Need good info. advice on Semi-auto 6PPC rifles.

[coolatula]

Hey,all it's been quite a while since I've posted.

I was wondering if there is some good web sites articles about semi-auto rifles shooting 6PPC.

Probably none of you remember but I had discussed re-barreling a Russian SKS into 6PPC as a design/platform study. Along with addressing other aspects of the design such as improved scope mounts/location,better stock choices etc.

Of course I've heard all the NEGATIVES such as "you can't make a silk purse out of a sows ear","why not just buy a 6PPC Bolt action,AR-15 etc.

That's great advice and I appreciate it dearly,but if nearly every new platform/cartridge was not improved,i.e. AR-15) then just about 95% of the cartridges/rifles on the market we enjoy today would not be available.

So,please just forget about it being for a SKS for a moment and
chime in as if it was for your buddy's trusty old AR.

I would have certain/added guidelines/restrictions to adhere to and here are but a few:

1. Keeping the working pressure @ 45,000 psi or less which seem pretty doable for the lower velocity PPC loadings.

2. Shorter than normal 6PPC O.A.L.,due to magazine length)

3. I want the availability/option to shoot heavy,high side) for caliber bullets for larger game such as deer/hog/coyote etc.

4. Short,varmint contour,18-20" barrel w/slower 1-8" to 1-10" twist preferably made from stainless steel.

5. slower than normal 2800-3000 f.p.s. bullet velocity due to working pressure,heavier bullets,semi-auto functioning,need to extend barrel//throat/chamber life,shorter cartridge O.A.L. etc.

6.No-turn neck chamber,this isn't a target rifle and it needs to function/chamber on it's own)

 

[billmo]

6mmAR.com is the best source for 6mm auto info. They are working with a necked dowm 6.5mm Grendel to accomplish most if not all of what you are asking for. There is not much difference in the
6mm PPC and the 6mmAR as far as size is concerned and you would get a little better performance from the later. Hope this helps. Bill

 

[coolatula]

Thanks!
Yes I just finished reading it and it looks great on paper.
One problem is looking at the specs my O.A.L. would be quite a bit shorter then what he's using.

I have to measure some Remington 7.62x39 I have to be sure,but the listed OAL for the military round is around 2.197" which is a lot shorter than his listed lengths. That may be due to him using
heavier/longer bullets,wanting more powder cap.,more contacts on the lands etc. I don't know?

My magazine/rifle MAY be able to handle longer loads,but I don't know what the longest it can take and still feed/function reliably. I have no trouble with any of the current factory loads,but they are usually on the short side just like all/most the other non-reloads out there.

Interesting he mentions using 7.62 X 39 brass as that may make for some cheaper "practice" loads. Thing is his case body is quite a bit longer and I wonder is the working pressure may also be too high for my rifle.

What I like about the 6PPC over the standard 7.62 X 39mm specs is what exactly gives the 6PPC it's advantage in the first place,different primer size,neck angle etc.. What I don't like is the added cost of said brass over more popular standard chamber brass although many use the somewhat cheaper .220 Russian and fire form it?

Someone suggested here before that I may just be able to neck down 7.62x39 brass to 6mm/6.5mm and get close the results I'm wanting without as much expense as going whole hog with a 6PPC chambering.

That would be great,but there are reamers on the market already for the 6PPC that does the job in one shot.

I don't know what is involved with a necked down 7.62X39 to 6mm or 6.5 mm as far as available reamers and if there is whether or not they can be had with a shoulder angle more like the 6PPC or even if that is needed?

Chamber and neck reamers for the 6PPC would/should do the same thing as chambering for 7.62x39 necked to 6mm shouldn't it? With the only difference being the more desirable shoulder angle of the 6PPC.

I don't want to have to have a custom reamer,s)made if a No-turn neck 6PPC will do the job just as well. There may already be a "wildcat" cartridge that uses the normal,less expensive) 7.62 brass chambered in 6mm or 6.5mm.

I would have to know what dies or mis-match of dies would be needed. There may already be some on the market that would work,maybe even full/partial 6PPC,or 6mmAR/Grendal) dies will work just fine?

It may be as simple as running re-sized 7.62X39 brass in 6PPC dies made for a 6PPC chamber and be done with it. It would be nice to be able to shoot both 6PPC for target/varmints shooting and re-sized/re-angled or fire formed 7.62X39mm brass for practice/informal shooting and still have both function/cycle as they should.





Specifications 7.62 X 39mm

Case type Rimless, necked
Bullet diameter 7.90 mm,0.311 in)
Neck diameter 8.64 mm,0.34 in)
Shoulder diameter 10.01 mm,0.394 in)
Base diameter 11.25 mm,0.443 in)
Rim diameter 11.30 mm,0.445 in)
Case length 38.65 mm,1.522 in)
Overall length 55.80 mm,2.197 in)
Primer type Berdan
Filling SSNF 50 powder
Filling weight 24.7 gr
Ballistic performance
Bullet weight/type Velocity
123 gr Spitzer 710 m/s,~2329 ft/s)
Energy 2010 J,~1478 ft·lb)