Rule of Thumb!?

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27-05-2018, 07:28 PM
Fireflite

Rule of Thumb!?

So what's your's for attaining the so called accuracy of your rifle?

MOA
. 3 Shots
. 5 Shots

Time
. between each round fired
. barrel temperature?
. dependent on Caliber?
. dependent on load pressure (high-low)
. dependent on barrel couture (taper/thickness/fluting)
. Blued or stainless (heat retention/dispersion)

The issue of a barrel walking/moving/twisting due to heat causing a change in POI.
Is this real or as any metal tube that is heated does the effect of the rifling on the projectile just reduce/relax due to expansion therefore a change in the pressure/friction (bore increases in size)effect on the projectile (same as pressure change due to powder load and the effect it can have on accuracy.

Cheers
27-05-2018, 08:20 PM
Kiwi Greg

Quote:

Originally Posted by Fireflite

So what's your's for attaining the so called accuracy of your rifle?

MOA
. 3 Shots
. 5 Shots

Time
. between each round fired
. barrel temperature?
. dependent on Caliber?
. dependent on load pressure (high-low)
. dependent on barrel couture (taper/thickness/fluting)
. Blued or stainless (heat retention/dispersion)

The issue of a barrel walking/moving/twisting due to heat causing a change in POI.
Is this real or as any metal tube that is heated does the effect of the rifling on the projectile just reduce/relax due to expansion therefore a change in the pressure/friction (bore increases in size)effect on the projectile (same as pressure change due to powder load and the effect it can have on accuracy.

Cheers

3 Shots for a hunting rifle/gong rifle .5-.75 moa, obviously less is more

5 shots for a competition benchrest rifle after 2 or three "sighters" .0 to .1 moa less is really more in this case.

Shot as they would normally be shot ie for a hunting rifle, boom....bugger... boom...oh shit...boom....!!!!

No point waiting for them to cool or shooting off 15lbs of sand bags etc, shot as they would be in the field ie with bipod & rear bag/fist
27-05-2018, 08:25 PM
Ryan_Songhurst

All my rifles are hunting rifles so I shoot them how I would while hunting either off a pack or bipod, three shots, bang, bang, bang.
27-05-2018, 08:30 PM
Fireflite

Quote:

Originally Posted by Fireflite

So what's your's for attaining the so called accuracy of your rifle?

MOA
. 3 Shots
. 5 Shots

Time
. between each round fired
. barrel temperature?
. dependent on Caliber?
. dependent on load pressure (high-low)
. dependent on barrel couture (taper/thickness/fluting)
. Blued or stainless (heat retention/dispersion)

The issue of a barrel walking/moving/twisting due to heat causing a change in POI.
Is this real or as any metal tube that is heated does the effect of the rifling on the projectile just reduce/relax due to expansion therefore a change in the pressure/friction (bore increases in size)effect on the projectile (same as pressure change due to powder load and the effect it can have on accuracy.

Cheers

What about thought's on this?
27-05-2018, 08:47 PM
csmiffy

Overthinking it a little I reckon.
like they said 3-4 shots for a hunting rig which may well have a slimmer barrel than a target jobbie. A few of them now may only have a single stack mag for 3 shots so anymore is getting superfluous.
Target one 5 shots or more-
I would suggest that how you go about it and consistency of that would be more critical including/especially your reloading
What about your shooting technique, quality of barrel, trigger and stock/bedding?
Some calibres are harder on barrels so if you were doing long strings it may wreck the barrel
27-05-2018, 08:53 PM
Fireflite

Thanks @csmiffy

But thoughts on this?

. Blued or stainless (heat retention/dispersion)

The issue of a barrel walking/moving/twisting due to heat causing a change in POI.
Is this real or as any metal tube that is heated does the effect of the rifling on the projectile just reduce/relax due to expansion therefore a change in the pressure/friction (bore increases in size)effect on the projectile (same as pressure change due to powder load and the effect it can have on accuracy.

Anyone read any studies on such?
27-05-2018, 09:04 PM
jim160

A lot of this theory depends on how far your shooting.
As I shoot out to 300m, (if I'm really unlucky), an inch and a bit group will suffice for my shooting.

Yet the long range rigs have to be touching groups as it makes a difference out to 1000m+

I'm sure everyone would agree that it depends entirely on the purpose its built for.

Ive been questioned by someone as to why I was happy with a 40mm group at 100m when i said it was good enough for hunting. The person said I wouldn't be able to hit an animal with a group that size. And yet he was offended when i laughed and said that i hit the paper so i could hit a deer at 100m.

People get too tied up in group size when they don't have to.
27-05-2018, 09:41 PM
GWH

Quote:

Originally Posted by jim160

A lot of this theory depends on how far your shooting.
As I shoot out to 300m, (if I'm really unlucky), an inch and a bit group will suffice for my shooting.

Yet the long range rigs have to be touching groups as it makes a difference out to 1000m+

I'm sure everyone would agree that it depends entirely on the purpose its built for.

Ive been questioned by someone as to why I was happy with a 40mm group at 100m when i said it was good enough for hunting. The person said I wouldn't be able to hit an animal with a group that size. And yet he was offended when i laughed and said that i hit the paper so i could hit a deer at 100m.

People get too tied up in group size when they don't have to.

Yes absolutely, all depends on what you are shooting and at what distance. Deer to 400 yards is quite different to rabbits at the same range
27-05-2018, 10:08 PM
ZQLewis

Yep I'm happy with 2" x 3 shot groups from my lever actions at 100 meters. one has an old euro 2.5x post & rail the other a 1-4 with german #4. Both setup for short range shooting.
For deer 12" group is good enough and for goats 6" group will do it. In either case I think I would limit myself to 200 mtrs.
My bolt action on the other hand has a #3 coutour 24" barrel and will shoot sub 0.5 if I do my bit.

By the way all these reports you read in gun mags make it seam easy to do this time after time. For it's not been that way for me.
I used to be able to get 99.x at 22rd indoor shoot so have some idea what to do.
Z
27-05-2018, 10:24 PM
Walker

Stress in a barrel will cause it to move with heat, but this only occurs if a barrel hasn't been de-stressed after machining. A quick check is to hold the action and tap the barrel with a piece of steel, it should ring like a bell, a dull sound indicates stress in the material. Heat in the chamber causes higher pressures in the cartridge on firing and will produce 'stringing' as well as increasing erosion of the throat.