22 creedmoor

[DIBBS]

@Roadrace33

Are you using the same lot # of powder, primers, and bullets as before when the rifle shot lights out?

My first thought was a carbon ring or barrel fouling, but you are currently addressing that potential issue.

Scope bases, rings, action screws all tight? Have you tried a different scope?

 

[Roadrace33]

@Roadrace33

Are you using the same lot # of powder, primers, and bullets as before when the rifle shot lights out?

My first thought was a carbon ring or barrel fouling, but you are currently addressing that potential issue.

Scope bases, rings, action screws all tight? Have you tried a different scope?

I have checked scope mount (Spuhr) and action screws. Did not check another scope. This is a brand new TT 7-35. Not that they are without issues, but I sincerely hope it does not have an issue.

Same lot of primers, same lot of bullets. Different lot of powder.

I did a really good clean on it. Will try a few of my regular charges tomorrow, with a new jug of 4350 and see what happens. A lot more copper than I anticipated pulled out of the barrel. Odd, because I cleaned it a good 4-5 times as normal. Nothing heavy, but few patches, few strokes of a brush after each shooting. Carbon ring looks much better.

 

[tekmann2377]

While some may disagree, if you were seeing velocities in the 3450+ range with H4350, I do think it may have just been too hot. Pushing an overbore cartridge like this is going to be tough to keep "in tune" if you are pushing pressure limits, the consistency just won't be there day to day.

 

[Roadrace33]

While some may disagree, if you were seeing velocities in the 3450+ range with H4350, I do think it may have just been too hot. Pushing an overbore cartridge like this is going to be tough to keep "in tune" if you are pushing pressure limits, the consistency just won't be there day to day.

Thanks, I do agree with this. However i am curious about the "too hot". How do you determine it? The lands have not eroded very much at all, if any. With a Hornady OAL tool, its within .001-.002 of how it was new. When its pushed around 3600-3650 i get heavy bolt lift, however in the 3400 range, bolt lift is completely normal.

3450 is very fast, and i do plan to tone it down to 3200 range. I'm embarrassed to say how dirty the bore was after letting c4 sit in there for about 8 hours. I'm fairly certain that this was the issue. After scrubbing the carbon ring, it is also so much better. Typically if i clean every 100-150 rounds, its more than enough.

I finally got some n555 to try, so that will be in the works as well to see how it goes.

 

[Roadrace33]

For reference, here is how it shot with just about any load I threw at it 3300fps and above. It seemed to get tighter and tighter up to 3450-3500fps, then decline slowly. This pic is also with 20mph cross winds, so it was pretty awesome.

It was hard to not love these groups, and I stuck with it. Those are .36 white squares and .72 orange.

We will see how it groups tonight or tomorrow. The plan is to find a good group with the VLDS, then try the 85.5 hybrids. Night coyote season has been done for a while here, and I don’t hardly do any hunting of them in the summer.