7mm Rem Mag Powder Input Sought

[ozzy1038]

I recently got my hands on a Remy 700 &mm Rem Mag 26" with a shrewd brake. I ha sa twist of 1:9.25. I was looking to run 180VLD's through it but based upon Berger's ballistic calculator and doing side by side comparisons on their .284 projos from 168-180gr I have settled on the 168's as they are projected to give me want I want out to 1000yds. Plus, my twist is probably a little too slow for the 180's.

Anyway I have researched powders to no end and am whittling it down to a couple selections. First I am a big Hodgdon fan and I want a stable powder so that leads me to the extreme powders.
I am basically down to either H4831SC or H1000 and possibly Retumbo.

The ultimate goal is accuracy. A combination of accuracy and velocity would be ideal, especially since I intend to send it way down range.

So based on that, what are your thoughts on these powders from an accuracy standpoint. What have you had success with?

I am open to other brands but stability is key as once I find a load that works I very rarely change and dont want to have to based upon temp fluctuations.

 

[GreatGonzo]

Re: 7mm Rem Mag Powder Input Sought

H1000 is the way to go for the 7mag and heavy bullets. Certainly start there.

 

[RobG]

Re: 7mm Rem Mag Powder Input Sought

I use R22 for 180s myself with great results but, I recieved lots of H1000, R25, Retumbo recommendations while inquiring about 180 loads.

 

[Clark]

Re: 7mm Rem Mag Powder Input Sought

I shot 3 deer in 2010 with 7mmRemMag 70 gr Re22 180 gr VLD 3.48" jammed into the lands, 3025 fps average. That load has ~ 2 gr safety margin from the long/short brass life threshold.

 

[Smokin99]

Re: 7mm Rem Mag Powder Input Sought

H4831 and 168gr VLDs were my combo and very accuate at long range, with cci250

 

[Carpenter07]

Re: 7mm Rem Mag Powder Input Sought

My 7mm likes H1000, I tried Re22, retumbo and 4831sc. The 4831 was promising but couldn't get the velocities I was looking for in the 168g bullets.

 

[glock24]

Re: 7mm Rem Mag Powder Input Sought

R E T U M B O

The slower the burn rate, the better. Let that long barrel and slow burn work its magic on bullet velocity, and also achieve the best case fill densities.

I run Retumbo out of my 28" 7mmRM using 168 to 180 grains. A 1/9" twist will work fine for all.

 

[Skyking]

Re: 7mm Rem Mag Powder Input Sought

I load Retumbo and H1000, CCI-BR2 berger 168's. Retumbo gives me the best speed and accuracy.

 

[mscott]

Re: 7mm Rem Mag Powder Input Sought

I like Retumbo with the 175 SMKs.

 

[Johnny Lately]

Re: 7mm Rem Mag Powder Input Sought

I use IMR-4831 with good results. When my 300WM build is complete I'll be using R22 and might try R22 in my 7Mag

 

[mdesign]

Re: 7mm Rem Mag Powder Input Sought

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mscott</div><div class="ubbcode-body">I like Retumbo with the 175 SMKs. </div></div>

+1, this combo runs very well in mine. Better velocity and accuracy than H1000 or H4831sc. RL22 was not good at all for accuracy.

RL19 was the best for lighter (140gr) bullets.

 

[ozzy1038]

Re: 7mm Rem Mag Powder Input Sought

Thanks guys. I wound up buying some Retumbo and some 168gr Berger VLD's and plan to ladder test them in a couple days. I am considering trying the Hornady 162gr AMAX as it is has a slightly higher BC than Berger's 168 VLD.

 

[tacdrver]

Re: 7mm Rem Mag Powder Input Sought

reloader 25 for 175gr about 2900fps

 

[banks74]

Re: 7mm Rem Mag Powder Input Sought

My gun likes H1000. Accuracy's great but a velocity a little slow.

 

[LDA338UM]

Re: 7mm Rem Mag Powder Input Sought

H-1000 and 162 a-max shoots great for me.

 

[RobG]

Re: 7mm Rem Mag Powder Input Sought

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ozzy1038</div><div class="ubbcode-body">Thanks guys. I wound up buying some Retumbo and some 168gr Berger VLD's and plan to ladder test them in a couple days. I am considering trying the Hornady 162gr AMAX as it is has a slightly higher BC than Berger's 168 VLD. </div></div>

If you want to experiment, give the Sierra 180 smk a whirl. I went from using R22/amax to R22/smk and the accuracy difference is night and day. Plus the smk's are cheaper than the vld's, an added little bonus.

 

[Wylie Custom]

Re: 7mm Rem Mag Powder Input Sought

My 7mm Mag loves 4831sc but also likes H1000. I have great results with 168VLD and 4831sc.

 

[head2h2o]

Re: 7mm Rem Mag Powder Input Sought

I have had good luck with Retumbo in 2 7mmRM pushing 160gr Nosler Accubonds.

 

[threewood]

Re: 7mm Rem Mag Powder Input Sought

I am also a fan of Retumbo. 1:9 twist, 27" barrel, 69.8gr of Retumbo under 162gr AMAX bullets gets me 3000fps and 1/2 to 3/4 moa accuracy

 

[oregon]

Re: 7mm Rem Mag Powder Input Sought

Similar thread at:

http://www.snipershide.com/forum/ubbthreads.php?ubb=showflat&Number=2477014

It contains this info readers here might find useful:
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Skyking</div><div class="ubbcode-body">
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mark42quin</div><div class="ubbcode-body">Anyone try H1000 and 168 bergers yet?</div></div>

H1000 is a great powder. I ended up using Berger 168 vld's over 72g Retumbo, CCI-BR2, +3200fps, factory savage. Be careful that is a hot load. Primer pockets loosened up after three reloadings.

Just try one thing at a time.

Three shot group at 1009 yards.

</div></div>

 

[mdesign]

Re: 7mm Rem Mag Powder Input Sought

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: RobG</div><div class="ubbcode-body">If you want to experiment, give the Sierra 180 smk a whirl. I went from using R22/amax to R22/smk and the accuracy difference is night and day. Plus the smk's are cheaper than the vld's, an added little bonus. </div></div>

Had the same experience going to smk from amax. More available and more accurate.

 

[Wild_Bill]

Re: 7mm Rem Mag Powder Input Sought

Hi Light projectiles or a short barrel H1000 but heavy projectiles the only powder is retumbo. i have used a hell of a lot of it. also using retumbo in a factory and custom 7mm Rem SAUM with 190gr Matrix projectiles. believe it or not the 190's stabalise out of the factory 9.25 twist 22" rem barrel in the model7 just awsome performance 4gr less powder inthe model7 because of the massive OAL diference but both are amasingly accurate. the model 7 also works well with the 190's and H1000.

Try Retumbo first i am sure you will get the accuracy and performance you are looking for. Also the factory Rem Sendero's stabalise the 180gr Bergers and 175gr Matchkings well past 1200 yards with the factory barrel go heavy as they wind drift is everything.

 

[justme]

Re: 7mm Rem Mag Powder Input Sought

I have not owned a 7 mag in years. The one I had liked IMR 4350.

 

[ozzy1038]

Re: 7mm Rem Mag Powder Input Sought

Well I loaded up 49 rounds the other day. 11 of the m were ladder test loads seated at 3.445 which is .005 off the lands. They ranged from 66-71gr in .5gr increments. These were out of a 28" barrel

66gr ---- 2698fps
66.5 ---- 2771
67 ---- 2793
67.5 ---- 2844
68 ---- 2845
68.5 ---- 2893
69 ---- 2926
69.5 ---- 2953
70 ---- 2997
70.5 ---- 3020
71 ---- 3049

There was only very slight primer flow at the top end. At 71gr the load was not compressed. The sweet spot seemed to be around 3.445" COL and 3.450" COL and a charge around 69gr. More fine tuning is needed but I am satisfied so far. Best 5 shot group was .920". That's .420" beyond acceptable to me, but considering the conditions at the time I am satisfied. It seems a lot more capable, but only trigger time will tell.

 

[oregon]

Re: 7mm Rem Mag Powder Input Sought

Ozzy, great information. Please tell us more about your methods at the range. Noticed your ladder has velocities for every load. Do you shoot for accuracy at targets through your chronograph? Have been afraid of shooting my chronograph so only test muzzle velocity when burn a bullet through it wasting ammo. Are you using the 'be careful' 'line up good' and 'buy another if you destroy' technique shooting through it as it appears? Have been working up the guts to go there to get speed and accuracy with every shot at the range is why ask.

 

[ozzy1038]

Re: 7mm Rem Mag Powder Input Sought

I loaded 49 rds as mentioned and one was a dummy round that I used to measure distance to the lands. That partiicular case had a groove on the shoulder so I wouldn't have loaded it anyway as it was a good candidate for a failure.

My ultimate goal is always accuracy. If I can get accuracy and velocity then even better. In addition to the ladder loads I loaded 3 rounds at 3.435, 3.440, 3.445, and 3.450 all at 68gr. At the lands and just off produced the best results.

I also loaded the remaining rounds at 3.445 at 68gr for my plinkers from 100-600 yds. Unfortunately the table I was shooting off of was not all that stable and made it all the more difficult for the longer range shots. I will say the Berger ballistic chart I printed out was GTG as The come ups were pretty darn close. My first shot out to 600 was just 2.750" low dead center. The target could have been just beyond 600 as my rangefinder is not the best one in the world.

400yds was pretty much the same thing. Grouping could have been better but once again I attribute that to the table. Going back and forth from 100 to 600 to 400 proved to me that the tracking on my scope was good ( Bushnell Elite 4200 6-24x50 mil dot SF ).

I also am looking forward to trying out the Strelok app that I downloaded for my phone. The drops were consistent with what Berger told me, but the neat thing is that it is programmed for many different reticles and shows you your holdovers which I am anxious to try.

I always am very careful setting up my chrony and most times will pull the bolt to look down the bore to make sure have it set up right. I also make sure to put it far enough out. Back when I had my Barret 99 I got some powder burns on it from having it too close. Of course 210 grains of powder is a lot of powder to burn and that was a light charge.

I have yet to make it back out to shoot, but I plan on building a solid bench to use at my friends place rather than his card table. I will most likely head to the local 100yd range to dial it in at 100 with the fine tuning loads before I go down to his place to shoot at distance.

We could reach out to 1000yds at his place and I have been talking to him about building some gongs/swingerrs for down range as well as a dueling tree for longer range. Now that would be fun!

I did go get a VLD chamfer tool to help when seating the bullets as I had some shaving of the copper going on. I also had my insert in my seater die making a little ring around the bullet as it is not meant for the Secant Ogive that the VLD's have. I did pull the seater insert out of my .223 die and it matches the contour nicely and should not leave any ring on the bullet.

Just to let you know my process I am uniforming the primer pockets, deburring the flashholes, and now having fireformed everything I will only neck size. The only thing I have not delved into yet is neck turning. That as well as a meplat trimmer are in my future.


Have you figured the twist yet on your rifle Oregon?

 

[oregon]

Re: 7mm Rem Mag Powder Input Sought

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ozzy1038</div><div class="ubbcode-body">Have you figured the twist yet on your rifle Oregon?</div></div>
Ozzy that is awesome information. Thank you for sharing methods. Is what I was curious about. Hot tip about using a smaller .223 seater insert. Where I'm at is - based on your help decided didn't need to know twist and just went ahead with the Berger 168 Match Hunting VLDs. Whatever my gun is 1 in 9.25, 1 in 10, or ... my guess is they will work in a stock barreled older Remy ADL. Will let you know if ever figure my stock twist. The Remy site says new 7mmRMs are 1 in 9.25. Found where to buy Berger Hunting VDLs locally and got 100 to try. Also picked up some Retumbo and Federal primers. So working to catch up.

Read in other threads finding a sweet spot 2950-3050fps is optimum speed for 168g VLD accuracy.

Usually shoot on the weekends here.

 

[ozzy1038]

Re: 7mm Rem Mag Powder Input Sought

I loaded up 5 each at 3.450" (touching lands) from 68gr to 69.4gr in .2gr increments all neck sized no crimp. Plan to hit the range today. BTW the .223 insert worked perfect. No marks on the bullet as well as no shaving of the bullet due to using the VLD chamfer tool.