7-08 powder tests

[m1aggie01]

With a little over 2 months to go for my TGR's arrival it's time to start loading development rounds. My plan is simple: load 3-5 rounds starting at the suggested load and increasing 1gr to max load. I'll use 140 gr bullets and look for which load gives the tightest grouping. Cleaning between strings with a fouling shot thereafter. Actual final bullet will br ABs in same weight. Now for powders.

RL-15 for sure. I'm considering IMR 4895 as well. Any others I'm missing and should consider for a max of three powders?

 

[CatskillCrawler]

I have used IMR-4064 and IMR-3031 with good success but settled with Varget. It works great in 3 different rifles using 120, 139, 140 and 150gr bullets.

 

[m1aggie01]

Thanks. I forgot I had a bunch of 4064. Varget sounds good as well.

 

[jimbires]

I've played about all summer with my one 7-08 . I get around 3075 FPS using a berger 140 with RL17 powder , it is pretty accurate too . my other 7-08 I use IMR4064 with a 139 SST or SPBT . I'm going to try RL17 in it after hunting season is over , just to see what happens. Jim

 

[YoteSmoker]

A half grain can show a big difference in accuracy that you might miss by stepping out 1 grain increments. A rule of thumb that works for me: Smaller the cartridge, smaller the increments. No matter the cartridge, I've had good luck starting at book half max and working up from there. The 7mm08 is one of my favorite and I've had good luck with 140 bullets using IMR 4350, Varget, and IMR 4064 in 5 different rifles and different bullets to include BT, AB, and TTSX.

 

[onesonek]

I agree, .5 gr. increments are better to start with, then possibly .1-.2gr. and seating depth once you get something promising. Personally, H4350 is my favorite in the 7-08 with medium bullet weights, unless you are planning running warm or hot. Then you may run out of case capacity. But if I need more than what it gives, then I switch calibers and or chamberings completely. As is, I feel the the 7-08 is mostly underrated if not highly under appreciated. It should serve you well !

 

[Bob in TX]

I switched to Big Game from R-15 in my '08 and have not looked back..........

 

[Murphdog]

I have had great luck with Reloader 19 in both my wife's Win 70 Compact and my Win 70 Featherwieght. I have used both 140 grain partitions and AccuBonds. Extremely effective on deer and coyotes. Both my wife and I have Cow elk B tags in North Central Montana this fall and I am planning to use the 7-08 with the AccuBonds. No griz to worry about were we are hunting and because we will be hunting deer, elk, and antelope all at the same time the 7-08 is a good choice.

 

[m1aggie01]

All good info and keep it coming.

My reasoning for using the RL-15 is that the claim is that it isn't effected by temperature fluctuations. So in my part of Texas I can work up a load in 90-110 degree temps and not have an issue during out 1 cold snap each year.

Do any of the other powders that are mentioned such as Big Game and Varget impervious to temp fluctations?

 

[YoteSmoker]

Varget and H4350 are "extreme" powders that perform well in a large range of temperatures. I don't know about the others. Hodgdon powders that have "extreme" on the label are temp insensitive though.

 

[jimbires]

so far I'd say RL17 is fairly temp stable .I've shot in the 40's up into the 90's . I haven't had the opportunity to shoot in the cold yet , but the mid 90* summer heat did not give me over pressure problems with a max+ load . Jim

 

[jmad_81]

Another vote for big game. Worked in my wifes 7-08 with 120 bt and 140 AB.


The rl-17 sounds worth a try as well.

 

[longrangehunter]

I had great success with R-15 behind a 140 BT and the 140 GK in my 7-08 and H414 w/ the 160 AB.

 

[vanguard]

the way i find a load is to try several powders about 2 gr under max, pick the best powder group then play with charge and or col.
every powder will produce a good group at certain velocity, it might be way low though and im not after that, i want somthing near or at max