New 7mm Rem Mag Load Development

[Splatt]

Wow!

That's alot of work, with sorting, measuring and such.

Here is Remington 1x fired brass in a test barrel, FL resized, 66.0 gr's of rldr 22, and just changed seating depth with 160gr accubonds.

0.020 off on the left, 0.030 off on the right, 4 rounds.

Not just a one time group.

Was verifying clicks to 900 yards last week, and here's a 3 shot group at 100 yards.

[rcdinaz]

Great write up, well done!

 

I am with Splatt on the case sorting, I don't do it anymore. After watching Shawn Carlock's videos I figured if they can keep shooting critters dead out to 1k yds his directions were sufficient. So far so good!

 

I also rarely do meplat trimming or annealing anymore. There are good reasons to do them I just don't get to shoot enough to spend the time doing some of the very, very small things anymore.

 

Not being critical at all you always do it right down to the last detail.

[CraigK]

Heck of a right up! Thanks for going through all the detail.

[Allforelk]

Love your work gentlemen.

[lancetkenyon]

I figure weight sorting, like primer pocket uniforming and flash hole deburring, is a one time deal, and can't hurt. I don't know if I can shoot good enough to tell a difference, but eliminating some variables can't be a bad thing. And even if all of those minor itwms add up to a .05" difference, a one time step is a benefit in the long run.

I still haven't trimmed meplats yet.

[rcdinaz]

Trimmed bullets look pretty!

 

I used to do it and for Rem and Win brass it probably is not a bad idea their stuff can vary a lot. When I was doing a lot of work on the 6x284 and using Lapua brass a lot of steps were not necessary, even flash holes since theirs are machined. Recently I have only been using Nosler brass and when I checked the first box of stuff I bought it was very good, even the mouths come already chamfered. For my use it is worth every penny. If I was teaching someone as you are then doing doing every step is the right way.

 

Keep up the good work!

[MathewQuigly]

I have to work up a 7MM load for myself and wondered did you specify the components he purchased?

 

If not what would you have used?

 

Great write up by the way

[CouesPursuit]

I used this same process (only exception measuring COAL instead of CBTO) with different components in the last couple weeks and Lance, I can't thank you enough for making this post so easy to understand and follow. As a first timer, I developed a respectable load with < 50 rounds fired. I've found myself re-reading this thread many times.

[lancetkenyon]

I did not specify components. The owner of the rifle delivered what he wanted his final load to utilize.

 

While some of the components would not be my first choice, the overall results worked very well, and should put anything in AZ down with authority.

 

The brass was an excellent choice, and I use some of the Nosler brand brass myself for other cartridges.

 

Primers were a great choice, hard to beat Fed GM215M for a magnum primer.

 

Bullets fly great. Good weight for an all-around hunting bullet. Good construction as well. BC is decent. So should perform at reasonable hunting ranges. I have had better accuracy results from the Accubond than the Accubond LR in every flavor I have tried. My personal preference for bullets tend to lean towards a green, yellow, or orange box. But the results don't lie for accuracy in this load.

 

Powder is not my first choice, but works very well for this application. It is a viable choice however. Temp insensitivity is not as good as some, but much better than others. From all I have read by numerous experts and tests, I think IMR7828 varies about .5fps per 1° of temp swing from testing temps.

[firstcoueswas80]

IMR 7828ssc shined in my 257 wby with 110 Accubonds. But probably the best of all, is its typically easy to find.

[MathewQuigly]

Lance what would be your first choice for powder for this round?

[lancetkenyon]

I use H1000 for my 7RM w. 168/180/183 gr. bullets. Not the absolutely highest velocities, but great accuracy, clean burning, and temperature stable.

I ahve also worked up loads for a few other 7RM for other guys and RL22 seems to always work very well. Good speed, good accuracy w. 160 to 180 gr. bullets, but pretty temp sensitive. About 1fps per 1° of temp change. But get a good accuracy node worked up, and the velocity change doesn't mess with accuracy, and your ballistic program can compensate for the velocity changes.

[MathewQuigly]

im just looking for an accurate round capable of long distance if needed

[lancetkenyon]

What do you consider "capable of long range"?

Hunting elk and deer @ 500? 750? 1000? 1250?

7RM is very capable in the hands of a skilled shooter and with a proper bullet choice. Many cartridges are as well. Some more so, some less so.

[PRDATR]

I use H1000 for my 7RM w. 168/180/183 gr. bullets. Not the absolutely highest velocities, but great accuracy, clean burning, and temperature stable.

I ahve also worked up loads for a few other 7RM for other guys and RL22 seems to always work very well. Good speed, good accuracy w. 160 to 180 gr. bullets, but pretty temp sensitive. About 1fps per 1° of temp change. But get a good accuracy node worked up, and the velocity change doesn't mess with accuracy, and your ballistic program can compensate for the velocity changes.

 

I would work up loads with that powder and sight in when it was about 50 degrees. Gives me some wiggle room.