Acceptable accuracy

[Tisto]

I have a Tikka T3 rifle chambered in 7mm Rem Mag that I've been working on for a while now. I'm trying to find a pet load for it. I fully understand that this is a hunting rifle, and that any moose, elk, caribou or ram I may take with it will never know what hit them. That having been said, I still want only to take clean, ethical shots.

The rifle itself is a stainless T3 lite, with a composite stock. It weighs very little, typical for a hunting rifle that is expected to be carried miles. It is topped with a Leupold VX-II 4-12X40, and the factory Tikka rings that came with the rifle.

Factory ammunition in various bullet weights from several manufacturers have been tested for accuracy, providing 5-shot groups ranging from 1" to well over 4" center to center. Since this is intended for large game animals approaching 1500 lbs, my choice is to use bullets on the heavy side for the caliber.

I began reloading for this gun hoping to improve its accuracy and terminal performance. I have tried several different bullets from Sierra, Nosler, Hornady, and Speer in various weights from 150 to 175 gr. I have combined these bullets with IMR 7828, 4831, 4955 as well as Alliant Reloader 25 powders. It seems that the best load combination so far is IMR 4955 powder (64.0 gr) with a Sierra 160 gr HPBT (#1925). Today's chronograph and accuracy testing for that load produced the following stats:

20 rounds were fired at a single target, for a single group measuring 1.350" The barrel was left to cool between 5-shot groups.
Muzzle Velocity (fps):
Average - 3013
High - 3050
Low - 2999
ES - 50
SD - 20.1

So I ask you, would you find this acceptable for a big game rifle ? I have always searched for the elusive 1-hole group, and find it hard to settle for "good enough". Should I call it good and load up the 400 pieces of once fired brass or should I keep searching ?

 

[Vapor]

Yes.

The question is for hunting how well do you shoot it off hand? Off shooting sticks? Hunting will never be nice groups off of a rest.

The boiler room on an elk or a moose is plenty big.

 

[dsdmmat]

You didn’t specify a distance if it is 100 yards it is acceptable, if it is 500 yards it is awesome. Did you shoot it off the bench or off hand? Again it would be acceptable or awesome depending on the answer. I wouldn't load all your brass Based upon this sample. How was the 5 shot grouping? Is it consistently under an inch? If so load em up and be done with it. If it was not consistent or below an inch at 100 keep playing with the seating depth until you get it consistent and under an inch.

I am not a hunter nor that great at bench rest shooting but To me the 20 shot group is acceptable if it was at a distance of 100 yards or beyond. if it was closer than that and you were on the bench you still have work to do.

 

[Podmonkey]

Didn't it used to be that 3-4 MOA was perfectly fine for any practical application? Like others have already implied sub MOA performance on the bench doesn't necessarily mean anything under field conditions.
If you found a load that can consistently group an inch @ 100 yards I would call that excellent.

 

[Vapor]

Didn't it used to be that 3-4 MOA was perfectly fine for any practical application? Like others have already implied sub MOA performance on the bench doesn't always mean anything under field conditions.
If you found a load that can consistently group an inch @ 100 yards I would call that excellent.

Yes, a 2-3 inch rifle is perfectly fine for hunting most of the time.

I know a man who has killed 100s of deer in NY whose shotgun is only good for about 6 inch groups at 100 yards...but he's doing that off hand, standing, in the cold. Its more than accurate enough to hit deadly vital area of a deer/black bear.

 

[dsdmmat]

Didn't it used to be that 3-4 MOA was perfectly fine for any practical application? Like others have already implied sub MOA performance on the bench doesn't necessarily mean anything under field conditions.
If you found a load that can consistently group an inch @ 100 yards I would call that excellent.

2 MOA is used or use to be the standard for military battle rifles and ammunition.

 

[Podmonkey]

2 MOA is used or use to be the standard for military battle rifles and ammunition.

For sniping weapons though right? I thought the military standard for the Garand, as with most infantry rifles of the period, was 4".

 

[Tisto]

You didn’t specify a distance if it is 100 yards it is acceptable, if it is 500 yards it is awesome. Did you shoot it off the bench or off hand? Again it would be acceptable or awesome depending on the answer. I wouldn't load all your brass Based upon this sample. How was the 5 shot grouping? Is it consistently under an inch? If so load em up and be done with it. If it was not consistent or below an inch at 100 keep playing with the seating depth until you get it consistent and under an inch.

I am not a hunter nor that great at bench rest shooting but To me the 20 shot group is acceptable if it was at a distance of 100 yards or beyond. if it was closer than that and you were on the bench you still have work to do.

Accuracy testing during all load development is done at 100 yards ( well, actually 103, but who's counting ? ) from a solid bench with a bipod front support and a sandbag rear.

All load development starts with 10 rounds of each charge weight . For example, using IMR 4955 and the 160 gr Sierra HPBT, starting charge was 60.0 gr. Increments of 1.0 gr up to max charge of 64.0 gr. Two groups of 5 rounds were shot so as to compare accuracy and velocities. The barrel was allowed to cool between shot strings. This process takes a lot of time, but I've found that it eliminates inconsistant results.

The load I did in-deapth testing on yesterday showed promise in both 5-shot load development groups, and justified further testing. Those two 5-shot strings produced 1.050" and 1.200" groups along with chronograph data in league with what my 20-round test produced.

Yes, I'm well aware that hunting conditions are never as good as a bench, which of course only detracts from the possible accuracy. Sure, the vitals on a N.Y. whitetail are a 10" target, and at 150 yards are no challenge. But caribou is a 300 to 500 yard game, and rams are frequently 600. That's a whole different playing field. Chasing a wounded caribou around a Nova Scotian island three times before it bleeds out doesn't sound like fun to me.

 

[dsdmmat]

did you clean the barrel in between shots? I assume you let the barrel cool to simulate hunting conditions where you will only expect to fire one shot. A build of of carbon or copper can screw with your velocities.

I would Play with seating depth On your tightest load and see if that closes the group. Your SD should be able to dip into the single digits.

 

[dsdmmat]

For sniping weapons though right? I thought the military standard for the Garand, as with most infantry rifles of the period, was 4".

there is a thread on this on the cmp forum The M1C specs were 2.5 inch and the M1 prior to the C was 3 inches.

 

[Podmonkey]

there is a thread on this on the cmp forum The M1C specs were 2.5 inch and the M1 prior to the C was 3 inches.

3" is a high standard for a 30s era self loading rifle.

 

[Tisto]

did you clean the barrel in between shots? I assume you let the barrel cool to simulate hunting conditions where you will only expect to fire one shot. A build of of carbon or copper can screw with your velocities.

I would Play with seating depth On your tightest load and see if that closes the group. Your SD should be able to dip into the single digits.

During load development, the barrel gets cleaned between charge increments, so every 10 rounds.

The 7mm Rem Mag is very much like most other extremely overbored magnums, the barrel gets HOT. REALLY HOT. FAST. After just 5 rounds, at a steady but reasonable pace, it's tough to touch the barrel. After 7 rounds, you cannot. There are several reasons for allowing the barrel to cool, not the least of which is the mirage effect in the scope.

Seating depth is already maxed out. The bullet is seated to max COAL. There is still a +/- .060" jump to the lands. It's just the way Sako ( Tikka ) chambers their belted magnum rifles.

I'm not saying that a consistant 1.25" group is bad, I just assumed I could make the gun do better, and may be a little disappointed - even if my disappointment isn't justified.

I guess what I'm really asking is, Should I be disappointed with these results and therefore keep searching for a better load or is this what I should expect and move on ?

 

[Shoots100]

I loaded rounds for a friend with the same rifle.
Being it has a 24" barrel with a 9.5" twist, the rifle should have success with the heavier 7mm projos.
He sometimes hunts in areas where lead is prohibited, so we tried a variety of monolithic projos.
I had good results with the hornady 139 GMX projo pushed moderately fast and he has killed a lot of animals over the years, at all different ranges.
SJC

 

[Podmonkey]

During load development, the barrel gets cleaned between charge increments, so every 10 rounds.

The 7mm Rem Mag is very much like most other extremely overbored magnums, the barrel gets HOT. REALLY HOT. FAST. After just 5 rounds, at a steady but reasonable pace, it's tough to touch the barrel. After 7 rounds, you cannot. There are several reasons for allowing the barrel to cool, not the least of which is the mirage effect in the scope.

Seating depth is already maxed out. The bullet is seated to max COAL. There is still a +/- .060" jump to the lands. It's just the way Sako ( Tikka ) chambers their belted magnum rifles.

I'm not saying that a consistant 1.25" group is bad, I just assumed I could make the gun do better, and may be a little disappointed - even if my disappointment isn't justified.

I guess what I'm really asking is, Should I be disappointed with these results and therefore keep searching for a better load or is this what I should expect and move on ?

Just to verify after re-reading your posts- you say on your best load you recorded and 5 shot group size of approximately 1.3" over 20 shots?
If so I think that is really very good for a production hunting rifle.

 

[dsdmmat]

During load development, the barrel gets cleaned between charge increments, so every 10 rounds.

The 7mm Rem Mag is very much like most other extremely overbored magnums, the barrel gets HOT. REALLY HOT. FAST. After just 5 rounds, at a steady but reasonable pace, it's tough to touch the barrel. After 7 rounds, you cannot. There are several reasons for allowing the barrel to cool, not the least of which is the mirage effect in the scope.

Seating depth is already maxed out. The bullet is seated to max COAL. There is still a +/- .060" jump to the lands. It's just the way Sako ( Tikka ) chambers their belted magnum rifles.

I'm not saying that a consistant 1.25" group is bad, I just assumed I could make the gun do better, and may be a little disappointed - even if my disappointment isn't justified.

I guess what I'm really asking is, Should I be disappointed with these results and therefore keep searching for a better load or is this what I should expect and move on ?

If you magazine is not limiting you seating depth push the bullet out further. I would try 10thousands Maybe 20 thousands off the lands You only need the width of the bullet in the neck of the case.

 

[Tisto]

I loaded rounds for a friend with the same rifle.
Being it has a 24" barrel with a 9.5" twist, the rifle should have success with the heavier 7mm projos.
He sometimes hunts in areas where lead is prohibited, so we tried a variety of monolithic projos.
I had good results with the hornady 139 GMX projo pushed moderately fast and he has killed a lot of animals over the years, at all different ranges.
SJC

Ironically, the best performing factory ammunition in my gun is the Barnes 160 gr TSX BT. ( +/- $ 60 / box of 20 BEFORE this latest price increase )

I bought a bunch of the 160gr TSX FB components, and couldn't seem to replicate the factory load. A VERY expensive undertaking. The BT version is not sold as a component.

Given that some of the game I intend to hunt is very tough, I want to stay with 160 gr bullets or heavier. The construction of most 140 class bullets is too light for what my next hunt requires.

 

[Tisto]

Just to verify after re-reading your posts- you say on your best load you recorded and 5 shot group size of approximately 1.3" over 20 shots?
If so I think that is really very good for a production hunting rifle.

Yes, you understand correctly. The two 5-shot strings during load development produced 1.050" and 1.200" groups, respectively. That lead me to further test that load with 20 rounds. Fired in (4) 5-shot strings at one target with cooling between strings, the 20 round group measured 1.350".

 

[Podmonkey]

Yes, you understand correctly. The two 5-shot strings during load development produced 1.050" and 1.200" groups, respectively. That lead me to further test that load with 20 rounds. Fired in (4) 5-shot strings at one target with cooling between strings, the 20 round group measured 1.350".

I personally would be very happy with that. But by all means, stay hungry and see if you can improve on that.

 

[Tisto]

I intend to do one more 20 round test. If the results are similar, I will order enough powder and bullets to load the 400+ pieces of once fired brass I have. All the brass is ready to go, sized, trimmed, polished, etc. it's just been waiting for me to develop a load. I'm getting tired of waiting on this one, and want to move on to a new project.

 

[Kent Goldings]

At 3000 FPS it’s gonna take more than 1/2 a second to reach the target at 500 yards. I wouldn’t care to shoot at an animal with any more lag than that. But, I think you’ll have plenty of energy at that range. Combine that with one of these Hornady ELDX bullets, it’s going to be lights out for the creature.

 

[SmallGameAddict]

I'll tell you what, if my fleaweight factory production rifle was grouping inside 1-1/2" @ 100 yards, I wouldn't complain.

It's your money. Over the years I don't chase my tail seeking the "it's junk if it don't shoot moa" ghost. 30-06 with 165 grain bullets, grab the IMR4350 and load up.

1-1/2" @ 100 yards = 6" @ 400, providing you can get a solid field rest and a comfortable position. That's venison on the freezer. An elk you're talking a 12-16" vital area.

I wouldn't lay awake at night losing sleep over it.

 

[Kent Goldings]

I’ve been guilty of chasing MOA accuracy when it comes to squirreling. But, I’ve noticed that bench accuracy is never realized in the field. Even though my squirreling rifles should be capable of head shots at 50 yards. I rarely attempt it at more that 30. I usually try for the lungs. With minimags, they don’t crawl off.

 

[SmallGameAddict]

I’ve been guilty of chasing MOA accuracy when it comes to squirreling. But, I’ve noticed that bench accuracy is never realized in the field. Even though my squirreling rifles should be capable of head shots at 50 yards. I rarely attempt it at more that 30. I usually try for the lungs. With minimags, they don’t crawl off.

And there it is. Practical field accuracy versus trying to win the High power Nationals at Camp Perry

 

[Shoots100]

Ironically, the best performing factory ammunition in my gun is the Barnes 160 gr TSX BT. ( +/- $ 60 / box of 20 BEFORE this latest price increase )

I bought a bunch of the 160gr TSX FB components, and couldn't seem to replicate the factory load. A VERY expensive undertaking. The BT version is not sold as a component.

Given that some of the game I intend to hunt is very tough, I want to stay with 160 gr bullets or heavier. The construction of most 140 class bullets is too light for what my next hunt requires.

The GMX is monolithic and usually retains 95% of it's weight.
He's shot big bull elk, stag and all sorts of African plains game with that load and has never recovered a bullet.
He's only found a fragment of a bullet in the hide of a big black bear he shot through the shoulders and bears are about as tough as they come.
If your getting great accuracy with other projo's, don't look back.
SJC

 

[Tisto]

Today's results:

This is the second 20-round test for this load. This group was not quite as good as the first 20-round test results, but I believe it is consistant. There was 1 flier ( low, left ) which threw the group off. Measuring center to center, the largest distance is still just 1.600" if you discount the flier, the group is right at 1.400". Today's test was shot in (6) strings of 3 shots, and a final string of 2 shots, totalling 20. The barrel was allowed to cool between strings. And, it was rather windy roday.

The chronograph results were in line with the prior testing, even a bit higher in velocities.

Muzzle velocity ( fps )
Average 3035
Hi 3059
Lo 3007
ES 51
SD 13.9

 

[meketrefe]

Tisto,
My 7rem is a savage and will print a tad below 1moa with quality ammo. It is expected of the 7RM as it is inherently accurate.
Do the spreads series in groups of 5 or 3 like several groups of 3 inside 300yards and then move to at least 4 groups of 5 beyond.
groups inside groups do not say much about the spreads.
RL 22 and 175gr berger are the most accurate combination so far.
If you are not going to shoot long range then don't worry so much about 1/2moa for hunting at average ranges but the 7mm
should be able of great accuracy even for a hunting rifle.
I would say play with some deadblow weight inside the stock and also the torque values of the action.

 

[Phauxtoe]

A one hole group is more about the shooter than the rifle.

 

[Kent Goldings]

Still have those mysterious flyers? Come to the dark side.

https://www.hornady.com/reloading/precision-measuring/precision-tools-and-gauges/lock-n-load-concentricity-tool

 

[Phauxtoe]

Start with great components...

Seirra match kings
Lapua brass
Varget or High end powder

BASIC STARTING POINT
your looking for low extreme spread numbers first, then adjusting bullet depth/ length for small groups, Then center the group.

 

[Tisto]

Tisto,
My 7rem is a savage and will print a tad below 1moa with quality ammo. It is expected of the 7RM as it is inherently accurate.
Do the spreads series in groups of 5 or 3 like several groups of 3 inside 300yards and then move to at least 4 groups of 5 beyond.
groups inside groups do not say much about the spreads.
RL 22 and 175gr berger are the most accurate combination so far.
If you are not going to shoot long range then don't worry so much about 1/2moa for hunting at average ranges but the 7mm
should be able of great accuracy even for a hunting rifle.
I would say play with some deadblow weight inside the stock and also the torque values of the action.

This is getting to my point, albeit in a roundabout way. Hornady reloading book says the 7mm RM is capable of fine accuracy. Lyman has stated similar. The problem lies in the fact that no-one will define what is "fine accuracy" or any similar description. If my 6mm PPC was shooting 1.3" groups at 100 yards, I would call it a POS and get rid of it. By the same token, if I got 1.5" groups out of my slug gun, I would think I had won the lottery.

Yeah, I get it. This is a hunting rifle. It's very light weight. It has a skinny barrel profile. I don't expect it to compete with my 6PPC in terms of accuracy. The question is, where do we draw the line as to what one can reasonably expect.

I've taken a lot of game. This rifle is intended to ETHICALLY drop big game, some of which is dangerous, and all of which will be large or very large, and much of which may be at extended distances. The 7mm RM is quite capable of dropping any animal that walks this continent. It may not be my first choice for some animals such as the big bears ( brown and polar ) but it is in fact capable of the task.

With factory ammo, I have seen a HUGE fluctuation in groups. As stated prior, the factory ammo that produced the best groups from this rifle is the Barnes Vortex 160 TSX BT. That ammo will shoot roughly the same as the 20-shot group of my reloads above. Other ammo, such as the Winchester Super X 150's consistantly shoots a 4- 1/2" group at 100 yards. I find that wholly unacceptable. Other factory ammo shoots worse than that !

I just wonder if I should be happy with the results above or if I should continue to look for something better that may or may not exist.