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30 Herrett

20K views 47 replies 16 participants last post by  MBW36330 
#1 · (Edited)
For those of you that do not visit the lower 48 forums.
Many of us have been talking about this cat for years. I decided to go ahead with it since many like the 30 cal bullets. This cat will be very close to Marty Terweem's 30HRT. Both use available 30 Herrett dies and 6.8 brass. The only difference is in the freebore length and the trim to length of the case. 1.580 is the length to the wall, 1.570 is trim to length. The shoulder is 30 degrees. The shorter case length I use allows all of the 125 and 130gr bullets and some 150gr bullets to be used correctly positioned in the freebore of the chamber. The 155 Amax should shoot well. The barrels have the same 1 in 11.25 twist 5R rifling that the 308 barrels have. For plinking the 147gr FMJs will be cheap. The 30HRT and 30 Herrett AR will push bullets apx 200 fps faster than the 300 BLK for those intending to hunt deer and hogs.

1680 is the #1 powder from all of the testing I have done. 4198 and Re7 work but the ball powder allows heavier charges.
28.5gr 1680 behind a 125 TNT hit 2500fps out of a 16" barrel.
30gr 1680=2594fps
30.5gr 1680 =2655 and I think there is a little more room to go up.

27.5gr 1680-150 Nosler=2360fps--close to max but I shot 28 with no problems.
 
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#9 ·
I don't need this, I don't need a 30 HRT, I don't have time for another project, I'm not sure where I'll get the money for it, I don't know which hand guard I want, I'll need another scope, should I get another lower dedicated for it, when will this madness stop?

You are not helping me, H
 
#16 · (Edited)
Starting the tests-16" barrel These loads are near max for one reason or another. Start 1-2gr lower and work up.
29gr Re7-149gr FMJ 2.295=2470fps Max load due to fill
30gr 1200r------------------=2440
30gr 2200-------------------=2426
31gr 2200-------------------=2510--starting to crater ...MAX LOAD
Seeing this with the 150 shows me there is no need to try 4198, N200 or 4227 with bullets near 150gr.

33gr 2200 behind a 125gr TNT at 2.295=2660. Max load due to fill, no cratering or swipes
 
#18 ·
30 Herrett ar request

H ...

I really enjoy your Scout Profile (16" barrel) in 6.8x43.

Any chance we will have an opportunity to have that option in 30 Herret ar?

Plus you can count me in on a 12.5" version. I'd be happy to pre-order if that becomes an option.

Thanks for the consideration. I look forward to my new build (ARP 12.5" 6.8 ).

HC
 
#22 ·
Im not what the difference is between this one and the 30 American is but the Hornady 125 gr sst's would not work . They are too long to fit in the mag and maintain proper seating depth.
 
#24 · (Edited)
Looking at the two, the 125gr SST and 150gr interlock look pretty close to being the same size with the 150 being just a little longer from the base to the ogive. The 125 is longer from the ogive to the tip. At 2.295 col, the ogive will be just forward of the case mouth. Then I looked at the 150gr SST. That bullet is way bigger than the 150gr interlock. The 150gr Nosler BT is a no go as well.

I think the 150gr interlock would give you a little more breathing room out front the case mouth but take away from powder capacity. I don't know the difference between the two cartridges either.



150 NOS BT 150 SST 150 Interlock and 125 SST
 
#30 ·
This is your quote right?
"Also the original 30 Herrett head spaces on the shoulder unlike the others to get optimum accuracy."
Rimless cartridges headspace on the shoulder. You said the rimmed headspaced on the shoulder and the rimless did not.

I've always tried to set the shoulder of every case .002-.004 under the chamber size rimmed, belted or rimless so the case isn't sloppy in the chamber. From the factory the Herrett is a rimmed cartridge which headspaces on the rim. The rest are rimless that headspaces on the shoulder.

The 30 Herrett, 30 HRT and 30 Herrett AR all use the original 30 Herrett dies and length to the shoulder. They are all close in OAL to allow using longer bullets. I made the "AR" a little shorter to allow using longer bullets. I can shoot the 155 Amax out of it. The 30 American shoulder is forward of the rest and the case OAL is longer than the rest.
 
#32 ·
I did shoot the 150gr SST with the bullet set to 2.305. it was a tight fit but can work. With the powders I had the base took up to much room to get any speed. Now I do have LilGun. May be worth a try. I have some 150gr Remington FB Corloks and 140gr FB Nosler CC's coming this week. Curious to see how they fit this cartridge. I have some 125gr Sierra TMK's. They are way to long from the ogive to the tip to be loaded correctly. The SMK's may be a different story? I don't have any to look at, at the moment.
 
#33 ·
I did shoot the 150gr SST with the bullet set to 2.305. it was a tight fit but can work. With the powders I had the base took up to much room to get any speed. Now I do have LilGun. May be worth a try. I have some 150gr Remington FB Corloks and 140gr FB Nosler CC's coming this week. Curious to see how they fit this cartridge. I have some 125gr Sierra TMK's. They are way to long from the ogive to the tip to be loaded correctly. The SMK's may be a different story? I don't have any to look at, at the moment.
I have some of the 125gr SMK bullets; they are too long for the 30 Herrett AR (30 HAR? harharharhar :a16:), the nose profile was designed for the 300 BLK which is considerably shorter. The 125gr TNT seems to be just about right though.
 
#35 · (Edited)


150gr Hornady interlock, 150gr Rem Core-lokt, 140gr Nosler CC and 125gr Hornady SST

The 150gr Core-lokt! If I knew these came in a blue Midway box I would have never bought them. These are blems. I wish Midway would state this. These bullets vary so much from bullet to bullet it's not funny. But so far these bullets look to be the best fit for the 150gr bullet. It looks like I can get another grain of LT-30 behind the bullet to run over 2400fps pretty easy and stay around 2.295 col. Need to try 1680 also and see what I can do with that powder.

The 140gr Nosler CC was a bit of a disappointment. The ogive is set way to far forward and the base will take up to much room for powder. May work Ok with 1680?
 
#36 ·
How about compiling a collective list of nose length measurements for different bullets that might fit the 30 Herrett AR? I'm sure a number of you have made these measurements on your own, but I haven't seen a list published anywhere.

A normal "ogive" measurement to the .300" diameter on the bullet nose doesn't tell the whole story, I propose measuring to the full diameter if a distinct line is visible (like many Hornady bullets), and to a .306" diameter point if not. The .306" diameter can be marked by locking your calipers at .306" and pressing the bullet nose lightly between the jaws while rolling it. Alternatively, the full diameter can be marked by rolling the bullet between a piece of glass and a file, to knurl it.

With a case length of 1.580" and mag length of 2.300", that leaves .720" for nose length. (As H has pointed out, preferably the nose is shorter, allowing some portion of the full diameter outside the case neck.)

I'll start with a few I have on hand (rounded to the nearest .005" for measurement error):

125 SMK - 0.765"
125 Nosler BT - 0.710"
150 Nosler BT - 0.720"
125 Speer TNT - 0.665"
110 Sierra HP - 0.485"
130 Barnes XLC - 0.635" (discontinued, is the TSX similar?)
150 Rem CL (I think) - 0.660"

I think those are all I have for now...
 
#40 · (Edited)
30 Herrett AR - load data



Tested my ARP 30 Herrett AR:
Using Cavity Back 125 MKZ loaded over Shooters World Blackout, CCI450, 2.280" oal, in neck turned SSA fire formed brass.
The Cavity Back 125 MKZ hits the lands in my barrel at 2.285", so loading .005" off the lands..
Oehler 35P chrono.
-
Blackout Avg
_______fps_ E.S. S.D.
27.8 gr 2576 67 34.
28.1 gr 2591 20 10.
28.4 gr 2635 32 16.
28.7 gr 2645 21 11.
29.0 gr 2658fps 17es 8sd...
-
There is more room available beyond the 29.0 load, but this load gave the best accuracy and no swipes or ejector stamps on my brass.
The 29.0 load of blackout is my current hog hunting load in my ARP 30 Herrett AR.

Dennis
 
#44 ·
Thank you Sir for making barrels of this caliber available again.
I just ordered one.
The barrel and gas length is just what I was looking for.
I have the Hornady 30 Herrett dies already from trying the BHW American 30 cartridge.
Have 1680, RL-7 and H4198 powders. Want to try the Shooters World Blackout in this caliber also.
And I do happen to have a few thousand of the MK319 MOD O 130 gr. OTMRP projectiles. Originally got them for my M1A Socom 16.

Again, I do appreciate you making these barrels available. Should be a good stable mate to my 6.8 ARP barrel.

Thank you,
Glenn
 
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