7mm Rem Mag help

220yotekiller

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I am in the middle of building a new load for my 7mm Rem Mag and I'm about to tear my hair out in frustration. I am using H4831 and 150 gr Nosler Balistic Tip bullets. I have had 2 occasions where I have shot under 1 inch groups one was .990 and the other was .908 when I shot the loads a second time they spread out to 1.320 and to 1.380. All were 3 shot groups shot off of a bench off of sandbags and a rest. I went out tonight and got a group that mesured .885, I have put about 30 rounds through this rifle without cleaning it. Should I clean it and then fire a fouling shot then shoot the group? I should add that this rifle is very accurate with Nosler Accubond bullets (.65 with 160 grain Accubonds) but we all know how avalable they are right now.
 
Do you set the COL with a comparator to the ogive?

I’ve been doing that with some of my different loads and it’s showing good results
 
Do you set the COL with a comparator to the ogive?

I’ve been doing that with some of my different loads and it’s showing good results
I do, I check each round and I make sure that they are within a thousandth of an inch or they get pulled and reloaded.
 
What happens if you have somebody else shoot the rifle?
 
I am in the middle of building a new load for my 7mm Rem Mag and I'm about to tear my hair out in frustration. I am using H4831 and 150 gr Nosler Balistic Tip bullets. I have had 2 occasions where I have shot under 1 inch groups one was .990 and the other was .908 when I shot the loads a second time they spread out to 1.320 and to 1.380. All were 3 shot groups shot off of a bench off of sandbags and a rest. I went out tonight and got a group that mesured .885, I have put about 30 rounds through this rifle without cleaning it. Should I clean it and then fire a fouling shot then shoot the group? I should add that this rifle is very accurate with Nosler Accubond bullets (.65 with 160 grain Accubonds) but we all know how avalable they are right now.
Have you gone over your rifle to see if something may have come loose? Also as stated above have someone else go over the rifle and shoot it too see if the results are still the same.
 
I would not worry about the difference in the size of those groups much. Strange thing about shooting groups, you seldom shoot the same spread group twice in a row, Has something to do with most us shooters! The difference between 1.380 and .908 just isn't that much! That's about .472, bit less than a 1/2". What would determine for me the value of the load would be the overall size of a number of groups. Somedays we just don't shoot as well as we do other days! Years ago I had a 7mm Rem Mag that I'd completely re-bedded and it shot great, averaged 5/8" groups. That does not mean every group was 5/8" but take a number of them and average them out and that's what I got. One of my most accurate shooting loads in it was with a 115gr bullet, not much of a big game bullet but boy did it shoot well. The way I decided what bullet to settle on is it got into a run off with the 160gr Speer and 154gr Hornady Spire Point! Speer won out by about 1/8" groups which didn't really amount to squat! But those were early years in reloading and at that time it ment a lot to me. Kind of ho-hum today!

Something you'll notice when shooting groups, 3 shot groups should be the smallest and it's one dumb animal that allows you more shots than that. But take that three shot group and shoot two more shot's often the group will open in size. Go to ten shots and normally will open more. I believe a lot of that is the shooter and the rest is a barrel getting dirty and hot. I've tried letting a rifle I was shooting on a to warm day sit about five minutes then touch the barrel and it's still hot! No idea how much that much heat actually effect's the bullet but probably some. Also I've super cleaned barrels thinking they would have to be more accurate and over the years I decided that I over cleaned them, the world famous fouling shot always seems to open the group some. Your out hunting and get a shot, the first shot you take will be the fouling shot!

if you shoot a number of three shot groups at a time, seem's they grow then too. maybe the heat, maybe the dirty barrel but some, has to be blamed on the shooter getting beat up with recoil! Seem's to wreack havoc with trigger control! So, go shoot several three or five shot groups over several days and figure out what the average size come out to.
 
I think this is a product of three shot "groups". You can randomly shoot decent three shot groups, but that doesn't mean that combo is repeatable. The only thing I can tell from 3 shot groups is what won't shoot.

Once I start shooting groups, 5 is the minimum. You really want to see what something can repeatedly do, shoot 10 shot groups. I shoot a group and let the rifle cool. Clean after each session. I'm not interested in owning a combo that can't be shot in this manner.
 
Your rifle is perfectly adequate, buy a steel plate, get off the bench and go shoot from field positions, that's what I do when I have a rifle/load that's not shooting to my satisfaction. It's pretty gratifying to walk out to 300 hang the plate and then over the next hour hammer the general center of the plate from an improvised position. That 1/2 inch variable is moot. If every round hit the 8 inch plate you got your Antelope or anything bigger.
I've seen other stuff you've written, you know your way around a rifle, I would tell you you're over thinking it. I would also ask if you're.01 to.02 off the lands with the Ballistic Tips.
 
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I would not worry about the difference in the size of those groups much. Strange thing about shooting groups, you seldom shoot the same spread group twice in a row, Has something to do with most us shooters! The difference between 1.380 and .908 just isn't that much! That's about .472, bit less than a 1/2". What would determine for me the value of the load would be the overall size of a number of groups. Somedays we just don't shoot as well as we do other days! Years ago I had a 7mm Rem Mag that I'd completely re-bedded and it shot great, averaged 5/8" groups. That does not mean every group was 5/8" but take a number of them and average them out and that's what I got. One of my most accurate shooting loads in it was with a 115gr bullet, not much of a big game bullet but boy did it shoot well. The way I decided what bullet to settle on is it got into a run off with the 160gr Speer and 154gr Hornady Spire Point! Speer won out by about 1/8" groups which didn't really amount to squat! But those were early years in reloading and at that time it ment a lot to me. Kind of ho-hum today!

Something you'll notice when shooting groups, 3 shot groups should be the smallest and it's one dumb animal that allows you more shots than that. But take that three shot group and shoot two more shot's often the group will open in size. Go to ten shots and normally will open more. I believe a lot of that is the shooter and the rest is a barrel getting dirty and hot. I've tried letting a rifle I was shooting on a to warm day sit about five minutes then touch the barrel and it's still hot! No idea how much that much heat actually effect's the bullet but probably some. Also I've super cleaned barrels thinking they would have to be more accurate and over the years I decided that I over cleaned them, the world famous fouling shot always seems to open the group some. Your out hunting and get a shot, the first shot you take will be the fouling shot!

if you shoot a number of three shot groups at a time, seem's they grow then too. maybe the heat, maybe the dirty barrel but some, has to be blamed on the shooter getting beat up with recoil! Seem's to wreack havoc with trigger control! So, go shoot several three or five shot groups over several days and figure out what the average size come out t
Your rifle is perfectly adequate, buy a steel plate, get off the bench and go shoot from field positions, that's what I do when I have a rifle/load that's not shooting to my satisfaction. It's pretty gratifying to walk out to 300 hang the plate and then over the next hour hammer the general center of the plate from an improvised position. That 1/2 inch variable is moot. If every round hit the 8 inch plate you got your Antelope or anything bigger.
I've seen other stuff you've written, you know your way around a rifle, I would tell you you're over thinking it. I would also ask if you're.01 to.02 off the lands with the Ballistic Tips.
I averaged out .990 and 1.380 and it averaged 1.185, just a touch over an inch. I think I am over thinking this thing haha.
 
Your rifle is perfectly adequate, buy a steel plate, get off the bench and go shoot from field positions, that's what I do when I have a rifle/load that's not shooting to my satisfaction. It's pretty gratifying to walk out to 300 hang the plate and then over the next hour hammer the general center of the plate from an improvised position. That 1/2 inch variable is moot. If every round hit the 8 inch plate you got your Antelope or anything bigger.
I've seen other stuff you've written, you know your way around a rifle, I would tell you you're over thinking it. I would also ask if you're.01 to.02 off the lands with the Ballistic Tips.
The .990 group was 60 thousandths off of the lands.
 
I think that’s just what the load and shooter can do on different days. Some days you are on your game sometimes you aren’t. If wanting tighter groups maybe switch powders. Always used 7828 and 150 grain ballistic tips to check the potential of 7mm Remingtons. If it won’t shoot that combo the gun won’t shoot.
 
Ok, several things strike me off the bat.

"0.060" off the lands".
No need to be that far back with the Ballistic Tip. Even though they are the same form, there is a huge difference between what at Ballistic Tip likes & what the Accubond likes.

Try 0.020" off the lands.
This has been my sweet spot for Ballistic Tips.

Shooting from front bag. I HATE TO HAVE TO ASK THIS, but stock resting on the bag, not the barrel?
Yes i see it all too often.

What make/model of rifle?
1.3" isn't too great for a bolt rifle.
Not bad for a BAR.
 
Ok, several things strike me off the bat.

"0.060" off the lands".
No need to be that far back with the Ballistic Tip. Even though they are the same form, there is a huge difference between what at Ballistic Tip likes & what the Accubond likes.

Try 0.020" off the lands.
This has been my sweet spot for Ballistic Tips.

Shooting from front bag. I HATE TO HAVE TO ASK THIS, but stock resting on the bag, not the barrel?
Yes i see it all too often.

What make/model of rifle?
1.3" isn't too great for a bolt rifle.
Not bad for a BAR.
.020 off the lands was 1.328" .040 was .990" then it expanded on the second shooting to 1.320"
haha the forend was on the bag with the rear of the stock on sandbags.
 
I actually havn't had anyone else shoot it, that is a good idea.
Subconsciously, you may have developed a flinch too.

Test this by having someone smack your shoulder and then randomly NOT smack the shoulder. Hard enough to mimic the recoil too.

I’d also check your muzzle under a scope for burrs/nicks. Consider recrowning if it shows cleaning damage.

And clean it less. Until accuracy falls off.
 
.020 off the lands was 1.328" .040 was .990" then it expanded on the second shooting to 1.320"
haha the forend was on the bag with the rear of the stock on sandbags.
Some rifles shoot better with more jump, that is probably why your rifle is grouping better at .040 as compared to. 020. Try experimenting with bullet seating to find that rifles sweet spot with that load, or try another type powder. Lots of variables.
 
Make/model of rifle?

I had to ask how you were resting your rifle. See it way too often with the barrel on the rest.
 
I'm finally happy with it. I loaded 3 more rounds that shot .885 last time. When I got out to the range I shot a group size of .690 I'm perfectly happy with that so I'm going to call it good and load up a bunch for hunting season. I think a big thing that changed for me was reading the breeze, light as it was. Only firing when it stopped. I also double, triple checked that my barrel wasn't touching anything. Thank you all for your advice.
 

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