I recently started reloading for a Tikka T3 7 Mag, 24 3/8" bl, 9 1/2" twist. The last load I tried was 140 gr Berger VLD Hunting bullet set a .064 off lands, remington brass, 66gr RL-22, CCI Mag Primer. Hornady book shows 66.7 gr RL-22 and 140 gr BTSP with a velocity of 3100 FPS. I'm getting average MV of 2860. Chronograph seems to be clocking my .243 and muzzleloader correctly. I'm wondering why my velocities are so low. Accuracy is sub MOA but I'm feeling a little short changed on speed. Any isight would be appreciated.
7 MM Rem Mag loads
- Thread starter rvaughan
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627PCFan
Member
My loads are about 150FPS short of advertised and Im runnning the 168 gr Bergers. I do think you sacrifice some speed with the 24 inch barrels if your running RL22 or slower powders.
You might try to step down to H4831 or even IMR 4831 for the 140 grain category. I like the IMR but others swear by the H4831
You might try to step down to H4831 or even IMR 4831 for the 140 grain category. I like the IMR but others swear by the H4831
I could live with 100-150 less than advertised but I'm averaging 240 fps less. That seems excessive even with the 24 3/8" barrel. I've tried H4831SC and IMR 4350 but have not tried to max out loads. I'll go back to the H4831SC and experiment a little. I just feel like I paid for a magnum rifle for long range hunting and I'm getting sub-mag performance in terms of velocity. I'm loving the accuracy despite the speed.
rvaughan,
I've had similar experiences with my 7mm RM. Especially with Hornady's published loads. They list 63.4g of RL-22 with their 154g bullets. Other load data I have in my notes (please verify before using):
I don't know why the Hornady data seems so downloaded. I didn't get anywhere near what they claimed I should with the 154g Interbond. I didn't even hit 2,800 fps let alone 2,900. Not exactly "magnum" performance.
Will Berger provide you with load data?
I've had similar experiences with my 7mm RM. Especially with Hornady's published loads. They list 63.4g of RL-22 with their 154g bullets. Other load data I have in my notes (please verify before using):
Code:
Powder Start MAX Source
------ ----- --- ------
Reloder 22 56.6 63.4 Hornady #7, 154g Interbond
Reloder 22 58.5 65.0 Alliant 2010, 160g HC
Reloder 22 58.5 65.2 Sierra #5, 160g Sierra SP @ 3.245
Reloder 22 60.0 67.0 Lyman #49, 154g Hornady SP
Reloder 22 51.0 66.0 Lyman #49, 168g Sierra HPBTWill Berger provide you with load data?
nastynatesfish
Member
I use 65gr of either rl22 or rl19 with a 162gr amax. Used the same for 154gr sst
happy1
Member
Try IMR 4064
ForneyRider
Member
I did 70gr of R22, Win brass, 139gr SST, and CCI 250 primer. I used the cannelure for COL. I got 3088fps with 26in barrel. I have seen 70.5gr as max in some data. But should be over 3250fps.
Try R19, IMR4350 or another powder that is one step faster than R22.
Try R19, IMR4350 or another powder that is one step faster than R22.
Grumulkin
Member
So, why are you not keen to push the load limit on powder? That's probably what those that advertised higher velocity did. If you're shooting a strong firearm and know how to look for pressure signs, there is nothing unsafe about pushing loads up to where they belong.
Give me a starting point for a load with a strong firearm, and I don't even need to know what the alleged maximum load is. I can easily figure that out for myself. I also do not use a chronograph to help me in load workup. If I get an accurate load with a given powder, I'm satisfied with the velocity though I may check it later just out of curiousity.
My 7mm Remington Magnum load with both 140 and 160 grain bullets is with RL-22 which easily give me sub MOA accuracy and my loads are certainly going to kill deer sized game at ranges out to at least 400 yards; are you going to shoot further than that?
By the way, I doubt the Lee FCD die will improve your velocity or your accuracy.
Give me a starting point for a load with a strong firearm, and I don't even need to know what the alleged maximum load is. I can easily figure that out for myself. I also do not use a chronograph to help me in load workup. If I get an accurate load with a given powder, I'm satisfied with the velocity though I may check it later just out of curiousity.
My 7mm Remington Magnum load with both 140 and 160 grain bullets is with RL-22 which easily give me sub MOA accuracy and my loads are certainly going to kill deer sized game at ranges out to at least 400 yards; are you going to shoot further than that?
By the way, I doubt the Lee FCD die will improve your velocity or your accuracy.
ForneyRider
Member
I don't crimp anything but revolver and lever action rounds. Lee doesn't supply a crimp die with deluxe die sets.
Grumulkin
Member
One other point. On another forum, a shooter who is also a gunsmith tested 10 different identical rifles (cartridge was 223 Remington if I remember correctly). The velocity difference between the different rifles was close to 200 fps with the same load.
Moral of the story, there can be significant velocity differences between identical rifles and even more between different ones.
Moral of the story, there can be significant velocity differences between identical rifles and even more between different ones.
I have opportunities at 600 yard shots with stable rest conditions (elevated box blind). I'm not sure what difference 2860 fps vs. 3000 fps has on bullet trajectory at 600 yards but it would be nice to know. What pressure signs should I be looking for if were to start loading hotter rounds.
Grumulkin
Member
1. Sticky extraction - stop.
2. Blown or pierced primer -way too high.
3. When working up a load, group size will generally decrease to a point with increased powder charges and will then start increasing in size again. Keep the load where the group size is the smallest. In all the cartridge I load for, pressure has never been excessive when I do it that way.
4. Primer appearance varies in different guns with increasing pressure. If there is still a little curvature at the periphery of the primer, pressure is probably OK.
The above is for strong bolt actions and single shots only. For weaker actions stick slavishly to the book and hopefully avoid even sticky extraction.
At huntingnut.com there is free ballistic software you can download that will give you a good idea of what the trajectory will be at varying velocities or you could buy Quickload software.
2. Blown or pierced primer -way too high.
3. When working up a load, group size will generally decrease to a point with increased powder charges and will then start increasing in size again. Keep the load where the group size is the smallest. In all the cartridge I load for, pressure has never been excessive when I do it that way.
4. Primer appearance varies in different guns with increasing pressure. If there is still a little curvature at the periphery of the primer, pressure is probably OK.
The above is for strong bolt actions and single shots only. For weaker actions stick slavishly to the book and hopefully avoid even sticky extraction.
At huntingnut.com there is free ballistic software you can download that will give you a good idea of what the trajectory will be at varying velocities or you could buy Quickload software.
JimKirk
Member
rv
Use this link to calculate your trajectory ... input the values and hit calculate. Check the zero at max point blank range to find out MPBR.
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
Jimmy K
Use this link to calculate your trajectory ... input the values and hit calculate. Check the zero at max point blank range to find out MPBR.
http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi
Jimmy K
JimKirk
Member
Trajectory
Ballistic Coefficient: 0.510 G1 Caliber: 0.284 in
Bullet Weight: 140.0 gr
Muzzle Velocity: 3000.0 ft/s Distance to Chronograph: 10.0 ft
Vital Zone Radius: 5.0 in
Maximum PBR: 365 yd Maximum PBR Zero: 310 yd
Range Drop
(yd) (in)
100 3.8
200 4.8
300 0.7
400 -9.1
500 -25.6
600 -49.7
700 -82.8
Trajectory
Ballistic Coefficient: 0.510 G1 Caliber: 0.284 in
Bullet Weight: 140.0 gr
Muzzle Velocity: 2860.0 ft/s Distance to Chronograph: 10.0 ft
Vital Zone Radius: 5.0 in
Maximum PBR: 349 yd Maximum PBR Zero: 296 yd
Range Drop
(yd) (in)
0 -1.5
100 4.0
200 4.6
300 -0.3
400 -11.6
500 -30.3
600 -57.5
700 -94.8
Using the above JBM Link
Ballistic Coefficient: 0.510 G1 Caliber: 0.284 in
Bullet Weight: 140.0 gr
Muzzle Velocity: 3000.0 ft/s Distance to Chronograph: 10.0 ft
Vital Zone Radius: 5.0 in
Maximum PBR: 365 yd Maximum PBR Zero: 310 yd
Range Drop
(yd) (in)
100 3.8
200 4.8
300 0.7
400 -9.1
500 -25.6
600 -49.7
700 -82.8
Trajectory
Ballistic Coefficient: 0.510 G1 Caliber: 0.284 in
Bullet Weight: 140.0 gr
Muzzle Velocity: 2860.0 ft/s Distance to Chronograph: 10.0 ft
Vital Zone Radius: 5.0 in
Maximum PBR: 349 yd Maximum PBR Zero: 296 yd
Range Drop
(yd) (in)
0 -1.5
100 4.0
200 4.6
300 -0.3
400 -11.6
500 -30.3
600 -57.5
700 -94.8
Using the above JBM Link
nastynatesfish
Member
I like the balistic calculator at biggameinfo.com
Clark
Member
There are white lies, lies, damn lies, statistics, and then there is 7mmRemMag published data.
How bad are they?
I can get more power out of 7x57mm Mauser handloads than I can from most of the 7mmRemMag published loads.
How bad are they?
I can get more power out of 7x57mm Mauser handloads than I can from most of the 7mmRemMag published loads.
Hello Forum,
I am reloading a 7 mm Remington magnum round. It is a 154gr , 56.2 H 8341 powder, winchester mag rifle primmer. Have a look at the pics. I am interested in the groove for the bullet that accepts a crimp. What do you think of it does it look right. I use dies from Lee. And it came with a crimp die that is used.
thank you for your thoughts.
I am reloading a 7 mm Remington magnum round. It is a 154gr , 56.2 H 8341 powder, winchester mag rifle primmer. Have a look at the pics. I am interested in the groove for the bullet that accepts a crimp. What do you think of it does it look right. I use dies from Lee. And it came with a crimp die that is used.
thank you for your thoughts.
NCsmitty
Member
SifuGun, I'm guessing that your powder is H4831, and what you mentioned is a typo.
Your load of H4831 appears to be a bit light compared to Hodgdon's reloading website, which has the latest data for 7mm Mag.
If this is a listed load from your load manual, then disregard my comment.
Your cartridge appears to be nicely put together, and you do not need to crimp the bullet. Your COAL should be near the book's dimension, seeing that you are using the bullet cannelure for reference. Check and make sure that the loaded rounds fit your rifle's chamber without issue.
Good shooting.
NCsmitty
Your load of H4831 appears to be a bit light compared to Hodgdon's reloading website, which has the latest data for 7mm Mag.
If this is a listed load from your load manual, then disregard my comment.
Your cartridge appears to be nicely put together, and you do not need to crimp the bullet. Your COAL should be near the book's dimension, seeing that you are using the bullet cannelure for reference. Check and make sure that the loaded rounds fit your rifle's chamber without issue.
Good shooting.
NCsmitty
Thanks NCsmitty,
right, it is h4831, did not have book in front of me at time of post. I am going with the lowest charge per Hornady 7th edition. The C.o.l. is specified as 3.29" and i went 3.288" or right at 3.29". And it calls for 56.3 grains as lowest load. But when i was getting consistent 56.2 grains from my Lee autodisk I thought i go with it instead. They load and unload nicely. So only thing left is to shoot'em off, weee!
right, it is h4831, did not have book in front of me at time of post. I am going with the lowest charge per Hornady 7th edition. The C.o.l. is specified as 3.29" and i went 3.288" or right at 3.29". And it calls for 56.3 grains as lowest load. But when i was getting consistent 56.2 grains from my Lee autodisk I thought i go with it instead. They load and unload nicely. So only thing left is to shoot'em off, weee!
I have a general question about 7mm rem magnum. Would it be safe to download the round. It calls for 56.3 grains of H4831 as it's smallest load. What would happen if I loaded it with say 45.0 grains. I am sure it will slow the bullet down But My main question is would it be safe?
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