450Bushmaster.net

Okay, heres the results of an evening meticulously loading and measuring.

First off, to answer Ed. Average wall thickness for three cases is .016 at the mouth and .021 where the heal of the 250gr FTX is located.

Edit: That was measured without the benefit of a case wall thickness specific tool. I just used one of my cheap calipers. If you simply use the math method of the case OD measured with the bullet seated using a high buck micrometer, minus the bullet OD, divided by 2, you get .0143 at the mouth and .01935 where the heal is located. I like the second method better. The brass was never fired, so there's no residue inside it and the mouths were deburred.

Good News, Bad News.

The good news is the bulge is not as bad as with the 200gr FTX, but a seated round in a case still does not plunk without resizing. Not by a long shot.

The 3 new, unfired, trimmed and sized .284 cases had average dimensions of:


With a bullet simply seated, they averaged this:

As could be expected, the the cases hung at the bulge where the bullet heal is located.

I resized in .001 steps, using the resizing die until they finally thunked without dragging:


The pulled bullet unfortunately, also got resized, but not as bad as the 200gr FTX:


So, if we don't want to sacrifice the bullet dimensions, we are back to reaming, either before or after resizing. I prefer after.

Odd to bed. 04:30 will come too soon.

Hoot

The picture is of two dummies I loaded last night to check the new brass. The diameter of the brass at the heel of the 250 grainer measures .483. The diameter of the 225 grainer at the heel of the brass measures .480. These dimensions track very closely with the brass I made in 2009, and I've fired hundreds of rounds of those with excellent accuracy and no issues. I keep my seating die set the same for all of the FTX bullets. The COAL with the 250s runs from 2.250 to 2.260. The 225s give me a COAL of 2.240 to 2.245. The variations are due to the poly tips. The seating variation checked with a Stoney Point COAL gauge is very minimal.

Looking at Hoot's last two posts, I'm thinking that there is some tolerance stacking working against him. His chamber seems to be tighter, and his brass seems to be thicker.

BD

BD1 wrote:The picture is of two dummies I loaded last night to check the new brass. The diameter of the brass at the heel of the 250 grainer measures .483. The diameter of the 225 grainer at the heel of the brass measures .480. These dimensions track very closely with the brass I made in 2009, and I've fired hundreds of rounds of those with excellent accuracy and no issues. I keep my seating die set the same for all of the FTX bullets. The COAL with the 250s runs from 2.250 to 2.260. The 225s give me a COAL of 2.240 to 2.245. The variations are due to the poly tips. The seating variation checked with a Stoney Point COAL gauge is very minimal.

Looking at Hoot's last two posts, I'm thinking that there is some tolerance stacking working against him. His chamber seems to be tighter, and his brass seems to be thicker.

BD

Wow, that's significantly different than mine, not just a little. What brand is your brass? Both batches of mine were bagged Winchester from two separate lots and equally thick. The OD measurements I made were using a Browne & Sharp #1 micrometer with carbide flats. It's also very handy for checking ID measurements made with my Harbor Freight digital caliper. If my resultant brass were only .480-.483 at the heel, they'd fall into the chamber with room to spare.

Hoot

DB1 was gracious enough to send me a care package that included some .284 brass and a few bullets. I told him I would report what I found. So here it is!

Left to right

225 SST
250 SST
300 SST rohk sent me this one! Thanks
325 SST
260 Remy

Stealthshooter wrote:DB1 was gracious enough to send me a care package that included some .284 brass and a few bullets. I told him I would report what I found...snip

Boy, I'm not seeing much bulge. I'm going to feel real dumb if it was just bad luck on the two lots of brass I got. BD1 is sending me some also to compare. Will report what I find as well. If that proves to be the case, it could be tricky finding a lot that works without committing the funds regardless. You'd think this could be tested by weighing them before starting the mod process.

Hoot

The brass I made in 2009 was a mixed bag of used .284 and 6.5-.284. To be honest I didn't pay much attention to the brand as it all seemed to work OK. The brass I made this week is all new Winchester I bought from a guy on the Cast Boolits forum who had a lot of 500.

Hoot, I don't know exactly how you're measuring the case wall thickness. I do know that I fought with that measurement for years until I broke down and spent the money on a Chinese made tubing micrometer, (about $100 ten years ago). The issue is that the tips of most calipers are sharp and pointy, and much harder than cartridge brass. It's pretty easy for them to "dig in" to an amount greater than the variation you're trying to measure. the tubing mike has a ball passive end that goes inside the tubing, a standard hardened active anvil on the outside, and a slip ratchet for adjustment that insures that the anvils are tightened together with the same amount of force each time.
BD

It will be better when I get my 450 dies! I couldn't take it any longer so I used my 7mm-08 seater to make the dummy rounds. Now that I have them and I can stare at them it's gunna make the wait for my upper even worse LOL

Thanks again DB1!!!

Stealthshooter wrote:It will be better when I get my 450 dies! I couldn't take it any longer so I used my 7mm-08 seater to make the dummy rounds. Now that I have them and I can stare at them it's gunna make the wait for my upper even worse LOL

Thanks again DB1!!!

There are worse fates. I got my dies, brass and bullets right away and had to wait 6-7 weeks for the upper. Drove me nuts.

Hoot

Revelations!

If I had not seen it, I would have had trouble believing it. BD1 sent me four pieces of his .284 Winchester brass to compare to four pieces of mine.

BD1's brass despite being longer than mine, was lighter in weight, with thinner walls and when a 250 FTX was seated in them, they thunked in my barrel without any resizing necessary. They even had a small amount of rattle room! Bill where can I buy that brass instead of the two bags of 50 I bought? I'd be shooting them tomorrow if I could get some that are for sure lighter and thinner walled. To be honest, it angers me the amount of time I put into trying to get the two different lots I bought to work. I'm talking man-days.

Here's the specifics:



Hoot

What about the rim diameter and groove diameter as compared to Hornady 450B brass?