Over max loads?

[daved20319]

New to the Grendel world, picked up my Howa barreled action yesterday, but stock won't get here until Monday. But in the meantime, I'm reading everything I can find, both on rifles and on loading for them. One thing stands out, I keep seeing lots of discussion about loads over published maximums, and it has me wondering about SAAMI pressure specs. Are they based on cartridge CASE strength, or is it rifle action? And if the latter, isn't a bolt action considerably stronger than a semi-auto? I know the Grendel was designed as an AR cartridge, and presumably, the SAAMI specs were based on that action, so it seems reasonable that a bolt action could handle a good deal more pressure, which should equate to higher velocity, a good thing if you're trying to reach out there. Maybe there needs to be bolt action specific data for the Grendel, along the lines of the Ruger specific handgun loads? Not trying to pick any fights here, just curious what the older, wiser heads think. Later.

Dave

[Joseph5]

The SAAMI pressure spec was set for use in an AR style action. You can safely load higher pressures in a bolt action, just make sure you do not accidentally put a bolt load in an AR. From what I have seen on here people that are shooting a Grendel bolt rifle at higher pressures say that Lapua brass is the best for that.

[JASmith]

Joseph5 is close to having it right.

We considered incorporating a bolt or strong single shot section for load data when we wrote the Grendel Reloading Manuals.

Bill Alexander's advice was something we could not ignore -- in essence, we cannot control how one chooses to use data and all too many ignore advice and jump right to the heaviest load they see. That would set us up for some bad doo-doo from broken bolts and worse.

We can live with this conclusion because it is all too easy to go with a larger cartridge in a slightly heavier rifle if the primary goal is muzzle velocity. In other words, why should we abuse a fine cartridge by asking it to do things it was not designed to to do?

[A5BLASTER]

The SAAMI pressure spec was set for use in an AR style action. You can safely load higher pressures in a bolt action, just make sure you do not accidentally put a bolt load in an AR. From what I have seen on here people that are shooting a Grendel bolt rifle at higher pressures say that Lapua brass is the best for that.

I like my Starline brass in my howa over the lapua I had started with.

Yes the bolt actions can handle more pressure then the ar grendels due too bolt design in the ar. Sammi case pressure for grendel is max 58k. If you load so your getting 200+ fps faster then an ar with the same length barrel as your bolt action. Your most likely over the 58k pressure rating for the brass.

100 fps is ok in my book and my howa grendel. 150 fps faster then a ar grendel with same barrel length might be a bit much.

I work my loads up the same way for both platforms, start low work up in .2tenth increments, 5 shots at each charge and stop when I see a spike or dump in velocity.

Then look just under that for the tight sd and es load and rework them changing seating depth a lil too find the best grouping.

If you have both a ar and bolt grendel my best advice is slow way down and take double time too double check you aren't mixing brass or loads between the 2 platforms.

I use Starline for both but my go back to hornady for the ar. Just to make it simpler too keep the two separate and not have any mistakes.

We have a 2 book set of grendel specific load manuals sold on this fourm. I highly suggest purchasing them.

Hope this helps gents.

[lazyengineer]

Joseph5 is close to having it right.

We considered incorporating a bolt or strong single shot section for load data when we wrote the Grendel Reloading Manuals.

Bill Alexander's advice was something we could not ignore -- in essence, we cannot control how one chooses to use data and all too many ignore advice and jump right to the heaviest load they see. That would set us up for some bad doo-doo from broken bolts and worse.

We can live with this conclusion because it is all too easy to go with a larger cartridge in a slightly heavier rifle if the primary goal is muzzle velocity. In other words, why should we abuse a fine cartridge by asking it to do things it was not designed to to do?

I would like to meet Bill Alexander some day.

[daved20319]

Thanks, guys. Was doing some more digging, apparently SAAMI pressure is restricted to 52K for the AR bolt, but it's 58K for the brass cartridge case. Don't have a Grendel AR, nor do I intend on buying/building one, it seems reasonable for me to load to somewhat higher pressures. That said, I don't intend to get crazy, I'm conservative by nature with such things, but it should give me an edge over my shooting partner and his AR Grendel . I'll just have to be careful not to let him use any of my bolt gun only loads.

Still debating with myself about brass, but I'll probably go with Starline, just because I've been so happy with their pistol brass. Will probably try some Lapua at some point, but unless I can get double the number of reloads vs. Starline, I just don't see an advantage. Maybe if I was a competitive shooter, but I do this for fun. But it looks like I need to order the Grendel load books ASAP. Later, and thanks again.

Dave

[daved20319]

We have a 2 book set of grendel specific load manuals sold on this fourm. I highly suggest purchasing them.

Hope this helps gents.

Sounds like just what I need, but where do I find them? I've looked, but no joy. Thanks.

Dave

[Zeus]

Here ya go Dave.....

https://www.shopalexanderarms.com/Brass_Reloading-6_5_Grendel_Reloading_Handbook_Volume_1.html

https://www.shopalexanderarms.com/Brass_Reloading-6_5_Grendel_Reloading_Handbook_Volume_2.html

[biodsl]

Sounds like just what I need, but where do I find them? I've looked, but no joy. Thanks.

Dave

Or here directly from LRRPF52 https://www.ar15buildbox.com/shop/65...-HandBooks.htm

[A5BLASTER]

Or here directly from LRRPF52 https://www.ar15buildbox.com/shop/65...-HandBooks.htm

Thank you sir. I'm not techy enough too do the link posting thing lmao.

[Clays23]

I usually go slightly over max in my Ruger American with no signs of pressure. Stay safe

[grayfox]

It's wise, IMO, especially for a new barrel and new loads, to heed what JAS is saying.

I did a small personal study recently on powders and pressure information, and -- aside from compression issues -- the powders I looked at should give basically 100 ft/s per grain increase over the ranges as listed in the manual, and anywhere from 3800 - 5400 psi increase. So a max 52 ksi charge in the test barrel would only see about 100 ft/s increase for a 4000 - 5400 psi increase, or up to maybe 56 ksi in the highest case I looked at. (note, actual pressure and velocity are not mathematically linearly-related but for the small range of the variables that rifle loads are inside of, the curve is pretty flat, so a linear approximation works pretty well.)

Another factor in the discussion is that when 2 guys are talking their rifles and MV's, actual barrel specifics can cause up to 50- 80 ft/s variation (and pressure variations too) for the same cartridge/load/charge. So most talk about "my barrel" and max or "over-max" loads can be greatly biased by non-powder issues such as barrel friction, chamber and bore diameters etc. This is why I believe the standard maxim is so important, for your barrel start low and work up carefully, your barrel must tell you what the safe loads are for your gun. The load data are just a guide so be careful.