Advice Needed - ES & SD

[wkdickinson]

I have a 6.5 Creedmoor, M70 Win w/Bartlien 1:8", 5R barrel (350 rds). I can't get the extreme spread and the standard deviation down where they need to be (see below). Here is my loading procedure - tumble, deprime, anneal, FL resize (Whidden FL bushing die - set to .0025 under size the neck), lube inside of neck, size neck with mandrel (-.001 neck tension), prime, charge (RCBS CM1500), seat bullet (Whidden Micrometer). I've done a ladder from 43.5gr to 45.3gr of H4831SC and found a node between 43.7 and 44.3, so I settled on 44.0. In limited testing I have been able to get the Hornady 140gr ELD Match to about 50% of ES & SD of the Bergers. Problem is I have a bunch of 140 Hybrids and few 140 ELDs.

Any suggestions would be appreciated!

 

[mikegaiz]

what does the group look like? SD is not everything...

 

[wkdickinson]

what does the group look like? SD is not everything...

Not very good - about .75 moa vertical and basically round at 200 yds.

 

[358WCF]

Fed 210 *may* not be the best choice for 4831?

It doesn't seem so if your #ed shots are in the order fired, but are you adding the 1st 2 or 3 shots from a clean barrel into the mix?

 

[Coyotefurharvester]

Neck tension, brand primer,way you hold the rifle, powder charge not in a sweet spot(alot of vertical in your group) seating depth. Try a second firing without annealing. Chronograph +,- error.

 

[Straightshooter1]

I have a 6.5 Creedmoor, M70 Win w/Bartlien 1:8", 5R barrel (350 rds). I can't get the extreme spread and the standard deviation down where they need to be (see below). Here is my loading procedure - tumble, deprime, anneal, FL resize (Whidden FL bushing die - set to .0025 under size the neck), lube inside of neck, size neck with mandrel (-.001 neck tension), prime, charge (RCBS CM1500), seat bullet (Whidden Micrometer). I've done a ladder from 43.5gr to 45.3gr of H4831SC and found a node between 43.7 and 44.3, so I settled on 44.0. In limited testing I have been able to get the Hornady 140gr ELD Match to about 50% of ES & SD of the Bergers. Problem is I have a bunch of 140 Hybrids and few 140 ELDs.

Any suggestions would be appreciated!

View attachment 1258824

Apparently, you're doing all the right things and using good tools. However, the ES's and SD's you're showing falls within a range I would tend to find when using my CM1500 that tends to have a +/- .08 grs variance in powder weight. For example, when the CM1500 says you have 44.0 grs of powder, you may actually have 43.92 grs to 44.08 grs. (Amended to correct decimal point error on original post) And, different powders and weights may have different spreads in actual weights.

I was having the same kind of issue in reloading for my .308. So, a little experiment I did showed me how my CM1500 was keeping me from getting the ES's and SD's I was looking for (like you). I weighed the charges on the CM 1500 then weight them on my GemPro 250 (which I found to be very close to the same accuracy as a FX 120i) and you can see the differences as I tried to find an insert that worked best in the CM1500. See pic below.

So, I feel you might want to take a close look at how your CM1500 is doing at throwing this powder.



(Amended to correct decimal point error on original post)

 

[wkdickinson]

Apparently, you're doing all the right things and using good tools. However, the ES's and SD's you're showing falls within a range I would tend to find when using my CM1500 that tends to have a +/- .8 grs variance in powder weight. For example, when the CM1500 says you have 44.0 grs of powder, you may actually have 43.2 grs to 44.8 grs. And, different powders and weights may have different spreads in actual weights.

I was having the same kind of issue in reloading for my .308. So, a little experiment I did showed me how my CM1500 was keeping me from getting the ES's and SD's I was looking for (like you). I weighed the charges on the CM 1500 then weight them on my GemPro 250 (which I found to be very close to the same accuracy as a FX 120i) and you can see the differences as I tried to find an insert that worked best in the CM1500. See pic below.

So, I feel you might want to take a close look at how your CM1500 is doing at throwing this powder.

View attachment 1258846

I've never had much confidence in the CM1500 rounding algorithm. I have done some comparisons using my GemPro 500 and they were never as far off as you've found, however I believe the GP 500 only resolves to 0.05. So it could be rounding errors compounded. I will look into that further. Maybe load a series trickling onto the GP 500.

Thanks!

 

[wkdickinson]

Fed 210 *may* not be the best choice for 4831?

It doesn't seem so if your #ed shots are in the order fired, but are you adding the 1st 2 or 3 shots from a clean barrel into the mix?

What primer would you recommend and why? I think this series started with a thoroughly clean barrel. I will take the first 3 shots out of the analysis and see what it does to the numbers.

Thanks!

 

[rardoin]

If you can, change powders. H4831 has never proven out to be a great choice for the 6.5 Creedmoor/140 class bullet. H4350/RL-16/H100V are all great choices. The latter being one of the best I’ve used but temperature sensitivity kept me from using it in competition. If you only have 4831 try another -.001” on the neck.

 

[Bc'z]

If you can, change powders. H4831 has never proven out to be a great choice for the 6.5 Creedmoor/140 class bullet. H4350/RL-16/H100V are all great choices. The latter being one of the best I’ve used but temperature sensitivity kept me from using it in competition. If you only have 4831 try another -.001” on the neck.

Bite your tongue Robin!! Lol
H4831SC is a awesome powder, it's all I shoot coupled with 136scenar.
I do agree with another. 001 tension could tighten things up.

 

[rardoin]

I need to get out more often Brett

 

[INTJ]

39-40ish grains of H4350 with Fed 210 and a 140ish grain bullet. Since H4350 is unobtainium right now, IMR 4451 might also be a good choice.

Also, as mentioned, the Chargemaster is not your friend. AutoTrickler/AutoThrow on an A&D FX-120i is a top choice, but a good balance beam scale--especially a tuned scale--will work very well too.

 

[Kymike]

make sure there is proper clearance in chamber neck to cartridge case neck to smoothly release bullet from case without causing pressure spikes

 

[Jarhead6870]

H4350 has been the go-to powder for most shooters since Hornady released their factory ammunition with the recipe using it written on the box. They had to go to a proprietary blend when the last big powder shortage hit us 4-5 years ago. They also reduced the speeds on the factory stuff to around 2750 +/- which increased brass life, this was before Lapua and others made brass for the CM, and helped reduce pierced primers and other problems associated with high pressures.

As for the Charge Master, I had no problems getting single digit SDs when I started out using one and you indicate your numbers are better using ELD-Ms vs what you get with the Berger 140s. Also remember the SAMMI spec freebore is .199 and was made for Hornady factory ammunition using the 140 A-Max. Unless you had a reamer made for the Berger’s you are jumping them a ways in your barrel which it may not like.

Bottom line is; I’d try to find H4350 and more 140 ELD-Ms. Do another load work-up using this combination knowing that most find a good node between 40.0 and 42 grains with the best speeds for accuracy around 2750 fps.

Hope this helps...

 

[FeMan]

As stated above, I would change powders. H4831 is too slow IMO to be optimal in that 6.5CM. I shoot 153s and it was too slow for them. H4350, IMR4451 or RL16. I'm using H4350 and my SDs was 3 fps for 25 rounds.

 

[wkdickinson]

As stated above, I would change powders. H4831 is too slow IMO to be optimal in that 6.5CM. I shoot 153s and it was too slow for them. H4350, IMR4451 or RL16. I'm using H4350 and my SDs was 3 fps for 25 rounds.

I have 5# or more of H4350. What is your charge weight to get SDS of 3?

 

[358WCF]

What primer would you recommend and why? I think this series started with a thoroughly clean barrel. I will take the first 3 shots out of the analysis and see what it does to the numbers.

Thanks!

Once upon a time it was common knowledge that any powder 4350 or slower absolutely needed a magnum primer as did ball powder. That's not necessarily true but there may be a bit of truth in there. No real recommendations. I've always thought of 210s as fairly to middlin' mild. I've had very good luck with WLRs in most everything, but have tried different primers if having what I imagine to be ignition problems. I tried 210Ms to cure flyers in my 6.5cm. They failed miserably. Federal 215Ms brought the SD & ES way down with RL26/140s but still had the flyers. A longer OAL may help with both groups & stats, depending on magazine limitations vs throating. A light jam made a very positive difference from .025" jump in my rifle... at least with Ballistic Tips, Sierra spitzers, & Partitions of all weights. After some adjustments, & another primer comparison, WLRs shoot better than 215s in my creedmoor. In between black & white are at least 565 shades of gray, so yours may be different.

Reading further I also see there may be a +/- .8gr problem with a questionable powder delivery device. Damn! Ain't technology grand?

RE: clean barrel... read that awkward sentence in prior comment again slowly. If the #ed shots are in order in your chart it apparently didn't matter much with your barrel. It was just a thought & more of a question than a statement.

 

[FeMan]

I have 5# or more of H4350. What is your charge weight to get SDS of 3?

I am shooting 41.5 grains with CCI 450s and 153.5s in mine with a 30-inch barrel. MV is 2760. Safe in my rifle but work up. I tried Tula primers I had and they were identical.

 

[BasicMagic]

First try other loading equipment and see if the problem persists.

4831 may just be a little slow.. You may want to try to raise your initial pressure by adding more neck tension, maybe mag primers, park bullet closer to lands, or add more powder and see if there is a node higher in pressure.

Whats ur barrel length?

 

[bozo699]

I have 5# or more of H4350. What is your charge weight to get SDS of 3?

Wkdickinson,
When you said your best node was I can’t remember I think you said 43.7 -44.3 what exactly did you mean best node, not being a smart ass here just wanting to know your terminology. When I’m running a ladder for powder I’m looking for low extreme spread not groups , sometimes I don’t even shoot at a target I tune my groups with seating depth and neck tension. In my mind looking at your chronograph data you never found a node.
I would make sure it was clean with no carbon ring , foul it then seat about .020 off jam and work on your ignition, ie powder and primers. I don’t use 4831 in my creedmoors but I have tested it and other than velocity was a little lower than I wanted it shot great.
Just my $.02 good luck sir
Wayne