Barnes TTSX 7mm Rem

Doc Holliday

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It seems like the max loads in the Barnes reloading manual are very weak compared not only to similar grain bullet data for other manufacturers (Nosler), but also compared to what the powder companies have on their websites. Is this because the grooves in the barnes ttsx creates higher pressure than solids?

I know it depends on the firearm and COAL/how deep bullet is seated, but what are you seeing for max loads on a 7mm rem mag? Care to share your recipe and velocity?
 

ZAK13

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No, actually I’ve found that you get a little more speed with Barnes for the same powder load. The grooves are to relieve pressure, not create it.
 

NorCalBowHuntr916

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To answer your first question, I think its because the barnes mono bullets are longer than than a similar weight bonded lead core bullet (nosler)
So case capacity is less.
 
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Doc Holliday

Doc Holliday

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To answer your first question, I think its because the barnes mono bullets are longer than than a similar weight bonded lead core bullet (nosler)
So case capacity is less.
That would make sense if it were true, but the load density and COAL data does not support that:

Barnes max load: 60 grains of IMR 4831 - 2963 fps, 87% load density 3.240 COAL

Nosler max load: 65 grains of IMR 4831 - 3240 fps, 89% load density (difference of 2%) 3.290 COAL (difference of .050)

These differences in load density and COAL are negligible, but 5 grains is a big difference, and so is the resulting velocity.


Barnes.jpg Nosler.jpg
 
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NorCalBowHuntr916

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5 grains is a huge difference...
I dont have experience with the 150's but I did work up a load with the lrx 168's and I ended up at 66.8 gr of h1000 which is 3 grains over and 150fps faster than the barnes published max load. I'm thinking barnes max loads are pretty wimpy.
 

35WhelenAI

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Poll:

Who is getting 3240 fps out of their 24" gun with 65 gr of IMR4831 and a 150 Nosler Accubond or Partiton? Historically Nosler velocities are higher than any other source.

Again, who is getting the Nosler published velocity of 3240 fps with one of the 150 gr Nosler bullets using a 65.0 gr powder charge of IMR4831 and 24" barrel length? Doesn't count if the charge weight is higher. Let's stick with published data.

When you run more than published charge weight, and get more than published velocity, it's not a close held secret the load has higher pressure all else equal. To each his own but it's folly to think the rules of pressure don't apply.

Hodgdon shows 65.0 as max for IMR4831 and the 150 TTSX, at 3075 fps. They are using the 150 TTSX, the same 65.0 gr charge weight as Nosler shows for their bullets, but getting 165 fps less.

Hodgdon also shows a max of 62.5 gr IMR4831 with the 150 gr Partition for 2925 fps vs 3240 fps from Nosler data for the same bullet using 65.0 gr IMR4831. 315 fps difference from 2.5 gr variance in charge weight with the same bullet.

The reason for load data difference between manufacturers could be any single one or any number of these... Different bullets, different cases, different lots of powder, slightly different OAL, different chambers, different barrels even if they are the same length, different primers, probably some other things called "variables" I didn't think of.
 

A382DWDZQ

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I'd say the Barnes data is conservative and Nosler is less so. Hodgdon 2022 shows Nosler Partition 150 at 58-62.5 and Barnes TTSX 150 at 60.4-65.0. Preasures respectively of 51,500 PSI - 59,400 PSI and 49,600 PSI - 59,600 PSI. Lee 2nd Ed. is in agreement for the Barnes X Bullet, 60.4-65.0.
 

35WhelenAI

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Lee does not make their own data. They harvest it from other manuals and condense it in one place. It probably goes without saying, what they are showing is the Hodgdon data.
 

A382DWDZQ

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Lee does not make their own data. They harvest it from other manuals and condense it in one place. It probably goes without saying, what they are showing is the Hodgdon data.
Ah, interesting. Thanks! I was typing my post up as you were posting yours. :)
 
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