How to pick the speed

[memo43]

ok here goes once again to much time to think.
When loading for ammo to compete how do you guys pick speed, and when is enough speed enough or not enough.
The way I have been doing it is:
1 No signs of pressure
2 Verify that I am still over speed of sound at the target 1125 fps
3 Still accurate

But is there more to it than that.

I have a 175 smk load that I avg 2780 fps coming out os a 31.25" barrel
I know I can get them faster according to Ql (finally broke down and got a copy)

I use wolf primers and have Varget, IMR 4064, IMR 4895, RL 17, 8208
all of which are in the neighborhood of 12 lbs plus.
using New Winchester brass, as well as LC LR brass.
Sorry if im over thinking it, but just wanted to ramble a bit

 

[DennisH]

I have my load for my barrels. Even when changing out a barrel with the same specs, all I do is fine tune the load. again same bullet, but the charge will vary 1/-1 , and the COAL (measure from ojive) will vary a few thousandths.

I do chrono the new loads just to make sure I am around my old specs.

Dennis

PS: Most of my most accurate barrels, I had the throat deepend, just a few thousandths. This seemed to make the most difference with all my barrels. I always sent in about 3 dummy rounds.

Dennis

 

[6BRinNZ]

memo43 - you pretty much have it - so long as the .308 load is above transonic at 1000 (assume you shoot that far) and is accurate you are done. If you take a ballistic programme and put an extra 30 or 40 fps in it you will see that it makes very little difference to drift in a full value 10mph wind (as an example).

 

[DataSmith]

Faster is not always better. A slightly slower load that gives a tighter velocity spread and good precision is generally better than one that's a bit faster but with more variation.

It's a balancing act.

 

[barefooter56]

memo43,
You have it right. Just keep in mind that its the RIFLE that picks the speed. We do not. Feed the critter what IT likes.

 

['Freak]

If you’ve already made it to whatever velocity was necessary to get done what you intended, be happy.

 

[Lapua40X]

OMG ... I thought it would never happen. Here I find a group of shooters that understand the balance between MV and accuracy. I've been flamed so many times by the "faster is better" crowd that I was beginning to feel insecure.
Nice to know you guys ................................

 

[Sniper338]

all of the above... find your accuracy load and dont worry about speed, it is what it is, maybe next barrel will be a little faster, maybe not.. Many don't do it like me, but I test loads until I find the accuracy I want, then when I finally find the pet load I chrono it and see what the barrel does, and thats that... Not worth my time setting up chrono every time I shoot just to see speeds if they dont shoot well anyways.

 

[Marksman63]

Keeping in mind the magic number rule (1.2 Mach speed at the target), I apply modelling and simulation techniques:
- Build my load through QuickLoad, checking barrel time for two main nodes;
- Verify it (real speed and pressure signs) at the range starting from 1 grain below the QL suggested weight;
- Calibrate QL using range measurements (speed, temperature);
- Verify again (accuracy test at 200 meters) using load development techniques (OAL, etc.)
- Fix and save my QL load for further tunings (temperature, OAL, etc.)

My 2 cents

 

[minnesotamulisha]

Higher velocity is irrelevant if the precision is poor. It just means you'll score 7s and 8s a few milliseconds faster .

Best advice I've heard in a while. Thanks!

 

[5spd]

I always load for accuracy then run them over the chrony to see the speed and work from that point on.

 

[Joe R]

memo43
ok here goes once again to much time to think.
When loading for ammo to compete how do you guys pick speed, and when is enough speed enough or not enough.
The way I have been doing it is:
1 No signs of pressure
2 Verify that I am still over speed of sound at the target 1125 fps
3 Still accurate

But is there more to it than that.

I have a 175 smk load that I avg 2780 fps coming out os a 31.25" barrel
I know I can get them faster according to Ql (finally broke down and got a copy)

I use wolf primers and have Varget, IMR 4064, IMR 4895, RL 17, 8208
all of which are in the neighborhood of 12 lbs plus.
using New Winchester brass, as well as LC LR brass.
Sorry if im over thinking it, but just wanted to ramble a bit

memo43,
Since you have a 31.25" barrel and have a copy of QuickLoad, I'm going to guess your intended purpose is not hunting but target. And since you're using the 175 SMK I'm also going to assume that its for F/TR. If these assumptions are incorrect please clarify.

Some guys are going to hate me for giving away the crown jewels and giving you what it takes most people months/years/never to uncover, but here it goes.

I believe in the old days, shooters looking for a good load stumbled aimlessly in the dark until they tripped over an accuracy node by accident. All that changed when Chris Long put is brain power to work and IMO made the biggest contribution to precision shooting since barrel rifling. IMO it is also the major reason for buying QuickLoad.

If you are not aware of Chris's work here's his link http://www.the-long-family.com/optimal%20barrel%20time.htm.
1. Read his white paper and digest it.
2. Download his OBT table from here http://www.the-long-family.com/optimal%20barrel%20time.htm.
3. Use QL to determine the OBT for your powder and bullet combination.
4. Apply the above, work on your reloading skills and practice a lot and you have as good a chance of winning a match as any of us do.

Its that easy.

Kindest regards,

Joe

 

[memo43]

Joe you are correct I am an active target shooter, I'm constantly in search of the next best thing and looking to stumble in the dark.

To the rest of the forum members thanks for all the positive response.
I have been competing for over a decade in pretty much every style of rifle comps.
I've been to Perry a few times with the Marine Corps rifle team, both as a shooter and coach.
From time to time I get asked what we would consider simple question's by beginning shooters an I'll post the question here.
Some of us don't have the answer to all of the questions an are to afraid of getting flamed for asking noib questions. But that's why we are here to learn and pass on knowledge.