129ablr & h4198 load data

[Jeepster18_88]

I've always noticed that most reloaders seem to think best accuracy is at or close to the maximum velocity. For long range it makes sense. Personally I've noticed that the best accuracy can be all over the charts as far as speed goes at a short distance of 100 yards. My first deer rifle was a 270 that has never shot better than 1" with reloads or worse than 2 1/2 with factory. I tried a cowboy load that was about 1300 fps and was shooting 1/2" groups at 100 yards with a 100 great bullet. It also shot the same with 140 great bullets that wouldn't shoot 1" with any conventional powder. IMO, velocity is often overrated at short distance. It matters, just not as much as people make it out to.

[lazyengineer]

I've always noticed that most reloaders seem to think best accuracy is at or close to the maximum velocity. For long range it makes sense. Personally I've noticed that the best accuracy can be all over the charts as far as speed goes at a short distance of 100 yards. My first deer rifle was a 270 that has never shot better than 1" with reloads or worse than 2 1/2 with factory. I tried a cowboy load that was about 1300 fps and was shooting 1/2" groups at 100 yards with a 100 great bullet. It also shot the same with 140 great bullets that wouldn't shoot 1" with any conventional powder. IMO, velocity is often overrated at short distance. It matters, just not as much as people make it out to.

In my experience, the hotter I run the ammo, the more consistent the powder burn gets, and the lower my standard deviations. But not all bullets like it that way. If I'm running any flavor of a military bullet (55, or 62 gr of the rather numerous 62 gr flavors now available); they all run large MOA (up to 3+ at times) at full-spec pressure and velocity. Back it off 150 fps, and almost all of them will drop down, sometimes to nearly 1 MOA or even better.

With match quality bullets, it tends not to matter much, and the hotter I run them, often the better they shoot.

[TXCrow]

Just trying to drop these hogs without blinding myself, both nightvision(pupil dilation) and debris wise, while I'm doing it. And to keep the '18 Tacoma from getting covered inside and out...

Here I am with half the barrel length of most of the published loads being told that its a terribly unsafe idea because the engineers didn't sign off. That doesn't work for me. Its not like I was asking about 160rn/greendot/cci350. It's a grendel powder with published loads for bullets 6gr lighter.. If I can get a clean load with a 4" MPBR of 180y I'm gold. save the mess for the 20" grendel.

As is now that the Midwest blast diverter came in I'm going to work back through a few loads with hotter primers and see whats what but from what I saw with a few hand loads i had left the issue has just been redirected. any headwind and itll be right back in my face. I threw together some 120eldm/h4198/205mar from 22-23gr and it did seem much better than the same load with benchmark and cfe223. I'm thinking 129ablr/h4198/205mar(wsr)/hornady brass 20gr-22gr in steps of .2. If after all of this this combo actually shoots in this barrel ill update. No velocity numbers yet. magnetospeed doesn't fit with the handguard on. Any fiddling with the ablr/4198 combo will be done on chrono first before any accuracy testing. Maybe some nighttime pics comparing flash between the factory ammo, 20" upper loads and the h4198 loads will happen too as well as a couple in the 20" grendel for comparison.

I have emails in to nosler and Hodgdon. Not holding my breath but that's about all i can do with my work schedule.

[Jeepster18_88]

I can't remember if you said it, but do you have a chronograph to help check for spikes? I'd be less worried going into uncharted territory with a strong bolt action and since the Grendel pressures don't appear before the gun is over pressured, I would recommend using one. A lead sled and remote trigger wouldn't be a bad idea either to be honest. My be a good job for my BCA upper since it isn't accurate. Lol

[TXCrow]

Jeepster

Any work with that combo will be done in small increments over a chrono after working with the powder in published loads.

[centerfire]

Just trying to drop these hogs without blinding myself, both nightvision(pupil dilation) and debris wise, while I'm doing it. And to keep the '18 Tacoma from getting covered inside and out...

Here I am with half the barrel length of most of the published loads being told that its a terribly unsafe idea because the engineers didn't sign off. That doesn't work for me. Its not like I was asking about 160rn/greendot/cci350. It's a grendel powder with published loads for bullets 6gr lighter.. If I can get a clean load with a 4" MPBR of 180y I'm gold. save the mess for the 20" grendel.

As is now that the Midwest blast diverter came in I'm going to work back through a few loads with hotter primers and see whats what but from what I saw with a few hand loads i had left the issue has just been redirected. any headwind and itll be right back in my face. I threw together some 120eldm/h4198/205mar from 22-23gr and it did seem much better than the same load with benchmark and cfe223. I'm thinking 129ablr/h4198/205mar(wsr)/hornady brass 20gr-22gr in steps of .2. If after all of this this combo actually shoots in this barrel ill update. No velocity numbers yet. magnetospeed doesn't fit with the handguard on. Any fiddling with the ablr/4198 combo will be done on chrono first before any accuracy testing. Maybe some nighttime pics comparing flash between the factory ammo, 20" upper loads and the h4198 loads will happen too as well as a couple in the 20" grendel for comparison.

I have emails in to nosler and Hodgdon. Not holding my breath but that's about all i can do with my work schedule.

I have no issues with that. You're within predicted safe loads. If that doesn't work out, Nosler suggested H4895 because it has higher case capacity despite being relatively close to the burn rate H4198.

[lazyengineer]

For what it's worth, this thread was part of the inspiration of some test work with fast vs slow rifle powder, in decrease BBL length. Results are here:

https://www.ar15.com/forums/armory/Test-results-affect-of-BBL-length-decrease-on-velocity-with-fast-vs-slow-rifle-powder/42-499814/?page=1

In a nutshell, the faster powder did increase in relative performance vs the slower powder as barrel length got shorter. But not by a lot. Going from 20" 5.56 Rifle down to a 10.5" borrowed pistol length barrel, resulted in a 15% velocity decline when using the faster powder, vs a 17% velocity decline with the slower powder; in this example with 55 gr reloads.

[CaptnC]

None of the responses have highlighted any major flaw in my logic(sbr application only) other than the fact that there is no specific load data. The powder has been tested in that chamber and if it weren't for Hodgdon having published load data(up to 123) for this powder I would not attempt it. My goal is a slow reliable load. +/-2000fps . I shoot 20+rds /week(hog and coyote) 200yd max 100yd average depending on the season from the driver window in my truck and since switching to the 12" the excess from the standard grendel(long barrel) powders makes one hell of a mess. Unburned powder blowing back on me, the truck etc.
All I want is optimal powder burn in the 12" barrel with wide temp stability 10* to 130* in the truck

Being the grey area that it is, I'm going to start with the published data with the same bullet referenced then come around to the 130 class. I'll keep y'all posted barring any new intel.

While I don't share everyone's desire to have a short barreled ANYTHING!

If I were, I'd be looking to do exactly what the OP is asking for the same reason.

I mean, hell...nearly every load used in a 12" Grendel is built on the idea of using a barrel at least 18" long! Ive said that in some of my poorly received rants!

A better way to ask the question; why use a rifle powder in a pistol application?

OP I get your logic!