142gr SMK @2160 fps Toughts? Viable Option

[erinmcmanus45]

What is everyones thought on the 142gr SMK or clone for the 6.5 Grendel?

I loaded some 120gr SMK 2450 fps and 142gr SMK @ 2160 fps. I have only shot on paper at 100yds and they group well. Once the weather gets a little nicer I want to test at 300,600 and 800 yds.

Is the 142gr SMK a viable option for the 6.5 Grendel?

Thanks,

Erin

[LR1955]

What is everyones thought on the 142gr SMK or clone for the 6.5 Grendel?

I loaded some 120gr SMK 2450 fps and 142gr SMK @ 2160 fps. I have only shot on paper at 100yds and they group well. Once the weather gets a little nicer I want to test at 300,600 and 800 yds.

Is the 142gr SMK a viable option for the 6.5 Grendel?

Thanks,

Erin

Erin:

There was a guy on the forum about fifteen years ago who loved the 142 and 140 Match Kings in his Grendel. From what I recall, his velocities were in the 2100 fps range for the 142's.

He shot them at 1000 and said they were supersonic at that distance. I think his range was a couple thousand feet ASL so he was probably right.

I don't think it is a efficient bullet for the Grendel unless you shoot it from a bolt rifle with a lot of free bore and don't care if the OAL is longer than the magazine.

If you seat the bullet so it feeds from a magazine, I think you will use up a lot of case capacity.

So, yes, they work but a viable option? If you think they are viable, then they are for you. I think most Grendel shooters stay in the 120 to 130 grain bullet weight range.

LR-55

[erinmcmanus45]

Erin:

There was a guy on the forum about fifteen years ago who loved the 142 and 140 Match Kings in his Grendel. From what I recall, his velocities were in the 2100 fps range for the 142's.

He shot them at 1000 and said they were supersonic at that distance. I think his range was a couple thousand feet ASL so he was probably right.

I don't think it is a efficient bullet for the Grendel unless you shoot it from a bolt rifle with a lot of free bore and don't care if the OAL is longer than the magazine.

If you seat the bullet so it feeds from a magazine, I think you will use up a lot of case capacity.

So, yes, they work but a viable option? If you think they are viable, then they are for you. I think most Grendel shooters stay in the 120 to 130 grain bullet weight range.

LR-55

I read some of the older posts on this loading. Graphed the 120gr SMK next to the 142gr SMK and they both make it to about 500yds with 1600 fps (+-) velocity left. The 142gr hold a little more edge out to 1000 for velocity but not much. On paper the 142gr is 1075fps at 1000 where the 120gr is 1028fps.

Would Grendel shooters buy a factory loaded 142gr SMK that is mag length and around 2160fps out of a 18" barrel?

Thanks,

Erin

[LR1955]

I read some of the older posts on this loading. Graphed the 120gr SMK next to the 142gr SMK and they both make it to about 500yds with 1600 fps (+-) velocity left. The 142gr hold a little more edge out to 1000 for velocity but not much. On paper the 142gr is 1075fps at 1000 where the 120gr is 1028fps.

Would Grendel shooters buy a factory loaded 142gr SMK that is mag length and around 2160fps out of a 18" barrel?

Thanks,

Erin

Erin:

I don't think you will get a mag length 142 much past 1900.

Run some searches here because there are pictures of cut away brass with various bullets seated so you can see how much of the powder space is taken up by the bullet.

LR55

[erinmcmanus45]

The ones I fired this weekend were 2.164 inches COL and fit in the AA E-Lander Mags.

AVG Velocity was 2172fps ES 56fps SD14.14 over 40 rounds.

LR55 If you have a link to the cutaways that would be awesome. Can't seem to find them on the search function?

Thanks,

Erin

[LR1955]

The ones I fired this weekend were 2.164 inches COL and fit in the AA E-Lander Mags.

AVG Velocity was 2172fps ES 56fps SD14.14 over 40 rounds.

LR55 If you have a link to the cutaways that would be awesome. Can't seem to find them on the search function?

Thanks,

Erin

Wish I did have a link to the pictures but unfortunately I don't.

Maybe someone here remembers where they were and can give the link.

LR55

[grayfox]

What powder were you using for the 142's.
And, gas gun or bolt?

[erinmcmanus45]

What powder were you using for the 142's.
And, gas gun or bolt?

Gas Gun JP Enterprises

Original Staball powder older lot. Going to try some of the new Staball Match soon.

Erin

[grayfox]

Why the OAL of 2.164, was this necessary to fit OAL for your chamber?

At 2172 MV and a BC of .584 listed for the 142 SMK, it goes transonic at about 575 yds. IDK what accuracy it would show at 1000 since bullets going transonic can wobble excessively. I'd also imagine that shot to shot, also inconsistent.

Also, at 2172 and 2.164, my grt model of this shows a compressed charge, 103.7%, so that's another problem you could have with this combo.

If you use a different powder, like Lever for example, you might get more MV and no compressed charge... you would need to do your own work up of course. Might be around 2300 MV possible, again just a model in my grt. But even this one, if possible, would hit transonic at about 650 yds. So still not promising for 1000.

These loads show seating depths of 0.734" into the case, or ~ 0.470" below the neck area... so pretty intrusive as '55 points out. This is over 50% of the bullet length being inside the case by the way...


Edit to add: "Would Grendel shooters buy a factory loaded 142gr SMK ..." If asking from a marketing perspective, my own answer is "No, not interested." 142 is too far out of the realm of more normal ammo, offers me no extra benefits, and represents yet another bullet that I would have to buy and load, since most commercial ammo is too expensive anyway. I have plenty of Grendel-oriented pills to play with. If someone wanted to roll some of their own, more power to them but I think they'll be disappointed in the end. Even in my creed's I have the 140 class already covered.

[erinmcmanus45]

Why the OAL of 2.164, was this necessary to fit OAL for your chamber?

At 2172 MV and a BC of .584 listed for the 142 SMK, it goes transonic at about 575 yds. IDK what accuracy it would show at 1000 since bullets going transonic can wobble excessively. I'd also imagine that shot to shot, also inconsistent.

Also, at 2172 and 2.164, my grt model of this shows a compressed charge, 103.7%, so that's another problem you could have with this combo.

If you use a different powder, like Lever for example, you might get more MV and no compressed charge... you would need to do your own work up of course. Might be around 2300 MV possible, again just a model in my grt. But even this one, if possible, would hit transonic at about 650 yds. So still not promising for 1000.

These loads show seating depths of 0.734" into the case, or ~ 0.470" below the neck area... so pretty intrusive as '55 points out. This is over 50% of the bullet length being inside the case by the way...


Edit to add: "Would Grendel shooters buy a factory loaded 142gr SMK ..." If asking from a marketing perspective, my own answer is "No, not interested." 142 is too far out of the realm of more normal ammo, offers me no extra benefits, and represents yet another bullet that I would have to buy and load, since most commercial ammo is too expensive anyway. I have plenty of Grendel-oriented pills to play with. If someone wanted to roll some of their own, more power to them but I think they'll be disappointed in the end. Even in my creed's I have the 140 class already covered.

Thanks for the information Grayfox PM Sent

Erin

[grayfox]

[kiwi shooter]

[grayfox]

You have to be careful with grt, and there are some tweaks I had to do to get something like reality from it with a grendel.
That being said, the numbers I came up with above, were from a grt model.
Grt also gives you the estimated max pressure for the load (in the curve) so if > 52ksi, will be too much for an AR style.
I can't say it is better, it IS cheaper, and easier to use... but quickload might be a better program.
I like it for a first-estimate kind of thing.