7MM Magnum 150 Accubond LR

[Rooster52]

Anyone have an accurate load for the 7MM Remington Mag and 150 grain Nosler Accubond Long Range ? I just can't get them to group as good as I think they should.Have tried RL22 and IMR4350.

 

[BR-549]

Sorry to say I had the same problem.... partitions too.
Someone will help I'm sure but I was disappointed to say the least.

I was trying 160's and just couldn't tune them in. I'm no expert though so don't give up on my account.

I may try again as I have several left.

I'm trying to get info on Barnes 150 TTSX. .... waiting on a call from a member as I type.

I will definitely keep an eye on this thread.
Good luck Rooster

 

[jryoung]

Anyone have an accurate load for the 7MM Remington Mag and 150 grain Nosler Accubond Long Range ? I just can't get them to group as good as I think they should.Have tried RL22 and IMR4350.

Have you measured bullet run-out after seating? Wondering if that long boat tail could be tweaking the seat?

 

[cowboy]

First of all - I have no personal experience with the LRAB. I did have an opportunity to personally visit with a host of an outdoor hunting show that has literally shot 1000's of these LRAB - but keep in mind that Nosler is now one of their sponsors - they were associated with Berger previously. This guy is a no BS been there and done that type personality and has has more shooting trophies than most people can imagine.

I mentioned to him that one of my sons was trying the LRAB and was just not getting the accuracy that he was accustomed to. The first response out of his mouth was - what was the twist of his barrel and how far off the lands was he seating the .284 - 150 gr.

He told me that they start testing a custom rifle at .070" off the lands and go deeper from there. Anything seated from touching to .050" off the lands was a waste of time, powder and bullets. He said these bullets are extremely accurate and have been personally proven with 100's of kills by himself, his family and his clients. He keeps very precise records and said these bullets act more like the Barnes X, TSX etc. than a Sierra or Berger where you start at the lands and go deeper by just a few 1000's from a reloading seating depth.

Take it for what it's worth but if I was to try some - I'd seat them at .070" off the lands and go deeper from there.

 

[Rooster52]

Never heard seating 70 thousands of the lands. I was experimenting at 10 -30.I will try this and see what it does.

 

[sbhooper]

I knew there was a reason why I did not buy any blems. I'll stay with my Interlocks and standard Partitons.

 

[cowboy]

Never heard seating 70 thousands of the lands. I was experimenting at 10 -30.I will try this and see what it does.

Get your hands on a Barnes reloading manual and read up on seating depth recommendations or go to the Berger website and read up on how to tune a VLD hunting bullet to zero in on a sweet spot. Berger recommends testing jump in .040" increments clean out to .130".

Whatever you guys do BEWARE that seating a bullet deeper with the same amount of powder will cause an increase in pressure which in turn causes an increase in velocity. My main hunting rifle shoots the Berger hunting VLD's best at .090" off the lands.

Always work your loads up gradually and remember the very same powder can have a significant difference from lot to lot.

I just finished reworking up a load for my son's 6.5 X .284 - he uses Retumbo. This new batch of powder showed pressure signs at 1/2 gr less than his previous batch of Retumbo which was well below max pressure signs. Bottom line is - it will take 2-1/2 grs less powder in this lot to equal the velocity of the powder he just ran out of - this is not a guess but chronograph results through a magnetospeed. Both lots were tested at same elevation and within a few degrees ambient temp - it's the burn rate of different lots of powder not the conditions.

Always work up gradually if you change anything in your reloading procedure or components.

 

[noharleyyet]

I knew there was a reason why I did not buy any blems. I'll stay with my Interlocks and standard Partitons.

..coming up with (IMO) above normal weight disparities with the 150 LRAB blems for the 7 mag recently purchased. Still tinkering with powders & jump....2nd test this weekend.

 

[jryoung]

Whatever you guys do BEWARE that seating a bullet deeper with the same amount of powder will cause an increase in pressure which in turn causes an increase in velocity.

If by "seating a bullet deeper" you mean into the lands (ie increasing OAL) then yes this is true. But if you mean deeper into the case, decreasing OAL then you are incorrect.

Bigger jump, less pressure, see Weatherby
No jump, higher pressure.

http://www.hornady.com/ballistics-resource/internal

To illustrate the effects of variations in bullet travel before the bullet enters the rifling, we'll compare a standard load with adjustments made only in the bullet's seating depth.

In a "normal" load with the bullet seated to allow about one 32nd of an inch gap (A) between the bullet and the initial contact with the rifling, pressure builds very smoothly and steadily even as the bullet takes the rifling. Pressure remains safe throughout the powder burning period (B), and the velocity obtained - 3500 fps - is "normal" for this load in this rifle.

Seating the bullet deeper to allow more travel before it takes the rifling, as in these next two illustrations, permits the bullet to get a good running start (C). Powder gases quickly have more room in which to expand without resistance, and their pressure thus never reaches the "normal" level. Nor does the velocity; with the same powder charge it only comes to 3400 fps (D).

When the bullet is seated to touch the rifling, as in the accompanying illustrations, it does not move when the pressure is low (E); and not having a good run at the rifling as did the other bullets, it takes greatly increased pressure to force it into the rifling. As the rapidly expanding gases now find less room than they should have at this time in their burning, the pressure rise under these conditions is both rapid and excessive (F). Velocity is high at 3650 fps - but at the expense of rather dangerous pressure. Many rifles deliver their best groups when bullets are seated just touching the rifling. Seating bullets thus can be done quite safely if the reloader will reduce his charge by a few grains. The lighter load will still produce the "normal" velocity without excessive pressure.

 

[cowboy]

If by "seating a bullet deeper" you mean into the lands (ie increasing OAL) then yes this is true. But if you mean deeper into the case, decreasing OAL then you are incorrect.

Bigger jump, less pressure, see Weatherby
No jump, higher pressure.

This is where info on the internet can get someone in trouble. If you haven't done it I would politely ask you to load 3 rounds of your ammo at .010" off the lands and 3 exact rounds at say .130" off the lands and run all 6 through your chronograph then PM me your honest results and we'll take this discussion further.

Bottom line is if you change something - work up carefully regardless what us keyboard commandoes say.