Looking for info on accuracy with a new build 40X

[sanitaryharry]

Recently built a Rem 40x in 6mm BR. Originally a 22-250 stainless barrel. Had a Shilen match stainless barrel, 1:10 twist, fitted and action trued. Also changed the stock to a H_S Precision and had the front of the action bedded including 1/4" of the barrel. I shoot 3 shot groups and almost always get two shots in one hole with one shot out about 3/8" to 1/2" out. I never know if it will be the first shot, second or third. I put o-rings on the barrel to try and settle harmonics , didn't work. Put a wedge between stock forend and barrel for slight "UP" pressure. Didn't work. Any suggestions? Using Lapua cases, 70 gr. Sierra Match Kings and Varget powder. Tried different charges of powder but didn't want to go too high and get pressure problems.

 

[47WillysGuy]

Aaaah! The quest begins! Read anything you can get you hands on, find a mentor.

This is what I do:
-start good new brass.
-Load and shoot it.
-Clean primer pocket.
-Clean flash hole both sides to remove burrs.
-Anneal after every firing.
-full size case pushing shoulder back .002".
-Trim all casenecks to same length after every firing.
-turn necks to an equal thickness on the circumference.
-Sort brass; either by weight, by water capacity, or by powder.
-find the thin side of the case and mark it.
-Procure primers
-Procure powder
-Procure projectiles
Put it all together, keep good records, go to range and find out how it shoots! They don't call it precision shooting for nothing. Good luck be safe and read!

 

[Ggmac]

What chamber was cut ? Modern Reamers have a long throat for heart bullets . What twist is it ? Sorry if it's been answered .
How long precision shooting , bench ? What front rest ? , rear bag ? , how many rounds down the barrel ?, what make barrel ? Wind flags ? Parallax setting correct ? , scope and mounts solid ?
Need more info.
Thanks Gary

 

[sanitaryharry]

What chamber was cut ? Modern Reamers have a long throat for heart bullets . What twist is it ? Sorry if it's been answered .
How long precision shooting , bench ? What front rest ? , rear bag ? , how many rounds down the barrel ?, what make barrel ? Wind flags ? Parallax setting correct ? , scope and mounts solid ?
Need more info.
Thanks Gary

Don't know the name of the chamber that was cut. What are heart bullets, not familiar with them. 1:10 twist. I don't consider myself a precision shooter, just trying to do better. No competition except myself. Front rest is a shot bag filled with kitty litter. Rear bag is a leather Protektor with hard base. Approx. 400 rds. Shilen barrel. No wind flags. Parallax adjusted properly. Scope and mounts are solid in place. Thanks, David

 

[stacy]

CHECK THE BEDDING AND MAKE SURE THE ACTION IS PROPERLY TORGUED SCOPE BASES ETC I SEEN PRIMERS DO THE SAME THING AS OTHER MENTIONED

 

[Ggmac]

Make sure that the bolt handle , trig , don't touch the stock . Have a buddy shoot it , and as was said check bedding and screw torque .
Try to load some bullets almost touching the lands .
Good luck , keep shooting , tiny groups are always rewarding .

 

['Freak]

Look see under Ernie’s “Gunsmithing Odds and Ends”, http://erniethegunsmith.com/catalog/c41_p1.html , for why a rifle in any manufacturer’s “aluminum bedding block stock” is still likely to benefit from having that one individual action bedded “stress free” to its own individual stock.
http://erniethegunsmith.com/catalog/i130.html
http://erniethegunsmith.com/catalog/i133.html
http://erniethegunsmith.com/catalog/i149.html
http://erniethegunsmith.com/catalog/i186.html

 

[LHSmith]

Before doing anything else, use survey tape at 25 yard intervals and learn when to shoot under the same condition. Without some form of windflags, you are just plinking. That accuracy potential of that rifle necessitates the use of wind flags. A 5 mph crosswind will move that 70 gr. bullet 3/8" @ 100 yards......shoot your group in a reverse (changed from a left to a right push and it will only take a 2 1/2 MPH wind to create the same 3/8" dispersion. Also, always discount the first shot or two from a cold, clean barrel, and attempt to shoot all shots in a group with the same barrel temp. -which may mean discounting the first shot from a cold barrel. If all is well ( a tuned load, good wind calling, and mistake free gun handling) that rifle should virtually shoot 5 shot groups as small as 3 shot groups.
I would recommend to remove the bedding under the barrel, and forget the wedge fix. That setup needs to be freefloating.
After re-reading your post, I got to ask what barrel contour is it wearing now?

 

[alintx]

Recently built a Rem 40x in 6mm BR. Originally a 22-250 stainless barrel. Had a Shilen match stainless barrel, 1:10 twist, fitted and action trued. Also changed the stock to a H_S Precision and had the front of the action bedded including 1/4" of the barrel. I shoot 3 shot groups and almost always get two shots in one hole with one shot out about 3/8" to 1/2" out. I never know if it will be the first shot, second or third. I put o-rings on the barrel to try and settle harmonics , didn't work. Put a wedge between stock forend and barrel for slight "UP" pressure. Didn't work. Any suggestions? Using Lapua cases, 70 gr. Sierra Match Kings and Varget powder. Tried different charges of powder but didn't want to go too high and get pressure problems.

I would try some 68gr benchrest bullets, after taking of the tuner and get that pressure off of it. Problem may go away

 

[swd]

I recently had a similar problem and it turned out to be my rest. So check the things you might not normally think of.

 

[Steve Ladino]

Recently built a Rem 40x in 6mm BR. Originally a 22-250 stainless barrel. Had a Shilen match stainless barrel, 1:10 twist, fitted and action trued. Also changed the stock to a H_S Precision and had the front of the action bedded including 1/4" of the barrel. I shoot 3 shot groups and almost always get two shots in one hole with one shot out about 3/8" to 1/2" out. I never know if it will be the first shot, second or third. I put o-rings on the barrel to try and settle harmonics , didn't work. Put a wedge between stock forend and barrel for slight "UP" pressure. Didn't work. Any suggestions? Using Lapua cases, 70 gr. Sierra Match Kings and Varget powder. Tried different charges of powder but didn't want to go too high and get pressure problems.

Various neck tensions...donuts....leaning on the stock could cause this grouping scenario too.