7mm Rem Mag Advice

[vodekzz]

Ok, this is what just happend. Last Sunday I went to the range and my 160 AB load with 66 gr of Rl-22 flies 2760 fps ? I shot about 6 times and the highest reading was 2789? As an example my 168 VLD with Retumbo 72 gr went 2950 fps. The temp was 15 F.
My rifle is Sako 85 with 24 inch barrel. It is new rifle with about 60 rounds through it.
I belive my 160AB should be in 2950 fps range? Brass Norma with GM215 primers.
What is wrong?
Thanks, Vodekz :shock:

 

[OU812]

Ok, this is what just happend. Last Sunday I went to the range and my 160 AB load with 66 gr of Rl-22 flies 2760 fps ? I shot about 6 times and the highest reading was 2789? As an example my 168 VLD with Retumbo 72 gr went 2950 fps. The temp was 15 F.
My rifle is Sako 85 with 24 inch barrel. It is new rifle with about 60 rounds through it.
I belive my 160AB should be in 2950 fps range? Brass Norma with GM250 primers.
What is wrong?
Thanks, Vodekz :shock:

Your right it should be around 2960, looking back at my 7mm, 160 AccuBond, RL-22 data. Did you shoot both the RL-22 and retumbo loads over the chrono on the same day? I would request a do over with that load. Don't take this wrong but is it possible the RL-22 loads were lighter than 66gr by some accident?

 

[AzDak42]

Fresh batteries in the chrono? I'd be more tempted to chalk that up to bad readings, rather than the load being that far off.

 

[3006]

Alliant claims their lot to lot powder consistency is within 10 percent????. What sort of pressure signs are you seeing? Might have to turn it up a bit if pressure is good to get the velocity you are looking for.

 

[SJB358]

Ok, this is what just happend. Last Sunday I went to the range and my 160 AB load with 66 gr of Rl-22 flies 2760 fps ? I shot about 6 times and the highest reading was 2789? As an example my 168 VLD with Retumbo 72 gr went 2950 fps. The temp was 15 F.
My rifle is Sako 85 with 24 inch barrel. It is new rifle with about 60 rounds through it.
I belive my 160AB should be in 2950 fps range? Brass Norma with GM250 primers.
What is wrong?
Thanks, Vodekz :shock:

Your right it should be around 2960, looking back at my 7mm, 160 AccuBond, RL-22 data. Did you shoot both the RL-22 and retumbo loads over the chrono on the same day? I would request a do over with that load. Don't take this wrong but is it possible the RL-22 loads were lighter than 66gr by some accident?

I am with Bill here. Ran a ton of 7mm Rem Mag and 66 grains of RL22 and never have gotten less than 2900, usually around 3000-3050.. Hope to see this one rundown. Good luck with it buddy.

 

[C.Smith]

My experience with that load is as Scott said easily over 2900 fps and have been creeping up to 3000 as I have been getting more and more rounds down the barrel.

Corey

 

[vodekzz]

All shots I did in about 75 min. The battery? no it was not new.????
The load 160 AB and 66 gr of RL-22 shot very consistent speed wise and very accurate, but not fast.
Retumbo was with 168 VLD and 72 gr it was 2950 fps average. No pressure signs at all. This set up could be great with new long range AB.
Well, new battery and next test with the same loads coming Saturday or Sunday.
I take written notes every time I reload or test my new loads. I will try again.
Thank you for your ideas,
Vodekz

 

[Oldtrader3]

Consistancy of 10% is 300 fps in a 7mm Mag!!!

 

[OU812]

All shots I did in about 75 min. The battery? no it was not new.????
The load 160 AB and 66 gr of RL-22 shot very consistent speed wise and very accurate, but not fast.
Retumbo was with 168 VLD and 72 gr it was 2950 fps average. No pressure signs at all. This set up could be great with new long range AB.
Well, new battery and next test with the same loads coming Saturday or Sunday.
I take written notes every time I reload or test my new loads. I will try again.
Thank you for your ideas,
Vodekz

What kind of chrono are you using? Did the sky conditions change, clouds move in or sun come out? Seems like you have things in order but I have never seen that load in a 7mm run that slow, possible first time for everything. Do keep us posted of your results.

Bill

 

[rofcrs]

The low temperature of 15 degrees catches my eye :?: . Suggest setting up the chronograph and test the system by firing 5 rounds of 22LR over the screens. I shoot the 22LR every time I set up the chronograph, a couple of boxes of 22's last a long time. Some powders/cartridges do better than others when the temp drops. The retumbo load is resonable. Suggest putting your test rounds in a cooler with a thermometer an maintain a constant warmer temperature. Shoot a couple of the Retumbo loads first to warm the barrel, put a couple Re-22 right behind them. Reloading has many variables, I have not found all of them yet. :mrgreen:

 

[vodekzz]

You guys are always help for me. Thank you.
I will work on it,. I want my 160 AB to fly 3000 fps. This is my goal.
168 gr with retumbo looks great than 160 AB whould work also.
If R22 with not get me there I will try another powder maybe N560?
Vodekz

 

[buckfever]

Maybe you should just use Retumbo with your 160 AB.

 

[AzDak42]

When in doubt, bore it out! I'm pretty sure that you can get 3000+ in a 7STW, even on a cold day!

 

[BeeTee]

I've found load data in the several manuals I have to be on the mild side in my Rem 700 7RM. To nearly achieve velocities published in the Nosler manual, for example, I need to go above the stated maximum charge by 2-3 grains of powder - and this is without any signs of overpressure. BT

 

[Bruce Mc]

If you don't want to worry about lot to lot variations and temperature variations, try H-1000. I found it excellent with the 160 AccuBond.

 

[300WSM]

I don't doubt your loading experience but could it be possible that you aren't getting a legit 66 grains in there?

Trust me when I tell you that it wouldn't be the first time a scale had been inaccurate.

I have an electric scale that I have to turn on and let it on a good 30 mins before loading otherwise I get some improper behavior from it.

Something just seems goofy here if the chrono checked out...and all other things being equal.

Another scale thing is...if you are using a digital are you calibrating it before each use?

 

[vodekzz]

BeeTee, I agree with you. I loaded my 160 AB with the same load but different lot # Rl-22. I will see this weekend. The next it is load it to "match my rifle pressure." Again my goal is to get 160 AB to 3000fps.
My 6.5x55 I shoot 48 gr of RL-22 or N560 49 gr, Norma MRP 48gr. These three loads are about 5% to 8% over manuals loads. My 270 win 150 gr shoots best with 58 gr Rl-22 when max load should be
54 gr?

Due to this post I want to make sure that everybody is responsible for their own loads and every rifle might shoot them with different pressure. Safety first.

Vodekz

 

[OU812]

BeeTee, I agree with you. I loaded my 160 AB with the same load but different Rl-22. Vodekz

I'm sure you did this but I'll ask any way. Did you check the lot numbers on the different RL22 to be sure it's not from the same lot?

This post got me thinking and I did some checking of my reloading notes and found something similar to what you saw velocity wise with an upper end charge. I had loaded a 220 grain bullet in my 8mm mag and used RL25 82.5 grains. The velocity was 2750 when it should have been in the lower to mid 2900's. The load shot 1/2 moa at 100 yards. Think I may very well retry the load with different lot# of RL25 and see if it hits the mid 2900's.


Bill

 

[Antelope_Sniper]

It's not unusual to loose 100 fps when dropping from 70 degrees down to freezing.
You can loose another 100 between freezing and zero.

Shoot that same load on a 100 degree day and you might be close to your 3k goal.

 

[vodekzz]

Antelope Sniper,
I kept two rounds in my pocket warm. The difference was 68FPS velocity between warm ( faster ) and cold slower.
But the difference is still almost 300 Fps. I will test them again this weekend.
Thanks for your input, Vodekz