Thread: 270 Winchester ammo

Having a play today and weigh sorted some factory ammo from various Manufacturers

60x Browning 134 REMT 8.4 gn and only 17 rounds within a grain what rubbish for a $3 a round
80x Sako 130 gn 2.4 across whole 80 same batch take out 3 and 1.2 grain variance that’s why it shoots well.
200x Perfecta 130 grain very surprising had an big extreme spread of 10 grains but take 5 out at each end and 170-175 that were able to batched into 1 grain lots of 17-20 rounds.

Browning $60 a box
Sako $60 a box
Perfecta $30 a box

The perfecta is anemic at 2850 FPS but shoots really well and have grouped it into 1” at 250 yards.

so now you have rubbished the browning ...you will have to pull the rounds an weigh the components to discover WHERE the difference is...just the one at each end of scale will surfice.... brass,projectile or powder ..... be interesting to see.

Okay I’m up for it will post results

Greetings Ariki,
1 grain seems a very low tolerance for cartridges, especially if the batches are not all from the same manufacturing lots. The boxes should have a lot number on them somewhere. Manufacturers don't use canister grade powders but alter the charge to give the target velocity. Along with Micky above I would be interested to see where the variance is and also how the heavy and light culls shoot in one group. Could save a lot of busy work for no return.
Regards Grandpamac.

All were from same lots @grandpamac not trying to reinvent the wheel. Just trying to correlate accuracy to rifle I’m using.

Any way this is what Browning ended up

Heavy

Proj 135.3
Case195.2
Pow58.3
Tot 388.8

Light
Proj133.7
Case189.7
Powder56.9
379.3

If it has no statistical importance why is the cheap Fiocchi branded Performa and Sako ammo got a lot less deviation?
And secondly I have not accuracy tested the Browning ammo as of yet.

Originally Posted by ariki

All were from same lots @grandpamac not trying to reinvent the wheel. Just trying to correlate accuracy to rifle I’m using.

Any way this is what Browning ended up

Heavy

Proj 135.3
Case195.2
Pow58.3
Tot 388.8

Light
Proj133.7
Case189.7
Powder56.9
379.3

If it has no statistical importance why is the cheap Fiocchi branded Performa and Sako ammo got a lot less deviation?
And secondly I have not accuracy tested the Browning ammo as of yet.

Greetings Ariki,
Interesting reading. To me the variation of 1.4 grains of powder is more of a worry than the 5.5 grains difference in case weight. Brass has a relative density of about 8.8 so the difference in powder capacity is only about 0.6 grains or about 1% difference. This would give a difference in velocity of around 10 to 20 feet per second. The difference in powder charge however would give a difference of around 60 fps, perhaps a little more. These figures are based on data in the late Ken Waters Pet Loads series. My experience with the .270 W is that it is pretty forgiving on variations of velocity so if these differences have any effect on accuracy, especially at shorter ranges, is unknown. Only testing will show that. In handloading we can measure all manner of things and assume that we can interpret what difference these measurements can make. Actual testing often makes fools of us. Been there and done that more than once.
All the best with your shooting and regards Grandpamac.

interesting indeed....weird BOTH projectile and powder heavier on that one load....had the light projectile been with heavy case,you hardly have noticed it.... for me,sub 200yards ,wouldnt matter a hoot...at hundy yards I can put any load in and KNOW it will hit within 2" of POA.... thats a dead deer every day of the week.