Sorting brass by weight.

[muleman]

Good Morning,
I was prepping brass yesterday for a recent addition to the safe and decided to weigh the brass and found a large difference among the cases.
These are 257 Weatherby cases that I purchased off GB and most have been fired at least once - some more.... along with some new ones. When I was prepping I found a few that had slightly crushed necks and surmised that these had been reloaded at least once(These were discarded). They had all been sized, deprimed and polished before reaching me. I resized, cleaned them in my sonic cleaner, trimmed them all to 2.539 and primed them with Fed 215s.
It was then that I thought to weigh them. Out of a hundred cases about sixty weighed 212 to 214gr. Thirty weighed in at 228 to 230gr. and I had eight that weighed 218 to 220gr. There was no pattern as to fired vs. unfired cases that I could discern. I'm thinking I might compare volume by water to see if the discrepancy continues.
I thought that that was a big enough difference to effect performance. What say you? Do I just keep the groups segregated and use the 60 for load development and the others for foulers, plinking and rough site ins?
I don't normally buy used brass but I couldn't find any new and wanted to play with this new gun.
I'm going to run 110 ABs and 120PTs at first and I'm hoping there is a 257 ABLR in the works.
The gun is a pretty interesting build. It is chambered in 257 Weatherby and has 31" barrel(advertised as a Douglas), Rem 798 action(commercial mauser), Mashburn trigger set 1.5lbs, all mounted in an older birdseye maple Weatherby stock. The bore is fabulous and the rest of the gun is in very nice shape. I picked it up for less $500 delivered.

 

[DrMike]

Scott,

You picked up a bargain. As to the brass, I don't know that this is unusual. I agree that it would be interesting to see what the internal volume is on at least some representative sampling from the three distinct lots. Am I to assume these are all the same manufacturer, though differing lots?

 

[kraky]

Just an idea but I find using a fine ball powder like win 760 or rs magnum usefull in comparing brass to one another less messy than water. Fill and lightly tap to settle the heavy cases...then dump to the lighter cases tapping the same...see how the "fill" differs.

 

[muleman]

Scott,

You picked up a bargain. As to the brass, I don't know that this is unusual. I agree that it would be interesting to see what the internal volume is on at least some representative sampling from the three distinct lots. Am I to assume these are all the same manufacturer, though differing lots?

Mike,
The cases are all stamped Weatherby. I assume they are mixed lot.
Thanks for the response.
Scott

 

[OU812]

It's ironic this subject is coming up now. First let me say I have never weight sorted any brass for any rifle in the past. That being said here is the situation I was in recently. I had sold my 8mm to Eric and was talking with him a while back and he said he was having issue with the brass not wanting to extract after being fired with one of my pet loads I had developed. I was kind of baffled as I had never had any issues with this load. When he bought the rifle I had about 400 pieces of brass for it and he said he did not need that much so he took about 200 pieces and I sold the rest. The brass all new but in different containers, I had 1 50 count bag, 8-10 20 count boxes and a big bag, all different lot numbers of Remington brass.

Fast forward to 2 weeks ago when I bought back my 8mm from Eric. I had been busy and last Friday I finally got the chance to get the the range so I loaded up some rounds using the same load data only this time I was using some brass I had not previously used, different lot numbers. When to the range and the first 3 rounds fired and extracted as normal. The forth was very difficult to extract so I stopped there and went home to try and figure out what the heck was going on. As it turns out the brass that stuck weighed 255 grains the other pieces that extracted fine weighted 260 grains and 263 grains.

I weighed all the brass and found 60-70 pieces that weighed from 254-256 grains and the rest all weighed 260-264 grains. I loaded up 2 rounds of the 255, 2 rounds of 260 and 2 rounds of 263 and headed to the range. Once again the the 255 did not want to extract but the other 4 rounds extracted perfect.

I can only surmise that the lighter brass is thin in the web area as that is where the rub marks on the outside of the brass was once I was able to extract them. Needless to say these lighter pieces will be used at a lower charge weight and have been labeled as such.

 

[IdahoCTD]

With today's electronic scales it's pretty easy to weight sort fairly fast. It's a good thing to save for the winter time but I do it quite often. Your results don't follow what I usually see but it doesn't surprise me. Usually you see a large cluster at 2-4 grains of difference and then the rest 2-4 grains above or below the large cluster. Someone could have done the weight sorting and kept the big cluster in the middle on you as well. That would explain the large gap in the middle.

 

[Kodiak]

OU,

I wt'd all my Wby. 257 cases (100) today.

210-212 gr. for new: same for once fired. All were bought at the same time about 3 years ago, from Graf's.

 

[Antelope_Sniper]

Muleman, you have two different lots of brass, that's why you have the big gap.

Keep your lots seperated, the 60 that are within 1% will make three nice boxes for serious work.

The rest, use as you see fit.

 

[SJB358]

I had the same thing happen with some Nosler 264 brass. I mixed it, not on purpose, but I mixed. One load would shoot a 3 shot group at around a 1/2 to 3/4".. The next would lock the gun up TIGHT! Turns out, I had a good 30-40 grains difference between the two lots. I ditched all of the lighter stuff, as I didn't have a ton of it, but it caused me a bunch of frustration with my 264. Once I had it sorted out, it ran as expected.

 

[Oldtrader3]

Both Nosler and Weatherby brass are made by Norma. I used o weigh random cases, maybe 1-2 per 10 and ever saw that much variation? I fact the .257 Roberts cases that I have are extremely uniform just my experience?