Shortmag Velocity Numbers
- Thread starter ryanb
- Start date
- Location
- Daysland AB
Have not tried retumbo or magpro yet, but i am getting 1/2" groups with both Imr7828ssc, rl22 and 140 accubonds at near max loads in my 270wsm
- Location
- South Cariboo, B.C.
Gatehouse said:
I dont know about that.
I've had lots of rifles pass through my hands that have had their most accurate loads for practice at lower velocities. My Ol'man's 270 and one of my 243 's were a good example. I also had some great accurate loads for other rifles that were 200 fps lower than what would be considered max.
I've read up a lot on the 6.5mm shooters and with the 6.5 06 (and the AI version) guys are holding the reins on the velocity for target because the harmonics seem to create that great accuracy at longer ranges.
I flip through many of my reloading manuals and a lot of the *most accurate loads* are at lower velocities, starting loads if you will.
It all depends on too many factors to list. You know the cliche, every rifle is different.
- Location
- South Cariboo, B.C.
That's not what Gatehouse said.
What you've said BIGRED does apply to my 270WSM though.
What you've said BIGRED does apply to my 270WSM though.
I have often found this:
In new rifles (lets say 10 years old or less) that are built to tight tolerances, I find that you get good accuracy at the low end of velocity, then as you increase veocity, you may lose some accuracy, until you get up closer to max charges, and the groups shrink back up. At a certain point, the groups start to open up again.
I've heard this described by a few people and it seems the theory is that low pressure loads won't flex things too much. As you increase pressure you are magnifying the rilfes flexing/distorting and any other imperfections that you may have, including the ammo you just made. But you haven't got to it's *sweet spot* yet. Eventually you get there...
But as with many things, it often comes down to the individual rifle, the loader, and the shooter. Somehting overlooked is that the high end loads recoil alot, too. Which also makes group shooting harder for some shooters.
In new rifles (lets say 10 years old or less) that are built to tight tolerances, I find that you get good accuracy at the low end of velocity, then as you increase veocity, you may lose some accuracy, until you get up closer to max charges, and the groups shrink back up. At a certain point, the groups start to open up again.
I've heard this described by a few people and it seems the theory is that low pressure loads won't flex things too much. As you increase pressure you are magnifying the rilfes flexing/distorting and any other imperfections that you may have, including the ammo you just made. But you haven't got to it's *sweet spot* yet. Eventually you get there...
But as with many things, it often comes down to the individual rifle, the loader, and the shooter. Somehting overlooked is that the high end loads recoil alot, too. Which also makes group shooting harder for some shooters.
- Location
- Daysland AB
+1 gatehouse, I had the same experience. At low end, accuracy was acceptable and then dropped off until I was within a grain or so of max with the 270wsm. On the other hand in a 280 remington lighter loads produced the best accuracy by far. I think it is all down to your particular rifle.
- Location
- South Cariboo, B.C.
A 280 Rem was another one of the rounds that I loaded for where a 150 gr Btip was a one holer 200 fps slower that Nosler's max load velocity for that powder.
I often wonder how many people just rush to max load while looking for good accuracy and pass very impressive results.
This particular rifle still shot decent groups with higher end velocities for hunting but like several other rifles I loaded for, the one holer was at a very modest velocity.
Here are some examples of what I often see with regards to Max load= Good accuracy.
223
50 gr Hornady V-Max bullets
Benchmark Powder
Fed 205M bullets
24gr powder- Very good accuracy, but velocity is lower than we woudl like.
25 gr- Looks like good accuracy, but I called a flyer on one shot. Actually yelled "GODDAMMM" as I pulle dthe trigger
25.5 Group is starting to open as we increase powder charge and velocity
26 gr Velocity and powder charge is getting higher, closer to max. GRoup starts to shrink
26.5gr -Max charge by the book, Goiod accuracy, velocity is rigth about where we weant it to be.
27gr High velocity, accuracy is very acceptable but looks like it is goign to open up a bit. Powder charge a bit over max, and the primer starts to crater. No point in cntinuing up withthis bullet..
This shows what I described in my previous post. Good accuracy at lower charges, loss of accuracy as you get higher, until you get closer to max and the accuracy returns.
Thsi si a example of only one, but it's easy to see it. and I've seen it happen many times.
Naturally, you may think 'the first load is the most accurate, why not use it? Well, if I was shooting targets at 100 yards, maybe I would. Since I'd like to knock off coyotes at 300, I think I will stick witht he load that gives very go9od accuracy, but alsovery good velocity.
As it is, these were all just starter loadings, I was really just checking to see how my bedding job worked out. I havent' tinckered or played with seating depth yet.
223
50 gr Hornady V-Max bullets
Benchmark Powder
Fed 205M bullets
24gr powder- Very good accuracy, but velocity is lower than we woudl like.
25 gr- Looks like good accuracy, but I called a flyer on one shot. Actually yelled "GODDAMMM" as I pulle dthe trigger
25.5 Group is starting to open as we increase powder charge and velocity
26 gr Velocity and powder charge is getting higher, closer to max. GRoup starts to shrink
26.5gr -Max charge by the book, Goiod accuracy, velocity is rigth about where we weant it to be.
27gr High velocity, accuracy is very acceptable but looks like it is goign to open up a bit. Powder charge a bit over max, and the primer starts to crater. No point in cntinuing up withthis bullet..
This shows what I described in my previous post. Good accuracy at lower charges, loss of accuracy as you get higher, until you get closer to max and the accuracy returns.
Thsi si a example of only one, but it's easy to see it. and I've seen it happen many times.
Naturally, you may think 'the first load is the most accurate, why not use it? Well, if I was shooting targets at 100 yards, maybe I would. Since I'd like to knock off coyotes at 300, I think I will stick witht he load that gives very go9od accuracy, but alsovery good velocity.
As it is, these were all just starter loadings, I was really just checking to see how my bedding job worked out. I havent' tinckered or played with seating depth yet.
Gatehouse very well said,Gatehouse said:I have often found this:
In new rifles (lets say 10 years old or less) that are built to tight tolerances, I find that you get good accuracy at the low end of velocity, then as you increase veocity, you may lose some accuracy, until you get up closer to max charges, and the groups shrink back up. At a certain point, the groups start to open up again.
I've heard this described by a few people and it seems the theory is that low pressure loads won't flex things too much. As you increase pressure you are magnifying the rilfes flexing/distorting and any other imperfections that you may have, including the ammo you just made. But you haven't got to it's *sweet spot* yet. Eventually you get there...
But as with many things, it often comes down to the individual rifle, the loader, and the shooter. Somehting overlooked is that the high end loads recoil alot, too. Which also makes group shooting harder for some shooters.
Boonerbuckboonerbuck said:
I had a Rem .280 with factory barrel 22" and with 53gr H 4831 150gr Btip would shoot better than a lot of bench guns I have seen 1/2 and under just amazing for a stock gun. My new wsm in 7mm is unbelievable with fairly hot load 3200fps 140gr Btip well under 1/2" but have not found a light load yet that's tight
manitou210 said:
I just purchased a 7 WSM and while I'm waiting for it to arrive I'm trying to determine which loading components to start with. What powder/primer are you using for the .5 3200 140 load if you don't mind me asking?
Thanks
wow - i just realized that this post is a over half a year old!
very happy with the handloads in my 325wsm(win-70) with 200gr sierra's,accuracy is better than I expected, haven't checked velocity yet but plan to.also to comment on ryanb's statement I find 2 shots between cleanings provides the best results.after 2 accuracy starts to fade.
mylesrom said:
Actually, I thought the 270 WSMs competition was the 270 Wby, in which case, not such an improvement. Still good numbers though, whether from a short case or a long one. - dan
