243 Load

[menial 1]

I understand your point Stag, but my concern was that after loading for different .243' in the past, Eric's loads seemed exceptionally high as starting loads and as he found out they didn't really group that well and showed signs of pressure.

I'd rather politely bring the point to their attention than sit back and say nothing.

Pete.

[stag1933]

Vihtavouri are quite clear in their loading info and tell us that their published loads are MAXIMUM and suggest we start 10-15% lower then work up.

 

HWH.

[eldon]

Interesting though in 2004 I would have been a grain off max yet in 2008 I am now nearly 3 grains off max.

So stag which is the maximum? presumably the 2008.

 

Has the powder changed that much ? or is there some marketing pressures to produce faster rounds than the next powder manufacturer ?

 

Call me cynical but I for one am not sure of the answer, please somebody enlighten me.

[Laurie]

Interesting though in 2004 I would have been a grain off max yet in 2008 I am now nearly 3 grains off max.

So stag which is the maximum? presumably the 2008.

 

Has the powder changed that much ? or is there some marketing pressures to produce faster rounds than the next powder manufacturer ?

 

Call me cynical but I for one am not sure of the answer, please somebody enlighten me.

 

 

If you're cynical, you'd say it might have something to do with Vihtavuori moving into the American market in a big way during the years between the two manuals being published, and that being a market where velocity sells.

 

If you're not, you'd say Viht got a new 6mm pressure barrel that gave different results.

 

Me? I'm not sure. I did some work for Nammo Oy on proofreading the current Viht manual, and I do know the company retested virtually every combination that's in the book using current production components and in many cases new bullet models.

 

What I do know from personal experience with some of the .243W loads in the 4th edition is that their maximum listed loads are 'hot' - and that is unusual, both for Viht and for reloading manuals in general. It doesn't apply to their .308W loads for instance, most handloading target shooters running at higher N140 charges than listed.

 

stag1933 Posted Yesterday, 07:53 PM

I have read these posts carefully and notice one significant detail.

There are no `standards` being used therefore the info. is not a rational study.

 

Each rifle is an individual which may be different to others.

Brass of different makers may not have the same internal capacity.

Primers used may have a different `burn rate`ie :- Magnums, Standards or Match etc.

Seating depth is not standardised.

 

HWH,

if you look at the Viht 4th edition manual, you'll note that primer make is never quoted in it, only size, so Viht itself doesn't appear concerned by one major variable not being known. Lapua brass is invariably used when available, and that is usually on the heavy / limited capacity side, so US made equivalents almost invariably produce lower pressures. Finally, all Viht loads are developed in and MVs measured on test barrels made to the appropriate CIP minimum toleranced dimensions which (again) are almost invariably on the 'tight' / short-thnroated side increasing pressures / MVs. If you read the US companies' manuals information carefully, you see that the loads are worked up in industry standard pressure barrels (except for those cartridges that lack SAAMI / CIP recognition and standards), but MVs are measured in 'real' firearms in most of them (Nosler excepted). This was done because the latter almost invariably produce lower pressures and MVs and with cheap chronographs letting the punters see what they actually get, the manufacturers were bombarded with complaints from American shooters that they couldn't get the velocities stated in the published loads data. it also led to some handloaders egging their loads up and up on the basis that if Speer, Hornady, Nosler etc could get 3,000 fps out of this cartridge and bullet combination safely, they should be able to as well.

 

What all this means is that even manufacturers' published data is a compromise and should be treated as a starting point for the sensible handloader. As the 'standards' used are generally meaningless and irrelevant to the average shooter since precious few of us have access to a CIP standard dimensioned and chambered barrel - the biggest determinant by far of the final pressures - or even know what those dimensions are, we're all working in the dark to a greater or lesser extent. The advice to knock 10% off charge weights, work loads up, and look for over-pressure signs, as often quoted by forum members giving their pet loads is always wise, irresective of data source.

 

Incidentally, if you want to see people quote 'standards' in loads data, you've missed what is sometimes the largest variable - powder manufacturing lot. Vihtavuori is very good indeed at having its products behave within a small range from lot to lot, but that doesn't always apply to many of the Australian manufactured (ADI) extruded powders marketed under the Hodgdon name, or the Swedish (Bofors) manufactured double-base powders sold under the Alliant Reloder name. There have been several instances recently of some powders giving noticeably different pressures between lots, to the point that buying a new supply in required working the load up again if it had been running at maximum levels on the old tin.

 

Laurie

[stag1933]

Laurie.

An excellent post and common sense.

I have always loaded for the smallest group and NEVER maximum velocity as my calibre used is always suitable for my quarry.

The Viht. powders have proved to be acceptable from batch to batch but of course I always range test before being used on game species.

The most variable powder I have ever used is Varget with a one-hole group in my .308 spreading out to one-and-a-quarter inches.

 

I have only had ONE rifle in 48 years which shot tightest at maximum velocities and that was a 5.6X61 Vom Hofe Super Express with Nobel powder.

That was about 30 years ago when mainly Nobel and Norma powders were available.

 

Eldon.

I would go with the latest info. from the manufacturer.

Perhaps there is a change or is it a fear of possible litigation ?

 

HWH.

[Laurie]

stag1933 Posted Today, 02:33 PM

I have always loaded for the smallest group and NEVER maximum velocity as my calibre used is always suitable for my quarry.

The Viht. powders have proved to be acceptable from batch to batch but of course I always range test before being used on game species.

 

I'll support you a 100% in this advice. Until I got into the 1,000yd F-Class game I never found a need for maximum loads, and over the years I've found most factory rifles simply don't perform well at maximum velocities.

 

[it can be a different story with really stiff and well-fitting custom actions though which perform right up to peak pressures. That, alongside the really well machined and smooth chambers that a good gunsmith provides in a custom gun, can set a bear-trap for the unwary as one increasingly hears of people running sooper-dooper pressure loads and apart from primer pockets going slack after two or three loadings not getting any of the traditional over-pressure signs like hard bolt-lift and extraction. Then, one day............a new batch of powder, or a charge inadvertently thrown/weighed a little on the high side, or who knows what, and it's a blown primer and the lovely custom action bolt-face with a burned in ring...or worse! I'm always reminded of a long dead shooting friend with some questionnable handloading practices who had one of the old Webley revolvers blow the locking latch off and the action open one day with bits of crap flying around the firing line. Quite unperturbed, he said to his white-faced fellow pistoleers: "That's funny, it never did that before!"]

 

Laurie

[eldon]

Stag,

I can't see it being litigation as the lower figures come first so the later info is more likely to result in court action if any.

 

The American markets desire for velocity seems more of a likely answer to me.

[menial 1]

None of my rifles have a barrel length of more than 22" and the old data has worked well enough for me in the past, with the quoted max loads being pretty much bang on the money. The new loads may well work wonderfully in a 26-28 pressure barrel but they're certainly way higher than needed in my rifles, if I wanted a mega muzzle flash and loose groups I'd go with the later data but for now I'll stick with the loads I personally have tested in my rifles up to super stiff bolt lifts and blown primers.

It's been said often enough, you're rifle will tell you what's right not the latest quoted figures.

Pete.

[jack]

Eldon

can you email me Vit load data for .222 please.

Tried to PM but it would not work.

jackg(replacethis)phonecoop.coop

Please (replacethis) with @.

 

I followed Pete's advice and tried some on the range starting at 42Gr for 87Gr Vmax.

I settled on 44Gr at 3072FPS, could have used 43.5 @ 3034FPS but I got slightly better group at 44.

Previously used 46Gr giving 3224FPS.

600mm barrel.

[eldon]

Jack, I will dig the info out and send you it.