How far or many rounds would one go before tossing a certain powder or bullet and how do you know which one is the trouble maker? I think a lot of the issues is the cold weather now. Working with a 308 match chamber designed for the 155gr bullets and got a crap ton of Nosler Custom Comp bullets and working with AR comp powder. Have run several OCW test and even repeated a few, may just give up till spring...no consistent results from one day to the next?
How far to go before giving up on a powder or bullet and which one?
- Thread starter Lefty Trigger
- Start date
Assuming you're using a suitable powder for the caliber you are loading, I'd would change bullets first. I've found that the type of bullet you choose has the most significant impact on group size again assuming the powder choice is appropriate.
PS: IMR 4064, Varget, and IMR / H 4895 are proven powders for the 308 especially for bullet in the 150 grain range.
PS: IMR 4064, Varget, and IMR / H 4895 are proven powders for the 308 especially for bullet in the 150 grain range.
Keith Glasscock
Gold $$ Contributor
A good barrel should shoot less than 3/4 MOA with nearly anything you put in it. If not, you are more likely to have a problem other than the load.
I'll just throw this out here:
My theory is that there are 3 kinds of nodes. Lets just call them full nodes, half nodes, and quarter nodes.
If I were to make an analogy, I would equate them to meeting girls.
A quarter node is really attractive, but is in need of constant attention. If you fail to anticipate anything, your dreams won't come true.
A half node is very attractive, but the attention requirements are reduced. You can make up with a half node if you get off track. For a point of reference, at least 3 of the last 4 F-Open national record holders were shooting a half node when they set the record.
A full node is the proverbial "Where have you been all my life?" It requires some attention, but never lets you down. Its bad day is almost as good as the other's good days.
While my calculator isn't ready for prime-time, I can give you a good guess as to which you are looking at. Here is what I need:
Bullet manufacturer, weight, and type I think you said Nosler, but what weight and type?
Case manufacturer and primer
Cartridge - I think you said 308 Win
Charge and chronographed velocity of your best load thus far.
Barrel length
From there, I can give you a good guess of where you fall in the spectrum.
I'll just throw this out here:
My theory is that there are 3 kinds of nodes. Lets just call them full nodes, half nodes, and quarter nodes.
If I were to make an analogy, I would equate them to meeting girls.
A quarter node is really attractive, but is in need of constant attention. If you fail to anticipate anything, your dreams won't come true.
A half node is very attractive, but the attention requirements are reduced. You can make up with a half node if you get off track. For a point of reference, at least 3 of the last 4 F-Open national record holders were shooting a half node when they set the record.
A full node is the proverbial "Where have you been all my life?" It requires some attention, but never lets you down. Its bad day is almost as good as the other's good days.
While my calculator isn't ready for prime-time, I can give you a good guess as to which you are looking at. Here is what I need:
Bullet manufacturer, weight, and type I think you said Nosler, but what weight and type?
Case manufacturer and primer
Cartridge - I think you said 308 Win
Charge and chronographed velocity of your best load thus far.
Barrel length
From there, I can give you a good guess of where you fall in the spectrum.
Here is MY experience in "troubleshooting" a poor shooting load. This of course, is assuming that all else is correct, i.e. bedding, good barrel, etc..etc.. Assuming you have shot the 155 bullets before and have a good idea where the seating depth should be. Here are two scenarios I get fairly often: A.) So let's say you are shooting 5 shot groups and 4 of the 5 shots are either touching or very tight, however, 1 flies off into the wild blue yonder. This "event" is happening in nearly every 5 shot group you shoot. This tells me 1.) you are on top of or very close to the correct seating depth; 2.) your barrel likes the bullet; 3.) however, your barrel / bullet does not like the powder. B.) Your 5 shot groups are "scattered" in a large "group", if you can call it a group. 1.) this tells me that you are NOT anywhere near a node: you may be running too low or too high, 2.) your barrel does not like the bullet OR your twist rate is slightly off; 3.) your seating depth a W-A-Y off.
These are 2 scenarios that are common and the above "diagnosis" will generally "cure" your problem(s). There is a 3rd possible issue: you have a bad barrel or a bad chamber / crown job. Generally these days, this is the LAST place to look.. If you use the 2 aforementioned diagnosis / cures, you should get to a place where fine tuning will be easy.. I hope this helps..
These are 2 scenarios that are common and the above "diagnosis" will generally "cure" your problem(s). There is a 3rd possible issue: you have a bad barrel or a bad chamber / crown job. Generally these days, this is the LAST place to look.. If you use the 2 aforementioned diagnosis / cures, you should get to a place where fine tuning will be easy.. I hope this helps..
I like your analogies Keith! They are pretty spot on!
And the quarter node sounds like high maintenance!
+1 on Keith's explanation. That is one to remember for sure!
Ccrider
Gold $$ Contributor
I can see how we can get accustomed to certain loads shooting right and expect similar results from different bullets. However, at times bullets don’t shoot when loaded to the conventional load. Then you have to be willing to try something different from what “should work” and has always worked in powder amount, distance from the lands or maybe neck tension. Or, try a different bullet or powder.
There is no magic number. If you can’t hit that magic load based on prior experience with the barrel, bullet and powder, methodically work your load up and confirm that it will or will not work. I go from a hard jam to as much as .30 off the lands using a mild charge, medium charge and warm charge. I fine tune from there based on what I see.
There is no magic number. If you can’t hit that magic load based on prior experience with the barrel, bullet and powder, methodically work your load up and confirm that it will or will not work. I go from a hard jam to as much as .30 off the lands using a mild charge, medium charge and warm charge. I fine tune from there based on what I see.
This info was from my first OCW using H4895 powder.
Bullets are Nosler 155gr Custom Competition seated at recommended length of 2.800 which is .008 jump in my barrel (1-12 twist 26" length)
Remington brass with Federal 210m primer
H4895 powder and OCW "velocity flat spot" is 41.0gr at 2743 and 41.5gr at 2749.
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skip the ocw, learn to work from a ladder, cheaper and quicker.
you would have an answer by now
you would have an answer by now
I was taught the ladder method by some good members on here but was never any good at figuring what the target was telling me. My biggest limiting factor with the ladder tests is I'm limited to 200 yards for testing and at that distance the bullets sometimes clump together and the test is un-readable. You folks that have access to longer ranges should consider yourself lucky. This is a big factor in keeping me from shooting more matches is my ability to test and practice. So my primary goal is tiny 3 shot groups at our local 300 yard matches.
You may not see the tiny 3 shot group initially shooting an OCW test.
Your looking for the poi trend.
Thanx, I wrote that down. Mike
Sideways latter. Horizontal.
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