Off-season project - 7mm Rem Mag

I didn’t die!

The bad news is that my target probably wouldn’t have either. I’m pretty sure I found the mixture but I think something is wrong with my scope. I think the rings are too light for the amount of recoil this gun produces. However, I was able to get MOA with factory rounds, so who knows.

85gr left, 85.5 gr right. Both 180 Accubonds with CCI primers.

IMG_0765.jpeg
 
When I see a "horizontal" group like that, I check out first, the parallax, could be your innards in your scope went wonky, or not up to the recoil of a 300 wby OR, its shifting in the mounts during recoil. Since I use Lock-Tite or nail polish on my screws, I don't worry about my bases, I do recheck the ring screws, for tightness. If that fails, I try another scope. If I don't have a proven scope as a spare, I will buy another, better quality scope than what's on the rifle. Always go forward, not backward! If its a Leupold, send it in for repair, etc. Stronger mounts on a 300 Wby makes good sense. It's a slow process, but honestly, a big magnum round like that is a tough one to begin your Reloading training, nothing wrong in doing it, just tough. Means its a good thing to check, recheck, ask questions, research online, etc. Take your time sir. Really study up on Benchrest Technique. You are doing OK. They are chambering, going bang and not blowing up! :)
 
RevJim said:
When I see a "horizontal" group like that, I check out first, the parallax, could be your innards in your scope went wonky, or not up to the recoil of a 300 wby OR, its shifting in the mounts during recoil. Since I use Lock-Tite or nail polish on my screws, I don't worry about my bases, I do recheck the ring screws, for tightness. If that fails, I try another scope. If I don't have a proven scope as a spare, I will buy another, better quality scope than what's on the rifle. Always go forward, not backward! If its a Leupold, send it in for repair, etc. Stronger mounts on a 300 Wby makes good sense. It's a slow process, but honestly, a big magnum round like that is a tough one to begin your Reloading training, nothing wrong in doing it, just tough. Means its a good thing to check, recheck, ask questions, research online, etc. Take your time sir. Really study up on Benchrest Technique. You are doing OK. They are chambering, going bang and not blowing up! :)
Click to expand...
Thanks for your comment. I've shot a 300 WBY for awhile. I really should shoot it more quite honestly, but FWIW the recoil is pretty nice for the small amount of shots I take at the range. I have the Warne Vapor rings on, and theyre lightweight aluminum. I had some worry when I did buy them, so I think I may buy the double screw rings and rezero the gun. Part of me thinks that flyer was a flinch too because I did jam my thumb on the gun after a shot due to poor hand placement. The scope is a Vortex Viper, it held zero on a 30-06. Eventually, it will get traded off for a heavier bell.

Truly am having fun though. Glad I decided to do it. Just need to mount the press on something better than plywood. Ill probably reinforce it on my work desk with a 2x4.
 
perma said:
I didn’t die!

The bad news is that my target probably wouldn’t have either. I’m pretty sure I found the mixture but I think something is wrong with my scope. I think the rings are too light for the amount of recoil this gun produces. However, I was able to get MOA with factory rounds, so who knows.

85gr left, 85.5 gr right. Both 180 Accubonds with CCI primers.

View attachment 315774
Click to expand...
I have been working up loads for my 7mm Rem Mag. Leupold VX-6HD with Leupold magnum rings/bases (steel, two-piece). Tightened everything to specs and put loc-tite on the base screws. Have now put >500 rds through it with no issues. Haven't seen any drift. I would check your rings/bases first and then lap the rings for a final fit-up to your scope. This all assumes the scope hasn't already been damaged. If you can move the scope to a different rifle that is a known shooter, you can see if that is the issue.

From my personal experience, I run 5 rounds at each powder charge and chrono every shot. I evaluate on velocity consistency and size of group within acceptable pressure. I start by running at least a 3-gr spread in 0.5-gr increments working up to max recommended pressure. Two or three rounds at each step doesn't really provide good statistics. Five rounds is somewhat better and provides a least a good indication without burning through too much of your supplies. Regardless of bullet brand and weight, I have found my 7mm likes the higher velocities for any given combination. This aligns to some analyses I have seen where you get better shot consistency/accuracy if the bullet is exiting the muzzle when it is still moving "up" to the ideal alignment (relative to the target POA) vs moving "down". The relative position is all a function of the barrel design (barrel harmonics). Looking at the Nosler load data, your 85 and 85.5 gr loads are on the low end of the velocities you could expect for a 180-gr AB and H1000 powder. Unless you are seeing pressure signs, I would continue to work up in charge/velocity to see whether the group tightens up or not. But stop if you start to see any signs of pressure. I have also found lower velocity spreads (at a given charge) with Federal primers than with CCI. That translates into tighter groups, both from a barrel harmonics perspective but from just a straight FPS perspective and resulting bullet drop.

You didn't say but I am guessing these targets were at 100 yds. If that is the case, you should be able to get much better than 2.5 MOA. If you can't improve much from that even after changing powder charge, primers, and bullet seating (distance to lands), then I would try a different bullet. I have done all of the above with AB's and my rifle just won't do any better than 1.2 MOA. I am now getting 0.52 MOA with Hornady CX's (150-gr) over 300 rounds to date at my final load parameters. If you keep working at it, you will get there. Just may take a liitle while.
 
Alpine01 said:
I have been working up loads for my 7mm Rem Mag. Leupold VX-6HD with Leupold magnum rings/bases (steel, two-piece). Tightened everything to specs and put loc-tite on the base screws. Have now put >500 rds through it with no issues. Haven't seen any drift. I would check your rings/bases first and then lap the rings for a final fit-up to your scope. This all assumes the scope hasn't already been damaged. If you can move the scope to a different rifle that is a known shooter, you can see if that is the issue.

From my personal experience, I run 5 rounds at each powder charge and chrono every shot. I evaluate on velocity consistency and size of group within acceptable pressure. I start by running at least a 3-gr spread in 0.5-gr increments working up to max recommended pressure. Two or three rounds at each step doesn't really provide good statistics. Five rounds is somewhat better and provides a least a good indication without burning through too much of your supplies. Regardless of bullet brand and weight, I have found my 7mm likes the higher velocities for any given combination. This aligns to some analyses I have seen where you get better shot consistency/accuracy if the bullet is exiting the muzzle when it is still moving "up" to the ideal alignment (relative to the target POA) vs moving "down". The relative position is all a function of the barrel design (barrel harmonics). Looking at the Nosler load data, your 85 and 85.5 gr loads are on the low end of the velocities you could expect for a 180-gr AB and H1000 powder. Unless you are seeing pressure signs, I would continue to work up in charge/velocity to see whether the group tightens up or not. But stop if you start to see any signs of pressure. I have also found lower velocity spreads (at a given charge) with Federal primers than with CCI. That translates into tighter groups, both from a barrel harmonics perspective but from just a straight FPS perspective and resulting bullet drop.

You didn't say but I am guessing these targets were at 100 yds. If that is the case, you should be able to get much better than 2.5 MOA. If you can't improve much from that even after changing powder charge, primers, and bullet seating (distance to lands), then I would try a different bullet. I have done all of the above with AB's and my rifle just won't do any better than 1.2 MOA. I am now getting 0.52 MOA with Hornady CX's (150-gr) over 300 rounds to date at my final load parameters. If you keep working at it, you will get there. Just may take a liitle while.
Click to expand...
Yeah I'm not sure what the deal is but I'll get to the bottom of it.

I definitely am on the low range. Nosler said the low end for 180g ABs were the most accurate so I decided to start there and see what it did. Like I said, I think I may be there. I should probably do what you said and load a few more rounds. Yeah, zero pressure signs. I can bump up the charge with H1000, just dont really see the need to yet. Not enough data for me to commit to that.

What I can say about the current setup I have is that I did overlap factory box AB's. All at 100 yards for now. My preference is to upgrade to e-tip since i had success with those but I figured that since the ABs shot well from factory, that I should start there. Plus, they were widely available. I'm interested in trying Barnes and Bergers next. Sierra is also on my short list.

CCI wasn't my first choice, just my only choice. I'm kind of at the mercy of making something work with these primers until I get some high quality ones. FWIW, I didn't see any residual gunpowder in the barrel so I felt they had a pretty decent burn. I feel pretty good about them.

I am curious about my bullet seating. I'm at 3.550" +/- 0.003" on this next load set I made (seated one a bit too far by accident, that one might be the flyer, others are within 0.001"). I did crimp them and loaded them into the magazine, they didn't fall apart.
 
The summer of 1988, when I was between semesters at Bible College, we lived in an apartment. I mounted my Rockchucker press on the end of short pc of 1x6 pine. I C-clamped it to the kitchen table to reload. Just had to take my time and not touch the table when using the Balance Beam scales ( I hate Balance Beams!) afterward, it all went under the bed until next time!
 
perma said:
Yeah I'm not sure what the deal is but I'll get to the bottom of it.

I definitely am on the low range. Nosler said the low end for 180g ABs were the most accurate so I decided to start there and see what it did. Like I said, I think I may be there. I should probably do what you said and load a few more rounds. Yeah, zero pressure signs. I can bump up the charge with H1000, just dont really see the need to yet. Not enough data for me to commit to that.

What I can say about the current setup I have is that I did overlap factory box AB's. All at 100 yards for now. My preference is to upgrade to e-tip since i had success with those but I figured that since the ABs shot well from factory, that I should start there. Plus, they were widely available. I'm interested in trying Barnes and Bergers next. Sierra is also on my short list.

CCI wasn't my first choice, just my only choice. I'm kind of at the mercy of making something work with these primers until I get some high quality ones. FWIW, I didn't see any residual gunpowder in the barrel so I felt they had a pretty decent burn. I feel pretty good about them.

I am curious about my bullet seating. I'm at 3.550" +/- 0.003" on this next load set I made (seated one a bit too far by accident, that one might be the flyer, others are within 0.001"). I did crimp them and loaded them into the magazine, they didn't fall apart.
Click to expand...
Three thoughts:

(1) As some of the guys have mentioned earlier, you will generally see the most consistent performance as you approach higher percentages of case-fill. That said-- be very careful with any all-copper projectile. For instances, Hodgdon calls for a max charge of 85.0gr. of H1000 for the 180gr. E-Tip with a pressure of 53,900 CUP. Hodgdon also says you can safely bump to 88.5gr. of H1000 with a 180gr. Speer BTSP and still have marginally less pressure. Always use starting loads and work your way up with any new projectile, but it is especially important for all-coppers.

(2) Due to inconsistencies in projectile tips-- especially softpoints but I've noticed it in plenty of polymer-tipped projectiles-- you're much better off measuring to the ogive of projectile using something like the Hornady Bullet Comparator.

(3) I've not loaded anything as high octane as the .300WBY (perhaps @mtmuley can chime in here) but generally speaking, crimping rounds for using in a bolt action is thought to have a deleterious effect on consistency and accuracy. Your neck tension on resized brass *should* be sufficient to hold the projectile in place.
 
perma said:
Yeah I'm not sure what the deal is but I'll get to the bottom of it.

I definitely am on the low range. Nosler said the low end for 180g ABs were the most accurate so I decided to start there and see what it did. Like I said, I think I may be there. I should probably do what you said and load a few more rounds. Yeah, zero pressure signs. I can bump up the charge with H1000, just dont really see the need to yet. Not enough data for me to commit to that.

What I can say about the current setup I have is that I did overlap factory box AB's. All at 100 yards for now. My preference is to upgrade to e-tip since i had success with those but I figured that since the ABs shot well from factory, that I should start there. Plus, they were widely available. I'm interested in trying Barnes and Bergers next. Sierra is also on my short list.

CCI wasn't my first choice, just my only choice. I'm kind of at the mercy of making something work with these primers until I get some high quality ones. FWIW, I didn't see any residual gunpowder in the barrel so I felt they had a pretty decent burn. I feel pretty good about them.

I am curious about my bullet seating. I'm at 3.550" +/- 0.003" on this next load set I made (seated one a bit too far by accident, that one might be the flyer, others are within 0.001"). I did crimp them and loaded them into the magazine, they didn't fall apart.
Click to expand...
Do you know how far off the lands you are with your current seating depth? With my CX's, I am 0.015" off the lands (edit: from the ogive as Sheltowee notes) and really didn't see any impact from 0.005 - 0.050. I settled on 0.015 just to be conservative but still keep the jump low. Also, from what I have learned, you headspace reloads from the shoulder, not the belt. You want minimum clearance at the shoulder otherwise when you fire a reloaded round, the case is going to want to expand to the shoulder in the chamber and after several reloads, you run a higher chance of a case head separation. Factory loads are headspaced from the belt so that they can run in any rifle without concern you have the bullet on the lands. Thus I always bump the shoulder back 0.002" when I resize and set my bullet seating based on the shoulder-to-lands length and back off from there. Just my approach so YMMV.

Nosler's results are all specific to their test rifle. A good place to start but your rifle is going to have its own sweet spot which is going to be different. But trying several different bullets is the biggest change that is going to get you tighter groups in the end so long as the bullet you select can get the job done when it matters.
 
Sheltowee said:
Three thoughts:

(1) As some of the guys have mentioned earlier, you will generally see the most consistent performance as you approach higher percentages of case-fill. That said-- be very careful with any all-copper projectile. For instances, Hodgdon calls for a max charge of 85.0gr. of H1000 for the 180gr. E-Tip with a pressure of 53,900 CUP. Hodgdon also says you can safely bump to 88.5gr. of H1000 with a 180gr. Speer BTSP and still have marginally less pressure. Always use starting loads and work your way up with any new projectile, but it is especially important for all-coppers.

(2) Due to inconsistencies in projectile tips-- especially softpoints but I've noticed it in plenty of polymer-tipped projectiles-- you're much better off measuring to the ogive of projectile using something like the Hornady Bullet Comparator.

(3) I've not loaded anything as high octane as the .300WBY (perhaps @mtmuley can chime in here) but generally speaking, crimping rounds for using in a bolt action is thought to have a deleterious effect on consistency and accuracy. Your neck tension on resized brass *should* be sufficient to hold the projectile in place.
Click to expand...
#3 has been in the back of my mind for awhile. I always read that if you have a mag cartridge that you should crimp. The neck doesn’t look/feel different when I do and it may not, but I’m not sure if I’m just wasting time or not.

Alpine01 said:
Do you know how far off the lands you are with your current seating depth? With my CX's, I am 0.015" off the lands (edit: from the ogive as Sheltowee notes) and really didn't see any impact from 0.005 - 0.050. I settled on 0.015 just to be conservative but still keep the jump low. Also, from what I have learned, you headspace reloads from the shoulder, not the belt. You want minimum clearance at the shoulder otherwise when you fire a reloaded round, the case is going to want to expand to the shoulder in the chamber and after several reloads, you run a higher chance of a case head separation. Factory loads are headspaced from the belt so that they can run in any rifle without concern you have the bullet on the lands. Thus I always bump the shoulder back 0.002" when I resize and set my bullet seating based on the shoulder-to-lands length and back off from there. Just my approach so YMMV.

Nosler's results are all specific to their test rifle. A good place to start but your rifle is going to have its own sweet spot which is going to be different. But trying several different bullets is the biggest change that is going to get you tighter groups in the end so long as the bullet you select can get the job done when it matters.
Click to expand...
Honestly I have not measured the lands on this rifle. Hasn’t even crossed my mind. I know not one fits all but I guess my ignorance said it wouldn’t amount to much.
 
perma said:
#3 has been in the back of my mind for awhile. I always read that if you have a mag cartridge that you should crimp. The neck doesn’t look/feel different when I do and it may not, but I’m not sure if I’m just wasting time or not.


Honestly I have not measured the lands on this rifle. Hasn’t even crossed my mind. I know not one fits all but I guess my ignorance said it wouldn’t amount to much.
Click to expand...
I never crimp. I just run the right sized bushing to give me 2-3 thousandths of neck tension. Never have had a problem so far.

How far you are off the lands matters in some rifles/bullets; others not so much. I measure some factory loads on my 308 and the factory loads were 0.256 of the lands. Shocked the h%)) out of me as I reload to 0.015. But my rifle could shoot those factory rounds under 0.9 MOA. I suspect if I tightened up that spacing I could get it under 0.5 MOA but for what I use that round for, there is no need. I tried some 150-gr partitions for my 7mm. Huge difference between 0.010 (1 MOA) vs 0.030 (1.7 MOA). Never could get them better than 1 MOA though. My rifle just didn't like partitions.
 
I use a LEE Factory Crimp die that is adjustable from a Fairy's breath to a Gorilla Grip! It gives the monos a good "bullet pull" on ignition and, if a compressed load, keeps the powder from pushing them forward in the case. I like it.
 
Alright you guys got me into the rabbit hole of finding my lands. I’ve done this with loctite and the jam method and end up at 4.010” on the smallest. That’s roughly 0.4” longer of SAAMI OAL. I drop it down to 3.980” and the bullet seems to protrude way far out and it won’t fit in the magazine. Bullet is lubed so it won’t stick to the barrel. What am I doing wrong?
 
perma said:
Alright you guys got me into the rabbit hole of finding my lands. I’ve done this with loctite and the jam method and end up at 4.010” on the smallest. That’s roughly 0.4” longer of SAAMI OAL. I drop it down to 3.980” and the bullet seems to protrude way far out and it won’t fit in the magazine. Bullet is lubed so it won’t stick to the barrel. What am I doing wrong?
Click to expand...
Nothing. Not uncommon at all to find the lands and the resulting bullets are too long for the magazine.
 
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