IMR 7828 and Berger 168 VLDs

[Ruger338]

I have a 7mm Remington Magnum with a 24 inch barrrel. I am loading 65 grains of IMR 7828 in Federal cases with federal 210m primers.

I have chronographed this load and the numbers are as follows:

First shot with cold clean barrel was 2892. The next three were 2866, 2867, and 2869.

this load shoots half inch groups at 100 yards.

My first question is this, is it normal for the first shot to be higher in velocity than the rest?

My next question is this, should i try to raise the powder charge to gain more velocity or do i need to try a different powder(which are hard to come by right now), or should i be satisfied with that velocity out of a 24 inch barrel.

 

[longrangehunterII]

Yes it is.

The first shot through a cleaned bore has more friction on the baring surface of the bullet, as the powder burns it acts a lubricant, and the velocity will taper off to a more normal level.

As far as your load being toped out? Hodgdon data shows about the same velocity as your load (2882) but with a 162 gr. Hornady bullet and IMR-7828. Since you're using a slightly heavier bullet I'd say with that powder you're there if the accuracy is what you want.

 

[trophyhunter1000]

in running Remington brass with cci 250 primers with a 77 grain charge of IMR7828SSC under a 165 grain nosler partition in my 300 win mag. My results were ad follows 3090, 3035, 3040, 3030, 3030. I am running 3 grains under noslers listed hi spec for this round. I think you can go up probably a couple grains. Just my 2 cents

 

[longrangehunterII]

in running Remington brass with cci 250 primers with a 77 grain charge of IMR7828SSC under a 165 grain nosler partition in my 300 win mag. My results were ad follows 3090, 3035, 3040, 3030, 3030. I am running 3 grains under noslers listed hi spec for this round. I think you can go up probably a couple grains. Just my 2 cents

Are you using a 7mm Rem. Mag.? Because at last check a 160 AB or Part. in the newest Nosler website Version 7.0 shows a max charge of 64.0 gr. of IMR-7828 w/ a velocity of 3,015 fps. from a 24" barrel........

There is a difference between a 300 Win. Mag. and a 7mm Rem. Mag. which makes your load 20.3% over the max listed for a 7mm Rem. Mag. Now what if this guy didn't notice you were using a 300WM and loaded up to your load? He'd have his bolt in his face for sure and just might kill someone standing/sitting next to him!

You should make sure you are giving load data for the same cartridge in question, other wise a mistake could be made. Just my 2 cents.

 

[Ruger338]

Thank you for the info. I am very happy with the accuracy of my rifle. i understand what trophy hunter is saying he is just showing an example of what his rifle does with a clean barrel versus a fouled one. I am happy that i am only getting 3 fps ES with a fouled barrel. I am looking forward to shooting at long range and see how she does and how well i can shoot at distance.

 

[trophyhunter1000]

longrangehunterII I was just using my .300 win mag as an example like ruger338 stated. No harm ever intended. I will not post in a forum again using another caliber as a comparative reference. The last thing I want Is someone getting seriously injured due to my post. Was just posting my clean vs fouled data him to see my difference. Truly sorry.

 

[longrangehunterII]

TH1000, forgive me for coming across like a reloading Nazi but your load caught me off guard by just taking the raw data in my head even though I read your post top to bottom.

I thought how could a different load be that far off? Only to reread your post again and realize we're talking about a completely different cartridge! A mistaken identity.......
but I realized someone else could/might read that and interpret the information wrong?And make a hugh mistake by accident, which it would be two fold. No less a mistake like that would have dire consequences.

I am not someone to come down on someone else just because it's easy to type words over the internet. I only barked off to avoid a future mistake that could very well harm someone.

 

[Methow Packer]

Thank you for the info. I am very happy with the accuracy of my rifle. i understand what trophy hunter is saying he is just showing an example of what his rifle does with a clean barrel versus a fouled one. I am happy that i am only getting 3 fps ES with a fouled barrel. I am looking forward to shooting at long range and see how she does and how well i can shoot at distance.

Good low ES. The difference in FPS increase may not be worth it. Reloading is fun and there is only one way to find out. You know the drill. Look for pressure signs on the primer surface, such as bolt face marks and heavy cratering. Keep in mind the longer you seat your bullet out to the lands the greater change in pressure and performance you'll notice. Many times for the better. More velocity as well as accuracy can benefit.lightbulb