Horizontal Stringing

[dwm]

The stock has a full aluminum bedding block. The action was making good contact on the bedding block, but the heavy duty recoil lug was not engaging very well.

I have now bedded the action with Devcon and can see that the recoil lug will be much better off being bedded.

Doug

 

[dwm]

By the way, Imperial Sizing Wax makes a great release agent.

Doug

 

[jb1000br]

Hey Boyd, nice to be here---

anyway--i have a 223 VS with full legth action bedding block. just for fun i smeared some steel bed behind the lug and under the action and it filled in the 1/16" gap running down each side of the action, that i couldnt tell were there originally. bedding that block cant hurt--let me know how it turns out.
Jason

 

[dwm]

Went to the range on Saturday with the action firmly bedded and a different scope.

Also, changed from shooting off the bipod to shooting off the regular front rest.

Pretty much the same results. I could get two shot within 1/4 inch at 100, but the other 3 could be off by 1 to 1 1/2 inches right and/or left. Vertical was less than an inch.

I thought if I shot WC872 at the same temperature (~90) each time that it would be ok.

I am getting what I think is great velocity, almost 3500 fps with the 160 GR Nosler Accubond.

Doesn't seem to be any pressure problems at 99.5 GR WC872, even with the bullets seated into the lands.

I tried different seating depths again, thinking that bedding the action and a different scope may do the trick. No change.

Going to go back to Retumbo.

Doug

 

[dwm]

Still stringing. Loaded some 160 GR Nosler Accubonds behind 93 GR of Retumbo.

Shot three and they hit in a perfect horizontal line about 1/2 inch apart.

They were flattening the primers, the bolt was somewhat hard to open, shiny spot on the case heads, etc. so I didn't shoot any more.

Guess I will back down to 91 GR Retumbo and try again.

Doug

 

[BountyHunter]

DWM

You are jumping around changing 2-3 things at once trying to cure one item.
Stop and regroup.

Horizontal could be from several things, some of which have been discussed. I am going to assume that an equipment problem has been eliminated as cause and wind was not a key factor.

-neck tension

-poor stock position and handling

- seating depth.

It sounds like you originally had a load that wanted to shoot and and you started shooting different loads of .005 depth changes, that is part of the tuning process. Seating depth changes will cause the horizontal. Keep the powder where it is at originally and shoot the .005 different groups to confirm which seating depth your gun likes and then shoot 2-4 more groups at varying ranges to confirm. The right seating depth will take out the horizontal. You can change neck tension by changing bushings or amount of brass turned off neck. Look for the group to tighten up and then start to open up again. Same way with incrementing the powder charges.

By changing powder weight and depth at once you are really hit or miss and you do not know what caused it to go bad or good. Only change one thing and shoot until you know where it tightens up and opens up.

BH

 

[rufous]

I too am having some problems with horizontal shots. I am shooting a 7mm Rem Mag with the 160 Accubond. I have tried varying the powder charge and the seating depth. I am pretty happy with the load I have come up with (8 groups averaging 0.85 MOA) but the larger groups are due to a shot off to the left or right. I was surprised by the comment that seating depth can have an affect on horizontal stringing. I had thought that powder charge and seating depth mainly affected vertical and that horizontal was mainly wind or gun handling or parallax. So far it seems that my gun is shooting this bullet best at touching the lands or 0.010" into the lands. Same basic accuracy at both. I have tried 0.010, 0.020, 0.025, 0.030, and 0.040" off the lands also. I have not tried 0.020" into the lands though. Maybe that would be even better? I did seat a bullet long (0.030" into the lands) and chambered the round just to see if the bullet would be pushed back into the case neck. It did not move. Neck tension must be farely high. I am using an RCBS competition full lenght sizing die, not the Redding bushing dies. Do you think there would be any point in trying 0.020 or 0.030" into the lands? Rufous.

 

[Guest]

ever tried letting the bullet seat its self in the chamber. it does work for some rifles I have seen it in several pull them groups right in there.

 

[338LM]

As mentioned, it could be a number of things.
You are getting to far ahead of yourself too quickly.
In my opinion the first obvious reason in horizontal stringing is trigger control. You can not troubleshoot any further until you are absolutely sure that you have your trigger control down and you are not pulling or pushing it off. You can not anticipate the shot, and you need to follow thru.
The next thing you need to critique is your shooting position and a natural point of aim.
Make sure you have the operators basics down first before you get into the technical issues of the rifle and your loads.
Everyone wants to always blame the rifle, loads, or shooting conditions, before they think about operator error.