6PPC Questions,Twist,bullets,F.P.S. & Pressures

[coolatula]

I have a few simply questions I hope you all can and will discuss freely here. All of your opinions are welcome so please chime in.

Please note that this is all hypothetical for the time being at least and for research purposes only. So,have fun with it! It's only a discussion and EVERYONE is welcome to contribute their thoughts and/or theories,practical knowledge etc..

I do not have a ballistic table/computer or else I could possibly do some of this research,but if with one I'd still want to hear from shooter with real world results.

Here is a few set parameters for possible 6PPC loads that you can you deviate from. Other than that feel free.

#1 WORKING pressure MUST be around 45,000psi. and not to exceed 50,000psi. under any circumstance.

#2 Barrel length not to exceed 22" with a bull/heavy barrel and as short as 18" would be even SWEETER unless performance would suffer to the point where the disadvantages outweighed the advantages.

#3 Bullet weight to be on the HEAVY end for caliber for most shooting,but with flexibility to shoot 75gr. V-Max or similar well. So,over 90gr. for most shooting? 1/10 twist?

#4 Maximum barrel life is a priority.

#5 NO neck turning,reloading needs to be as simple and straight forward as possible. Going more for varmint/casual target shooting NOT bench rest performance.

#6 Maximum effective range need not exceed 500-600 meters,but if shoots well beyond that it's a bonus. A 250-300 meter practical range would be ideal.

With that out of the way lets proceed and see what we can get "away with" and still be within the above set of uh..restrictions if you will.

Of course just like any other Male out there I want the best performance,so I don't know if 3,000 fps is a reality with say 105gr bullets and a 18" minimum length barrel? If not is it possible with a 22" while still staying under 50,000psi?

 

[janderson0]

I think parameter #1 eliminates the PPC
Jim

 

[tightneck]

"Of course just like any other Male out there I want the best performance,so I don't know if 3,000 fps is a reality with say 105gr bullets and a 18" minimum length barrel? If not is it possible with a 22" while still staying under 50,000psi?"

Staying around 45,000 PSI and obtaining 3,000FPS with 90+ grain bullets will require the use of a large capacity cartridge, with a very slow powder, in a long barrel. And I still have my doubts if your could obtain what you are looking for. But then, I've never had such a lofty goal. Best of luck...

 

[Cheechako]

cool

You are asking an awful lot from that tiny PPC case. It will do most of the things that you want,I have done them personally), BUT, not all at the same time.

It reminds me of a shooter going to a major tournament. He looks up and down the line and sees some very good, world-class, shooters. He says, "I can beat any shooter here. But not all on the same day!"

With all of the cases to choose from you picked the wrong one to meet your criteria.

JMHO

Ray

 

[coolatula]

"Of course just like any other Male out there I want the best performance,so I don't know if 3,000 fps is a reality with say 105gr bullets and a 18" minimum length barrel? If not is it possible with a 22" while still staying under 50,000psi?"

Staying around 45,000 PSI and obtaining 3,000FPS with 90+ grain bullets will require the use of a large capacity cartridge, with a very slow powder, in a long barrel. And I still have my doubts if your could obtain what you are looking for. But then, I've never had such a lofty goal. Best of luck...

Yeah,I already figured that 3,000+f.p.s. while staying under the 50,000psi max may not be obtainable with the heavier bullets. I thought that might be shooting for the moon somewhat. Thank you for your honesty and not giving me a B.S. "Oh you can get that easy with no overpressure concerns whats-so-ever" answer. If something just won't work in theory and or practice I want to know that as well.

Do you feel it would be obtainable with say a 75gr Vmax and if so would it be obtainable in a short 18" barrel?

How does the mid-weight,75gr.) Vmax's perform at those velocities? Still fly true and expand,explode)when they hit soft tissue/harder bone?

I probably should have turned it around and put question #3 more on the conservative side and started with the lighter,75gr.)
bullets and a 3,000fps target with that set working pressure. I even thought of it and almost went back to change it,but left it as is.

I should have put #3 as:

#3 Bullet weight to be in the medium weight range,75gr. Vmax or similar)for caliber for most shooting,but with flexibility to shoot HEAVY for caliber bullets for use on say larger varmints up to Coyote size.

 

[coolatula]

cool

You are asking an awful lot from that tiny PPC case. It will do most of the things that you want,I have done them personally), BUT, not all at the same time.

It reminds me of a shooter going to a major tournament. He looks up and down the line and sees some very good, world-class, shooters. He says, "I can beat any shooter here. But not all on the same day!"

With all of the cases to choose from you picked the wrong one to meet your criteria.

JMHO

Ray

OK,which is workable and which is not?

Here's a spec. sheet of a typical 7.62x39mm which we all know inspired the .220,which the 6PPC derived from.

Given the working pressure of this round I didn't think it would be wrong to feel TOO far out of the ball park in chopping the weight down to 90gr.,which is a full 32 to 34gr. off of a standard 7.62x39mm ball round)and getting close to 3,000fps with a 6mm bullet.

It's already over 2,400fps at the muzzle with a 122gr. pill and well within the max working pressure of 50kpsi.

Cartridge - 7.62 x 39 Soviet M43,Type PS ball)
Muzzle velocity - 2411 fps,20"/1 in 9.45" Brl.)
Bullet weight - 122 gr.
Working pressure - 45,000 psi

I DO know that compared to the typical 6PPC load that downloading would be MANDATORY. I believe I've even read on this forum where people have had very good results with down-loaded 6PPC loads for medium range varmint hunting while still maintaining good velocity,2,800-3,000fps)and effect on target.

 

[Cheechako]

Just an example, or two:

I have shot the 95 grain BIB in an 8T at 3000 fps. But that was out of a 28" barrel and it was a max load for a PPC which means well over 55,000 psi. Well over.

I shoot the 71 grain Berger in a 12T at 3385 fps but, again, out of a 28" barrel. Very accurate at 600 yards. Another max load at 55,000+ psi.

I could conceivably load these down to 45,000 psi and even shoot them in an 18" barrel but the ballistics would suffer, a lot.

Why don't you get one of the Internal ballistics programs and run a few charts to see exactly what you can do within your parameters?

Ray

 

[coolatula]

Just an example, or two:

I have shot the 95 grain BIB in an 8T at 3000 fps. But that was out of a 28" barrel and it was a max load for a PPC which means well over 55,000 psi. Well over.

I shoot the 71 grain Berger in a 12T at 3385 fps but, again, out of a 28" barrel. Very accurate at 600 yards. Another max load at 55,000+ psi.

I could conceivably load these down to 45,000 psi and even shoot them in an 18" barrel but the ballistics would suffer, a lot.

Why don't you get one of the Internal ballistics programs and run a few charts to see exactly what you can do within your parameters?

Ray

Thanks,I'll try to do some #'s on one as I know there are some free ones on the web,but I haven't messed with them. I would have to get all the bullet specs unless they already have a drop-down menu or some thing with the more popular bullets and powders etc. I don't know,remember if the free ones have that or not.

I would be interesting to see on paper at least how things can be plugged in and out and how the magic numbers come out.

I like the parameters to stay using the 6PPC and of course the 45Kpsi working pressure. I know .220 Russian would be kick ass on paper,but I REALLY didn't want to resort to a hopped up .223 Rem. level.

I like to at least keep the 6mm/.243 diameter even if that means utilizing a little bit lighter bullet. I'd rather have a 6mm over a .22 even if they are close to the same weight.

I have nothing against the .22s as far as actual shooting/paper punching wise. In fact I LOVE shooting the .223 Remington round in both bolt action and semi-auto/auto,but for real deal animal hunting I'd like to have just a little bigger hole and the punch that goes with it.