Bearing surface of bullets?

[Sakoh]

Hi all,

Looking into some potential bullets for reloading and have been browsing other conversations on various shooting websites...

I see a few people touching on the subject of the "bearing surface" of bullets but not go into much detail.

Looking at different brands range of bullets though, it doesn't seem to be something that's ever included in the bullet specs?

Is it something worth considering/researching or not important?

[Norton]

Bearing surface is the amount of contact area between the sides of your bullet and the barrel of your rifle.

This will be determined by the shape/design of the bullet you're shooting.

I wouldn't worry about it specifically, just try a variety of well regarded bullets from different brands until you find the bullet that shoots best in your rifle.

[Blackened]

More bearing surface can increase accuracy... Also depends on what you're shooting, how far etc.

As an example, flat base bullets will have more bearing surface than equal weight boat tails because the tail curves inward away from the barrel reducing the bearing surface.

Due to this, the flat base bullet can often be the more accurate of the two when shooting up to 200 or 300 metres.

On the flip side of that coin, the boat tail will have a higher ballistic coefficient which would typically make it more accurate than the flat base over distances greater than 300 metres (or wherever the swing point is for the two particular bullets).

Ultimately this is all theory though, in practice your rifle may love or hate a particular load/bullet combination regardless of what should theoretically be best.

As Norton said, try a variety of bullet types and use what shoots best in your rifle.

[Lorgar]

I've found flat base Sierra's to be the best bullet by far in my Ruger Hawkeye. Whether or not that's due to the increase bearing surface I couldn't say for sure, but the results speak for themselves.

Here's a picture of some of my load testing...

sierra pro hunters

sierra-pro-hunters.jpg (31.47 KiB) Viewed 4274 times

Hornady 150gr SST's (boat tail) on the left, Sierra 150gr Pro-hunters (flat base) on the right, both at 100 metres.

Had similar or worse results with half a dozen other boat tails before trying the Pro-Hunters. Haven't bothered trying any others since they shoot so well. Haven't done any testing at longer ranges to share with you unfortunately.

Anyway, hopefully that's of some help to you.

[Lorgar]

...and that's in .308 Win.

[Vati]

Not bad Lorgar,

You have a Ruger Hawkeye if I recall correctly?

[Lorgar]

Not bad Lorgar,

You have a Ruger Hawkeye if I recall correctly?

Cheers,

You're correct. Hawkeye Standard in Walnut/Blued.

[Redwood]

Decent group, stringing out a bit quick there though?

Hot barrel, or shooter factors?

[Lorgar]

Decent group, stringing out a bit quick there though?

Hot barrel, or shooter factors?

More my fault than the rifles at that point I'd say.

I'd been at the range for a few hours testing a dozen different loads and was a bit over it by then, lol.

Those two loads/groups were the last pair of the day, and from memory I shot the Pro-Hunters very last thing.

By then I was just pumping out the rounds for the last few groups one after the other without giving it time to cool down at all.

I've loaded up a bunch more handloads using the Pro-Hunters with 0.1 gr increments on either side of that load for fine tuning.

Will get to the shooting range some time in the next couple of weeks and see what's best.

[Turkle]

By then I was just pumping out the rounds for the last few groups one after the other without giving it time to cool down at all.

I've loaded up a bunch more handloads using the Pro-Hunters with 0.1 gr increments on either side of that load for fine tuning.

Will get to the shooting range some time in the next couple of weeks and see what's best.

You should be in for some good results by the sounds of things if that last group was shot while hot.

I'm reasonably new to reloading so still working through my hand loads to fine what's best, but I'm getting about 50% more spread than that, and more random too. Nothing in a straight line like that.

Looks good to me