Strange Day at the Range Part 2

T

thekubiaks

New member
As if I wasn't having velocity variation issues with my Haevy Gun, my factory Remington 7mmRM Sendero decides it want to act up too.

I finally found a consistent load that shoots amazingly well in this factory gun.

70.2 H1000, GM210M, 168SMK's, .020" off the lands.

The strange thing is the first shot (after two fouler shots) hits the bullseye at 200 yards. The second shot hits 9 o'clock at 1". THEN, the 3rd thru 10th shot make a nice .90" hole at 9 o'clock at 2". In other words, once the barrel warms up, the point of impact moves and pretty much stabilizes. What does this indicate?? A bedding issue?? Some kind of metallurgical thing with the barrel?? I'm about ready to just rebarrel with a Krieger but I'd like to make this barrel work if able. Thanks for the replies.
 
Sounds like Barrel Stress to me but 12 shots through a factory hammer forged barrel seems to be asking a lot. How long do you wait between shots? I had the exact same gun as yours but it did not show that tendancy....it shot fabulously. But I only shot 5 shot groups with it. I always let it cool after a couple of foulers.

Hovis
 
one question there cuz ,,,,,,,,,,,,,,,,,,, wind flags?,,,,,,,,,,,, if no wind flags your just working on your form / technique ,,,,,,,,,,,,,,,,,,,,,,

the wind is my friend,,,,,,,,,,,,,,,,,,,

DD
 
david dumas said:
one question there cuz ,,,,,,,,,,,,,,,,,,, wind flags?,,,,,,,,,,,, if no wind flags your just working on your form / technique ,,,,,,,,,,,,,,,,,,,,,,

the wind is my friend,,,,,,,,,,,,,,,,,,,

DD
Click to expand...

cuz,
thanks for the reply. Wind was calm, all flags were laying flat so that wasn't an issue.
 
ok, glad you are flagging, I hate to take anything for granted here,,,,, 1)barrel free floated??
2)bedding ok?
3)action screws tight?
4)age/number of loading cycles on brass (maybe a few work hardened case necks,ie: different tension/release)
5)as hovis ask, did you try 3 or 5 shot groups, 7 mag and 7STW really make heat,,,,,,,
6)did you recheck rings and bases?
7) have you got a extra scope to rule out a scope problem?
just throwing out possibles,,,,,,,,,,,,,,,,,

the wind is my friend,,,,,,,,,,,,,,,,,,,

DD
 
After checking action screws, ring bases, and rings for correct amount of foot pound tightness, without cleaning bore, reload those same 8 cases (shots 3 through 10) with exactly same components and shoot them without any sighters or barrel warm up rounds.

If they group at 9 o'clock 2" from bull as they did before, in my humble opinion there is nothing wrong with barrel growth, barrel floating, action bedding, or scope/bases/ or rings.

I would concentrate on a consistent bore cleaning technique. If your bore was squeeky clean and dry when you started shooting and say you made 25 passes through bore, try only 15 passes. If you use 2 wet patches to flush bore after brushing, try only 1 wet patch. If you use 3 dry patches to dry bore, try only using 1 or 2.

This isn't my brainchild, but passed along to me 15 years ago by an old eastern Kansas benchrest gunsmith when I was struggling during a match with same thing you are experiencing, and it worked!

Other opinions will vary.

Old Cob
 
Kub
A massive cleaning as Bob suggested is a first go to. Second have a stock smith check your bedding. Read what Jim Carmichael says in any of his books on guns about straying shots, not the barrel or load or scope it's a bedding problem.

Stephen Perry
Angeles BR
 
Exactly what corncob bob said! Your barrel may need more fouler shots to settle in where it will shoot the best.
 
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