Accurate load falls apart after 100

[silverhair]

As stated before, known and repeated under 1/2 moa at 100. This was the first chance I had to take it further. Hoping to repeat 250 today

How are your results today? Inquiring minds want to know. ;-)

 

[Satterlee Scott]

not a novice. ran into something I haven't seen before. Long story short..fired 3 diff bullets today out of the same cases, same primer, same powder just testing and playing. 26 Nosler 140 smks, 135 atips, 143 eldxs, smks and atips under 1/2 moa at 100 eldxs just over 1/2 moa. Took the smks and eldxs out to 250 and they both opened up to 4". As a control for wind we shot groups at 250 with a 243 and 6.5x47 that shot well. Anybody seen this before? Couldn't test the atips as I didn't load enough but the smks have consistently shot 1/2 or better at 100. I'm going to try them again but I'm curious if anyone else has come across this. Thanks

This time of year? What was the mirage like?

 

[Grizz1148]

This time of year? What was the mirage like?

Mirage was minimal. Not a mirage issue.

 

[skipglo]

I had the similar situation happen last weekend with a 6.5x06AI literally 1 hole at a 100 and 6" at 500. A .020 seating depth change brought it to .5 m.o.a at 500

Yuppers. Just got the same this week. Playing with seating depths. COAL MAX 2.80....SHOOTING real well, just touching lands at 2.80. A little stiff to load. .250 at 100
.375 at 300. Loaded five at 2.794...group opened to 3.8"@ 300....

 

[Bro Dave]

Yuppers. Just got the same this week. Playing with seating depths. COAL MAX 2.80....SHOOTING real well, just touching lands at 2.80. A little stiff to load. .250 at 100
.375 at 300. Loaded five at 2.794...group opened to 3.8"@ 300....

Skip, are you saying you set your bullet back .006 and it upset your group 3.425" ? or is there a typo?

 

[trappers son]

Mirage was minimal. Not a mirage issue.

Your barrel is running outta life... You have a loose action, scope ,mount, that is causing an larger variation in poi at range, the bullets might be way outta align concentricity could be way out and causing it... They would have to be 10 thousandth or more though.... Accidentally put different powder charges in cases or your scale is acting up.... Double check it with a second scale... Shooter error.... That about covers the possibilities.... Run through and retest with a fresh batch of loads after you tighten everything down on your rifle and clean out the barrel really good.... If it still shoots like **** it's your load or barrel... If it shoots good it was your previous loads if everything was tightened down without movement and your barrel wasn't too dirty.

 

[skipglo]

Skip, are you saying you set your bullet back .006 and it upset your group 3.425" ? or is there a typo?

That's correct! Shocked me.... I've been reloading 44 years

 

[Bro Dave]

That's correct! Shocked me.... I've been reloading 44 years

wow! that will make a guy think.

 

[Greyfox]

Given a stable bullet/twist, the only times I have experienced "consistently" tight groups/low ES at 100 yards, and the described type of deterioration, at 200-300 yards(ruling out a crazy wind), the issue has been the scope(parallax, turrets, or power ring), or, a change in rifle support(ie faulty front/rear rest) to accommodate the longer distance which introduced instability. IMO, for the groups to change so radically in such a short range span, it implies a mechanical influence as a result of increasing the distance. Occurring with different bullets is a tip-off.

 

[snookntarpon]

Try running a q-tip around the crown.. I had a rifle do something similar and I had a small burr on the crown. the burr will catch the cotton on the q tip. No clue how it got there but i must have hit it at some point. no noticeable ding, just a burr that i could not see with the naked eye.

 

[Grizz1148]

Try running a q-tip around the crown.. I had a rifle do something similar and I had a small burr on the crown. the burr will catch the cotton on the q tip. No clue how it got there but i must have hit it at some point. no noticeable ding, just a burr that i could not see with the naked eye.

I'll try that but I've never shot or carried it anywhere without the brake on it.

 

[snookntarpon]

well, mine had no brake...

 

[Mt rummy]

Crazy, but I would look at slumping. The bullet is changing shape due to perhaps a tight barrel, to fast of rotation and speed or perhaps you found the magical formula where all three contribute. Slumping is not a new phenomena.

Load down to another node and retest your different ranges. If "group opening" is not happening you may be on to something. My two bits.

 

[TwoMore]

Check your brake for any lip that will form on the edges of the bore from the blast, I usually have to "hone" my brakes after 200 to 300 rounds also if the brake is close to the crown I have had the blast damage the crown