Doing detective work, anyone care to help??

[darcy32171]

LOL. Yeah, when I first got into reloading I asked the question about the factory Winchester 45gr JHP 22-250 cartridges. I wanted to duplicate them, but everyone had mentioned that the factory uses multiple types of powder and it would be near impossible.
Since then, I found a good load using IMR 4895 and 55gr V-max`s using 34.5gr.
Most max loads I`ve seen have been around the 36.5gr. This morning I thought I`d tear apart a factory shell. It has a very very fine ball type powder. I through it on my scale and it is 41.7gr. On the box it says 4000ft/sec, not sure how accurate that is, but they sure do shoot very nice and group very well.
My question is: Knowing how many grains (41.7). Knowing that it is a very fine ball powder. Knowing that it is stated on the box 4000ft/sec. Knowing COL is 2.327. With these four variables, using the Hodgdon site....could a guy come very very close in finding a close match to the powder????

 

[H4831]

Forget the powder a factory usess to load their factory cartridges with.
Forget the velocity figures written on a box of factory cartridges.
There are several powders out there that are good for your 22-250.
Look at the loading charts and choose the slower burning powders they reccommend for it.
Any case that has a big capacity for the size of the bore, is more critical to load, than is one with a large size bore, as compared to the case size.
By critical, I mean it is easier to get more pressure than you bargained for, in such a case.

 

[darcy32171]

Just checked Winchester site. 22-250 45gr cartridges, winchester 760 ball powder recommended.
Went on Hodgdon site: Safe load is: 38gr 3537ft/sec 2.350COL
Max load is: 41gr 3899ft/sec 2.350COL

If Winchester highly recommends this powder, then in their factory cartridges I have, it is 41.7gr. Does a company normally sell "hot load" cartridges???? And these cartridges, the COL is 2.327 which would make the pressure a little higher yet.

I do understand that under the reloading charts, these numbers posted are usually to protect the company itself...so the max load could be exceeded somewhat.

 

[CyaN1de]

There is also a good chance that they are using a powder that is not available to the genreal public, so trying to figure out could lead to disastrous failures.

 

[Ganderite]

Powders are made in batches of several thousand pounds, to a recipe. If that particular batch is close to the canister spec (retail powder) it is put aside for you to buy. If it is too fast or too slow it is sold as a commercial use powder and the ammo factory decides what to use it for and how much to use.

Your factory round could have a slow lot of 760 in it.

For example, the Red Dot you buy is all the same speed, but when the ammo factory buys it, the drums are labelled RD1, RD2, RD3 or RD4. Four different speeds, to give the ammo factory an idea of what it is. A slow lot of Red Dot is almost the same speed as a fast lot of green dot

There are a lot of powders made that are not sold to consumers. Your powder could be Win 755.