7mm rem mag and H4350

[AbeS]

For a long time now I’ve been wondering why a guy couldn’t get the same kind of accuracy from a 7mm rem mag as the 284 win and yes some good shooters have explained their opinions to me. But I couldn’t help think that if a 284 win sends a 175 win down range at 2700fps wouldn’t it be nice to have a rem mag with a 1:8 twist that’s able to stabilize the longer higher bc bullets shoot a 180 at 2900fps. It just seems nice for a high end hunting rifle loaded for top accuracy less than .5 moa at least. Well in my head that sounded great.

So just a few days ago I got my hands on a seekins precision in 7mm rem mag with a 26”barrel and 1:8 twist. I added a EC tuner break from Erik Cortina.
*Best brass I could find was Nosler premium brass
*Primers I have federal 215 match and cci 250
*Bullets I have Hornady Eld-M with a G1 Bc of .796 and a G7 of .401
But I have only two pounds of H1000 which will not last me long enough at all. I do however have a lot of h4350

My concern is case fill capacity because max charge for h4350 is listed at 56gr where as h1000 is listed at 69. I’m worried about inconsistent velocities and ignition with the lower case fill of h4350 and accuracy lacking because there of.

I know the seekins will shoot I am a big fan of the gun makers as my seekins in 6mm creed shoots .2-.35 moa consistently depending on my own performance. I do load Berger VLD in the 6mm and I have not been able to buy Berger for the rem mag yet

I was hoping someone here smarter than I am or with some experience with h4350 and the rem mag could shed some light on my current situation. Will it be a waste of time loading h4350 if I’m seeking less than .5 moa accuracy??

 

[RegionRat]

You can't push a rope....

The H4350 will hit pressure too soon and without giving you the speed you asked for. It is that simple.

Try some other appropriate powders and you will get the speed and performance your rig and ammo are capable of.
H1000, Retumbo, RE19, RE25, N560, N565, or something long those lines for the 7 mag with 180's. YMMV

 

[Mike Casselton]

You could easily trade some of the 4350 for an appropriate powder.
I'll also add in RE-22 and good old 4831, or even 7828.
All of them are great in the 7 mag

 

[redbullitt]

Primers are too expensive to pop 4350 in that cartridge. In the before times, sure why not toss weird powder choice plinkers lol, but these days i try to make em count.

 

[db2000]

7mm REM Mag

Weatherby Vanguard 22” barrel I believe

50 degrees F
160 Accubond
RL23 64 gr
2988 fps w/ Magnetospeed V3
No pressure
0.75” 3 shot group

 

[Cr1775]

I use IMR 4350 cant see why it won't work. My first choice is RE 22 but i haven't seen it in 2 years now? Only difference to me is that it pushes slower but the accuracy is right on. At least i get to have the rifle at the range!

 

[RegionRat]

I use IMR 4350 cant see why it won't work. My first choice is RE 22 but i haven't seen it in 2 years now? Only difference to me is that it pushes slower but the accuracy is right on. At least i get to have the rifle at the range!

Nobody is saying H4350 doesn't function in the OP's application, we are saying it won't get to the velocity range requested because it will show high pressure signs too soon to get there.
The other powders will get there and several of them have been available on occasion in the last two years, but like everything else one has to search hard and jump fast to get them.

 

[Cr1775]

Sorry i thought he was just worried about getting under half inch groups becouse to much mt space in case.
I honestly dont know if you can get it up to anywhere neer 2900 fps, but i do have a good load that matches my groups with RE 22 out to 600 yards.

 

[AbeS]

Sorry i thought he was just worried about getting under half inch groups becouse to much mt space in case.
I honestly dont know if you can get it up to anywhere neer 2900 fps, but i do have a good load that matches my groups with RE 22 out to 600 yards.

What is your load with imr4350? And what is your velocities?

 

[Cr1775]

Wont get home until Friday. Off the top of my head maybe 53 grains under a Sierra 168 with Remington large rifle magnum. Haven't put it past the radar because i know its slow but it shoots great.

 

[Cr1775]

When i get home I'll load it up and go to the range and clock it as long as it aint snowing.

 

[RegionRat]

These will give you a rough idea.
Try not to assume IMR 4350 and H4350 are identical, you can see below they are close but not identical.
The specific bullets are shown, but Hornady 10th doesn't show IMR or H4350 for the 175.

 

[nightman89]

I'll put in a plug for Ramshot Magnum. Just shot some under 180g ELD-Ms recently, and at around 68g I was hitting 2800fps. Going to bump the ladder to around 70g to see if I can hit 2900fps.

27" 7mm magnum x-caliber barrel.

Magnum is easy to find, and fairly inexpensive as well. One of my main reasons for using it.

 

[Mr Tibbs]

For a long time now I’ve been wondering why a guy couldn’t get the same kind of accuracy from a 7mm rem mag as the 284 win and yes some good shooters have explained their opinions to me. But I couldn’t help think that if a 284 win sends a 175 win down range at 2700fps wouldn’t it be nice to have a rem mag with a 1:8 twist that’s able to stabilize the longer higher bc bullets shoot a 180 at 2900fps. It just seems nice for a high end hunting rifle loaded for top accuracy less than .5 moa at least. Well in my head that sounded great.

So just a few days ago I got my hands on a seekins precision in 7mm rem mag with a 26”barrel and 1:8 twist. I added a EC tuner break from Erik Cortina.
*Best brass I could find was Nosler premium brass
*Primers I have federal 215 match and cci 250
*Bullets I have Hornady Eld-M with a G1 Bc of .796 and a G7 of .401
But I have only two pounds of H1000 which will not last me long enough at all. I do however have a lot of h4350

My concern is case fill capacity because max charge for h4350 is listed at 56gr where as h1000 is listed at 69. I’m worried about inconsistent velocities and ignition with the lower case fill of h4350 and accuracy lacking because there of.

I know the seekins will shoot I am a big fan of the gun makers as my seekins in 6mm creed shoots .2-.35 moa consistently depending on my own performance. I do load Berger VLD in the 6mm and I have not been able to buy Berger for the rem mag yet

I was hoping someone here smarter than I am or with some experience with h4350 and the rem mag could shed some light on my current situation. Will it be a waste of time loading h4350 if I’m seeking less than .5 moa accuracy??

The 180 Gr is on the heavy side for the 7RM, H-4350 is probably a too fast burning powder for that bullet weight. A more appropriate powder would be IMR-8133, Ramshot Magnum ,even Retumbo. With these slower burning powders make sure your neck tension is set properly, this will help with inconsistent velocity’s, CBTO will also aid a lot.

 

[Grim's Reapers]

I'm using 70.2gr H1000 in Winchester brass, CCI 250 primers out of a Douglas 26" barrel 1:8 twist running 180gr ELD-M. It's at 2920 fps no pressure signs. I'm still trying to figure out if it prefers them jumped or against the lands as I've not had time to really tweak that part. Right now it's .010 off the lands. I posted a thread on the Bolt Action section of this Forum seeing if anyone has had experience with the bullet jump in a similar setup.

Anyway, back to the thread... I wouldn't use 4350 personally, as I have a pretty good gut feel that powder burns too fast to get the muzzle velocity you're looking for before getting pressure signs. I suppose I could be wrong and there's only one way to find out. LOL

 

[supercorndogs]

2800 fps with 180 looks OK to me. ¹