Howa 20 HB, XBR, AR-comp, and me

[grayfox]

http://kwk.us/pressures.html

[grayfox]

Footnote: the Grendel Book vol 2 has 3 entries for Hornady 123's and AR Comp, 1 for Amax and 2 for sst, topping out at 28.0 grs.

[LRRPF52]

Bolt Gun Loads Discussion

Grendel brass yield was designed with 60,000psi per Bill A. from my conversations with him, which leaves a good safety margin between max loads for the AR15.

You can push to 60ksi in a bolt gun if you want to, but brass life will suffer.

Where I'm at is what is this cartridge really good for?

Is it ideal being pushed to the extreme limits trying to mimic .260 Rem performance with 10gr less powder, or does it behave really nice when I keep around 50ksi and let its mild recoil and high BCs work together for Goldilocks rather than drag racer with hair on fire?

The bolt guns you can push a little harder, depending on the action diameter and lug lengths, but keep in mind rifle manufacturers will be looking at SAAMI when doing the engineering on the pressure containment components.

I personally wouldn't worry about loading a regular diet of 55ksi in my Howa if I wanted to, but it does feel great to shoot with the standard mild Grendel loads.

For CFE223, you can go up to 31.9gr and still be within 50ksi, at least with the powder lot we tested in a Manson SAAMI-chambered, single shot pressure test action.

My 31.2gr load of CFE223 under the 123gr AMAX produced an average of 2592fps from my 22" Howa, and that is a mild load that I've shot for years now thanks to Bwild97 turning me onto CFE223 here on the forum several years ago.

You can shoot 32.0gr of CFE223 under a 123gr AMAX in the Howa and be fine, at least the powder lots that I have been shooting and the ones that were tested.

32.8gr of CFE223 was just under 55ksi, with over 2600fps from a 16" AA barrel.

Bolt Gun Loads Discussion

[lrgrendel]

I’m glad you brought this up. For novice reloaders it is absolutely imperative that AR15 loads are not confused with bolt loads.
Quick question. Are action diameters related to barrel diameters?

[grayfox]

Bolt Gun Loads Discussion

Grendel brass yield was designed with 60,000psi per Bill A. from my conversations with him, which leaves a good safety margin between max loads for the AR15.

You can push to 60ksi in a bolt gun if you want to, but brass life will suffer.

Where I'm at is what is this cartridge really good for?

Is it ideal being pushed to the extreme limits trying to mimic .260 Rem performance with 10gr less powder, or does it behave really nice when I keep around 50ksi and let its mild recoil and high BCs work together for Goldilocks rather than drag racer with hair on fire?

The bolt guns you can push a little harder, depending on the action diameter and lug lengths, but keep in mind rifle manufacturers will be looking at SAAMI when doing the engineering on the pressure containment components.

I personally wouldn't worry about loading a regular diet of 55ksi in my Howa if I wanted to, but it does feel great to shoot with the standard mild Grendel loads.

For CFE223, you can go up to 31.9gr and still be within 50ksi, at least with the powder lot we tested in a Manson SAAMI-chambered, single shot pressure test action.

My 31.2gr load of CFE223 under the 123gr AMAX produced an average of 2592fps from my 22" Howa, and that is a mild load that I've shot for years now thanks to Bwild97 turning me onto CFE223 here on the forum several years ago.

You can shoot 32.0gr of CFE223 under a 123gr AMAX in the Howa and be fine, at least the powder lots that I have been shooting and the ones that were tested.

32.8gr of CFE223 was just under 55ksi, with over 2600fps from a 16" AA barrel.

Bolt Gun Loads Discussion

Also very glad to see this (again, I think I remember seeing it but search-fu not so great...) '52.
As mentioned I'm concerned that 2600 give or take from the howa/123 gr load might be too much over the limits but didn't have any data for it.
The 31.4 I'm using of CFE gives 2529-2540 and is a great node in my 20" HB, I'm happy with that node.
The 28.4 of AR-Comp... might be a less temperature-sensitive entry at that velocity.

[jason miller]

Bolt Gun Loads Discussion

Grendel brass yield was designed with 60,000psi per Bill A. from my conversations with him, which leaves a good safety margin between max loads for the AR15.

You can push to 60ksi in a bolt gun if you want to, but brass life will suffer.

Where I'm at is what is this cartridge really good for?

Is it ideal being pushed to the extreme limits trying to mimic .260 Rem performance with 10gr less powder, or does it behave really nice when I keep around 50ksi and let its mild recoil and high BCs work together for Goldilocks rather than drag racer with hair on fire?

The bolt guns you can push a little harder, depending on the action diameter and lug lengths, but keep in mind rifle manufacturers will be looking at SAAMI when doing the engineering on the pressure containment components.

I personally wouldn't worry about loading a regular diet of 55ksi in my Howa if I wanted to, but it does feel great to shoot with the standard mild Grendel loads.

For CFE223, you can go up to 31.9gr and still be within 50ksi, at least with the powder lot we tested in a Manson SAAMI-chambered, single shot pressure test action.

My 31.2gr load of CFE223 under the 123gr AMAX produced an average of 2592fps from my 22" Howa, and that is a mild load that I've shot for years now thanks to Bwild97 turning me onto CFE223 here on the forum several years ago.

You can shoot 32.0gr of CFE223 under a 123gr AMAX in the Howa and be fine, at least the powder lots that I have been shooting and the ones that were tested.

32.8gr of CFE223 was just under 55ksi, with over 2600fps from a 16" AA barrel.

Bolt Gun Loads Discussion

First, the Grendel is based on the PPC case- which regularly gets run at higher pressures than just about anything. It seems to me that thinning the case web/head would have been an extra and unnecessary step in turning a PPC case into a Grendel case. But I haven't sectioned any to find out, so it is a possibility. I doubt, though, that any self-respecting engineer would design something like a cartridge case to fail if pushed a mere 20% beyond its intended range of use. And I really doubt that Hornady or Lapua are using different metallurgy than they do in all their other brass that is made to regularly run at 65,000 psi. But again, I could be wrong. I do know, however, that in every other modern cartridge, primers and primer pockets give out way before brass. I haven't blown either so far. If my primer pockets hold up for half a dozen loadings, i will personally consider my loads safe in my rifle. And if primer pockets get loose enough to noticeably feel less resistance when seating primers, I throw the case away.

Second, I don't think anyone is trying to turn a Grendel into a 260. It would be a silly venture, because a 260 should easily push a 123 near 3,000 fps. At the 2600 that my rifle seems to like, I'm still 400 fps short. But at similar pressures, my Grendel's 2600 fps would be similar to running a Creedmoor at 2960 fps. Totally doable.

I understand that after primers and primer pockets, followed by the brass itself, the lugs on the bolt and my receiver itself are the next limiting factor and my little Howa is more diminutive than standard bolt action rifles. But standard bolt action rifles are usually designed to withstand at least 90,000 psi proof loads in worst-case scenarios. I'd be surprised if a regular diet of 60K using a measly 29 grains of powder is ever going to blow my rifle up.

I haven't ever seen it mentioned specifically, but I've gathered that the load data manuals for sale through this site were developed with the pressure-testing action you reference? Just curious.

Finally, 2600 fps from a 16" barrel should be stepping right on the heels of 2700 fps with just another 4" of barrel. And is that with a gas tube, or no? I would assume, maybe incorrectly, that bolt rifles should be more efficient and yield higher velocity at the same pressure since they don't waste some of the gas to cycle their bolt. It could be insignificant. I'd be interest to see testing on the subject.

All-in-all, I appreciate that so many people on this forum are concerned for the safety of others. But I also think that most of those people have an "AR first" mentality about this cartridge. And isn't this the bolt-action sub-forum? Any sane handloader, bolt or AR, should work up carefully, watch for signs of excess stress, and back off when needed. I'm personally very interested in seeing how long my brass holds up with 123's at 2600. And I'm just as interested in seeing how others fare over time, too. The Grendel is an efficient little cartridge(all little cartridges are relatively more efficient than their larger counterparts), and I'm excited to see what it's capable of.

[grayfox]

As the OP for this thread, I can speak to my own reasoning for writing. First off, I like ARs fine but beneath it all I prefer a bolt if I can get one, that's just me. I do like the GRrrrr plenty in both AR and bolt and am in process of building yet another... in AR.
Now my own background is not in shooting science but in nuclear operations, accident analysis and response, engineering and regulatory affairs, 40+ years.
I do respect those that have the depth of background in small arms and in the Grendel in particular - I want to hear from and learn from those guys and they are here, so I'm glad I'm along for the ride.
That being said and mindful that anything engineered well has, indeed, margins of safety built in (I've worked with and relied on this for years throughout the big nuclear plants), I did mention that I was concerned that you all may be using some loads that would challenge the cartridge limits. I just didn't have the data to back up the limits.
And yes, part of me wanted to see for myself what some of the loads would do, but I did not want to go too far (in my opinion) in doing that. So I shot a few of the loads over my chrony to see what I could see.

But a bigger issue for the forum was to get the discussion going for benefit of others as to where the Grr limits are and yes, in a bolt gun you can probably exceed them some, but in general it's not best IMO to push it too far. How far- is up to the individual loader and for that y'all have the right to do so.

I am glad to see that the loads worked ok for your rifle and apparently you're aware of the risks. And I'm glad to perhaps find (AR-Comp) a less temp-sensitive powder for my 123's as a result of all of this...

So I tested a few of the loads, and wrote up what I wrote. And thanks to all for contributing. Being safe, after all, is paramount, so that we all can shoot again another day.

[xlcc]

I agree that this bolt action data should be separate from the AR platform.It good to see many participants producing,collecting data for others to view.As always what may seem like a good load in my Howa Mini Action should be approached cautiously by others.It is also a good thing to have others watching over that may have more experience offer constructive discussion.

[LRRPF52]

First, the Grendel is based on the PPC case- which regularly gets run at higher pressures than just about anything. It seems to me that thinning the case web/head would have been an extra and unnecessary step in turning a PPC case into a Grendel case. But I haven't sectioned any to find out, so it is a possibility. I doubt, though, that any self-respecting engineer would design something like a cartridge case to fail if pushed a mere 20% beyond its intended range of use. And I really doubt that Hornady or Lapua are using different metallurgy than they do in all their other brass that is made to regularly run at 65,000 psi. But again, I could be wrong. I do know, however, that in every other modern cartridge, primers and primer pockets give out way before brass. I haven't blown either so far. If my primer pockets hold up for half a dozen loadings, i will personally consider my loads safe in my rifle. And if primer pockets get loose enough to noticeably feel less resistance when seating primers, I throw the case away.

Second, I don't think anyone is trying to turn a Grendel into a 260. It would be a silly venture, because a 260 should easily push a 123 near 3,000 fps. At the 2600 that my rifle seems to like, I'm still 400 fps short. But at similar pressures, my Grendel's 2600 fps would be similar to running a Creedmoor at 2960 fps. Totally doable.

I understand that after primers and primer pockets, followed by the brass itself, the lugs on the bolt and my receiver itself are the next limiting factor and my little Howa is more diminutive than standard bolt action rifles. But standard bolt action rifles are usually designed to withstand at least 90,000 psi proof loads in worst-case scenarios. I'd be surprised if a regular diet of 60K using a measly 29 grains of powder is ever going to blow my rifle up.

I haven't ever seen it mentioned specifically, but I've gathered that the load data manuals for sale through this site were developed with the pressure-testing action you reference? Just curious.

Finally, 2600 fps from a 16" barrel should be stepping right on the heels of 2700 fps with just another 4" of barrel. And is that with a gas tube, or no? I would assume, maybe incorrectly, that bolt rifles should be more efficient and yield higher velocity at the same pressure since they don't waste some of the gas to cycle their bolt. It could be insignificant. I'd be interest to see testing on the subject.

All-in-all, I appreciate that so many people on this forum are concerned for the safety of others. But I also think that most of those people have an "AR first" mentality about this cartridge. And isn't this the bolt-action sub-forum? Any sane handloader, bolt or AR, should work up carefully, watch for signs of excess stress, and back off when needed. I'm personally very interested in seeing how long my brass holds up with 123's at 2600. And I'm just as interested in seeing how others fare over time, too. The Grendel is an efficient little cartridge(all little cartridges are relatively more efficient than their larger counterparts), and I'm excited to see what it's capable of.

Yes. There are Factors of Safety above the designed working pressure of the brass of course.

I also agree that 2700fps from a 20-22" Grendel bolt gun should be doable with 120-123gr cup and core bullets using CFE223 or LEVERevolution.

I have some 140gr AMAX loads to test from the Howa with CFE223 that should be interesting, as I'll run the ladder up within a range that pushes performance without going too crazy.

140gr AMAX on steel at 1000yds sounds cool no matter what you shoot it from, kills things dead too.

As to the gas port and its effects on muzzle velocity from ARs versus bolt guns, in fleet testing, Bill A. said he didn't see any measurable difference.

I've had higher average muzzle velocities from my 18" Grendels (several of them with different barrel and rifling profiles), shooting the same ammunition, than my 22" Howa for some reason also, but I can push the bolt gun faster as I increase the charge weight in my ladder testing. This seems to be consistent with what I'm seeing from everyone else.

I placed the red reminders for those who aren't members or might come across the info via a relevancy-based search engine as an added precaution, not as a warning to those who are already forum members and understand the deal with the bolt gun sub-forum. I've seen this before where people have just pulled data from online, then applied it as a recipe right out of the gate, and were getting .260 Remington speeds with 6.5 Grendel AR15s, then came here to "help" us understand why they were getting so much more speed. Maybe the red words will help prevent that.

2700fps with a 123gr from a 22" Grendel bolt gun is nipping the heels of 6.5CM and .260 Rem though, not much performance difference for the layman. It is a very efficient little case for sure.

[jason miller]

Yes. There are Factors of Safety above the designed working pressure of the brass of course.

I also agree that 2700fps from a 20-22" Grendel bolt gun should be doable with 120-123gr cup and core bullets using CFE223 or LEVERevolution.

I have some 140gr AMAX loads to test from the Howa with CFE223 that should be interesting, as I'll run the ladder up within a range that pushes performance without going too crazy.

140gr AMAX on steel at 1000yds sounds cool no matter what you shoot it from, kills things dead too.

As to the gas port and its effects on muzzle velocity from ARs versus bolt guns, in fleet testing, Bill A. said he didn't see any measurable difference.

I've had higher average muzzle velocities from my 18" Grendels (several of them with different barrel and rifling profiles), shooting the same ammunition, than my 22" Howa for some reason also, but I can push the bolt gun faster as I increase the charge weight in my ladder testing. This seems to be consistent with what I'm seeing from everyone else.

I placed the red reminders for those who aren't members or might come across the info via a relevancy-based search engine as an added precaution, not as a warning to those who are already forum members and understand the deal with the bolt gun sub-forum. I've seen this before where people have just pulled data from online, then applied it as a recipe right out of the gate, and were getting .260 Remington speeds with 6.5 Grendel AR15s, then came here to "help" us understand why they were getting so much more speed. Maybe the red words will help prevent that.

2700fps with a 123gr from a 22" Grendel bolt gun is nipping the heels of 6.5CM and .260 Rem though, not much performance difference for the layman. It is a very efficient little case for sure.

I also loaded up some more 140's to try. A 123 eld is barely supersonic at 1,000 yards here, while a 140-147 would add some cushion even with a 200 fps disadvantage at the muzzle. Please post your results. I'd be interested to see them.

Interesting about the gas port. Thanks for sharing.

I think these Howas might just have "loose" bore dimensions. Factory ammo only did a smudge over 2400 in mine. And since velocity=pressure much more so than powder charge=pressure, I don't mind at all if I have to bump the charge over listed max loads to achieve appropriate velocities in my rifle.

I agree that the Grendel sure is an efficient little bugger. Smaller cartridges always are. How much powder does a 22LR use? But I still think that nipping on the heels of a Creed or 260 is a bit of a stretch. That's about like saying that a 7-08 is nipping on the heels of a 7mm Rem mag or a 30-06 is nipping on the heels of a 300 Weatherby. But for all practical purposes out to common distances, there really isn't a lot of difference between a 123 at 2600+ fps and a 140 at 2700.. Although Quickload seems to think that RL26 in a Creed could push a 140 more like 2900 fps- which would be pretty interesting...