dumb AR around 20-24"

[Steve300xcw]

I've found that case design has more effect on temp stability than powder type.

I do not understand

 

[[486]]

H380 a little tiny ball, looks like sandblaster silica sand but black

what on the case design?
I'd always heard double base powders (with NC and NG) are more temperature sensitive than single base powders (with only NC)
not so much on case aspect ratio or whatever

yeah that short fat cases burn more consistent than long skinny, but...
maybe that's feeding into it

 

[78bronco460]

White Oak Arsenal sells great stuff for NRA High Power. You can buy the parts or the whole upper and have a solid target rifle to punch paper for score. I have an old DPMS heavy barrel A4 upper that I use but the White Oak is the go-to for match guns. They aren't cheap but they run well.

Shop White Oak Competition Service & Match Rifle Uppers | White Oak Armament

Find the best selection and prices on in-stock White Oak Competition Service & Match Rifle Uppers.

www.whiteoakarmament.com

 

[Chevy_man]

I do not understand

Certain powders can be highly unstable in 1 cartridge, yet be very stable in a different cartridge.

I'm just saying you have to test everything for yourself.

 

[[486]]

guess other explosives have critical diameters and shit where they won't detonate unless they're packed in a shape with a radius of (whatever) diameter
so maybe burn rate versus temperature changes with diameter

the hot from a hot chamber working its way into the powder would def happen quicker with a long skinny than a short fat

 

[[486]]

50gr jsp
21.5, 22 and 22.5gr imr4198
nice rounded primers, not cycling hard enough to even lock open consistently
still some room in the case, only filling up to the shoulder, but already over max in every book I look in (not that that means anything at all)
10F so it ain't even like it was all that cold out, but if I get it up where it should be I'm concerned that the fucking shits are gonna be extra angry when it's 95 out and the barrel's about 300F because of impatience

 

[[486]]

did 22.6, 22.8, 23 and 23.2 of imr4198 behind a speer 50gr JSP
the 20" still wasn't cycling even all the way up there
it was cycling a middy gas upper but just barely
both of them really liked the 22.8, accuracy wise
35 deg F

thinking 4198 is just too fast for anything but little stubby chode uppers with carbine or pistol gas
gonna try some h335 next
not because I expect great accuracy results but because there's a bunch on the shelf and I've only got a single pound of benchmark

maybe I'll screw around with more h380 and 77s
that's way more fun than boring old h335 stuff that's been done a billion times
prolly do 27gr right on out to whatever'll fill the case right up to a sixteenth below the case mouth

 

[78bronco460]

Get some superformance powder for the 50gr but only run them in rifle gas.
Edit: obsolete data for this powder

 

[Chevy_man]

did 22.6, 22.8, 23 and 23.2 of imr4198 behind a speer 50gr JSP
the 20" still wasn't cycling even all the way up there
it was cycling a middy gas upper but just barely
both of them really liked the 22.8, accuracy wise
35 deg F

thinking 4198 is just too fast for anything but little stubby chode uppers with carbine or pistol gas
gonna try some h335 next
not because I expect great accuracy results but because there's a bunch on the shelf and I've only got a single pound of benchmark

maybe I'll screw around with more h380 and 77s
that's way more fun than boring old h335 stuff that's been done a billion times
prolly do 27gr right on out to whatever'll fill the case right up to a sixteenth below the case mouth

I'm still burning up H335 in cardboard canisters with the red plug....

Just because it's boring and normal doesn't make it wrong

Turns out, it might be normal because it just works. I know you love to be a contrarian, but maybe you don't need to be all the time

 

[[486]]

Get some superformance powder for the 50gr but only run them in rifle gas.

that's way slow
like next to r-19 and 4831 levels of slow
they'd probably cycle, but how fast would they be going with a case jam packed full?

ETA: I've got an old brake fluid can of "4831" which is probably surplus pulldown powder
think I'm gonna load me up a couple cases plumb full, smash a bullet down onto them and see what they do

I'm still burning up H335 in cardboard canisters with the red plug....
Just because it's boring and normal doesn't make it wrong
Turns out, it might be normal because it just works. I know you love to be a contrarian, but maybe you don't need to be all the time

I'm in it to interest myself, not to get any particularly good results.
I already know I'm a terrible shot when compared to most everyone online who can post their 25yd groups as 100yd ones. That don't bother me at all.

 

[[486]]

was able to fit 27gr of 4831 into there with some tapping on the bench
smashed it down with a 77, just for a little extra snozz
betting it's gonna be just about smoky, like a load of 3gr of bullseye behind a 125gr bullet in .38spl

 

[78bronco460]

that's way slow
like next to r-19 and 4831 levels of slow
they'd probably cycle, but how fast would they be going with a case jam packed full?

Thanks for pointing that out. I had saved s as n old recipe for that powder with 223 that’s not recommended. My bad.

 

[[486]]

It's all good man, I'm all for trying weird shit.

The 4831 loads (I only made two) did indeed cycle, and they had enough pressure to set the primer back into the case
but not anywhere near enough to even start flattening out the primer
no chronograph, but they did poke a hole in 1/4" steel, but basically any 223 will do that

On the H380, I loaded five round sets in .2gr increments from 27 out to 27.8 where the bullets started deforming from being seated on the powder charge (lol)
they were most accurate from 27 to 27.4, with the best right in the middle at 27.2 being a little tiny (for my poor shooting) 1/2" group at 60yd

also loaded up fifteen with... well I bought 500 "blemished" 77 smk, and weighed them out
there were only about fifty of them outside of the 76.9-77.1 grain range, and most of those were able to be loaded into 'groups' of similar weight

I loaded up the last of the outliers into mixed commercial and military brass with the same 27.2 load, and these made a nice round 1.5" group, so the effort of sorting crappy bullets and maybe the effort of sorting cases is worthwhile? Dunno, certainly sorting the bullets out was worth the effort but sorting the brass might not be worth it.

Oh right, the h380 never showed any pressure signs, even out at the "maximum I could smash into the case" of 27.8 grains behind a 77smk loaded to "aluminum mag length"

 

[[486]]

so which end of the range should I load to for ammo that's gonna probably get shot when it warms up
I was thinking toward the light end, as it should speed up as it warms up, since it is currently relatively cold out

but maybe that's backwards?

 

[Chevy_man]

so which end of the range should I load to for ammo that's gonna probably get shot when it warms up
I was thinking toward the light end, as it should speed up as it warms up, since it is currently relatively cold out

but maybe that's backwards?

If you're not flattening primers don't worry about it.

Most of my loads vary less than 25fps from 20* to 90*.

Just have to shoot them warm and see how they do.

 

[Steve300xcw]

You can alway load lighter next time. Fill em up

 

[[486]]

Not so much pressure that worries me, but departing this... "accuracy node" I guess it'd be called for somewhere in between them
but suppose that'd be affected by more than just velocity.

Like, I bought some norma superduperhighzoot stuff and it shot like shit, but after sticking a brake on there it changed the harmonics enough that it shoots decent.

 

[[486]]

loaded up 50rds of 50gr, used some shooter's world tactical rifle and h335
25.6
25.8
26
26.2
26.4
26 was the max load on the data, but none had any pressure signs
the tactical rifle powder was total shit across the board, very consistent 2" groups

the h335 seemed to hit a node a little before the beginning and right at the end, so I think I'm gonna figure out what an actual max load is by blasting them into a pipe full of rubber tire mulch, then bother to develop a load from there
hopefully I run into pressure signs before 26.8, then I can just chase the one around 26.4

 

[[486]]

looked in the other loading manual, an ancient lyman
their max was 27.5 for the same bullet
so I plopped together two of each, from 26.9 out to 27.7, in .2gr increments
see where the primers start flattening (and if any of the bullets vaporize from the 1:7 twist)

 

[78bronco460]

Pressure is on the hodgdon data:

 

[Roc Doc]

I'm using Power Pro Varmint for my 77g SMK loads. Will post up data later. This in the Les Baer .223 "match" chamber upper. I have used 4831sc in 6.5CM, same with 4350, but I don't feel either is suitable for .223.

 

[[486]]

Pressure is on the hodgdon data:

Yup those numbers match what's printed on the bottle itself, and is what my initial 25.6-26.4 group was based on
For whatever reason load data seems to vary a whole lot, so it is only really useful as a starting point guideline sorta deal.

like, basically everything in that old lyman manual I mentioned is way hotter than anything put out lately, some of the starting loads are well above current "maximum" loads

I have used 4831sc in 6.5CM, same with 4350, but I don't feel either is suitable for .223.

oh yeah, that 4831 try wasn't really earnest (I only loaded two rounds) there just ain't enough case capacity for such a slow powder, it might even be too slow for 22-250
even h380 which is quite a bit faster on the chart than 4831 is too slow for 223, I wasn't able to get any pressure signs even with a full case smashed down by a 77, which is why I felt totally comfortable smashing as much would fit into the case when doing the two rounds of 4831 rather than 'sensibly working up from a reduced starting point'

 

[[486]]

27.5 is when the ejector swipes started getting significant, so the ancient lyman book proves its worth once again
decided not to shoot the 27.7 ones, I'll pull them
primer wasn't near as flat as I've seen with these primers which is interesting

 

[[486]]

so loaded up some 50gr 223, ten each of
26.4, 26.6, 26.8, 27, 27.2 h335
shot 5 of each with my 16" pencil and the 20" heavy
the accuracy nodes were once again the same across the two barrels which is really nice and convenient, both the 77s and these 50s are doing that
one node was right around the starting and the other was right around the max that I'd loaded, kinda sucky not straddling one to see where the middle is but w/e
Only got 100 more of these 50s, so I'll probably just load them up at 27.2 rather than dicking around more

 

[Roc Doc]

White Oak Arsenal sells great stuff for NRA High Power. You can buy the parts or the whole upper and have a solid target rifle to punch paper for score. I have an old DPMS heavy barrel A4 upper that I use but the White Oak is the go-to for match guns. They aren't cheap but they run well.

Shop White Oak Competition Service & Match Rifle Uppers | White Oak Armament

Find the best selection and prices on in-stock White Oak Competition Service & Match Rifle Uppers.

www.whiteoakarmament.com

I have a 20" White Oak barrel waiting for install. I'll do the full receiver lapping and sleeving compound routine, it should be 1/2 MOA with the right load.

 

[Roc Doc]

so loaded up some 50gr 223, ten each of
26.4, 26.6, 26.8, 27, 27.2 h335
shot 5 of each with my 16" pencil and the 20" heavy
the accuracy nodes were once again the same across the two barrels which is really nice and convenient, both the 77s and these 50s are doing that
one node was right around the starting and the other was right around the max that I'd loaded, kinda sucky not straddling one to see where the middle is but w/e
Only got 100 more of these 50s, so I'll probably just load them up at 27.2 rather than dicking around more

I usually find the best node up near the listed max.

 

[Chevy_man]

I usually find the best node up near the listed max.

There's usually several. Lots of times they're at the extreme ends of the spectrum.

 

[[486]]

I usually find the best node up near the listed max.

as seen from #80, my 'starting' was over listed max, lol

imagine the powder's gonna be burning best at max pressure
I know light pistol loads burn way smoky, but when you start flattening primers it gets a whole lot cleaner
pretty much pick your velocity based on burn rate, load them all to basically the same pressure but the slower powders will get you more speed (until you run outta case capacity)

 

[Roc Doc]

as seen from #80, my 'starting' was over listed max, lol

imagine the powder's gonna be burning best at max pressure
I know light pistol loads burn way smoky, but when you start flattening primers it gets a whole lot cleaner
pretty much pick your velocity based on burn rate, load them all to basically the same pressure but the slower powders will get you more speed (until you run outta case capacity)

full or nearly full cases do better as well. No tilted powder column in the case.

 

[Roc Doc]

I have a 20" White Oak barrel waiting for install. I'll do the full receiver lapping and sleeving compound routine, it should be 1/2 MOA with the right load.

Slight change in plan. Still planning on truing the face of the receiver by lapping, but going with a BCM themo-fit upper as they are slightly undersized, (.003 IIRC), so you heat up the portion of the receiver where the barrel extension goes, and once the receiver cools it is what amounts to an interference fit. Supposed to make a noticeable difference.