7.62 X 39mm AR-15...A gift to the Precision shooter?

[redshooter]

I posed a similar question in Gunsmithing, and looking at the replies I realized I didn't really ask my query clearly, and it would likely fit better here anyway...

The M43 isn't known as a tack driver, but without a doubt it's offspring are. I've been dreaming about a dual purpose AR-15 that I can add to my stable, but alas I'm not in a position to do this for at least another six months (I've thought of trying crowd funding...). The up side of this is it gives me plenty of time to refine my ideal rifle combo.

I'd love to have a 10"-16" 7.62 X 39 and a 20"-24" upper chambered in 22 PPC or 6 PPC.

PPC

PPC = superior accuracy and the ability to drive high BC bullets at a respectable velocity. The short case and limited powder capacity may seem to hobble them, but because of the 2.26 COL of the 5.56 NATO it may be possible to seat the bullets longer and actually gain some powder space, not loose it like loading 80's in the 223/5.56. The only issue I can see is the case geometry effecting extraction and if there would be any issues with all that bullet sticking out of the short case while feeding/chambering.

Opinion's???

 

[Mystic Precision]

Go 6.5 Grendel... the engineering is well establised and quality barrels are no problem

I think you may find the PPC a bit much wrt to gas port pressure and volume

Let me know if you need barrels.

Jerry

 

[beltfed]

6PPC in ARs has been done for some time and is well established as a viable option if you want to run 6mm bullets.
The good thing that 6PPC offers is good availability of brass with Lapua producing realitively inexpensive 220 Russian and Norma making 6PPC brass. There is an excellent selection of 6mm bullets that will run well at mag length too.

Practically speaking, 6ppc will do just fine v. 6.5 Grendel at distance as well.
6mmAR is another excellent option.

22 PPC? - doesn't offer anything 223 won't do, and less case capacity.

6.5 Grendel? Meh - leaves a bad taste in my mouth due to the proprietary nature one of two inventors of it has placed on it...ymmv

 

[redshooter]

22 PPC? - doesn't offer anything 223 won't do, and less case capacity.

I have to disagree on this one. All the data I could dig up gives the 22 PPC a 100-200 fps edge on the 223. Also the 22 PPC has an advantage in it's C.O.L., by default you can gain some powder space by loading long, or in the case of 75 gr A-Max and the 80 gr VLD's I'd extrapolate and say that they could be loaded to magazine length and give similar performance as the 223 loaded to 2.390" (in the case of A-Max bullets).

I know the topic has been done to death, but I believe there is a difference in this case d). Don't get me wrong, 5.56 is hard to beat, and most of the ranges I have access too limit me to 600 m, so 75/77 gr HPBT's are just ducky. That said, all the info I could find on AR-15 rifles and the PPC were from prior to anyone offering AR rifles in the M43 Cartridge. I like off the shelf as a rule, my bank account doesn't support much custom in my life. Here's where I see this being a fantastic idea, a short rifle for CQB or just banging away, and a 20"-24" LR upper in 6 or 22 PPC with as many components shared as possible to keep the price down. Originally I was thinking of 5.56, and 6 TCU, or 7 Ingram as my max bang for buck combo, and then I realized that for shooting groups PPC's are the standard and the PPC is based on the M43. Two parent cartridges that can be had cheap, and made to perform at mid to relatively long range, but I really like the M43 PPC combo on principal alone, not sure if it's really practical though.

As for the Grendel I have to agree Jerry that it's a great cartridge for the AR-15, but it would defeat my goal of as many shared parts as possible for two uppers.

Regarding the gas port, for simplicity could you just have it sized a bit big and use an adjustable gas block rather than trying to figure out the optimum size?

 

[EHG]

It takes a dedicated well made bolt action to shoot those tiny groups with a 6PPC.

I've read many articles where guys have experimented with the 6PPC and AR15's. Lots of tuning and mag reliability.
In the end, you are left with an upper that will shoot as good as a custom .223 barrel. It's your money, but a 6PPC gives you diminishing returns in an AR platform.
If your looking for MOA at long range then yes there will be an advantage with longer VLD 6mm bullets, but who are you competing with in a range only gun with that?

Don't know of anyone who has tried it in Canada, so yes that are few comments about it.

 

[Mystic Precision]

The Grendel is based off the 7.62X39 case... just like the PPC. In fact, it is pretty much a 6.5 PPC.

So everything except what is attached to the barrel is similar.

Semis have limits on the energy they can handle through the BCG. I prefer to let others do the R&D on support parts and springs and ports and blocks on something as complicated as a precision AR.

I just got my AR to shoot very well but it took a while to get all the parts balanced.... going bigger with likely more pressure and volume would up the job again... or maybe not.

That is something you will need to decide how much R&D you want to do. If you say you are on a budget, experimenting gets expensive real fast.

Sub MOA at 600m regardless from the case will be a challenge. Why make it harder when you also have to develop the parts to make it all work?


Jerry

 

[redshooter]

The Grendel is based off the 7.62X39 case... just like the PPC. In fact, it is pretty much a 6.5 PPC.

So everything except what is attached to the barrel is similar.

Semis have limits on the energy they can handle through the BCG. I prefer to let others do the R&D on support parts and springs and ports and blocks on something as complicated as a precision AR.

I just got my AR to shoot very well but it took a while to get all the parts balanced.... going bigger with likely more pressure and volume would up the job again... or maybe not.

That is something you will need to decide how much R&D you want to do. If you say you are on a budget, experimenting gets expensive real fast.

Sub MOA at 600m regardless from the case will be a challenge. Why make it harder when you also have to develop the parts to make it all work?


Jerry

I was looking over the Grendel in my manual, pretty much similar in overall performance. I can see your point as to why go through all the hassle of getting everything to work together, part of the exersize, I didn't even consider the tuning. It shouldn't be a big problem, but a match barrel and upper receiver wouldn't leave me with much money to be fiddling with buffer springs and extra mag floor plates (duhh, followers)...or what ever else is required. I think I would enjoy the process, but I'm not sure I'd be able to afford it on reflection.

As to why, I love the AR platform, I also love precision shooting with a bolt gun. Because of the current ruling party I think not adding an AR to my safe would be a mistake...I have 12(6), I trust I don't need to expand on that. Therefore I'll be buying an AR the minute I can pay for one. I'm betting I could put together an upper from the EE and a nice new quality 20" tube for 2/3 of the cost of a new heavy barrel bolt gun (Savage 12 VLP for over $1400 crap!). Since a DI rifle can pretty much out shoot me I figure I can have two rifles for the price of one.

who are you competing with in a range only gun with that?

Just me...precision shooting is my meditation, I'm way too inconsistent to be competing.

 

[beltfed]

I've read many articles where guys have experimented with the 6PPC and AR15's. Lots of tuning and mag reliability.

6ppc feeds awesome in XCR 7.62x39 pistol mags. Far better than 7.62x39 ammo in fact due to the reduced case taper that works better within the confines of a typical rectangular AR box magazine.
Mine are reduced to 8 rounds for reliability and spring compression sake however. It is a peach of a round IMHO.

I agree with the comment about diminishing returns. If you weight it all, It often just makes sense to jump to the AR-10 platform.
However, if you really enjoy an extremely accurate cartridge/rifle combo and low recoil, combined with the increased performance over mag-fed .223, one of the 6.0 or 6.5 cartridges mentioned can really hold their own at long range (out to 800m) and reduces the recoil and weight that the AR-10 platforms introduce to the equation.

I'm not convinced with the 22 PPC. You'd be better off running a 100-120 gr 6mm bullet than a 80-90 gr .224 bullet - but it is your experiment.

 

[redshooter]

Thanks Gents!

I'm not convinced with the 22 PPC. You'd be better off running a 100-120 gr 6mm bullet than a 80-90 gr .224 bullet - but it is your experiment.

I agree that you'd be better off with the 6mm as I'm pretty sure the cost to have a barrel chambered in either would be exactly the same. I wish I could say it's because I'm frugal...as many common components as possible, but it's for the other reason. You'll never hear me say money is no object, at least not going forward.

Just for kicks I've thought of giving crowd funding a try...that or try to talk people out of their tired old #### that will still work (if barely).