Nosler E-Tips, be careful.......

Had a rifle dropped off to me that I've previously loaded for with a 90 gn Barnes projectiles to a load just above the recommended book max. In this gun it was fine with reasonable velocities and no pressure signs. I'd run out of these so got some of the 90 grain Nosler E-Tips to try out.

In the packet there was a warning note to start off at starting loads and not to exceed mid loads.

In light of this and of hearing that the E Tips copper alloy was slightly harder than other lead free projectiles I did as recommended. I loaded up for a ladder test with one load each of 45, 46, 47, 48 and 49 gns of AR2213SC. I realise the last three are above mid loads but thought I'd take them with me to the range in case the factory warning was simply the manufacturer being fearful of being sued.

So first shot with the starting load from the ADI manual resulted in a pretty flat primer and slightly sticky bolt lift. Velocity was 3122fps! The ADI manual states their velocity through a 24 inch test gun as 3020fps for this load. This raised my eyebrows somewhat.

I decided I'd give the next one a whirl. This was 1gn above the book starting load. This gave a velocity of 3197fps!

This same rifle with the same batch of powder didn't achieve this with 48gns behind the same weight Barnes solid copper projectile. With 48gns it achieved 3150fps, the E-Tips got 50fps past this with just 46gns.

Here's the problem, it was not a safe load! The bolt took a herculean effort to open and when I managed to extract the case the primer pocket had opened up big time and the primer fell out during extraction.

You don't need to be too familiar with measuring casehead expansion to know you've got an issue there!

The photo below is of an unfired case beside the 46gn load. It measures .207" inside the primer pocket. The 46gm load expanded this out to .221". Thats .014" expansion at the strongest end of the case!

http://i898.photobucket.com/albums/a...ps4c4ad0a9.jpg

This next photo is the buggered case with a new primer in it. You can see the gap around it showing how much the numbers above look like in reality.

http://i898.photobucket.com/albums/a...ps37e8b591.jpg

It wasn't a hard decision to stop firing at that point. I went home, pulled the remaining loads and started again at 43gns with 43.5 and 44gn loads also. 43gns ended up being a decent load with the others still too warm.

So a word of warning if your intending to load with E-Tips. They're good projectiles but definitely start low and don't do what a lot of us experienced reloaders do and start above the book starting load because we're used to these being ultra conservative. With these projectiles they aren't.

Noted, and thanks.

Cheers for the heads up.

Do the noslers have any bands cut in like the Barnes ?

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Good info. Would need to watch the use of heat sensitive powder too if they cause spiking like that.

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Originally Posted by veitnamcam

Cheers for the heads up.

Do the noslers have any bands cut in like the Barnes ?

Sent from my GT-S5360T using Tapatalk 2

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No grooves, long bearing surface, hard projectile, gives more pressure & speed.

Combine that with soft brass, not starting low enough & ignoring initial pressure signs.....Nek Minit.....opps

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Originally Posted by Kiwi Greg

No grooves, long bearing surface, hard projectile, gives more pressure & speed.

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What I was thinking.

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Originally Posted by Kiwi Greg

hard projectile

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I would have thought the reverse? Hard bullet takes more pushing so more powder required.

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Originally Posted by Wirehunt

I would have thought the reverse? Hard bullet takes more pushing so more powder required.

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Na, lighter pill moves easyer so won't build as much pressure and needs more powder or faster powder.

So for same weights the harder to force into the rifleing and longer the bearing length the more pressure will build and less powder can be used.

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Originally Posted by Wirehunt

I would have thought the reverse? Hard bullet takes more pushing so more powder required.

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Solid copper is lighter than lead so more is required for a certain weight, bullet is longer, usually increasing the bearing surface, resulting in more friction.

So requires less powder and/or slower powder to keep pressures to an acceptable level.

The exception to this is a bore rider projectile like a Cutting Edge,

The bearing surface remains the same so they have completely different characteristics to "normal" projectiles.

Does a bore rider projectile sit on top of the lands? would the gas not get past?

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Originally Posted by Toby

Does a bore rider projectile sit on top of the lands? would the gas not get past?

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The projectile in front of the bearing surface sits on top of the lands.

The bearing surface seals the gas in :)

Google image helped make sense. It seems like a clever idea