I had some 160gr. AB's loaded with RL-22 from 61-62.5grs in .5 gr increments and the velocity was sad. 62.5gr= 2764 fps avg. I've got a Sendero with a 26" barrel, so by the Nosler #6 it should be about 3000 fps (with the guide usually being off by 100 fps or so). My question is how is that possible to be only 2764 fps? The odd thing is, the 61gr charge avg is faster by 2 fps! I'm getting some good scales tomorrow and check his charges. He is usually pretty close on the velocities in the book though. Is the powder burning up in 24" and losing on the other 2"? I wouldn't think so but I'm out of ideas. I'm also tired of not knowing for sure, so I'll be getting the rest of my stuff to roll my own this week. Should I keep bumping it up (no pressure signs yet) or try another powder?If anyone can sort through this and help me out, I'd really appreciate it.
x-low 7mm Rem Mag velocity
- Thread starter bteate
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DrMike
Ballistician
- Nov 8, 2006
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bteate,
From your post, I take it that a friend loaded these for you. While it is possible that you have a slow barrel, the charge seems like a mild load. QuickLoad projects a somewhat higher charge before reaching maximum pressures. To be certain, I use a considerably higher charge with 160 grain Fail Safe bullets and ReLoder 22. However, it is always wise to bear in mind that the loads listed in the Nosler Guide are pressure-tested. I would suggest that you are getting a 99 percent burn of your powder before the bullet exits.
From your post, I take it that a friend loaded these for you. While it is possible that you have a slow barrel, the charge seems like a mild load. QuickLoad projects a somewhat higher charge before reaching maximum pressures. To be certain, I use a considerably higher charge with 160 grain Fail Safe bullets and ReLoder 22. However, it is always wise to bear in mind that the loads listed in the Nosler Guide are pressure-tested. I would suggest that you are getting a 99 percent burn of your powder before the bullet exits.
My books show 65 grains with 160 and 3000 fps out of a 24 inch barrel?
Are you using magnum primers?
Careful here.I've seen instances where switching from a LRP to a LRMP have made HUGE differences in both presures and velocities....
Also,my experience with Remington 700s (my favorite rifle) is that they have alot of freebore.I don't own one with that I can get close to touching the lands in the barrel at magazine length.Freebore usually equals free velocity in my experience.
If RL22 isn't giving you the desired results I'd also look at RL25,H1000 and Retumbo
Howard
Are you using magnum primers?
Careful here.I've seen instances where switching from a LRP to a LRMP have made HUGE differences in both presures and velocities....
Also,my experience with Remington 700s (my favorite rifle) is that they have alot of freebore.I don't own one with that I can get close to touching the lands in the barrel at magazine length.Freebore usually equals free velocity in my experience.
If RL22 isn't giving you the desired results I'd also look at RL25,H1000 and Retumbo
Howard
- Oct 30, 2004
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My load was always 66 gr of rl22.
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DrMike, my loads with the 140's are pretty much on velocity wise with 64.5grs of IMR 4350 average of 3205 fps. What exactly does a "slow barrel" mean? I'll know more when I check the ones I have left, I kept two of each just to check.
HTDUCK, he used Win. mag primers loaded .040" off lands.
POP, the loads I shot today with a grain and a half increase gave me no increase in velocity (assuming the charge was correct, which I will find out for sure). Is 4 more grains going to give me 200-plus fps? I know that speed isn't everything, but I'd like it to perform like a magnum if I can.
HTDUCK, he used Win. mag primers loaded .040" off lands.
POP, the loads I shot today with a grain and a half increase gave me no increase in velocity (assuming the charge was correct, which I will find out for sure). Is 4 more grains going to give me 200-plus fps? I know that speed isn't everything, but I'd like it to perform like a magnum if I can.
Guy Miner
Master Loader
- Apr 6, 2006
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65 grains of RL-22 is recommended by Sierra for their 160's and usually I see around 3000 fps with that load.
I'd start working up from where you are...
Guy
I'd start working up from where you are...
Guy
DrMike
Ballistician
- Nov 8, 2006
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I used 66 grains of ReLoder 22 with the 160 grain Fail Safe for a velocity of 3164 fps from a 24 inch barrel. This is safe in my rifle with no pressure signs and good life in my brass with this load.
A "slow barrel" is one with a bore size that is at the outer limits of allowable specs. Hence, pressure will be somewhat lower causing somewhat lower velocity.
Finally, four grains is quite a bit; it is in excess of six percent compared to 62 grains. I would anticipate at least 200 fps differential with ReLoder 22.
You might try working upward toward 66 grains in half grain increments. Again, remember that you are responsible to watch for pressure signs as you work up. This is beyond the 63 grains listed in the Nosler Guide (and beyond the 61 grains listed in the Barnes Manual for 1 160 grain TSX, beyond the 65.5 grains listed in the Swift Manual for a 160 grain A-Frame, beyond the 65 grains listed in the Speer Manual for a 160 grain BTSP, beyond ... you get the picture). Bear in mind that each represents a different set of conditions, and your rifle presents its own unique situation. These are pressure-tested loads, and since you do not likely have access to laboratory equipment to test pressures, you must assume responsibility to watch for pressure signs.
A "slow barrel" is one with a bore size that is at the outer limits of allowable specs. Hence, pressure will be somewhat lower causing somewhat lower velocity.
Finally, four grains is quite a bit; it is in excess of six percent compared to 62 grains. I would anticipate at least 200 fps differential with ReLoder 22.
You might try working upward toward 66 grains in half grain increments. Again, remember that you are responsible to watch for pressure signs as you work up. This is beyond the 63 grains listed in the Nosler Guide (and beyond the 61 grains listed in the Barnes Manual for 1 160 grain TSX, beyond the 65.5 grains listed in the Swift Manual for a 160 grain A-Frame, beyond the 65 grains listed in the Speer Manual for a 160 grain BTSP, beyond ... you get the picture). Bear in mind that each represents a different set of conditions, and your rifle presents its own unique situation. These are pressure-tested loads, and since you do not likely have access to laboratory equipment to test pressures, you must assume responsibility to watch for pressure signs.
- Nov 4, 2004
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bteate
That is a very low velocity you are etting. I wouold agree with the others and go to 65.0 grs RL 22 and see what you get. You might also try a different brand magnum primer, Federal GM215M primers have always worked well for me.
Keep us posted on your load development.
JD338
That is a very low velocity you are etting. I wouold agree with the others and go to 65.0 grs RL 22 and see what you get. You might also try a different brand magnum primer, Federal GM215M primers have always worked well for me.
Keep us posted on your load development.
JD338
- Thread starter
- #9
Thank you, DrMike, for explaning that slow barrel thing. Wouldn't the 140 AB show signs similar to that of my experience with the 160 AB? Or would the pressure needed to get the 140gr moving quickly, be low enough to not effect velocity that much? I'll start bumping it up slowly.
Thanks again,
Brandon
Thanks again,
Brandon
DrMike
Ballistician
- Nov 8, 2006
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The pressure required to engage the lands will be constant for your rifle regardless of difference in bullet weight. With the additional information about the velocity of the 140 grain AB, I would be inclined to say that your charge of ReLoder 22 is simply too low. The experience of all the other posters would seem to verify this. The difference in your experience and that which is posted in the Guide can be attributed to lot-to-lot variations in powders, differences in barrel employed, etc. This is one of those places where a good chronograph is exceptionally valuable.
Again, I can't stress too much that we are responsible for our own loads whenever we move beyond tested loads. This is not to say that the loads you develop will be inherently unsafe, but it is stated simply to remind you that a hand loader cannot shift responsibility for what he is doing onto someone else.
Again, I can't stress too much that we are responsible for our own loads whenever we move beyond tested loads. This is not to say that the loads you develop will be inherently unsafe, but it is stated simply to remind you that a hand loader cannot shift responsibility for what he is doing onto someone else.
Well awhile back I loaded up some Nosler 160 PT for my 7Mag. I used IMR 4350 powder at 58 grains to achieve around 2943FPS. I used Winchester cases and Win. Mag primers. They done a good job for me in my Savage 110. My 7 Mag manual shows 160gr. Nosler PT with 63 grains of RL 22 at 3058 FPS. You should be able to get about the same with 160gr.AB.
7 Mags forever!
7 Mags forever!
Guy Miner
Master Loader
- Apr 6, 2006
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BTW, like Dr. Mike, I've had absolutely no problem running 66 grains of RL-22 and a 160 Nosler Partition in my current 7mm Rem mag Ruger Number One. It's a grain over "book" max, but has proven perfectly safe in my rifle, even in summer temps. No problems with brass life either.
Dr. Mike's cautions about venturing beyond book max are very worthwhile. If you're not comfortable with that, stop at 65 grains... Just be aware that the various different load manuals and on-line sources have different max loads listed.
Alliant lists 65 grains of RL-22 with a 160 gr bullet, which is the same as Sierra recommended to me.
I think you're just being a little conservative with your loading is all. To me the advantage of the 7mm Rem mag lies in bullets with a good high BC, and a decent muzzle velocity. Otherwise, what's the point? :grin:
Regards, Guy
Dr. Mike's cautions about venturing beyond book max are very worthwhile. If you're not comfortable with that, stop at 65 grains... Just be aware that the various different load manuals and on-line sources have different max loads listed.
Alliant lists 65 grains of RL-22 with a 160 gr bullet, which is the same as Sierra recommended to me.
I think you're just being a little conservative with your loading is all. To me the advantage of the 7mm Rem mag lies in bullets with a good high BC, and a decent muzzle velocity. Otherwise, what's the point? :grin:
Regards, Guy
Yup, I fell into the same thing when loading my first 160gr Accubonds for my 7mm Rem Mag. Guy and few others noted that my load of 63gr's was more like a 280 than a 7mm RM. Well, I went back to the drawing board, and loaded up to 66gr of RL22. Well, that has netted me one of the most accurate loads for my 7mm RM, and also at 3100 it is very quick. Nosler, is kinda low on quite a few loads, but they are very safe. The best way is to step up .5gr's at a time like Mike said. I would bet money, between 65 and 66gr's of RL22 and the 160gr AccuBond will give you an excellent group and more than adequate speeds. Good luck. SCotty
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Big Squeeze
Handloader
- May 29, 2007
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.....................................bteate.........bteate":30u08puu said:
Assumming your RL22 charges were correct and your chrony is in good working order, I`d have to say that your big culprit here is a slower bore.
First, I`d continue working up your loadings in 1/2 gr increments using the RL22 using the 160 gr AB until you see small pressure signs. Then back off a 1/2 gr, consider that load as maximum and then chrony it to see where you at.
If you still consider yourself lagging behind in the velocity dept, then change your bullet to one that has less of a bearing surface touching the bore. A different ogive. That just might gain you about 50-100 fps there alone.
I`d also try some different powders and be sure to use a large rifle magnum primer.
From a 24" barrel, a 160 grainer moving at a minimum in the very high 2800s to mid 2900s, is more like what a 7mm Rem mag should be able to do.
In my 49th ed Lyman manual, I read that 63.0 gr of RL22 (max) using a Swift A-Frame offers 2931 fps.
Sierra Manual says; 160 gr
60.4 gr RL22 @ 2900 fps..........61.6 gr RL22 @ 2950 fps.........62.8 gr RL22 @ 3000 fps ..........64.0 gr RL22 @ 3050 fps and..........65.2 gr RL22 (max) @ 3100 fps. All with a 26" tube.
If say, that you could get 2950 to 3000 fps max with a 160 grainer and if it were me, I`d be satisfied with that.
