo available in the 6.5x47, so that lets PRE out - until you establish how much Powder it takes to reach the CHE Max - then you can also record the PRE as a back-up.

A sincere Best of luck to you.

I've still got about 30 unfired cases so I can go that route inaddition, Midway has 100 and 108 gr factory in stock. Even my dealer price is $55 and $58 respectively!

Alan

quote:

Originally posted by GSSP:
Hot Core,

I agree. I've used CHE & PRE in developing NATO spec MK 262 loads for my AR.

You aren't going to get Mk262-spec velocities watching pressure. Mk262 loads are fire once and discard the (now trashed) brass.

BECoole,

Really? Could fool me and my 5x fired brass and still going!

quote:

Originally posted by GSSP:
I've still got about 30 unfired cases so I can go that route inaddition, Midway has 100 and 108 gr factory in stock. Even my dealer price is $55 and $58 respectively!

Alan

I hear you about the $$$Prices$$$, makes me want to go throttle someone. Just don't know who to grab.

That is really good news about having Factory Ammo available - " IF " - you want to try PRE with a properly established Benchmark Standard. However, there is nothing at all wrong with just using the CHE (per the instructions).

The reason I mention the instructions so much, is because there are some very minor Tricks in them that make CHE a bit more accurate than just randomly going about it. It is also important to realize the Case Head does not always expand perfectly circular. There are times they just tend to go Oval and that really hoses-up the readings. That is why it is nice to do more thna one Case at each Load Level when verifying the Load.

I still do one case at each Load Level when first running the Audette Method to determine not only the Harmonic Nodes, but the "suspected" upper Pressure Limit.
-----

I'd think gett ing 5 reloads(still with reliable Ejection) in a semi-auto speaks extremely well for your Reloading Technique.

Best of luck.

quote:

Originally posted by GSSP:
BECoole,

Really? Could fool me and my 5x fired brass and still going!

What load are you running?

LC 90+ cases, primer pockets cleaned up and flash holes trued. "Old" nickel plated Win Sm Rifle primers. H4895. Hornady 75 BTHP, my own cannulure rolled on with a CH-4 cannulure tool. Crimped with the Lee factory crimp die. Runs 2750 fps from my RRA 16" 1:9. Groups 10 shots in 10" @ 600 yds @ 20 deg F with a 2x, TA47-2 compact ACOG.

Alan