6.5 Creedmoor case weights and water capacities.

This came up as a question in the rifle forum, specifically regarding how Peterson brass compared capacity-wise to other brands.

Having a fair selection (I shoot whatever I find) of CM brass on hand I figured Id weight and capacity check one of each from the brands I could find. If I turn up others ill update the list.
If someone is REALLY interested in a specific brand ill do a sample of 5.....but lazy dont expect it quickly.

Standard cautions apply to accepting these numbers at face value.....also these are a sample size of 1, weighed on MY scale, with MY range of user error.

The scale was zeroed, weight checked, then tared after the initial case weight was taken. The process was repeated for each brand of case.
One case of each brand was full-length sized, primed with the same new primers.
Each was weighed, then filled to overflow in the sink and the excess/dribbles on the cases wiped off.
If the meniscus was noticeably different (concave vs convex) they were dumped and weighed again. The process was repeated three times per brand.

Numbers are an average of 3 weights.

Starline, case weight 166.5, water capacity 51.46
R-P(rem), case weight 161.4, water capacity 52.1
Sig Nickle, case weight 163.5, water capacity 51.6
S&B, case weight 162.8, water capacity 52.66
Peterson, case weight 175.6, water capacity 51
Federal, case weight 178.3, water capacity 50.76
Win, case weight 164, water capacity 52.23
Hornady, case weight 151, water capacity 53.36

Weight range for all 8 cases was 151-178.3
Water capacity range was 50.76 to 53.36

I'm impressed with how close the capacity was between all the cases with only a 2.6gr difference between the highest and lowest....thats less than Ive seen in some brand of brass in other cartridges.

243winxb said:

Great test Ty.
My Hornady is on the light side also, more so then your other brands. Wonder why?
View attachment 1079585

After benchrest prep of brass, i sort into lots of 3/10 grs. for 243 Win.
Not buying more 6.5 to sort for a 1.25" moa Axis.

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Not really sure probably thinner and lighter alloy id guess.
Im too lazy to section a case for each brand eight now, but next time i get some gumption ill see if dads got a metal blade for his band saw.

South Prairie Jim said:

Nicely Done, yeah they are fairly close although the difference between Hornday and the others should be significant enough to see on paper at mid range or less.
people have reported lack of capacity and speed on Peterson brass for other calibers like Dasher and 284 win that later discovered the Peterson once sectioned showed a considerable difference in base thickness.

Did ya sort your primers first ? Lol

Thank you
J

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..... sort my primers he says, sort my primers!!!
I don't usually even sort my brass by brand!


I run the same load thru two guns and usually don't bother sorting for range ammo as moa is really all i need. My work ups have all been done in hornady brass and then checked with the others for pressure signs (im always leery of a federal sneaking in dor every rifle cartridge i load).
I have mostly been using stuff in rhe 52-53gr capacity range tho.
The Federal and Peterson are both fairly new.

Ive been very happy with my Peterson 28 Nosler brass. It takes pressure better than the Nosler branded cases, and so far ive not seen a noticeable jump in ES, which is how i usually judge load consistency.....as we know im a fairly non-critical shooter lol.
Ill do a bit of data collection on the Peterson creedmoor cases, and see what the functional difference are between those and the hornady....since i have the most of those two.

Blue68f100 said:

I do not see where you trimmed the brass to the same length. Was this done after sizing?

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Thats a good question!
I didn't standardize the lengths, didnt even think about it.