Maximum FPS for Grendel Loads

[stlg67]

I was wondering if anyone has any ideas on maximum FPS for bullets with 26 BHN for the Grendel? I recently started making some 92g bullets and they are 26 on the BHN, these bullets are linotype. I would like to hog hunt with them but I haven't ever hunted with cast bullets. Also what would be the optimum FPS for good expansion on cast bullets and the best hardness on the BHN scale for the Grendel that are powder coated and gas checked? Thanks in advance for any advice.

 

[Hawk]

I'm not any of the resident experts on this forum, but I don't think you're going to get any expansion from a 26 BHN bullet.
I would suggest powder coating and casting a softer alloy for expansion.
It would be helpful if you told what mold you were using, nose configuration and whether round nose, flat point or hollow point.
Maybe some pics of the bullet.

 

[Rick]

I'm not any of the resident experts on this forum, but I don't think you're going to get any expansion from a 26 BHN bullet.
I would suggest powder coating and casting a softer alloy for expansion.
It would be helpful if you told what mold you were using, nose configuration and whether round nose, flat point or hollow point.
Maybe some pics of the bullet.

Bingo . . . .

 

[Bret4207]

I was wondering if anyone has any ideas on maximum FPS for bullets with 26 BHN for the Grendel? I recently started making some 92g bullets and they are 26 on the BHN, these bullets are linotype. I would like to hog hunt with them but I haven't ever hunted with cast bullets. Also what would be the optimum FPS for good expansion on cast bullets and the best hardness on the BHN scale for the Grendel that are powder coated and gas checked? Thanks in advance for any advice.

I'll tell you the same thing I've told you multiple times before. Forget Bhn being the answer to how fast you can shoot cast, or how accurate it will be or how much it will help. In fact, just forget Bhn entirely. For hunting you want something preferably with a FN or HP or at least a blunt round nose. If you want expansion, you need a fairly soft alloy, like not over 15Bhn. If you're talking the 6.5 Grendel, then you're talking a pretty light bullet for the caliber so penetration, especially on hogs, is going to be an issue and expansion is extremely unlikely at 26 Bhn.

There are innumerable posts here on hunting with cast. Try looking through a few of them and seeing if you find a pattern.

 

[fiver]

jeezus christ allmighty.

 

[Ian]

 

[Spindrift]

This sounds like the Arsenal 266-92 «spitzer» design. It has worked well for me, in my 6,5x55 rifles. I use it for recreational target shooting. I’ve never (yet) shot an animal with my cast bullets, and I’m by no means an expert. But I’ve done a fair bit of experimentation developing my moose load in .35 Whelen, and I’ll give you my thoughts on the subject (and- hopefully, in a couple of weeks , some moose will accomodate my desire to put my load to the final test!).


Your bullet has a quite small meplat, and is also very light weight- with low sectional density. In a hunting context, I would consider it more like a small- game bullet.

Cast bullet expansion is a balancing act. You want to acieve controlled expansion, and avoid bullet failure- resulting in inadequate penetration.

Three factors must be harmonized:
- the shape of the tip of the bullet, particularily the meplat size
- the properties of the alloy
- the desired terminal ballistic properties in the type of game animal you’re hunting (taking into account the anatomical obstacles the bullet must handle on it’s way to the vitals).

The following dependencies apply:
- a large meplat- bullet will have a lower expansion threshold than a smaller meplat bullet.
- but a large meplat bullet will also be more partial to over- expansion with incrasing velocity
- when velocity drops below the expansion threshold, a large-meplat bullet will leave a larger permanent wound channel (2x meplat diameter), while a small meplat bullet will «pencil through»
- with increasing antimony content, the bullet will become increasingly brittle. This is undesirable when controlled expansion is what you want.

So, you need a malleable alloy driven at a velocity were expansion is neither to great, or to limited.

I’ve never hunted hogs, but if they’re anything like the wild boar we have here in Europe, I would consider the otherwise excellent 6,5 Grendel to be a marginal cartridge even with the best, toughest jacketed bullets.

To make the best of your cartridge and bullet, I would use an alloy where bullets age- harden to around BHN 13- 15. Then do load development, and try to obtain sufficient accuracy around 2200fps. Then, I would do an expansion test at various ranges to gauge the behaviour of the bullet. Remember, you’ll have a range limit where impact velocity is below the expansion threshold, and you’ll just pencil through.

 

[CWLONGSHOT]

I have a few Grendels and haven't felt the draw of cast bullets thru them. They both shoot jacketed so accurate I couldn't hope for better. But I have Read enough stories of frustration with cast in 6.5's and in the fast twist barrels. I have experienced it with my 300 BO barrels. Only way I was able to accomplish acceptable was with ultra hard @ moderate velocities. I have some friends who are zincers and they have been doing some real respectable accuracy achievements. (Zinc is about 40 BHN)
Expansion is not something that fits this equation.

I do not want or mean to discourage or disparage! I wish ya luck!

CW

 

[358156 hp]

Historically, cast bullet performance on game is almost exclusively a product of bullet design. Small diameter cast bullets with tiny meplats are best relegated to medium small soft game like coyotes, and other similar sized critters. Hogs can be challenging with even much larger calibers! I recommend testing your super hard bullets in a ballistic media to determine their suitability for medium game before taking them hunting. The concern that the others are skirting around is that hard cast bullets at extreme velocities tend to break apart (fragment) on impact, reducing penetration dramatically, and that bullets with small diameter meplats tend to penetrate medium and larger game in a manner much like trying to stab the critter with a pencil. You should also not expect 26 bhn bullets to expand at any velocity.This is one of those combinations that I would recommend a good quality jacketed hunting bullet (not a target bullet) for. My personal preference for cast hunting bullets starts at 30 caliber and goes up from there. Will you be hunting with an AR?

 

[fiver]

insert clappy hands here for Spindrift.

 

[Ian]

If you're gonna hunt pigs with a Grendel, get on utoob and binge watch Todd Huey on his show Lone Star Boars. A few years back he wrung out the Grendel thoroughly as a hog hunting tool by doing extensive ammunition testing in the field and his results were very enlightening regarding bullet design. I won't spoil it for you.

 

[Tom]

There's a lot of good advice here from guys who have way more experience than I do. I'll share with you what little I know.
Hardness has it's place, but it's not everything. Glass is hard, but very brittle. The same can be said for linotype. On game, it will usually do one of two things. 1: punch straight through like a fmj, not conducive to leaking. 2: break apart, not conducive to penetration.
There's satisfaction in making your own, but with all the great jacketed bullets in 6.5, I'd lean towards the hornady 129 gr ablr or the speer 120 gr gold dot. There are many other suitable 6.5 bullets in the 100 to 130gr range, as well.
If taking game with your own cast bullets is the goal, I'd find a design that shoots well in your rifle, cast it in a much softer alloy, and powder coat it.

Edit to add: powder coating, done properly, serves as a jacket. Though not as hard as a copper based jacket, it will allow you to do things with softer alloys, giving you good expansion and penetration.

 

[Ian]

Case in point: https://www.artfulbullet.com/index.php?threads/swedish-mauser.8308/

 

[Tom]

Case in point: https://www.artfulbullet.com/index.php?threads/swedish-mauser.8308/

Yeah, Inge, my swede convinced me that 1700 was the upper limit. I quickly decided that 140gr Sierras weren't that expensive. I suppose I could've done better, but I didn't spend that much on hunting bullets.
In all fairness you guys went the extra mile to find a combination that worked in the 6.5x55. I gave up and decided it wasn't worth the effort.

 

[stlg67]

This sounds like the Arsenal 266-92 «spitzer» design. It has worked well for me, in my 6,5x55 rifles. I use it for recreational target shooting. I’ve never (yet) shot an animal with my cast bullets, and I’m by no means an expert. But I’ve done a fair bit of experimentation developing my moose load in .35 Whelen, and I’ll give you my thoughts on the subject (and- hopefully, in a couple of weeks , some moose will accomodate my desire to put my load to the final test!).


Your bullet has a quite small meplat, and is also very light weight- with low sectional density. In a hunting context, I would consider it more like a small- game bullet.

Cast bullet expansion is a balancing act. You want to acieve controlled expansion, and avoid bullet failure- resulting in inadequate penetration.

Three factors must be harmonized:
- the shape of the tip of the bullet, particularily the meplat size
- the properties of the alloy
- the desired terminal ballistic properties in the type of game animal you’re hunting (taking into account the anatomical obstacles the bullet must handle on it’s way to the vitals).

The following dependencies apply:
- a large meplat- bullet will have a lower expansion threshold than a smaller meplat bullet.
- but a large meplat bullet will also be more partial to over- expansion with incrasing velocity
- when velocity drops below the expansion threshold, a large-meplat bullet will leave a larger permanent wound channel (2x meplat diameter), while a small meplat bullet will «pencil through»
- with increasing antimony content, the bullet will become increasingly brittle. This is undesirable when controlled expansion is what you want.

So, you need a malleable alloy driven at a velocity were expansion is neither to great, or to limited.

I’ve never hunted hogs, but if they’re anything like the wild boar we have here in Europe, I would consider the otherwise excellent 6,5 Grendel to be a marginal cartridge even with the best, toughest jacketed bullets.

To make the best of your cartridge and bullet, I would use an alloy where bullets age- harden to around BHN 13- 15. Then do load development, and try to obtain sufficient accuracy around 2200fps. Then, I would do an expansion test at various ranges to gauge the behaviour of the bullet. Remember, you’ll have a range limit where impact velocity is below the expansion threshold, and you’ll just pencil through.

That is the mold I am using, and thanks for the advice.

 

[stlg67]

Historically, cast bullet performance on game is almost exclusively a product of bullet design. Small diameter cast bullets with tiny meplats are best relegated to medium small soft game like coyotes, and other similar sized critters. Hogs can be challenging with even much larger calibers! I recommend testing your super hard bullets in a ballistic media to determine their suitability for medium game before taking them hunting. The concern that the others are skirting around is that hard cast bullets at extreme velocities tend to break apart (fragment) on impact, reducing penetration dramatically, and that bullets with small diameter meplats tend to penetrate medium and larger game in a manner much like trying to stab the critter with a pencil. You should also not expect 26 bhn bullets to expand at any velocity.This is one of those combinations that I would recommend a good quality jacketed hunting bullet (not a target bullet) for. My personal preference for cast hunting bullets starts at 30 caliber and goes up from there. Will you be hunting with an AR?

Well this casting bullets is new to me, I will be using AR for these loads on the grendel. I have made 160g .30 caliber for 300 blackout and these are 15 on the BHN scale. I haven't shot anything but paper with these bullets and these are powder coated / gas checked as well. I'm planning on in the future making some .30cal for the .308 and .3006. Then maybe hunting with them on deer but will need to do like you said to test them and see the performance on some ballistic gel or something comparable.

 

[358156 hp]

At 15 bhn you do have a good chance of expansion depending on the makeup of your 15 bhn alloy and the impact velocity. Cast bullets are more reliable as hunting bullets when they're designed for hunting from the start, not all designs have hunting in mind. I think you're on the right track with your testing and you should have your answers when you get to test your bullets. We all hope your project works out the way you want it to. Please let us know your testing results, and please ask all the questions you need to.

 

[stlg67]

At 15 bhn you do have a good chance of expansion depending on the makeup of your 15 bhn alloy and the impact velocity. Cast bullets are more reliable as hunting bullets when they're designed for hunting from the start, not all designs have hunting in mind. I think you're on the right track with your testing and you should have your answers when you get to test your bullets. We all hope your project works out the way you want it to. Please let us know your testing results, and please ask all the questions you need to.

Thanks for the information, when I get time I'll test them and let you know.

 

[Bret4207]

At 15 bhn you do have a good chance of expansion depending on the makeup of your 15 bhn alloy and the impact velocity. Cast bullets are more reliable as hunting bullets when they're designed for hunting from the start, not all designs have hunting in mind. I think you're on the right track with your testing and you should have your answers when you get to test your bullets. We all hope your project works out the way you want it to. Please let us know your testing results, and please ask all the questions you need to.

Keep that at the forefront of your thinking. A flat nose, a blunt round nose, a hollow point, not anything pointy or streamlined. In 30 cal something like the RCBS 30-180FN will work, and I can tell you it works good! And if you want expansion, you don't want anything "HARDCAST". I will repeat, forget Bhn! It's just one tiny part of the whole game, not the major factor the commercial bullet makers would have you believe. If it was that easy we'd all be shooting 30Bhn!