quote:

Originally posted by henryrifle:
Zak over at TBAC confirms your point--that the Ultra 9 adds between 0 and 20 FPS to the MV.

Zak doesn't pull punches...on pretty much anything.

His Thunderbeast company makes good suppressors. His Competition Dynamics group produces quality rifle matches. He's not one to be overly talkative, and wouldn't be your first choice for a beer and wings bull session after work. And don't get whiny about petty points at one of his competitions.

He's a good dude.

Quickload is a WAG. Every barrel is diff, every test platform is diff, you will never have identical test conditions.

I understand that Quick Load is just a model and one that is partially dependent on the user inputting quality data for the configurable fields. I also understand that that there are numerous factors not addressed by Quick Load that I don't yet and may never fully understand. I'd enjoy spending some time with someone who could walk me through all of the events that occur in the case/chamber/throat/barrel. I have always enjoyed the "whats" that undergird the event. Here is a partial (very partial) list of things I'd like to understand more fully or even some:

1. What is the exact impact on initial pressure and ultimately barrel time and MV of using a magnum primer? (I know pressure and MV increase while barrel time decreases)
2. What is the impact on initial pressure and ultimately barrel time and MV of increasing neck tension? (same as above)
3. What are all the factors to be considered when changing seating depth?
4. Is there more to loading a projectile long than slightly increasing the volume of the case and slightly decreasing initial pressure until you load into the lands?
5. Does the projectile wobble somewhat in the throat and if so, is one of the goals of changing the loaded length to facilitate the projectile entering the lands more straight?
6. What is the impact on the pressure curve, barrel time and MV by using a suppressor
7. Does it make a difference if you are using a 30 caliber suppressor (larger holes in baffles and end cap) for a smaller diameter projectile like a 6.5?
8. Does tumbling brasss in stainless steel media really clean the inside of the neck more than tumbling in dry media and therefore increases effective neck tension and initial pressure?

I belive I know the general direction of the answers to the questions above but I would like to know how to account for them.

Perhaps some/many/all of the above have a very marginal impact on pressure/barrel time/MV.

Is Optimum Barrel Time theory correct or does it just happen to correlate with some but not all good loads?

From my perspective and maybe mine alone it would be interesting to use a program like Quick Load to predict a good load for a new rifle, be able to verify and or tweak that load slightly, true the math model to that particular rifle and use the program to find other powder, projectile and case combinations that yield the same good results. I could finally do something with all that crap brass I have laying around but don't want to discard.

Maybe all of that is just a lot playing rather than the real fun of shooting but as a working stiff it is a way to think about what I enjoy doing while doing what I have to do - work.

Henryrifle

I think you are over thinking a lot of this. Barrel time, who cares? Yes chaning oal affects pressures & vel, just understanding that is most of the oal issue. I call it chasing numbers. Load for accuracy & functioning, the rest is minutia imo.

quote:

Originally posted by fredj338:
I think you are over thinking a lot of this. Barrel time, who cares? Yes chaning oal affects pressures & vel, just understanding that is most of the oal issue. I call it chasing numbers. Load for accuracy & functioning, the rest is minutia imo.

Fred is absolutely right, you are just chasing a bunch of numbers that are unnecessary. First decide what you are going to use your rifle for, hunting or bench rest shooting. If for hunting I am sure your rifle will shoot much better than you are capable of shooting in the field. Get a couple of manuals from bullet manufactures and use their data. They have spent Millions of dollars and thousands of man hours putting that data into the manual. Most manuals from a manufacturer will even list the best load that worked for them with certain bullets. That would be a good place to start. You will be hard pressed to beat that data until you have spent many hours at your reloading bench and hundreds of dollars on the newest gadgets. The fun comes from picking loads listed in a manual and following their instruction to the letter while getting it to work for you, "SAFETY" always comes first! Be safe and keep very good notes that you can refer back to. Have fun with your new adventure and shoot straight.