Imperial & Metric Headaches

Mulga · Post by **Mulga** » Wed Oct 19, 2011 6:32 pm

I have been doing some reasearch into seating depths or more specifically seating distance off the lands for my .17 Remington. I understand this is critical to accuracy. I normally use a bit of guess work in this area and haven't really thought of it too much (a quater turn here or there on the seating plug). Talk of 10 - 40 thousanths of an inch didn't mean much to me as im in my mid 30's and was schooled in the metric system, that's until I got my vernier out.

The Mitutoyo non-digital unit I use has metric (0.02) and Imperial (0.001). Now I find the metric easy to read, but imperial to 0.001 is a real challenge. So I went and got my feeler guages out

10 thousandths inch = 0.25 mm
20 thousandths inch = 0.51 mm
30 thousandths inch = 0.76 mm
40 thousandths inch = 1.02 mm

These are small numbers and I have realised I have proably been seating some of mine in allot deeper, though still achieving good results.

And here is my vent:

Inches, yards, feet per second, minutes of angle are just a pain in the arse to use, millimetres, centimetres, metres, metres per second and mill radians to name a few are easily divisable by 10 and are much easier to use IMHO

I hope the imperial/statute system dies off soon, but I won't hold my breath.

Regards

Dan

xa-coupe · Post by **xa-coupe** » Wed Oct 19, 2011 6:41 pm

I was born in 67 and even though technically imperial was phased out, I was raised half half. Some things like shooting are all over the place.. thousands and mm are kind of interchangeable depending on the situation.... but with my cars, it's all imperial.
We will all need to be gone before it has a chance of really standardising.

The Raven · Post by **The Raven** » Wed Oct 19, 2011 8:51 pm

Like xa-coupe I was raised with both systems. I am a firm believer in metric, so it was quite a shock when I spent a few years in the US and had to us imperial/US measurements. Try changing from all metric draughting (as in drawing boards) to weird imperials scales.

Having said that I like metric, there are some plain old imperial measurements that just seem to fit the real world better. I like HP, I like torque in ft/lbs, and a 1/4 mile is a quarter mile.

stinkitup · Post by **stinkitup** » Wed Oct 19, 2011 8:56 pm

Being 30 I am imperially challenged as well, although I can understand 0.1/0.01/0.001 of an inch as technically its units of 10 again

I laugh though we measure baby's born in cm's and kg but everyone wants to know how many lb's they are

One good thing about going back to UNI for engineering last year is I am now pretty good and conversions

Haha no cars should be metric too who cares 350 cubic inches is but I know how many buckets hole 5.7 litres

KW, NM and a quarter mile is 402m

I do feel sorry Raven, my draughting I did do a little bit on other systems and yeah they get funky!

Ryan

chappo555 · Post by **chappo555** » Wed Oct 19, 2011 10:28 pm

Mate most of the shooting info comes from the good old US so we are stuck with imperial. I like measuring load/chamber stuff in the thou and target groups by MOA and I'm only 39!
If u have an iPhone just get multi convert app and your set.

Mulga · Post by **Mulga** » Thu Oct 20, 2011 5:31 am

I persevere, just somtimes gives me the shits. I think from now on im goint to try to communicate in metric. However its pretty hard not use both for one thing or another. Old habbits die hard.

As a last note I love how property owners like to talk in Acres rather than Hectares. I think it makes them feel they have more dirt.

Dr G · Post by **Dr G** » Thu Oct 20, 2011 1:12 pm

I am with you Raven and xa, I was raised with both systems (being a child of the early seventies). My brain is a mish mash. I am six feet tall but I am 140kg

With petrol cars I cant think of them as anything other than cubic inches, 250, 253, 308, 327, 350, 351 etc but shift to diesel and it becomes metric. When I shoot all of my ranging and distance measurement is given in metres but group size, reloading and case prep measurements are all in imperial despite the fact that I think about linear measurements in mostly metric. I fish in imperial but I weigh my fish and what I shoot in kg.

Some days I feel very confused

Dr G

malcolm · Post by **malcolm** » Thu Oct 20, 2011 7:49 pm

I wouldn't get too carried away----------- our world still works with both systems. Go and buy a door for your house--820mm standard. Go and buy a tyre for your car-- 13 inch or 15 inch. All young girls still want -- 6 foot two,--eyes of blue. Try and tell a surfer to buy a board 1500 mm's instead of a 5 ft 6 inches.
My mate owns a timber yard and to this day he still gets-------- " I want a piece of hardwood, 4inch by 2 inch -- 6 meters long."
We Aussies are so adaptable.
Cheers Malcolm

Camel · Post by **Camel** » Thu Oct 20, 2011 7:53 pm

malcolm wrote:" I want a piece of hardwood, 4inch by 2 inch -- 6 meters long."
We Aussies are so adaptable.
Cheers Malcolm

Yeah but try fitting the "new" 4 x 2 into a house built in the 1920's with old 4 x 2.

chris.tyne · Post by **chris.tyne** » Thu Oct 20, 2011 9:00 pm

I am a 1970 model and it was all metric at school but I have learnt imperial as well,It just sounds right with firearms related stuff,thou's,inches,pounds and ounces

.

Regards Chris.

The Raven · Post by **The Raven** » Fri Oct 21, 2011 8:57 am

Metric, imperial, and any other measurement systems all have their place. When it comes to firearms I'm still trying to wrap my head around grains, drams and other measurements. Yes, metric is a good leveller but some stuff just needs to be left with it's historic measurements. Just be glad we're not sailors having to learn all sorts of arcane terms and measurements that few others use.

sbn · Post by **sbn** » Fri Oct 21, 2011 12:04 pm

G'day Mulga,
you reckon firearms are bad,try chainsaws. Made in Europe, used in America there is a horrid mish-mash of inches (fractions), inches (decimals) and metric.
Keeps my students confused for days!
Cheers Dugald

Mulga · Post by **Mulga** » Fri Oct 21, 2011 1:08 pm

sbn wrote:G'day Mulga,
you reckon firearms are bad,try chainsaws. Made in Europe, used in America there is a horrid mish-mash of inches (fractions), inches (decimals) and metric.
Keeps my students confused for days!
Cheers Dugald

No doubt it keeps them on their toes

trevort · Post by **trevort** » Fri Oct 21, 2011 10:35 pm

every single life insurance application needs height and weight. Almost invariably its 5'10" and 94 kgs. No one is metric height

Mulga · Post by **Mulga** » Sat Oct 22, 2011 5:55 am

My Qld drivers licence has height in Centimetres.

AusVarmint