Giving OCW a try

[pmclaine]

The results Im seeing with Mr. Newberry's system have been impressive.

Im still on the wait list for a scope for my "new" rifle but I need ammo now.

I just loaded up some .223 with 77 grn Nosler cc's for a 16 inch chrome lined LMT carbine. Im using CFE 223 and loaded 5 each of 23.4, 23.6, 23.8, 24, 24.2, 24.4 (24.4 is .01 over Hodgdons published max). As a control Im going to fire 5 Nosler factory "Match Grade" 77 grn rounds. I chose my powder range from noticing most "Pet Loads" for the powder and bullet fall at or about 24 grains.

Other ammo details include
WCC 08 1X brass
Win SRP
COAL 2.25

Some guys can hold irons and get results equal to their scoped guns but Im not that guy. Ive been banging away with this rifle using KAC 200-600 backups and benched/bagged have held the 10 ring with the Nosler "Match Ammo" at 100 yards. I intend to fire my ammo round robin but probably havent exactly followed the OCW program in my loadings. I admit to making my ammo before studying exactly what Mr. Newberry requires in his program.

Expecting to get groups perhaps 2 inch minus will I get useful OCW type info?

 

[Twoboxer]

From what you wrote it's not clear whether you have actually read Dan's program . . . if you haven't, of course you should otherwise you won't know how to interpret results.

Your load range is pretty much spot on - the method would call for (21.9, 22.3, 22.8) 23.2, 23.4, 23.6, 23.8, 24.0, 24.2, 24.4 so your "short" low-charge "sighters" and 23.2. Frankly, I now bypass the three low loads and start with 9 rounds of the lowest charge (23.2gr in your example), using 3 for sighting/fouling, 3 as part of the rotation, and 3 as foulers after cleaning the rifle when half the rounds have been fired. It's nice to find two good nodes - they can help confirm each other - and it can take a ~6% range to do that, so you may or may not find 2.

As for usable results . . . it all depends

 

[pmclaine]

As for usable results . . . it all depends

...and what it depends on is the weak link - ME! In two regards 1. skills and 2. an inability to apply the proper time to do a fulll blown work up.

Im trying to do this fast and dirty and really there are no shortcuts but I dont have the luxury of a lot of time. Ill get an hour or so after work on Sunday hoping to find something to work with of the loads I bring to the range. Cleaning and a generous barrel cool down wont be happening in the time alotted.

I guess truth be told I wont be doing OCW just more of what I have done in the past - putting some loads together and picking the one that makes the best group whether that be reality or luck. As opposed to what I have done in the past I will incorporate round robin. That makes a lot of sense as to how it can show a better representation of what the load is consistently capable of.

Thank you for the response Ill add some more sighters/fouling rounds to try and keep more variables equal across the board.

Edit - Ill load some 23.2 in hopes the wider spread will show two nodes at the expected dispersion. Maybe the marksmanship wont be all it needs to be but if something looks like it fits the pattern this may still be helpful.

 

[flashhole]

Expecting to get groups perhaps 2 inch minus will I get useful OCW type info?

No.

 

[pmclaine]

Well that went horrible. Kind of as I expected, not through fault of the system, but through operator error and lack of time.

No scope, no spotter and other shooters on line so no walking down range to check impacts.

I held my iron sights using data I had from shooting my factory Nosler 77's some months ago. What kept me in the black back than had me sailing above paper today.

A total clusterfuck of my making.

Being high was a surprise as my thinking would be the cold temps would drop impact. I was shooting at 100 yard reduced SR1 centers with a sub 6 hold. Even the 23.2's went high. ARRRRGH! Wheres the mirror so I can yell at the fuckup that did this.

From what I could discern 24 grains of CFE 223 made the tightest "pattern" with my 77 Nosler CC's. Any corresponding results from 16 inch rifle owners?

Im intending to load up some blammo to get me through until my USO arrives than try again in hopes I can hold better and experiment with the Varget, CFE 223 and 8208XBR I have on hand.

 

[Twoboxer]

Sorry about the results, but +1 for coming back and telling it like it was lol.

I've tried a bit of CFE223 (and Varget) with 75gr and 80gr bullets, but out of a Sako 24" barrel. In all four cases, N140 performed significantly better (0.5" to >1.0" smaller groups) for me. YMMV.

You'll be back lol

 

[Pinecone]

And remember, you are not looking for the tightest group, you are looking for a series of groups that shoot to the same POI.

Then adjust seating depth to see if that will tighten the groups.

 

[pmclaine]

I think Im getting some free time this week to make up some more rounds.

Im curious to see how this works so Ill just replicate what I already did with a sight adjustment. Ill bring my spotting scope with me this time to confirm impact. My 24.4 load showed no sign of pressure at .01 over suggested max so I'll extend my powder range out to 24.6. Hopefully I can be tight enough to get some info with the BUIS. Wont have time/daylight available to perform the full OCW but Ill get what info I can.

One thing I did note, not that it has any impact on impact, was CFE 223 certainly has an ammonia smell to it when you light it off.

 

[Dan Newberry]

One thing I did note, not that it has any impact on impact, was CFE 223 certainly has an ammonia smell to it when you light it off.

I guess if the ammonia smell gets strong enough, it could kinda mess with your respiratory faculties... then everything would start going downhill from there.

The only OCW I ever shot using irons was done with an old model 94 Winchester 30-30. I didn't know how it would go... but target set-up really helped, and I was able to prove an OCW using 170 grain bullets and 32.6 grains of RL15 in Winchester brass. It worked.

The target spots were 4" squares of black construction paper, and the background was white. You need a big target board, so you can get all of the squares on it with enough room in between them. Lining up the iron sights so there is just a tiny *sliver* of light (white) between the black target square and top of front sight post seemed to work the best. Use some sight black of some sort on the front sight post if it doesn't have well defined edges. Reproducing that sliver of light as the target spot (or square) floats over the front sight blade is key, and it's do-able. If you try to bring the blade onto the target spot, you will not be sure how far up on it the sight post actually is.

Some sights are more conducive to shooting tight groups than others. Combat sights are for just that--combat... so it's going to be harder (though not impossible) to get a steady sight picture for each shot with front blade, rear aperture type sights I would think.

Dan

 

[pmclaine]

Sir,

Thank you for your response. I really like my KAC 200-600 backups for what they are designed to do. I really enjoy whacking steel with them and that is the type target they are designed for.

Im waiting on a USO 1-8X and that should be a good scope to allow me to get a better group but Im in the waiting game.

The targets I used was a SR1 reduced which has about a 6.5 inch black. I was holding at 6 oclock making a lollipop. I lined my targets up, all nine, left to right in line and fired off a bipod with a rear bag. It was actually kind of fun to fire.

I put too much faith in prior data and totally botched my sight hold. Too much confidence that past experience would get my shots on paper ended up with groups on the backer board just above my targets. I had a good idea which impacts were mine but not 100 percent.

One minute Im torn between trying again the next minute I just want to load some blammo and go back to shooting steel wth intents to try again when my scope shows up. Either way its all fun.

The 24 grns of CFE 223 looked more than adequate for hitting a torso at 2-300 yards if I load blammo. I dont have a chrony so I have no idea what my velocity is coming in at. Ill make a trip over to one of teh calculators and see what comes up for my rifle/load.

 

[pmclaine]

...I dont have a chrony so I have no idea what my velocity is coming in at. Ill make a trip over to one of the calculators and see what comes up for my rifle/load.

Disregard...

 

[bruddah]

And remember, you are not looking for the tightest group, you are looking for a series of groups that shoot to the same POI.

Then adjust seating depth to see if that will tighten the groups.

Can someone explain to me again why the tightest group is not the best? I read it awhile back but I think I might not quite understand it. What if playing with the bullet seating depth doesn't make for as tight a group?

 

[Pinecone]

The reason is, you may hit a small group that the SLIGHTEST change will make a into a huge group. So while you get a small group today, tomorrow when it is warmer or cooler, you get not so good groups.

With OCW, you are looking for a range where you get a nice group, that will repeat day after day week after week.

So far, everyone who has followed the procedure (not sort of, but actually followed it) has been happy with the results.

When I ran it, the group sizes when doing the OCW for charge weight were good, but not great.

Then I did seating depth, and for my rifle, as I loaded longer and longer, the group got smaller and smaller. I was limited to my mag length.

Some day, I might be fun to load even longer and single feed to see what happens.

But the load works, and hits out to 1200 yards work for me.

 

[Thumper580]

The reason is, you may hit a small group that the SLIGHTEST change will make a into a huge group. So while you get a small group today, tomorrow when it is warmer or cooler, you get not so good groups.

With OCW, you are looking for a range where you get a nice group, that will repeat day after day week after week.

So far, everyone who has followed the procedure (not sort of, but actually followed it) has been happy with the results.

When I ran it, the group sizes when doing the OCW for charge weight were good, but not great.

Then I did seating depth, and for my rifle, as I loaded longer and longer, the group got smaller and smaller. I was limited to my mag length.

Some day, I might be fun to load even longer and single feed to see what happens.

But the load works, and hits out to 1200 yards work for me.

Pinecone.... Load some out just off the lands and single load them. You will be surprised!! Groups shrink like crazy.

 

[bruddah]

The reason is, you may hit a small group that the SLIGHTEST change will make a into a huge group. So while you get a small group today, tomorrow when it is warmer or cooler, you get not so good groups.

With OCW, you are looking for a range where you get a nice group, that will repeat day after day week after week.

So far, everyone who has followed the procedure (not sort of, but actually followed it) has been happy with the results.

When I ran it, the group sizes when doing the OCW for charge weight were good, but not great.

Then I did seating depth, and for my rifle, as I loaded longer and longer, the group got smaller and smaller. I was limited to my mag length.

Some day, I might be fun to load even longer and single feed to see what happens.

But the load works, and hits out to 1200 yards work for me.

Not arguing, just trying to understand. Is this a concern if using a temp stable powder like Varget or IMR 4046 or IMR 8208 XBR?? If the powder is temperature stable you should be good to go all other things remaining the same right?

Again, just trying to learn here.

 

[pmclaine]

The benefit I hope to attain is so that when I'm loading on my progressive if my powder drop is a smidge or two one way or the other it won't really matter with an OCW load.

A trickled and pampered, custom, loading the accuracy may not be as tolerant of these differences.

 

[damoncali]

Can someone explain to me again why the tightest group is not the best? I read it awhile back but I think I might not quite understand it. What if playing with the bullet seating depth doesn't make for as tight a group?

The theory is that if variations of the powder charge don't create differences in elevation, then you are probably in a good spot vibration-wise, and you can figure this out while shooting only a few rounds. In practice, I've not always found this to be true. Sometimes it works, sometimes it doesn't.

Another problem is that statistics creep in even when it works. Unless your rifle is very accurate, the inherent (lack of) precision of the rifle overwhelms any differences in elevation. And since you're only shooting a few three shot groups, you might see patterns that are not actually there. That's why there are so many posts saying "Help me interpret my OCW!".

Bottom line is that while observing how the POI shifts with charge weight can be insightful, you will still have to shoot some groups to get an idea of which load is the best shooter.

 

[Dan Newberry]

Horizontal dispersion can be just as bad as vertical--as it's no more likely for a barrel to throw shots up and down as it is for it to throw them left/right... this is why we want to run the test at 100 yards initially, then interpret those results and come up with a potential good load recipe to then try, as Damon says, at longer ranges.

 

[bruddah]

The theory is that if variations of the powder charge don't create differences in elevation, then you are probably in a good spot vibration-wise, and you can figure this out while shooting only a few rounds. In practice, I've not always found this to be true. Sometimes it works, sometimes it doesn't.

Another problem is that statistics creep in even when it works. Unless your rifle is very accurate, the inherent (lack of) precision of the rifle overwhelms any differences in elevation. And since you're only shooting a few three shot groups, you might see patterns that are not actually there. That's why there are so many posts saying "Help me interpret my OCW!".

Bottom line is that while observing how the POI shifts with charge weight can be insightful, you will still have to shoot some groups to get an idea of which load is the best shooter.

Horizontal dispersion can be just as bad as vertical--as it's no more likely for a barrel to throw shots up and down as it is for it to throw them left/right... this is why we want to run the test at 100 yards initially, then interpret those results and come up with a potential good load recipe to then try, as Damon says, at longer ranges.

Thanks guys.

 

[damoncali]

Horizontal dispersion can be just as bad as vertical--as it's no more likely for a barrel to throw shots up and down as it is for it to throw them left/right...

Have you read Harold Vaughn's book? He presents some compelling evidence that up-down vibrations are a different animal than side-to-side vibrations due to the symetry of the rifle (or lack thereof). Really interesting stuff.

 

[Dan Newberry]

I have read Vaughn's book... while I do agree with much of it, some of it just doesn't make sense--maybe my problem, not his... His reasoning as to why moly coated bullets need more powder to make the same velocity, for instance.

From reviewing countless targets of OCW load tests shot at 100 yards over the years, it's clear that barrels can and do throw shots just as far wide as they throw them high and low. I can't claim to know definitive reasons for this, but simply share what seems to be the case.