Autorotate19
Well-Known Member
Will do thanks for all the help. I'm not sure what I'm going to do yet, Im kinda the type that believes if it isn't broke then don't fix it and my gun is shooting good so Ill think about it. Thanks Guys.
Best Powder for 7mm Rem
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MSLRHunter
Well-Known Member
I would suggest trying the H1000 next. I load for both the 7mmRemmag and 300 winmag and have tried retumbo, H1000, RL22, etc. While retumbo usually had the higest velocity, H1000 was only about 50-75fps slower, but the H1000 was usually significantly more accurate.
Fitch
Well-Known Member
Out curiosity, have you tried N570? Accoding to QL that will give the highest MV of any commercially available powder. I'm asking because I see it in QL but I've not tried it yet. I do have some Retumbo to try. But haven't been able to beg, buy, or steal any 168g VLD's from anyplace. EABCO didn't actually have them, they were backoarded.
The other powder that is a few fpa faster, in QL, is Ramshot magnum (Big Boy). I haven't tried that either.
Finallly, would you be willing to let me know the H2O capacity, OAL, and barrel length on the 7 MAG you got those velocities with? I'm looking for ways to calibrate QL with Retumbo to the real world.
Thanks.
Fitch
I've not tried any of the Vihtavuori powders. I think they make top rate powder from what I've read but they're a bit pricey. And i have never owned or tried Ramshot Magnum.
1) Barrel length is 24 3/8"
2) COAL from case head to tip of the Berger 168 VLD was ~3.451". The length of the Berger VLDs can vary +/- 0.004", however the distance from the base of the bullet to the ogive is pretty darn consistent. More like +/- 0.001
3) I've never measured H20 capacity. What's the best technique? And do you want that capacity on a fired case? I could weigh a fired case with the spent primer intact and then weigh the same case filled with water to the top of the case mouth? Then convert the weight of the water to a volume? What unit of volume would you like?
Fitch
Well-Known Member
Yes. Weigh a fired case with spent primer, fill it level full of water, weigh it again, subtract the first weight from the second to get the weight of the water in grains. I just need the weight of the water in grains. QuickLOAD will do the conversion for me. If you want to be a trifle more accurate, pop the spent primer out, turn it upside down, put it back in, then do the weighing.
If you have a digital scale just zero the scale with the fired case on it, then fill it with water and the scale will read the grains of water in the case which is the number I'm looking for.
Thanks.
Fitch
Okay,
Believe it or not I couldn't find a fired case that hadn't already been neck sized in a Redding bushing style neck sizing die. This is the competition style bushing neck resizing die. It's not the Redding S style full length resizing neck bushing die. Only the neck is sized down with a neck bushing. I placed a spent primer in backwards and weighed 249.08 grains. I then filled the case with water level to the top of the case neck and then weighed 334.1 grains. This yields a water weight of 85.02 grains.
I measured the length of this case at 2.507". I had already measured my chamber length in this rifle at 2.550". That 0.043" of excess chamber length would also act to increase the effective case capacity. I don't know if QuickLoad can accept actual chamber lengths or not. But for purposes of clarification, I don't need to trim case length for cases in this chamber unless they exceed 2.550" in length.
Fired case neck ODs measure 0.315" in diameter. Resized case neck ODs measure 0.311" in diameter. So if this case had not been neck resized the water weight would have been ever so slightly greater.
This should be enough information to keep you dizzy & busy.
Any questions - let me know.
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Fitch
Well-Known Member
Okay,
Believe it or not I couldn't find a fired case that hadn't already been neck sized in a Redding bushing style neck sizing die. This is the competition style bushing neck resizing die. It's not the Redding S style full length resizing neck bushing die. Only the neck is sized down with a neck bushing. I placed a spent primer in backwards and weighed 249.08 grains. I then filled the case with water level to the top of the case neck and then weighed 334.1 grains. This yields a water weight of 85.02 grains.
I measured the length of this case at 2.507". I had already measured my chamber length in this rifle at 2.550". That 0.043" of excess chamber length would also act to increase the effective case capacity. I don't know if QuickLoad can accept actual chamber lengths or not. But for purposes of clarification, I don't need to trim case length for cases in this chamber unless they exceed 2.550" in length.
Fired case neck ODs measure 0.315" in diameter. Resized case neck ODs measure 0.311" in diameter. So if this case had not been neck resized the water weight would have been ever so slightly greater.
This should be enough information to keep you dizzy & busy.
Thank for the data. When I get back from feeding the horses I'll do some modeling in QL. I'll post the results here.
FYI: Fired brass out of the Ruger 77 MK-II measures like this:
Federal: 84.9wg
Remington: 85.1
Winchester: 85.8
I haven a new (arrived here yesterday) Savage BVSS in 7mag I haven't fired yet. I'm going to be interested to see how it measures.
Fitch
thorbird
Well-Known Member
I use h4831sc in my 7WSM. Has given outstanding accuracy with 175 grain bullets.
The 85.02 gr capacity was one of the cases I currently use, and used while chrono'ing the MV data. It's a Federal 338 Win Mag case necked down to 7mm and then outside neck turned for uniform neck thickness. I do this to end up with a slightly thicker case neck (gain about 0.001" thickness) in order to take up some of the slop in my factory chamber. 338 Win Mag casings are identical to 7mm Rem Mag casings in every way except for their different case neck calibers.
I also measured a fired Winchester 7mm RM case capacity at 85.4 grains. It was the only fired (and not neck resized) casing I could find. This is versus your Winchester case capacity of 85.8 gr wc.
I have two Tikka T3 7mm RMs. The casings I'm weighing were fired in the one with the slightly smaller diameter (tighter) chamber. I would measure slightly greater wc from a fired case in my other Tikka T3.
I also measured a fired Winchester 7mm RM case capacity at 85.4 grains. It was the only fired (and not neck resized) casing I could find. This is versus your Winchester case capacity of 85.8 gr wc.
I have two Tikka T3 7mm RMs. The casings I'm weighing were fired in the one with the slightly smaller diameter (tighter) chamber. I would measure slightly greater wc from a fired case in my other Tikka T3.
Fitch
Well-Known Member
Okay,
Believe it or not I couldn't find a fired case that hadn't already been neck sized in a Redding bushing style neck sizing die. This is the competition style bushing neck resizing die. It's not the Redding S style full length resizing neck bushing die. Only the neck is sized down with a neck bushing. I placed a spent primer in backwards and weighed 249.08 grains. I then filled the case with water level to the top of the case neck and then weighed 334.1 grains. This yields a water weight of 85.02 grains.
I measured the length of this case at 2.507". I had already measured my chamber length in this rifle at 2.550". That 0.043" of excess chamber length would also act to increase the effective case capacity. I don't know if QuickLoad can accept actual chamber lengths or not. But for purposes of clarification, I don't need to trim case length for cases in this chamber unless they exceed 2.550" in length.
Fired case neck ODs measure 0.315" in diameter. Resized case neck ODs measure 0.311" in diameter. So if this case had not been neck resized the water weight would have been ever so slightly greater.
This should be enough information to keep you dizzy & busy.
I put your data into QuickLoad. The model predicts velocities about 4.6% less than what you are measuring. The pressures all look just fine. I think it would be hard to put too much retumbo in a case. Your max load is just under 105% of capacity, i.e. ~5% compressed. This is all good to know. Gives me a calibration on Retumbo models for the 7MAG.
I just picked up a pound of RL25 to try in mine. I'll post when I have some data. It may be a while, I'm going to pillar glass bed the rifle before I take it out and shoot it.
Thanks Again
Fitch
retiredcpo
Well-Known Member
I just got back from the desert today.
I dont have QL or a chrono all we can do is find something that works and stick with it.
Before today The furthest I have shot this gun is 500 yards.
Im running 64.5 gr of 4831sc under 168 gr bergers.
I used the calculator on the best of the west web site to get a drop chart to 1000 yards put a steel plate(18x18) out at 700 today dialed it up and hit first shot minor addjustments and everything was good.
Ill stay with the 4831 nothing else shot well in this gun
retiredcpo
I dont have QL or a chrono all we can do is find something that works and stick with it.
Before today The furthest I have shot this gun is 500 yards.
Im running 64.5 gr of 4831sc under 168 gr bergers.
I used the calculator on the best of the west web site to get a drop chart to 1000 yards put a steel plate(18x18) out at 700 today dialed it up and hit first shot minor addjustments and everything was good.
Ill stay with the 4831 nothing else shot well in this gun
retiredcpo
Autorotate19
Well-Known Member
What velocity matched your drops?
retiredcpo
Well-Known Member
I finally came up with 2900 its probably not right but put me on a 11 in circle the first shot
