H4831 and 140 Grain Barnes

[laweidauer]

What is everyone's opinion on using H4831 with a low weight bullet like a Barnes 140grain ttsx in 7mm rem mag. I have a good load with 168 grain Bergers but I'm looking for something lighter for whitetail and with the powder availability situation I might have to use what I have available.

 

[Michael Courtney]

What is everyone's opinion on using H4831 with a low weight bullet like a Barnes 140grain ttsx in 7mm rem mag. I have a good load with 168 grain Bergers but I'm looking for something lighter for whitetail and with the powder availability situation I might have to use what I have available.

Should work fine. Many reloading manuals have loads with burn rates appropriate for that combo including H4350, H4831, H1000, and Retumbo.

 

[Shootin4fun]

I've used IMR4831 with the 140 TSX and gotten good accuracy. 62.9 gr, OAL as they specify. .5" groups @100, 3250+. (I thought that was kinda fast for a 140, but others here and elsewhere have posted similar velocities from 24" tubes using other bullets.) Good groups were thrown from 62.3, 62.6, 62.9.

However it turns out I somehow I may have used Hogdon data for the 140 N Partion, and those loads are several grains hotter than what Barnes has posted today. I could swear that the Barnes data had higher mins and max before this ("New" as they indicate) page. I'll note that I was approaching pressure signs. After the 4th reload, some cases caused very stiff bolt opens.

I am calling Barnes today to see if they lowered the weights for these loads. The page that is there now is right out of their printed manual, in color. Other pages not marked "New" look the same as before, black and white charts.

To anyone reading this, is 3250fps generally too hot for a 139/140gr pill from a 24" barrel in 7mm RM? I know its all based on individual chambers and pressures, but in general is that pushing the limit?

 

[Shootin4fun]

Spoke with Barnes tech support. Great company, great service. Yes, they lowered the weights for this round. Now showing 59.6 IMR 4831. Used to be 63.0.

I guess the bottom line is, pay more attention to pressure signs than numbers on the scale or chrono.

 

[Lefty7mmstw]

I've used IMR4831 with the 140 TSX and gotten good accuracy. 62.9 gr, OAL as they specify. .5" groups @100, 3250+. (I thought that was kinda fast for a 140, but others here and elsewhere have posted similar velocities from 24" tubes using other bullets.) Good groups were thrown from 62.3, 62.6, 62.9.

However it turns out I somehow I may have used Hogdon data for the 140 N Partion, and those loads are several grains hotter than what Barnes has posted today. I could swear that the Barnes data had higher mins and max before this ("New" as they indicate) page. I'll note that I was approaching pressure signs. After the 4th reload, some cases caused very stiff bolt opens.

I am calling Barnes today to see if they lowered the weights for these loads. The page that is there now is right out of their printed manual, in color. Other pages not marked "New" look the same as before, black and white charts.

To anyone reading this, is 3250fps generally too hot for a 139/140gr pill from a 24" barrel in 7mm RM? I know its all based on individual chambers and pressures, but in general is that pushing the limit?

The 7rem is usually capable of close to 3200 fps with a lead core 140; ymmv with mono bullets though and I wouldn't be surprised to be topping out around 3100 fps while staying at reasonable pressures.

 

[Shootin4fun]

The 7rem is usually capable of close to 3200 fps with a lead core 140; ymmv with mono bullets though and I wouldn't be surprised to be topping out around 3100 fps while staying at reasonable pressures.

Thanks Lefty. I think 3200 does not generate unreasonable pressure with these Barnes, but case life is shorter...expanded primer pockets after about 4 go 'rounds of 3250+ and some causing sticky bolt. Thing is, in my experience, Barnes are most accurate when pushed to near max. I will now try Barnes' new "max" which is 59.6gr IMR4831 (down from 63gr)...maybe I can find an accurate node down there somewhere. I'm not bent on the highest accurate velocity right now, just an accurate lower pressure node.