AR15 in 30-30 via the 30HRT (150g bullet load workup)


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R.W.Dale
June 9, 2010, 03:44 PM
(load data is not pressure tested, use at own risk)

I thought I'd make a quick post to share my chrony results from beginning load workup on 30HRT shooting 150 grain Remington RN bullets. For those not in the know 30HRT stands for Herrett Tactical Rimless or 30herrett formed on a 6.8 case instead of 30-30

Cases; Formed Hornady 6.8spc
Primers; CCI#41
Propellant; H-335
C.O.L. XXX or .020" off the rifling
Firearm; White Oak Precision 20" 30HRT upper
Temp; 95 degrees

I lost a couple data points on the first two charges as my Jard trigger went out of adjustment and the rifle started doubling So I single fed rounds for the last two strings for safety sake.

27.0g 2120 FPS no accuracy data

28.0g 2230 FPS no accuracy data

28.5g 2237 FPS 5shots @100 2.2"

29.0g 2269 FPS 5shots @100 2.07"


Ejection was nice and soft, brass and primers appeared to not be worried in the slightest. I'll likely proceed towards 30.0g or 2300fps whichever comes first at which point this load will equal what every 20" 30-30 I've owned will do with 150g bullets. Then I'll play around with COL and see if I can't better the accuracy of this load.

http://i3.photobucket.com/albums/y96/krochus/f31a39b2.jpg

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FLAvalanche
June 9, 2010, 04:06 PM
I just have to ask...why in God's name, with all the .30 caliber rounds out there to match performance with, did you chose to match the .30-30?

You must have a specific reason because I would have chosen at least 3 different .30 caliber performance markers to match before .30-30.

Jim Watson
June 9, 2010, 04:22 PM
Because the 6.8 is the same head diameter as the old .30 Remington, originally known as .30-30 Remington Rimless, maybe.

R.W.Dale
June 9, 2010, 04:23 PM
I just have to ask...why in God's name, with all the .30 caliber rounds out there to match performance with, did you chose to match the .30-30?

You must have a specific reason because I would have chosen at least 3 different .30 caliber performance markers to match before .30-30.
OK

name each and every one that will work in the AR15

Daizee
June 9, 2010, 08:15 PM
This is both ridiculous and cool.
My first centerfire is a .30-30, so it appeals...

Can you fit spitzer bullets in the magazine?
You'd get a solid 300yd gun with twice the bullet mass of the .223 and beat the .30-30's downrange energy to boot.

-Daizee

R.W.Dale
June 10, 2010, 01:32 PM
Can you fit spitzer bullets in the magazine?
You'd get a solid 300yd gun with twice the bullet mass of the .223 and beat the .30-30's downrange energy to boot.


Yes but you have to be cautious about bullet selection. It's really easy to end up with under expansion because you're using a bullet designed to work in 300WM. My longer range load (to 300m) use 125g bullets @2600fps+ as such loads offer a bit better balance of velocity vs BC. The 150g load is more of a shorter range thumped load project hence the use of 30-30 bullets which can be relied on to expand well at lower impact velocities.

MovedWest
June 10, 2010, 10:11 PM
That's awesome!! I seriously want one now!

Is that built on a 6.8 lower?

MovedWest
June 11, 2010, 01:32 AM
After some research it looks like there's no difference in 6.8 and the 5.56 lower? (Sorry... I'm more of a revolver kinda of a guy)

Can you use a 6.8/30HRT upper on a standard AR-15 lower? I've got a complete 5.56 lower that I've been trying to figure out how to build.

R.W.Dale
June 11, 2010, 01:38 AM
Yes the HRT uses a STD lower in all aspects as with the upper too with the exclusion of the bbl, bolt and mags

Tim the student
June 11, 2010, 09:52 AM
Thats pretty cool right there.

NG VI
June 11, 2010, 09:59 AM
Awesome, I always love reading up on your projects Krochus, this one is no exception.

FLAvalanche
June 11, 2010, 11:08 AM
Because the 6.8 is the same head diameter as the old .30 Remington, originally known as .30-30 Remington Rimless, maybe.
OK. Now it makes sense. That's why I asked. I wasn't trying to be a turd I was just curious as to why .30-30.

brian923
June 11, 2010, 11:38 AM
I think the 30 HRT is a cool round. A true 30 cal in an AR that out performs the 7.62x39 in every aspect.

Kernel
June 11, 2010, 01:05 PM
C.O.L. 2.738"

What does it use for magazines?

R.W.Dale
June 11, 2010, 02:12 PM
What does it use for magazines?
OOPS good catch!

I just threw that number up from my notes not realizing that it's a number not reflecting COL but rather an overall distance from casehead to bullet ogive using my bullet comparator. I'll change that ASAP

The magazines are C-products 6.8spc

General Geoff
June 11, 2010, 02:18 PM
I'm thinking you could generate similar ballistics with .311" projectiles (designed for 7.62x54R cartridges), loaded into a 7.62x39 case. The numbers you're pushing suggest a slightly hotter round than .300 Whisper.

R.W.Dale
June 11, 2010, 02:32 PM
UPDATE 6-11-10


29.5g 2329 FPS 5shots @100 2.2"


30.0g 2364 FPS 5shots @100 3.27"

Looks like 29.5 grains will be the MAX due to a couple reasons, notably the accuracy drop off and bullet pushback after seating such a compressed load. Brass appearance with all loads was good with ejection at 4 to 5 o-clock appx 5 to 7 feet out.

I'm thinking you could generate similar ballistics with .311" projectiles (designed for 7.62x54R cartridges), loaded into a 7.62x39 case. The numbers you're pushing suggest a slightly hotter round than .300 Whisper.

Purely from the benefit of a stronger case and bolt (7.62x39 AR's are hard on brass and bolts) the above numbers are about 150 to 200fps faster than what x39 can do in an AR15 with a 20' bbl. As to the whisper you'd be pushing some real thermonuclear pressures to get within even 100fps of what 7.62x39 will do much less the 2300fps + I'm getting. I'm sorry but the 300fireball just doesn't have what it takes under the hood to get there

R.W.Dale
June 11, 2010, 03:01 PM
I think the 30 HRT is a cool round. A true 30 cal in an AR that out performs the 7.62x39 in every aspect.
Yep

A quick list of the Pros and Cons compared to 7.62x39 in the AR platform

PROS
A much wider, cheaper and more modern bullet selection sized for the bore. from the light but high BC 125g Nosler to heavier 30-30 bullets that can be relied on to actually expand at lower impact speeds.

a case shape that's well suited to the AR's magazine geometry

a case that's much stronger at the web without the taper that only serves to increase bolt thrust allowing you to run higher pressures. With the x39 case and bolt at SAAMI pressures you're already at the limit of what the platform and brass can handle

a well defined shoulder

a stronger bolt

a far far higher quality brass supply, Hornady 6.8 cases are so much superior to even Lapua 7.62x39 cases it's pathetic. (this I why I got out of the x39 business in the end)

Better magazines

AFIK just about all 30Herrett reamers are pretty much match chambers with tight necks and short throats.

CONS

No factory ammo

case forming is an intricate process

Maverick223
June 11, 2010, 03:05 PM
Hornady 6.8 cases are so much superior to even Lapua 7.62x39 cases it's pathetic. (this I why I got out of the x39 business in the end).Wow, I don't know what is more surprising. A Hornady case besting a Lapua case, or you abandoning the 7.62x39mm. I suppose you have to cut your losses somewhere down the line.

FWIW, I am still waiting for my perfect intermediate, intermediate cartridge (something between .223cal. and 7.62cal with moderate case capacity). Something like a 6mmSPC or 6.5SPC would be perfect IMO.

:)

R.W.Dale
June 11, 2010, 03:19 PM
Wow, I don't know what is more surprising. A Hornady case besting a Lapua case, or you abandoning the 7.62x39mm. I suppose you have to cut your losses somewhere down the line.


A little clarification is in order.

7.62x39 cases

Remington small primed cases handle pressure rather well (not as good as SPC brass) but you'll end up working with lots of cases with wildly differing weights and capacities. One batch I sorted varied in weight by over 10 grains from high to low with an almost even distribution at all points in between.

Lapua large primed cases are much more uniform in weight and length. BUT like all larged primed x39 cases in the AR after three or at most four full pressure loadings they're done, toast, fried

Somewhere I've posted a pic showing how much more expansion you get above the case head using Lapua x39 cases vs Rem the result was very telling indeed.

Maverick223
June 11, 2010, 03:32 PM
krochus, I doubt that I will ever delve into reloading 7.62x39mm (unless the market changes), but nevertheless that is good to know. One question though...is the former 7.62x39mm/7.62x39mmAI guru soon to become the .30HRT guru instead?

:)

R.W.Dale
June 11, 2010, 06:37 PM
krochus, I doubt that I will ever delve into reloading 7.62x39mm (unless the market changes), but nevertheless that is good to know. One question though...is the former 7.62x39mm/7.62x39mmAI guru soon to become the .30HRT guru instead?

:)
You give me way too much credit!

Don't get me wrong I shot a lot of GREAT groups with the x39 and x39AI but after awhile I got up against what I felt were the accuracy limits of the brass I had available and to be honest shooting itty bitty groups at 100 and 300m with a 24lb rifle wearing a 36x scope just got boring.

The new project is a hoot for sure. But somehow I doubt the HRT pictured on the previous page will end up shooting holes in peoples preconceived accuracy notions as the 7.62x39 Stevens 200 did.

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