Imr 4955 in the .284

[buddy.223]

Anybody using this combo with 180g bullets, getting pressure signs over 2800, not great es eithor, i find it nearer 4350 than 4831, speed - load wise.

 

[buddy.223]

Any body ? . Or tried it in another calibre, Tried some in my 300 wm same result pressure early poor es.
Would as someone suggested a variation in the kernel sizes - as on inspection the vary greatly, a lot of dust within the tub.

 

[358WCF]

It seems no one is using your combination. Barrel length? Barnes shows nothing over 2500fps with 175s. Berger gets close to, but not over, 2700fps with 180s; both books using 24" barrels. Neither book has 4955 data. Hodgdon's 2021 Annual has no 284 Win. data at all, but does show the similar capacity 280 Rem. with 175s using 52.2 gr of 4955 as max. at 2530fps. Maybe you really are over max.?

Guessing, but unsure if, your kernel sizes are 3 different powders? Maybe IMR4955, one of the many 4350s, & either H or IMR 4831? The kernel size would be part of how each particular powder is made & its burn rate controlled, but have very little to do with relative burn rate.

Maybe if you phrased your queries into coherent questions you might get a better answer.

 

[buddy.223]

Thanks for your reply, as i cant get H 4831 or 4350 i was looking for a replacment powder for mt f class .284 win rig bat actioned 30 " kreig 1 8.5 tw mtu. Imr 4955 has been advertised as a sub for the 4831 s - gave it a try results were poor to say the least pressure signs at what for my rifle were moderate speeds, i tend to run mine in the 2820 - 40 range, ive never had a pressure sign with this rig up to 2900 but with 4955 pressure signs at 2800, with sudden pressure spikes and large es spreads . ladder test was the worst ive ever conducted. Those kernels are all from the same tub of 4955, would a proportion of say more of the smaller kernels give the spike as say one of the larger bits ?.
Ive gotten a few replies from other forums pressure with moderate speeds seem to be a big problem accross various calibres so i guess i will have to keep looking.

 

[Ned Ludd]

Thanks for your reply, as i cant get H 4831 or 4350 i was looking for a replacment powder for mt f class .284 win rig bat actioned 30 " kreig 1 8.5 tw mtu. Imr 4955 has been advertised as a sub for the 4831 s - gave it a try results were poor to say the least pressure signs at what for my rifle were moderate speeds, i tend to run mine in the 2820 - 40 range, ive never had a pressure sign with this rig up to 2900 but with 4955 pressure signs at 2800, with sudden pressure spikes and large es spreads . ladder test was the worst ive ever conducted. Those kernels are all from the same tub of 4955, would a proportion of say more of the smaller kernels give the spike as say one of the larger bits ?.
Ive gotten a few replies from other forums pressure with moderate speeds seem to be a big problem accross various calibres so i guess i will have to keep looking.

It sounds as though the IMR4955 simply isn't the right powder for your .284/180 Hybrids. It may be a bit too slow, it may be a slightly lower energy powder than H4831sc or H4350, or both. The kernels in the image look very much like AA4064 powder; which has similar very short, medium, and very long kernels. I strongly doubt that selecting small/medium/large kernels would ever work to ease the pressure issues. In fact, using exclusively the small kernels might make the problem worse due to having a larger surface area-to-weight ratio. In any event, selecting kernels by size isn't something you really want to have to do. In order to use the IMR4955, it sounds as though you may have to realistically accept a slower tune for your 180 Hybrid load. That's not the greatest option to have, but at least it can work while you continue to scour the internet and/or local gun stores for H4350/H4831sc.

 

[KMart]

I used some about a year ago in a 25-06. Started out loading some 2 shot groups to find where it pressured out. Started about midrange of Hodgdons low/high data. I immediately got pressure on the first load.
Pulled bullets and started over with the starting load. Long story short, eventually found a VERY accurate load with a 115 Berger with a velocity around 3150 fps

 

[Loudenboomer]

Had some interesting results from some Informal testing yesterday during barrel break in.
.284 Win Rem action 30.5" Bartlein Barrel. Fire forming factory new Peterson Brass. 180 JLK VLD 2 thou. neck tension.
H4831 SC 55.2 gr Fed 210 primer 2 groups Ave. vel. 2824 High Extreme Spread 18 Low ES 12
IMR 4955 53.4 gr CCI 200 primer 2 groups Ave. vel. 2798 High Extreme Spread 18 Low ES 12
I was gunning for Vel . spread but I did shoot the 4955 a little better.
These are indeed similar performing powders.

This is a copy and paste from my thread last June

 

[buddy.223]

Thanks again, Ned l - yes dont think this combo any good for me, i never considered sorting the kernels, id noticed when the chargemaster threw some of the charges the bigger ones would slow up dispensing letting more of tiny ones past, then large ones would drop in the next charge, i wondered if this would give the speed - pressure spike. If i haddened opened the new tub my self the way its performing and looks youd think a differnt powder had been accidenly mixed in.
K mrt - similar results, did get a bit of a node at 2750 ish no pressure, bit slow sd average, going to try diff tub.
Loud n boom - the 53g s @ 2800 would be more in line with my 4350 loads, the 55 s is where im at too with 4831. Did u shoot any 5 shot groups with the 4955 @ 2820 odd i get maybe 3 with a poorish es with 1 or 2 spiking in pressure & speed jumping 2850 s, with deffinate pressure signs.