R700/308/168/CFE223 inconsistent results

[ScottMcc]

I have a 308 r700 with 24" 5R barrel and the HS Precision fiberglass stock, all original except for timney 2 stage trigger. Roughly 1360 rounds total. I'm loading large primer lapua brass with 168 Berger hybrids and Vld's with 46.5-47.5 grains of cfe223. By the books that is barely a starting load, yet I get well over 2800 fps on the Labradar. I have also tried Varget and 8208, but cfe223 gives me 100-150 fps more and meters a lot better. I have tried oal's from 2.800 to 2.870 with seemingly no change in accuracy or pressure. It has surprisingly long freebore, considering the twist is only 11 1/4. For case prep, I sort by weight, +- .5 grain, with a light neck turn. I decap and neck size on a rock chucker, then prime, powder, and seat on a Dillon xl750 with dillon seat die. Runout is typically 0 to .010 at the tip. For load development I weigh every charge on a dillon electronic scale.

My problem is inconsistency in the numbers. One group of 5 will show es of 14, sd of 8, then the next 5 will be something like 44 and 23. I have tried Rem 9-1/2, 9-1/2M, and Fed 210 primers. I saw identical velocities between the two rem primers, but they were both good for about 50fps more than the Fed primers.

Questions -

Would 10 shot groups be worth the effort for more reliable data? If so, how do you go about a 10 shot group to control barrel temp?

Reloading books used to recommend magnum primers with ball powders like blc2 and 748. Is cfe223 harder to light?

I have a deal pending for CCI LR Benchrest primers. I will also try Fed 215's when I can find some. How do you guys rank primers for consistent es and sd?

scott

 

[Zero333]

210 primers are almost as hot as 215 mag primers. cci BR2 are much weaker than Federal primers.

If you prefer a ball powder, I would try W-748. Most of the time you just need a powder/bullet the rifle likes.

At the same time, you only tried a spread of 1 gr of cfe223 powder which could easily be between nodes.

Ball powders are not the best for low ES/SD, but are capable of small groups at shorter ranges out to 300 meters. I've seen 10 shot groups under 1 inch at 300 meters that had ES of over 100 fps.

 

[std7mag]

I tried CFE223 in my 7mm-08AI.
As mentioned, shot pretty good accuracy wise out to 300 yards.
But i could never get the ES/SD to settle down.
It had been suggested to use magnum primers.
But by that time i had shot through what i had & wasn't interested in revisiting it.

 

[rijndael]

But i could never get the ES/SD to settle down.

I've had the same experience in my 308 and CFE223. I get great groups but the ES is huge. I use it at my 100Y indoor range where I only care about the groups.

In my older rifle, it was a 700 5R, it gave me the best groups of any powder at 100Y. I'd get 5 shot groups well under 1/2" and it was very consistent.

It meters really well from my Harrell's measure.

 

[Fuj]

What's the throat and lead look like since you say you have
1360 rounds thru it ?? I'd check there before chasing components.
If your jumping into something that is eroded, your numbers can
be all over the place.

 

[CharlieNC]

To obtain consistent SD results a sample size of 5 is inadequate, 10 is decent. What were SDs for the slower powders? You can use excel to determine if the results are statistically different.

 

[rijndael]

With CFE, my 18 shot ES is 35 and the SD was 19.6.

 

[Coyotefurharvester]

So you are loading different bullets with different charge weights on a progressive press and the velocity varies?

 

[CNC-Dude]

I get pretty consistent 5-7 sd with VV N150 using 167g Lapua Scenars and Lapua lrp brass. I get average .3 MOA at 600 with my Savage 12FV.

 

[6bra1k]

try measuring all the loaded rounds ogive to base
dillons are not br seaters.
i love dillons but they are not very consistent

 

[Ned Ludd]

Switching from 5-shot groups to 10-shot groups is unlikely to "improve" your ES/SD numbers. It might provide better statistical relevancy, but it's probably not going to somehow magically turn what are already mediocre to poor ES/SD values into "good ones". In fact, ES will likely only increase with 10-shot groups.

Save yourself the time, effort, reloading components, and barrel life and stick with your current testing method. Further, listen to what your rifle is already telling you, which is something confirmed by others' experiences listed above; i.e. that CFE223 may not be the best powder choice for your specific application if low ES/SD is important to you. You've already tried a few different primers, which is a good approach when the ES/SD values are unacceptably high. It apparently didn't solve the issue, suggesting the choice of primer may not be the problem. There are certainly other things you could try, such as weighing powder to +/- 0.1 gr, or improving brass prep (i.e. neck tension consistency), or possibly even turning necks. Unfortunately, if the powder itself is the problem, you will have expended a great deal of effort that may still not solve the issues you're having.

IMO - CFE223 is on the slow side for your specified application. If you have access to any H4895, I'd give that a try. I've had good luck pushing the 168 Hybrids with H4895. In my hands, the velocity in a tuned load with H4895 and 168s will be a little better than with Varget, and the precision will be equal or better. H4895 may not give you quite the sheer speed you can get with a ball powder such as CFE223, but velocity isn't everything. If H4895 (or some other powder) provides good precision and reasonable ES/SD values, I think you will find that you won't miss the extra velocity too much.

 

[std7mag]

What's the throat and lead look like since you say you have
1360 rounds thru it ?? I'd check there before chasing components.
If your jumping into something that is eroded, your numbers can
be all over the place.

It's a 308, Fuj.
I doubt it looks too terribly bad yet.
I had 6,000 rounds down the 7mm-08 before i took it off.

 

[dc.fireman]

I've had the same experience in my 308 and CFE223. I get great groups but the ES is huge. I use it at my 100Y indoor range where I only care about the groups.

In my older rifle, it was a 700 5R, it gave me the best groups of any powder at 100Y. I'd get 5 shot groups well under 1/2" and it was very consistent.

It meters really well from my Harrell's measure.

I had this same experience with CFE 223 in 2 different rifles in .308 - SD was higher than I'd liked. Groups were just 'OK'. I used a 210M and a 168 HPBT.

 

[ScottMcc]

Ok thanks everyone. The throat is pristine. It actually just fully broke in recently, now going up to 200 rounds between cleanings with no traces of copper, not even a yellow haze. Maybe cfe really works.. I'm going to keep trying different primers, and do a few 10 shot strings anyway. I don't expect 10 shots to 'improve' sd numbers, just produce more statistically valid info. I have tried 748 and Tac too, but nothing really stands out yet.

What is the difference between a Fed 210m and a 215? The 215 is the magnum primer developed with weatherby, right?

 

[6bra1k]

here is a problem...you are worrying about numbers that are based on large number samples..in excess of 1000 sample size.
lest see some targets some group sizes////
the numbers mean nothing if there is no group to go with it...
so when you have some groups under 3/4...with some consistency, then we can look at details

 

[Zero333]

Ok thanks everyone. The throat is pristine. It actually just fully broke in recently, now going up to 200 rounds between cleanings with no traces of copper, not even a yellow haze. Maybe cfe really works.. I'm going to keep trying different primers, and do a few 10 shot strings anyway. I don't expect 10 shots to 'improve' sd numbers, just produce more statistically valid info. I have tried 748 and Tac too, but nothing really stands out yet.

What is the difference between a Fed 210m and a 215? The 215 is the magnum primer developed with weatherby, right?

Yes, the 215 primer was developed for the 378 Weatherby.

 

[ScottMcc]

I went to the range saturday and shot seven 10-round groups at 100 yards with different primers. All loads were Lapua lp brass (neck turned and one previous firing), Hornady 168gr ELDM at 2.850", and 46.0 grains CFE223 (hand weighed). Since my first post I bought a Redding die set with FL neck bushing size die with a .334 bushing and micrometer seating die. The seating die made a real difference over the dillon seater - the worst runout I had was only .003" on the tip. I started shooting at 7am and mid 70's F. After each 10 round group, I gave the barrel 3 one-way passes with a dry bronze brush. I cooled the barrel down with a neck cooling towel and a spray bottle with purified water with a little 70% rubbing alcohol mixed in for enhanced evaporation. I could get it down to ambient in about 5 minutes.

I wasn't shooting for group size; just looking for es and sd data. I fired fairly quickly to minimize heat soak in the chambered round. After each shot, I got back on target before chambering the next round, then tried to fire within 5 seconds or so. Here are the results, in the order they were fired:

CCI 200__________2811 87 25.0
CCI BR-2_________2809 30 9.2
WIN WLR________2827 18 6.1
FED 210__________2810 37 14.5
FED 215Match___2800 95 27.8
REM 9-1/2_______2801 64 19.8
REM 9-1/2Mag__2809 55 17.7

I was surprised by the good performance of the wlr's, and disappointed by the 215m's. The wlr's also appeared a little flattened, while none of the others did. QL usually shows the performance is 6-8% faster than expected. This rifle has always run fast, getting max vel numbers with starting loads by most books.

None of the groups were good, worse than expected even with the rapid firing. I bore scoped it when I got home and was surprised to see copper buildup. My bad. It's sparkling clean now though.

For the next trip to the range, I will try BR-2s and WLR's with Varget and 8208, again with the 168 eldm's. I will try H4895 when I can find some. When I get consistently good es/sd, I will load up with 168 hybrids and vld's and try for those cloverleafs.

 

[mac86951]

I went to the range saturday and shot seven 10-round groups at 100 yards with different primers. All loads were Lapua lp brass (neck turned and one previous firing), Hornady 168gr ELDM at 2.850", and 46.0 grains CFE223 (hand weighed). Since my first post I bought a Redding die set with FL neck bushing size die with a .334 bushing and micrometer seating die. The seating die made a real difference over the dillon seater - the worst runout I had was only .003" on the tip. I started shooting at 7am and mid 70's F. After each 10 round group, I gave the barrel 3 one-way passes with a dry bronze brush. I cooled the barrel down with a neck cooling towel and a spray bottle with purified water with a little 70% rubbing alcohol mixed in for enhanced evaporation. I could get it down to ambient in about 5 minutes.

I wasn't shooting for group size; just looking for es and sd data. I fired fairly quickly to minimize heat soak in the chambered round. After each shot, I got back on target before chambering the next round, then tried to fire within 5 seconds or so. Here are the results, in the order they were fired:

CCI 200__________2811 87 25.0
CCI BR-2_________2809 30 9.2
WIN WLR________2827 18 6.1
FED 210__________2810 37 14.5
FED 215Match___2800 95 27.8
REM 9-1/2_______2801 64 19.8
REM 9-1/2Mag__2809 55 17.7

I was surprised by the good performance of the wlr's, and disappointed by the 215m's. The wlr's also appeared a little flattened, while none of the others did. QL usually shows the performance is 6-8% faster than expected. This rifle has always run fast, getting max vel numbers with starting loads by most books.

None of the groups were good, worse than expected even with the rapid firing. I bore scoped it when I got home and was surprised to see copper buildup. My bad. It's sparkling clean now though.

For the next trip to the range, I will try BR-2s and WLR's with Varget and 8208, again with the 168 eldm's. I will try H4895 when I can find some. When I get consistently good es/sd, I will load up with 168 hybrids and vld's and try for those cloverleafs.

Interesting. This makes me recall a German Salazar article about primers and the most consistent being the mildest primer that will achieve consistent ignition, or some such like that.

I'm interested in how the BR2s perform for you; then I'm also curious what if you replace your firing pin spring? Seems meaningless, though I've heard many suggest it makes a difference.

Finally, there are a LOT of variables at play here, I'd recommend foregoing the barrel cleaning and shoot them 'round-robin' and see if the results are repeatable.

-Mac

 

[ScottMcc]

My firing pin is a Tubb lightweight with Tubb dual springs. I have not seen an accuracy improvement with it yet, but I shoot on a pretty good rest. I had several failures to fire with remington 9-1/2M primers and the stock pin over a two year period, so I put in the Tubb stuff maybe 6 months ago. Have not had a ftf since.

 

[CharlieNC]

I went to the range saturday and shot seven 10-round groups at 100 yards with different primers. All loads were Lapua lp brass (neck turned and one previous firing), Hornady 168gr ELDM at 2.850", and 46.0 grains CFE223 (hand weighed). Since my first post I bought a Redding die set with FL neck bushing size die with a .334 bushing and micrometer seating die. The seating die made a real difference over the dillon seater - the worst runout I had was only .003" on the tip. I started shooting at 7am and mid 70's F. After each 10 round group, I gave the barrel 3 one-way passes with a dry bronze brush. I cooled the barrel down with a neck cooling towel and a spray bottle with purified water with a little 70% rubbing alcohol mixed in for enhanced evaporation. I could get it down to ambient in about 5 minutes.

I wasn't shooting for group size; just looking for es and sd data. I fired fairly quickly to minimize heat soak in the chambered round. After each shot, I got back on target before chambering the next round, then tried to fire within 5 seconds or so. Here are the results, in the order they were fired:

CCI 200__________2811 87 25.0
CCI BR-2_________2809 30 9.2
WIN WLR________2827 18 6.1
FED 210__________2810 37 14.5
FED 215Match___2800 95 27.8
REM 9-1/2_______2801 64 19.8
REM 9-1/2Mag__2809 55 17.7

I was surprised by the good performance of the wlr's, and disappointed by the 215m's. The wlr's also appeared a little flattened, while none of the others did. QL usually shows the performance is 6-8% faster than expected. This rifle has always run fast, getting max vel numbers with starting loads by most books.

None of the groups were good, worse than expected even with the rapid firing. I bore scoped it when I got home and was surprised to see copper buildup. My bad. It's sparkling clean now though.

For the next trip to the range, I will try BR-2s and WLR's with Varget and 8208, again with the 168 eldm's. I will try H4895 when I can find some. When I get consistently good es/sd, I will load up with 168 hybrids and vld's and try for those cloverleafs.

Quite definitive, adequate sample size to achieve significant results. And the targets demonstrate changes from vertical to horizontal stringing. But that CFE is no good