Optimum Barrel Time

[Joec7651]

I would like to become more knowledgeable in finding the optimum barrel time a bullet should exit any given barrel to avoid the shockwave or reduce the impact of harmonics. I won’t muddy the water with incorrect Information on my behalf. I’d like for someone more technically adept at it to point me in the right direction regarding research and information. There’s a site I referenced but I suspect it’s more involved than checking a chart or spreadsheet. the site is as follows. It’s not an advertising site to build a website. Not sure why it says “create your website”.

Pierre van der Walt on Cartridges, Rifles & Hunting is under construction

Create Your Website

pierrevanderwalt.com

Pierre van der Walt on Cartridges, Rifles & Hunting is under construction

Create Your Website

pierrevanderwalt.com

Any direction on where to start will be greatly appreciated. Thanks guys.

 

[RL338]

If you are using QuickLoad read this http://www.the-long-family.com/optimal barrel time.htm

I use this chart after I correct QL to my real velocities.

http://www.the-long-family.com/OBT%20Table.pdf

 

[Joec7651]

If you are using QuickLoad read this http://www.the-long-family.com/optimal barrel time.htm

I use this chart after I correct QL to my real velocities.

http://www.the-long-family.com/OBT%20Table.pdf

That’s a great start, thank you very much. I have been loading for 30+ years drawing on my own trial and error. I don’t discount that as it’s still gained experience, but As far as the scientific aspects go I would be hard pressed to consider myself much more than a novice. I have my loading journals from over the years but past that I haven’t collected much data. Its all hand written. I’ve been kicking around buying Quickload for a bit. It seems as if it’s much more than just a tool to ascertain what velocity a powder may give.

 

[xphunter]

I would like to become more knowledgeable in finding the optimum barrel time a bullet should exit any given barrel to avoid the shockwave or reduce the impact of harmonics. I won’t muddy the water with incorrect Information on my behalf. I’d like for someone more technically adept at it to point me in the right direction regarding research and information. There’s a site I referenced but I suspect it’s more involved than checking a chart or spreadsheet. the site is as follows. It’s not an advertising site to build a website. Not sure why it says “create your website”.

Pierre van der Walt on Cartridges, Rifles & Hunting is under construction

Create Your Website

pierrevanderwalt.com

Pierre van der Walt on Cartridges, Rifles & Hunting is under construction

Create Your Website

pierrevanderwalt.com

Any direction on where to start will be greatly appreciated. Thanks guys.

I guess my main questions is what are you wanting to accomplish, once you know this?
Is this for in the field or off the bench?
Short range or long range?
Hunting rifle or comp rifle?
If hunting, biggest game animal and max distance you would want to kill it at?
What chamberings are you considering?

 

[Joec7651]

My goal is a deeper Understanding of what takes place when the trigger is pulled. I’ve got the time now to get back into competing. It’s been some years now and like with everything improvements can be made that we haven’t attempted yet.

1. For field and bench.
2. For ranges out to 1000 yards but no hunting at that distance.
3. I’ll be applying the knowledge to every cartridge I load. I always work towards improvement.
4. I‘m going to build a long action 284 Shehane with a 30-32” barrel working around the 180 grain class projectiles at 2950-3100 fps. For the time being I’ll use a 26” heavy sporter barreled 7mm Remington Magnum with 1:8 rate Of twist.

 

[xphunter]

sounds like an F-Open rifle to me
The 284 Winchester and the 284 Shehane, are the probably two most used chamberings for 1000 yard F-Open.
I would use a single shot action (Kauger Arms, Borden, BAT, Kelbly’s, etc…), Brux, Bartlein, Krieger, and the like barrel maker. 8 or 8.5T, 1.250 straight with a reputable barrel tuner. Sub-5 ounce trigger, great glass.
Building a match Rifle, is a systems approach., of which the shooter is the biggest problem most of the time
Good front rest and rear bag…I know a guy
Good reloading equipment that keeps run out to a minimum, and that can be very consistent. Use quality brass (Lapua 284 win or the 6.5-284 necked up) powders that you know work with the 180 grain hybrid, and bullets like it.
Go shoot!
Some people have trouble making consistent reloads, but the biggest hindrance for most people is the 6 inches between their ears when they’re shooting under pressure, and spending the time on the range to learn how to read conditions.
If you are considering F class, there are plenty of people if you go to a match, who will help a new shooter or someone who’s come back into the game, and help them get on their feet and be a good mentor.
The same is true for 600 and 1000 yard Benchrest as well.
Be around to spot for others or to be spotting, while other people are shooting.
You can learn so much by spotting for others whether through your rifle scope or through a spotting scope.
Paying attention to the wind directions, plural, versus what the wind flag say (wind flags will lie ), versus what the mirage says, and then have your rifle scope with it focused on your target let’s say 1000 yards and your spotting scope somewhere around 600 yards and be watching how the mirage is different at each distance.
Head knowledge is good and important, but even more important is learning from the men and women who have been doing it for a while and have it figured out.
They can tell you what’s of greatest importance, and the things to not worry about. Sometimes, some of the very finesse things they do, you don’t need to worry about right now, because your shooting skill (I am not trying to be offensive) is not to the level to where you could tell a difference.
You do not need to re-discover, because the solutions and the loads and the builds that they use, have proven to work consistently.
Shooting clean at a grand, will always make you feel good
If you knew all these things or most of these things, realize, that I’m not trying to insult your intelligence.

 

[xphunter]

Some pictures of what I use.
Now you guys know that I do shoot rifles occasionally
F-Open Rig (284 Winchester), 6.5-284 Lapua brass, H-4831sc, Fed match primer, and 180 Berger Hybrids

15 shots at 800 yards (180 grain Hybrid)

F-TR (308 Winchester)
Seb has the TR rig (308 Winchester). This is when we hosted the World's (F-Class) at the NRA Whittington Center.
Shooting 200 grain Hybrids back then, now it is 200.20X (2620 fps). Palma brass, Varget, and Fed match primers.

Some cold weather load development, getting ready for the SW Nats

Dan called the flier when he was shooting. Nice group for 600 yards in brutally cold weather. Four were right around an inch. Still a good group for 600 yards for 5-shots. Still sub half MOA shooting blind.

Even on a light weight rig-Sub 7.5 pounds (Scope and all), you can do good. Three 5-shot groups at 500 yards

Heavy Pistol at a grand

1000 yard shoot off at a 1000 yards.

Barrels in these set-ups vary: Broughton, Brux, Bartlein, and Krieger.
I may do one or two comps a year. I actually enjoy LR field shooting on steel more than anything else with XP-100's and other specialty pistols more than I enjoy bench shooting.

 

[xphunter]

Shooting close up is easy

1K

Stretching things past 1K with a 22 centerfire with wind, is both fun and humbling.

 

[xphunter]

My goal is a deeper Understanding of what takes place when the trigger is pulled. I’ve got the time now to get back into competing. It’s been some years now and like with everything improvements can be made that we haven’t attempted yet.

1. For field and bench.
2. For ranges out to 1000 yards but no hunting at that distance.
3. I’ll be applying the knowledge to every cartridge I load. I always work towards improvement.
4. I‘m going to build a long action 284 Shehane with a 30-32” barrel working around the 180 grain class projectiles at 2950-3100 fps. For the time being I’ll use a 26” heavy sporter barreled 7mm Remington Magnum with 1:8 rate Of twist.

Your 7RM, must have a custom barrel, since it has a 8T-Cool!
Will you be using the 7 Mag for hunting?
Will you be using the 7mm Shehane for hunting too?
The Shehane could be a short action single-shot.
If, I am going for gold ring in terms of accuracy, I will choose a stiffer single-shot action over a mag fed one.
Will this be prone shooting (fixed position shooting and or bench) with the Shehane?
What front rest or bi-pod do you plan to use?
What rear bags do you use?
Good LR stocks for comp shooting typically will have a 5/8" or 3/4" flat width on the bottom of the buttstock, for great tracking.
3" wide forend will work great as well. It is easier to drive a gun that is made well with a front rest and rear bag that matches your stock.
If you are considering a bi-pod for fixed position shooting, I would suggest one that tracks (F-Class or ELR) compared to field bi-pods like Harris or Atlas.
For hunting you will want a field bi-pod.

 

[Joec7651]

First and foremost, thank you for taking the time to express so much information. There is a LOT to take in and I’ll be re-reading your posts more than a few times. I will be using the 7mm RM as one of my hunting rifles(I have for a few years now). It shoots 180gr Hybrids and 175gr ELD-X well. It will give 1/2-3/4 MOA to 450 yards across bean fields with a portable bench and rangefinder. It’s just a hunting rifle I built so not even close to the same realm you speak of.

The Shehane will not see any hunting. Strictly fixed/prone, and I was seeing a single shot for the action. As far as the bipod and rear bag goes, I haven’t began to address it. Even the planning of this will be a time consuming endeavor and I’m looking into local matches in surrounding states to attend as a spectator this spring and summer before jumping in waste deep. I have to admit, its somewhat intimidating getting started.

 

[xphunter]

Your single shot Shehane, is typically used in F class, in the open division.
They typically use a front rest, but you could use a bi-pod.
F-Class does not allow muzzle breaks or suppressors. In open class, which you would be considering with the chambering you were looking at, has a maximum weight of 22 pounds. The front rest and the rear bag does not count against you. But your scope and your basin rings do go as a part of your overall weight.
If you chose to use a bipod for open, the Bipod would be a part of that total weight, because it’s permanently fixed to the forend.
The JOYPOD-X weighs under a pound and a quarter.
You can see that Bipod in the video of Dan shooting at 600 yards in the dead of winter.
A front rest would be more advantageous for shooting an open class, but it would cost more than the Bipod does.
If you have questions about what kind of competition shooting you want to get into, send me a private message, and I will give you my phone number and my email address.
The best time to ask questions and get answers, is before you start a build

 

[Joec7651]

Also, apologies for my response not being as in depth as I’d like. I just got in from work and am just settling in for a bit. It was a late night.

 

[xphunter]

You have Absolutely Nothing to apologize for.
Everyone has to start someplace.
Cartridge wise you picked one of the best.
I might have suggested the 284 Winchester (The parent case of the Shehane), simply for the reason, that there is no need to fireform it into it's future state, but ultimately you will be "fully forming) a straight 284 Win from brass dimensions to your chamber (non-wildcat) as well, but it the difference is not noticeable to the eye.
F-Class is a score game, that has long shooting strings (15-20). They use pits after every shot or the electronic targets, that have a pause before you can shoot again. You will be shooting prone on concrete, gravel, or grass. It has been called "belly benchrest"
You have a much longer time to shoot as compared to 600 yard/1000 yard benchrest, where once you go to shooting time, the 5 or 10 shots, get fired from single-shot rifles extremely fast, to get all shots in the "condition"
The X-Ring is one half MOA, so at a grand the X-Ring is 5" in diameter, and the 10 Ring is 1 MOA, so it is 10 inches in diameter
The X-Ring is one half MOA, so at 600 yards the X-Ring is 3" in diameter, and the 10 Ring is 1 MOA and is 6" in diameter.
Gotta run for a bit-More later if you so desire

 

[xphunter]

To me, F-Class has more practical roll over skills into LR field shooting and hunting, then benchrest does, since in F-Class you have to learn to read the conditions (and those conditions will be changing during the time of your relay).
I have competed in both disciplines. They are both fun, but if I had to choose one, I would surely pick F-Class.
TR (Target Rifle) is the bi-pod class, and the only two cartridges you can use is the 223 Remington or the 308 Winchester. No brakes or suppressors allowed, and the weight the rifle, including the bi-pod cannot be more than 18 pounds and 2 ounces (Approx).
There is also a 22lr FT-R as well that is picking up in popularity.
99% of the upper level shooters in F-Class will be using scopes where the reticle is in the second focal plane (SFP)
Whereas in the PRS/NRL/ LR steel matches, the majority of the scopes have the reticle in the FFP (First Focal Plane)
In F-Class and in benchrest, the majority of shooters use MOA based scopes, whereas in the whereas in the PRS/NRL/ LR steel matches, the majority of the scopes are MIL based.
In any of these disciplines, new shooters are warmly welcomed, to bring and shoot what they have. In all of the disciplines mentioned I have seen shooters loan their rifle (after they were done) or their spare to a new shooter.
We want new blood in the shooting disciplines.

Now if you want to go a little more off the reservation, I put on a shoot once a year, for handguns of all kinds (No Rifles). It is a steel shoot and a prairie dog shoot in June that starts the Monday after Father's Day. I even have loaner specialty pistols that can be used if you are new to the game at no cost...Well, you do have to pay for your ammo usage. We have folks who have never shot past 200 or 300 yards feeling fairly confident about hitting 10 inch steel at 400 and 500 yards (or further) fairly consistently, depending on the conditions.

WY-SHOT 2025 is June 16-18

Looking forward to WY-SHOT 2025! WY-SHOT is a Handgun Only shoot that is designed for folks of all ages. There is a two-part component that makes this shoot unique. It is a prairie dog shoot and a …

sebrests-usa.com

 

[Joec7651]

Ernie, I can’t thank you enough for the breadth of information you have given me. I’m still digesting it, and researching components for the build.
This year I’m going to break out my PRS rifle and equipment to compete in 2-3 matches this year. The rifle recently received a fresh barrel, it’s familiar, I’m at the end of load work up for the new barrel, and I’m already geared to the circuit. As it stands, my F-Class build will commence mid to late summer with the the plan being to humble myself next Spring or early Summer. LOL.
Again I can’t thank you enough for being so generous with your time and expertise.

 

[xphunter]

Ernie, I can’t thank you enough for the breadth of information you have given me. I’m still digesting it, and researching components for the build.
This year I’m going to break out my PRS rifle and equipment to compete in 2-3 matches this year. The rifle recently received a fresh barrel, it’s familiar, I’m at the end of load work up for the new barrel, and I’m already geared to the circuit. As it stands, my F-Class build will commence mid to late summer with the the plan being to humble myself next Spring or early Summer. LOL.
Again I can’t thank you enough for being so generous with your time and expertise.

Did you see the private message I sent you? If not, I just sent another short message, so it will pop up in your notifications.
You are welcome.
Shooters and hunters should be there for others. Every one has to start somewhere. We all have had help along the way.
I communicate with multiple F-Class shooters every week. They range from rank beginners to folks on Team USA.
If you ever want to chat off forum, I am good with that.
I can give you some recommendations on some good smith's as well, if you so desire.
I hope to get in a couple of steel matches myself this year and hopefully one LR BR match

 

[noslerpartition]

You are welcome.
Shooters and hunters should be there for others. Every one has to start somewhere. We all have had help along the way.

Amen to that.
I am active on a few forums, American and German.
But THIS is the only one where threads don't go south after a few posts.
Thanks to the mods for keeping it that way!
Cheers
Frank (Germany)