The Accurate Reloading Forums
7.62x39 improvement

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https://forums.accuratereloading.com/eve/forums/a/tpc/f/6521043/m/3041023042

24 March 2018, 21:02
matt salm
7.62x39 improvement
So I've been messing with a few of the Howa mini's. I bought a couple of the 7.62x39's for the actions to barrel a few wildcats off the grendel case. I did a 224 lbc that's shooting 53gr v-max over 3500 with no pressure signs in a flyweight 22" platform weighing 5.5lbs. Also did a 6mm grendel using the same reamer and a .274" chucking reamer for the neck and a 6mm throater. Both of these are doing what I was hoping for in having a light handy rifle, great trigger and usable dbm for varmints, truck, youth rifle, etc... the 6.5 Grendel's shoot well as is, but I will probably put a custom barrel on one just to see how that works looking for better accuracy although there isn't too much room for improvement IMO.

THIS BRINGS ME TO THE 7.62's. I mounted a scope on a factory rifle, and the thing shoots great, about 1 MOA. Only thing I'd like to see with this one is a better velocity window for improved performance on medium game. My thought is to use a 6.5 Grendel reamer to open up the body dimension of a factory chamber and use a 6.5 FL bushing die to resize brass after fire forming. It would leave the factory neck and throat and just blow it out to the 30 degree shoulder and less taper.

Was hoping to see 2600 or so with 125gr bullets vs. the 2350-2400 the round is capable of now. Not to mention loading these in a bolt action should allow a slight increase in operating pressure too. This would make a great 200yd deer rifle and since these came with youth stocks would make a great performing kids rifle.
What do you think?


Shoot straight, shoot often.
Matt
25 March 2018, 01:09
craigster
The thought has crossed my mind as well. Came across this some time ago and saved it.

http://demigodllc.com/articles...e-military-standard/


Should give you some insight.
25 March 2018, 01:50
jeffeosso
30 ppc if you must do something .. but decent loading practice, good brass, and great bullets, you get a "30-30" in a bolt gun ... a highly accurate one, from time to time, but one that matches THE cartridge that has taken just about every head of game under 2 tons

if it shoots, shoot it


#dumptrump

opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
25 March 2018, 02:33
butchlambert
Pictured below are 5 groups of 5 shots each with a 30PPC. Shooting 112s at 2950fps. This should have been a World record 5 group aggregate, but I think politics got involved.





H4198 powder in a compressed load. I do have a 270X39AI reamer which is a 270PPC. A very accurate deer cartridge for a young person.
25 March 2018, 07:12
craigster
I think Butch has answered the question quite well.
25 March 2018, 09:01
matt salm
Very impressive Butch. I see all sorts of development off the Grendel case which is just the ppc with she shoulder pushed forward .070”. I wouldn’t be able to clean up the chamber without setting back. The barrel on the mini’s are .311 groove diameter also. I have one of the takeoff 7.62’s on the benc, I might just put it in the lathe tomorrow and see what I can come up with. I have a few ppc reamers along with 3 different Grendel reamers inclusing a ‘bolt gun’ marked Grendel reamer which should have a little tighter dimensions. I don’t think the mini action should be pushed as much as a full sized rifle as the lugs are substantially smaller but I’m thinking there is velocity to be had. Some guys are now using that Hogden CFE BLK powder and getting another 100+FPS with the 125’s...we shall see.

Thanks for the comments/ideas.


Shoot straight, shoot often.
Matt
25 March 2018, 09:05
matt salm
I also see Starline is offering a ‘basic’ Grendel case with straight walls. It would allow me to size brass to fit the chamber and have virtually no fire forming! And have the small rifle primer of the Grendel case.


Shoot straight, shoot often.
Matt
25 March 2018, 20:09
butchlambert
My Mini started as a 7.62X39 barre;led receiver. The rifle shot decent. Back in 1996 Shilen chambered it in 270X39AI. It was a very accurate deer rifle for a young person as recoil was almost non existent. I decided to rebarrel it about 5 years ago to 220Beggs {Russian}. I also had it restocked. It has been in the gunsafe since. Ammo is loaded, I just need to mount the scope and shoot it.




The 311 groove diameter limits the choice of bullets Lots of 308 bullets available.
25 March 2018, 20:31
butchlambert
Matt, Michael Ezell on the Accurate Shooter forum has done a lot with the Grendel case, especially the 30.
26 March 2018, 00:11
matt salm
Butch, you make some wonderful rifles. I’m busy today watching maple sap boil otherwise I would have stuffed a Grendel reamer in that factory 7.62 barrel by now. That rifle of yours above reminds me I have a 527 that I rebarreled to 6.5 Grendel 10 years ago sitting on a shelf. Need to finish inletting into a stock and finish the woodwork. That was for my daughter as a first deer rifle...figured out she was left-eye dominant in the middle of the project and put together a little 250 Savage for her on an early Browning BLR.

I’ve read a bunch on the 30 cal wildcats used in benchrest. Still thinking there is usable performance available with this little Howa platform. They are really very decent rifles and my lathe cuts metric so it’s not any major problem to play with them. James Anderson mentioned in another site about some hinged floor plates he’s re-purposing and working on the mini. He says they’re a lot less work to get up to snuff than the 527’s.


Shoot straight, shoot often.
Matt
26 March 2018, 00:54
butchlambert
My bottom metal came from James. At the time he wasn't going to make anymore. He really does nice work.
26 March 2018, 02:35
bartsche
quote:
Originally posted by butchlambert:
My bottom metal came from James. At the time he wasn't going to make anymore. He really does nice work.


old And so do you. that is great repeatability and accuracy . beerroger


Old age is a high price to pay for maturity!!! Some never pay and some pay and never reap the reward. Wisdom comes with age! Sometimes age comes alone..
26 March 2018, 02:48
butchlambert
quote:
Originally posted by bartsche:
quote:
Originally posted by butchlambert:
My bottom metal came from James. At the time he wasn't going to make anymore. He really does nice work.


old And so do you. that is great repeatability and accuracy . beerroger


Roger, if you are speaking of those groups, Those belong to Jackie Schmidt of Houston, Texas. I have one that will shoot like that occasionally, but not 5 targets at one time like that.
26 March 2018, 05:37
matt salm


Well I ran a 6.5 Grendel bolt gun reamer in that takeoff barrel, the shoulder on a 7.62x39 is considerably longer and I lucked out as I fed the reamer in and felt the shoulder cut. Ended up cleaning up the chamber right to the start of the neck. I spun a barrel off a 7.62 Howa mini and spun this one on. The factory markings lined up spot on, headspace with a 7.62 round measured w/in .002” of the original chamber and it looks as though I need a faster powder to fire for.

A fired ‘improved’ brass has about only 2 grains more water capacity near as I could tell but I like the dimensions of the case. I did order some basic Grendel brass that should minimize case forming.


Shoot straight, shoot often.
Matt
20 April 2018, 05:51
kaytod
The 30 ARX is another version of the 7.62x39 Imp.
02 May 2018, 19:02
matt salm
Yep, but I'm working with things I have in the shop, namely 6.5 Grendel reamers and factory barrels. This was a way I could take a factory 7.62X39 Howa barrel with .311 bore diameter and possibly get enough velocity to make it more useful for general deer/hog hunting. I haven't had the time to play with loads yet but I have 250 Starline 6.5 Grendel basic brass I will form and load without the need for fire forming. I'm thinking 125gr Cavity Back Bullets at 2600 fps will do an impressive job and provide a better trajectory than the parent case. This should produce a light, handy 250 yard capable rifle with a bit more terminal effect than the 6.5's and smaller bore diameters.


Shoot straight, shoot often.
Matt