7 RM powders

[Guest]

Just starting load development for 7 RM. First try is using 63 gr of RL 19. Case is not full. How important is it to have the case full? I plan to work up from here so the case will be fuller as I add more powder but just curious.

Concern # 2: Target is set at 94 feet. Bullet is hitting 4 inches to the left. Vertical alignment is perfect. According to my calculations I need to go 51 clicks to the right. That is a lot. I haven't moved it yet. What impact will this have on keeping the cross hairs centered in the scope? Thanks for your input.

Rifle is a Rem Sendero and scope is a Leupy VXL 4.5 x 14 x 56.

 

[JD338]

RL 22 is a excellent powder for the 7mm Rem Mag. The fuller the case, the more consistent powder ignition you will have as the powder will be in the same location within the case. You will be fine so don't sweat it.

If you have windage screws on the rear base, I would start there first and use scope adjustments to fine tune it.

JD338

 

[DrMike]

You could do a whole lot worse than RL22. It is a great all around powder for that cartridge. Over seventy percent of my "pet loads" are built with RL22.

 

[1Shot]

H-4831 & AA-3100 are also very good 7mm Rem mag powders.
Don't worry about how many clicks you have to move the scope at that short of a distance. If you have Leupold mounts and rings you can back off in the right back screw a touch and tighten the left back screw that holds the rings on the base. This is why these type of mount and ring set up is called windage adjustable mounts.
The best way to sight in a rifle is to use a one inch grid marked target. Set the rifle in a solid bench rest with a target at 25 yards. Remove the bolt and look through the bore and place the center of the target in the center of the bore as you look through it. Then holding the rifle still adjust your scope cross hairs until they are centered on the center of the target. Then shoot one shot. If the bullet does not strike where you were aiming place the cross hairs back to your point of aim and holding the rifle still adjust the cross hairs from the point where you were aiming and move then to the center of the bullet hole. This will get you real close when you move your target out to 100 yards to where you should finish your zero work. If you can shoot and your rifle and load is capable of shooting to the same point of impact you can shoot one shot on the one inch grid target and then do the math of how many clicks you will need to move your cross hairs to where you want the gun to shoot. I can usually sight in a rifle with three shots. If you will sight in that 7mm Rem mag 3 inches high at 100 yards you bullet will not rise or fall over 4 inches from muzzle to around 350 yards. If you are hunting deer size game just aim in the center of the front shoulder and squeeze the trigger and you will hit the deer in the vitals for a killing shot out to around 350 yards and not have to worry about if you are going to shoot over or under it.

To answer to your question on "What impact will this have on keeping the cross hairs centered int eh scope? The cross hairs are self-centered. They will always appear centered. You might run out of adjustment but they will still be in the center. Like I said, use the back screws on the Leupold mounts to center your point of impact as close as you can then use the scope adjustments.

 

[Guest]

I'll differ a little in opinion in terms of the crosshairs being centered all the time. They will 'appear' centered, but they will be at or near the end of the range and you will potentially have issues with edge distortion as well as proper adjustment (because the tube is round, not square, so at the edge of the range, many scopes adjust somewhat diagonally).

The best choice is to figure out why the scope is so far off. If you're using front dovetail mounts (the original Redfield design, most people know as Leupold nowadays) you can readjust the rings to correct most of this problem, as JD said. If you're using Weaver rings, try removing the entire setup and reinstalling it, paying careful attention to keeping things lined up. Use a 1" oak dowel to align the rings when you mount them, and it is much easier to get everything lined up properly. If you're stuck with misaligned holes in the receiver and are using Weaver-style bases, you can get a set of Burris Signature rings and the offset inserts, and fix the problem that way. In reality, it's probably about the same cost to do that as it would be to order a set of rotary dovetail rings and bases and use the windage feature on them. Six of one, half a dozen of the other.

As for RL22 and the case not being full, JD is right on that, again. Case fullness has a bearing on consistency, but there are great loads that aren't 100% full. I've used H1000, Accurate MagPro, H4831, and IMR7828 to good effect in the 7mmRemMag, as well.

 

[quentin9595]

IMR 7828 is a good powder for the 7mm rem mag. with like the 162s i use H retumbo it gets the 162s out at 3071 fps at 15 ft over a chronograph out of a 24 in barrel and 73 grains of powder.

 

[buckfever]

Another vote for Retumbo and RL 22 are my two favorites.

 

[Divernhunter]

You did not say which bullet you use. I shoot 140gr PAR or BT in my 7RM. My best load is with RL19 with RL22 a close second. and the case is full.

 

[YoteSmoker]

My M70 really likes 63.5 grains IMR4350 with 140 BT/AB and 62.5 grains RL-22 with 160 AB and 63.0 grains RL-22 with 160 Partitions.

140's run just over 3100 FPS and 160's run right at 2900 with 26" 9 twist.

 

[DrMike]

I like heavy for calibre bullets, and consequently, I shoot a lot of 175 grain Partitions in my 7mm RM. A charge of 61.5 grains of RL22 with F215 primers gives good velocity and sub-MOA groups.

+1 to dubyam on the scope adjustment. That is a fair crank if you are starting from centre.

 

[Guest]

I am using 140 NBT bullets. The scope mounts are Leupy PRW so I don't have any adjustment in the bases. Thanks for all your input. Al

 

[remingtonman_25_06]

If your using 140g bullets, most definately give RL-22 a hard look. As a matter of fact, 90% of my loads that shoot 3/4" or under with 8 different bullets from 140-180g are with RL-22. Definately buy a pound to at least try out, it will still work great on up to the 175-180's. Not much good for under 140g bullets, but I have no intentions of shooting anything less then a 140g through a 7mm hole.

Thats what I use for my pet load in my rem 700 7 RM. 140g nbt, 68.5g RL-22, Rem case, fed 215, OAL 3.350", 3250fps, 1/4-1/2 MOA out to 400 yards from a bench. Scary accurate and consistent for a factory tube.

 

[quentin9595]

I am using 140 NBT bullets. The scope mounts are Leupy PRW so I don't have any adjustment in the bases. Thanks for all your input. Al

i am using the 140 nbt with IMR 7828 70.3gr going 3131fps at muzzle over a chonograph. i am getting .348 inch groups at 100 yds and 2 inch groups at 800 yds

 

[JD338]

I am using 140 NBT bullets. The scope mounts are Leupy PRW so I don't have any adjustment in the bases. Thanks for all your input. Al

i am using the 140 nbt with IMR 7828 70.3gr going 3131fps at muzzle over a chonograph. i am getting .348 inch groups at 100 yds and 2 inch groups at 800 yds

Nice shooting load quentin9595.

JD338

 

[quentin9595]

I am using 140 NBT bullets. The scope mounts are Leupy PRW so I don't have any adjustment in the bases. Thanks for all your input. Al

i am using the 140 nbt with IMR 7828 70.3gr going 3131fps at muzzle over a chonograph. i am getting .348 inch groups at 100 yds and 2 inch groups at 800 yds

Nice shooting load quentin9595.

JD338

thanx JD338

 

[Guest]

I really appreciate all the responses. Some of you have gone in great detail to explain your views and those explanations are great. I will try RL22 and IMR 7828 powders. It will take me a few weeks to complete the process. My available shooting ranges are a long ways from my house. I can't just run out after supper and run a few round through the guns. I will post my results when I finish.

 

[DrMike]

Sounds good, 260fan. Some of the powders available today work very well indeed in the large magnum cases such as the 7mm RM. The two mentioned (RL22 and IMR7828) work very well indeed in that cartridge. I don't think you'll be disappointed. It is a great cartridge, and one could do worse if restricted to one rifle.