Nosler E-tip v Barnes TTSX and accuracy loss when adjusting COAL to fit internal mags

[bdubb78]

To start, I am really looking forward to participating in these forums as a new member!

I have a bit of a combo question for everyone, so here goes:

1. I have read volumes about how great the penetration and devastation of a Barnes TTSX bullet is, but does anyone share that opinion of the Nosler E-tips?

2. Does anyone know why Nosler recommends seating the E-tips to 2.750" in a .308 rather than at the SAAMI depth of 2.800" as most other recommendations go?

3. Along with #2, wouldn't/shouldn't you expect a drop off in accuracy from the lower seating depth as you are now even further from the lands?

4. Along with #3, I have long lamented the loss in accuracy I see by seating to 2.8" to accomodate the internal magazine of my rifle when I have a chamber that accomodates, and loves, a much longer bullet. My Sierra Matchking BTHP's are very long when I single feed and are the most accurate round I have ever loaded, yet dropping them to 2.8" to work with the magazine more or less doubles my MOA figures--same thing with hunting bullets. Anyone found one of the "superior" hunting bullets with a curvature/profile such that the COAL can be at 2.8", but with the ogive much more forward in the round? Although not a hunting round, and admittedly a weird choice bullet, I stumbled on this magical combination with the Match grade Prvi Partizan rounds when I happened to buy a box for next to nothing at Cabelas. They are 2.8" COAL yet if you measure the OAL to the ogive they are much longer than many bullets and happen to be almost a perfect match with my chamber. They are exceedingly accurate in my rifle for lower quality ammo.

Looking forward to any insight that can be given for any or all of these questions. Thanks!

[std7mag]

bdubb,
First off welcome to the forum!
Ok, now to the issue at hand.
Monolith bullets (Barnes, ETip, GMX, Cutting Edge) due to their construction like to have a running start to the lands, to help imprint the rifling in the solid bullet.
I know Barnes recommends 0.050" off the lands. Appearantly so does Nosler.
A light crimp also helps to keep the bullet in the neck so the primer going off doesn't start the bullet traveling. Think of the bang, before the kaboom. It could give you some nasty pressure spikes.

Hopes this helps at least some.
Stay safe!

Std7mag

[Dufus]

Regarding bullet jump: you are under the misconception that seating the bullet for a small jump to the lands increases accuracy. Fact is, it does not unless you are using a barrel designed for bench rest shooting. The TTSX and other monolithic bullets usually shoot best with more than 0.050 jump.

My most accurate hunting rifle shoots a Cutting Edge bullet into 3/8" consistently with 10 shot groups. The bullet jump is 0.204".

[Unclenick]

OK, some terminology to start. COAL and OAL are the same things: Cartridge overall length, with "cartridge", truncated in the second instance. COL and OL also mean the same thing, but with the A dropped, consistent with the drop of the hyphen from over-all that occurred in the 1950's. The hyphenated form comes from before then, when the convention was to hyphenate over-all when it meant physical length to distinguish it from Chaucer's overall that meant all things considered. Many still include the A, though it is technically obsolete usage.

I infer you were using OAL to refer to bullet length, which I suppose could be BOAL or BOL in modern usage, but thus far that term has not presented itself that I have noticed.

First, backing off from the throat does not always mean reduced accuracy (see here, and item 3. under Load Development, here). Being close to the lands usually helps a bullet that is canted in the case to straighten, and that can cut groups by half to one moa or so, depending on the bullet and gun. However, if you equip yourself to seat your bullets straight and minimize loaded cartridge runout, then that help becomes redundant and the world of different seating depths opens up to you.

Getting close to the throat also increases pressure when you get very close to, or touching the lands, and that shortens barrel time, reducing the timing of the bullet exit. So, one school of thought is that the reason adjusting the seating depth can tune a load is that it tweaks the barrel time.

In your shoes, I would look into loading procedures to minimize runout. We have many posts on the forum on this topic.

Bullet makers frequently recommend shorter COL's. The military maximum 7.62×51 COL is 2.800" and the SAAMI maximum 308 Winchester COL is 2.810". A shorter recommendation is most often because that was the COL that was tested in their loads. They may have chosen it to increase the neck's grip on the bullet, especially if the bearing surface of the bullet (the cylindrical widest part) is short, or because the shape of the ogive and tip may be blunter than the military style FMJ bullets those lengths were originally meant to work with, so that using the FMJ COL will get you too close to the lands for their measured pressures to remain accurate enough.

[old roper]

bdubb78, Welcome

This is from Barnes on seating depth.

http://www.barnesbullets.com/faq/

I've taken cow elk using 30-06/150gr E-Tip, both one shot kills. I've also used the Barnes on buck tags here in Co and I used 140gr TSX in 270.

If you read Barnes sheet they mention between .030" to .070" and start .050" and I would do that.

Nosler has a forum so you can ask over there on seating depth if you want to confirm anything. https://forum.nosler.com/. You can start at .050" off but you'll seat deeper.

[bdubb78]

Thank you all so much. I am working out an ELD-X load here right now, but I will take all of this to heart for not only this round, but the aforementioned Barnes loads when I order a set of those as well. No to just decide between TSX, TTSX, and LRX. Most likely just TSX, as that helps with the COAL and is probably more than fine for my usual hunting ranges of under 400 yards.

[jmr40]

Barnes is the most commonly used, and the only one I have personal experience with. But by all accounts the Nosler and Hornady solid copper bullets perform very much the same. All of them seem to shoot a little better when seated deeper than you would with conventional bullets. But that isn't always the case. You'll just have to experiment.

A few factors about copper bullets that some people misunderstand.

Load data is much different. You can't just use the same loads you find for the same bullet weights with conventional bullets.

Drop down at least 1 bullet weight lighter than you'd normally use for the game you plan to hunt, maybe 2. This is for 2 reasons. Copper is lighter than lead and in the same bullet weight the copper bullets are much longer. Also, copper is much harder and needs faster impact speeds in order to expand.

I'll use 308 for example. A 130 gr copper bullet is about the same length as a 180 gr conventional bullet and will give about the same penetration in game. I shoot 130's in my 308 @ 3050 fps at the muzzle. At "normal" ranges that bullet will take anything I'd shoot with a 300 WM with 180's. I wouldn't recommend anything heavier than 150's in a 308. The 150's are about perfect in 30-06. The 165's can be used in 308 or 30-06, but are best used in one of the 300 magnums. I'd certainly never use a 180 solid copper bullet in anything other than a magnum.

Since they need fast impact speeds in order to expand the copper bullets are not the best option for long range shooting. Where a conventional bullet will still expand down to about 1800 fps, copper needs at least 2000 fps at impact and 2200 fps is even better.

I'm finding the ELD-X bullets to shoot better in my rifles. They are a LOT less expensive and seem to perform as well as most anything else on game. They are certainly better long range bullet. Both are good,

I think the copper bullets are a great choice if you're using a rifle traditionally viewed as borderline for the game hunted. If I had a 243 and wanted to elk hunt I'd use them. But if I were hunting elk with something bigger a conventional bullet would be at least as good, maybe better.

[std7mag]

Bdubb,

I've noticed IN MY RIFLES that the ELDX seems to like about 0.020" off the lands. Seems to work pretty well with a lot of lead core bullets. The exception being Berger VLD.