5.6x57 development

[Camel]

Big variation for sure mate, any indication of wether the batches have a big age difference in them ? Batch numbers have big differences ??

[stinkitup]

I would be trying to weigh like for like cases eg. All cases at least fired once, deprimed sized and trimmed to the same length. If you have tools for flash holes and primer pocket tidying do that then weigh them.

I am away but could post my pocket reamer and flash hole tool if you like.

In the virgin cases was it like 5 cases at the extremes and 10 the same or within one grain? You could have 2 cases at the extreme and the rest very consistent.

Sounds like a lot of work but could make a big difference.

[Waldo]

Camel, I haven't checked the numbers on the boxes (good idea though) but the brass has come from three different boxes, ie:
factory loaded FMJ's
factory loaded KP's (of which I now think I only have 15 empties as I swapped the loaded stuff with Beretta for the new brass)
new virgin brass (that I got from Beretta)

I originally had the FMJ and KP brass in together but without pulling all the FMJ's (59) and testing them can't be 100% sure.

Stinkitup, most of the virgin brass was a bit closer than the 3.3g range and weighing the max./min got the range up to 3.3g variation. I do get some cases that don't fit into the shell holder (was worse with the Lee shell holder but better with the RCBS I picked up ) so I'll cull out any of those out and retest them if they are tight in the shell holder they be a bit fatter on the bottom?

I do have a hand chamfer tool and primer pocket cleaner, I don't have a flash hole tool which I assume is just a smaller version I'll check out the LGS. By the time I go thru and check all cases feed, sized, trimmed, cleaned and prepped I'll go thru them and check weights again and see how close the finished articles are. If I get a chance this morning I'll throw a dead primer on the scales to see what they weigh to see how close the virgin and FMJ brass is.

Yep, still learning

Cheers,
Waldo

[Waldo]

OK, I'll retract that earlier statement about some of the virgin brass not fitting the "Redding" shell holder, just tried a box and it all fitted fine

A dead primer on the scales came in at 5grains so add that to the virgin brass average and it comes up to 243g which against the fired brass (light versions) of 221g average is still a fair whallop of a difference.

The real annoying thing is I have to go to work now when I'd rather stuff around in the shed load up some rounds and talk to my dogs

Cheers,
Waldo

[Waldo]

That was kinda interesting?

I had 55 pieces of previously fired brass put aside so set about sizing, trimming, chamfering, cleaning etc. finished up with 25 pieces!

Culled out 21 that wouldn't feed into the shell holder because of what appears to be extractor marks around the rim. I put these on the scales and these were all on the heavier side of when I weighed them all, so may explain occasional slightly sticky bolt with the factory FMJ loads? Looks like I'll pull the remaining FMJ loads to save stuffing the brass.

I ended up 25 prepped cases with a 5grain variation within 212.3g to 217.3g.

Also culled out one light weight item that came in at 211.35g and 8 tubby ones that were over or above 218.5g.

If I get a chance this arvo I'll prep a box or two of virgin brass and see where I end up with that, at a glance they appeared more consistent?

I'll load the 25 cases with the Amax and load the newer brass with the BT's when they arrive, should be able to stumble upon a sweet spot there some where .

Good thing it's a bit hot to go deer hunting so I have a bit of time to play

Cheers,
Waldo

[Camel]

Interesting findings mate, can only speculate the vast differences might be because the Europeans don't do any where near as much shooting as we do over here therefore don't reload much. They shoot em and drop em.
I reckon pulling the FMJ would be the go, doubt they would be much good except maybe for skin shooting.

[Waldo]

Yeh, I was going to shoot the FMJ's just for giggles at the range (or nail a Sambar with em) but if I'm going to "scar" a percentage of the brass I'll just pull em.

Kinda surprising to see the variation in german manufactured (?) product as they do have a bit of a reputation for quality engineering, if it was the Italians I could understand it

Cheers,
Waldo

[aaronraad]

I believe part of the variance in brass issue is from the calibre itself.

The frequent large production runs just aren't there for the unpopular calibres as compared to 308W or 6mmBR. Supply of strip coils from the mills varies over the years and manufacturers have to essentially work with what they get at the time and manipulate the metallurgy to suit their deep drawing. RWS possibly only scheduled production runs of 5.6x57mm every 4-5yrs and they could have sub-contracted out the case deep drawing to the like of Norma or others so allow them to concentrate other calibres.

The calibre doesn't have any target or military requirements either, so there is no large customer base demanding higher tolerances. Nor do they have to obviously compete against any other suppliers.

The irony is that a lot of these cartridge and projectile designs are a result of manufacturing and not necessarily ballistics designers and engineers. Worn tooling that is 'allowed' to produce a significant volume of what would be scrap brass or bullet jackets all of sudden becomes a new cartridge with the same case head size or bullet weight same calibre. You know the saying, its not a mistake it's a design feature.

[MISSED]

Wow waldo that is a steep learning curve yo have been climbing.

And you are doing well to get your head around it all.

But a Sambar with a 22 cal how unethical would that be

Awesome Posts you have made in this thread Aaron.

You need to come along to a get together so we can pick your brains.

[Waldo]

But a Sambar with a 22 cal how unethical would that be

.

Rest easy, just a bit of a dig at those that consider Sambar bulletproof. Kind of thought well at least the FMJ should be OK with that armour plated brown fur

[MISSED]

There has been a few shot locally with 222`s and 22/250`s

[Waldo]

There has been a few shot locally with 222`s and 22/250`s

Hey, what are those Victorian deer doing up there!

[Waldo]

Back on track (for a minute at least)

Sized, trimmed, etc. a box of virgin brass, across the scales came up a min. 236.35g and a max. of 239.8g for a 3.45g variation which is looking pretty good.

Looks like I'll have 2 x distinct groups of brass with a few outside that range to put aside.

If I get a chance tomorrow I'll run up a few of the Amax and re-test them over the chrono and at the range, hope the BT's turn up next week so I can run up a few of them too. Hopefully the velocity variation should resolve itself and this thing will shoot like a demon.

Cheers,
Waldo

[aaronraad]

Awesome Posts you have made in this thread Aaron.

You need to come along to a get together so we can pick your brains.

The unedited version is a whole different story...but it's always great to catch up with shooters face-to-face, put some rounds through the barrel and knock the top off a stubby or two.

Contiki need to put together a few Australian varmint hunting tours. You know 12 nights Brisbane to Adelaide, hunt or range time 8hrs, spotlight 8hrs, sleep on the bus for 8hrs between destinations. Store a few 2-man ATV's underneath the coach for remote property access, reloading bench up the back, tow along a chiller box for anything too big for the BBQ that night. Probably need another bus just for the armoury.

[B4408]

Contiki need to put together a few Australian varmint hunting tours. You know 12 nights Brisbane to Adelaide, hunt or range time 8hrs, spotlight 8hrs, sleep on the bus for 8hrs between destinations. Store a few 2-man ATV's underneath the coach for remote property access, reloading bench up the back, tow along a chiller box for anything too big for the BBQ that night. Probably need another bus just for the armoury.

What a great idea... But i would need to be 20 again to survive that schedule or die trying.

Bruce