Need help. Loading 7mm Mag. Can't get consistent accuracy.

[Fursty]

Ok, here are the charts of the H4831SC from 58gr up to 67gr.
FPS from 2580 up to 2950.

The gun likes the lower FPS, but the groups jump up vertically after about 2800 fps.

 

[artbosco]

I suggest that you be realistic. You are not going to get the accuracy of a precision $$$ rifle out of a dollar two nighty eight bottom of the barrel rifle. You can't make a silk purse out of a sows ear.

+1 If you can keep your shots within an 8 inch circle at 100 yards you've got what you paid for. $65 factory barrels won't give you want you're looking for.

 

[fdshuster]

You may find this interesting.

 

[Spin Drift]

You may find this interesting.

How old is that article?

 

[Fursty]

Ok I just went back to check my Oal to ogive length and with the SST bullet was 2.733 but now it is showing 2.748. So, what is going on? Throat erosion?

 

[Spin Drift]

Ok I just went back to check my Oal to ogive length and with the SST bullet was 2.733 but now it is showing 2.748. So, what is going on? Throat erosion?

How many shots has it been since you last checked? Did you use the exact same bullet for both tests? I always save the bullet in my drawer to check with later because there can be a difference from bullet to bullet.

When I check the length I do it many times until I start to get consistent numbers. It's a tricky thing to measure

 

[Fursty]

No I did not keep the same bullet. About 150-175 shots since first measured.

 

[Spin Drift]

No I did not keep the same bullet. About 150-175 shots since first measured.

Your throat should not have moved that far already.

It's probably either inconsistent measuring techniques or the 2nd bullet is a bit different.

 

[searcher]

I'd not be too quick to ditch the gun as some might suggest. I have/had a few 7mm Rem Mag's that did not seem to want to shoot at all. One is a custom built BAT action, Krieger, Jewel, McMillan number that shot 2" and 3" groups with most loads offered, including your 154SST with 4831. Experimenting pays off. Settled on Reloader 22 and Barnes TTSX 140 grn at 1/3 M.O.A. for hunting and Nosler 150 Ballistic Tips with IMR 4064 for plinking. Speer 120 H.P.'s with IMR 4350 make for very accurate varmint rounds in my rifle. When you find the good combo, you'll know.

 

[Spin Drift]

I'd not be too quick to ditch the gun as some might suggest. I have/had a few 7mm Rem Mag's that did not seem to want to shoot at all. One is a custom built BAT action, Krieger, Jewel, McMillan number that shot 2" and 3" groups with most loads offered,

The 7RM can be a fussy cartridge but that is just a crying shame. That really sounds like you got a dud or maybe you are playing with bullets that aren't optimal for your twist rate?

Besides, the OP is having poor accuracy with factory ammo as well.

 

[searcher]

The point was to not give up on finding a good load until you have been through the wringer with it. My two "difficult to tune" rifles all have a load they like very much - it just didn't happen without some extensive testing of powder/bullet combos on a few of them. I might add that those "tough to tune" rifles are both "pencil" barrelled sporters - which tend to be the pickiest. Once they found the right powder combo - they shot quite well indeed. They surely could have been classified as "duds" by one not willing to go further with them. And that is the way it works with a lot of rifles or barrels that people write off as a piece of "!?*&" far too early.

 

[boltgunluvr]

If you desire accuracy then don't assume you can shoot the speed you really want. Fact is, rifles tell us what they like and what they don't like. We just have to be patient and listen. All of my rifles love very mild loads. I'm good with it because they shoot well, day after day. Try the lower end of the velocity spectrum.

 

[Fursty]

Is it unreasonable to expect both velocity and accuracy?

I am going back to a lower velocity that had the best groups to try 5 round groups and just prove that the gun is capable of good groups. Or maybe disprove. Go from there.

 

[Spin Drift]

I am going back to a lower velocity that had the best groups to try 5 round groups and just prove that the gun is capable of good groups. Or maybe disprove. Go from there.

That's a pretty good plan.

Sometimes it is a hard battle to get accuracy and speed at the same time. I really don't like slow speeds either.

Do you have a run out gauge? It is possible your loads are wonky, that can do terrible things to groups. If you don't have the gauge you can use a nice smooth flat table or counter and roll your ammo and watch the bullet to see if it's perfectly straight.

And maybe you answered this already but how sure are you of your shooting skills? Have you had better results with other rifles?

 

[Fursty]

I am not so sure of my shooting skills at this point, but if I can replicate those good groups that should give me some confidence that I can shoot fairly consistently. Trust me, I haven't ruled myself out of the equation.

I will also try from bags and the sled to see how that compares.

As far as runout, I will see if I can see anything visually as I don't have a gauge. I have been loading the bullets half way and then rotating 90 degrees and then finishing the seating to try to eliminate runout issues. I read that someone else used that method to fix their problem. Is that an accurate solution?

 

[Spin Drift]

I have been loading the bullets half way and then rotating 90 degrees and then finishing the seating to try to eliminate runout issues. I read that someone else used that method to fix their problem. Is that an accurate solution?

I've done a bit of experimenting and I found that it depends on the dies. I have one die that if I do anything like that the run out gets worse so for that one I just seat in one single press stroke as smoothly as I can and it gets the best results that way. Another set likes for me to just barely start the bullet, then I turn about 90 degrees and it gets seated all the way and has produced the best results with that method.

I am not so sure of my shooting skills at this point, but if I can replicate those good groups that should give me some confidence that I can shoot fairly consistently. Trust me, I haven't ruled myself out of the equation.

I will also try from bags and the sled to see how that compares.

Experimenting with different rest methods is a great idea. Make sure you write on the target or journal what rest you used so you can compare later. It is often tough to determine if it's the equipment or the shooter. I have recently hit a point with one of my rifles that is shooting amazingly well where the only reason it doesn't shoot even tighter is because of my own personal skills. My other rifles never really allowed me to see that so clearly and this is opening up a whole new level of vision for me on how I am performing as a shooter.

If you can find someone in your area that is willing to give you a few tips (look for the guy at the range who seems like he never goes home and he's shooting bug hole groups). Even ten minutes with someone that really knows what they are doing will do wonders for your technique. It's also helpful if they shoot your gun to see if its you or the rifle.

Check out this video. Some things will be a bit different if you are using bags front and rear but the fundamentals here are key.
https://www.youtube.com/watch?v=_FhxVS5A3gk
These guys make also make some other good videos that have been helpful to me.

 

[South Paw Sammy]

Fursty, good afternoon.

just read this, a load I have had great success with has been
69grns RL 25
160 Nosler Accubond
Remington Brass
and Fed GM215M Primers

 

[boltgunluvr]

Fursty....I forgot to mention I always shoot a flat base bullet with mild load first for initial testing to make sure a rifle is relatively decent. Some rifles just don't shoot boat tail bullets well and some bullets perform much better when they are jumped, sometimes quite a bit. I'm jumping a few as much as .065-.075(in). Not sure of your exact bullets. Are they tangent or secant ogive, flat base or boat tail? My small caliber rifles....223s and smaller shoot flat base much better, night and day difference. Just some things to consider without costing money.

 

[Fursty]

Tangent ogive. Boat tail. Shooting Nosler Accubond LR 168 Gr

 

[boltgunluvr]

Tangent ogive. Boat tail. Shooting Nosler Accubond LR 168 Gr

7mm Rem Mag, right? Does your barrel have the appropriate twist for that weight/shape bullet? Sometimes the weight may be alright, but the shape doesn't give enough bearing surface to stabilize the bullet. Do you have flat base bullets on hand? If so, which one? Don't get too upset yet. The answers can be right in front of us. By any chance, could it be your scope/rings?