Quickload Barrel Length Comparisons

[mdbruce]

Generally how accurate is the increase or decrease in velocity when inputting various barrel lengths in Quickload? I'm looking more at the percentage of change rather than actual velocity

Here's an example of how I would like to use the data: Compare the velocities and velocity changes in a 20,21, 22" barrel in a .308, 30/06, 300 WSM. Really input any cartridge there.

If the barrel length input isn't necessarily an accurate "what if" representation, then I need to wing it.

Thank you

 

[mikecr]

It's not a rule of thumb.
Barrel length affects are tied to all else about a load.

 

[mdbruce]

It's not a rule of thumb.
Barrel length affects are tied to all else about a load.

thank you. Whether literal or just conversational...I’ve always been told a short barrel 300 Mag is a 30-06, and a short barrel 30-06 is a .308, and etc etc.

Assuming the barrel length functionality is accurate, QL “proves” otherwise —that the larger case is always faster.

My end goal is to get a nimble short-barrel (20-21”) medium game rifle. I didn’t want excessive recoil without the velocity. So I was using QL barre length as my guide. I’m leaning towards a 300 WSM.

 

[Murray Brook]

I believe that when you use a short barrel in conjunction with large capacity cases you must keep in mind that not only is velocity reduced, but muzzle flash increases, barrel whip and recoil may increase as well. Things to keep in mind.

 

[charcher]

mdbruce, I have seen 2 or 3 tests where the particular person has started with 30" or 32" long barrels and recorded the velocities, then chopped an inch at a time down to around 20" to 21" recording the fps loss after each cut. This was on the net somewhere and one in particular, if my hazy memory is correct, a couple of tests by barrel makers, and the principal reason behind said tests was to prove if you needed a faster burning powder as barrel length was reduced and I think Sisk barrels was one of them. It's not exactly what you are asking, but it may be of interest to you.
Sorry if I'm not much help'

Kevin

 

[CharlieNC]

For a short nimble barrel I would not worry about losing 200fps vs a long barrel. Unless you plan on shooting well over 500yd a 20-22in 308 will drop medium game just fine vs a magnum. And the right powder will make up quite a bit of the velocity compromise.

 

[mdbruce]

For a short nimble barrel I would not worry about losing 200fps vs a long barrel. Unless you plan on shooting well over 500yd a 20-22in 308 will drop medium game just fine vs a magnum. And the right powder will make up quite a bit of the velocity compromise.

Thank you for your reply. I'm right there with you about the terminal yardage and a .308.
I am more curious about the barrel length input in Quickload being accurate enough to get a general idea on velocity.

Is where the barrel length input gets useful is when evaluating TC Encore barrels that are 11-15" long. Or trying to narrow down a cartridge based on performance at a set barrel length and pressure.

So for example, if I can get 200fps more from a magnum then it might be worth it... if it's only 50 fps at that barrel length then it might not be worth it.
I was using the QL barrel length input to get a general idea...but figured I would ask to see if that functionality is remotely accurate.

 

[CharlieNC]

QL seems relatively accurate for effect of barrel length. In terms of chasing velocity, you can use the evaluation tab in QL to find a powder and charge that will yield the desired velocity. But more importantly find out the minimum terminal velocity which your hunting bullet requires for proper performance, typically 1700 fps is a normal. Use this as a guideline for loads and max range vs arbitrarily higher velocity.

 

[mdbruce]

QL seems relatively accurate for effect of barrel length. In terms of chasing velocity, you can use the evaluation tab in QL to find a powder and charge that will yield the desired velocity. But more importantly find out the minimum terminal velocity which your hunting bullet requires for proper performance, typically 1700 fps is a normal. Use this as a guideline for loads and max range vs arbitrarily higher velocity.

Thank you. It sounds like QL can provide a good general idea on effect of barrel length, which is all i can realistically expect.

If it ends up being off, it's still the best prediction tool I have...other than searching for results from others that have already tried it.

In the real-world of terminal performance it probably won't make a difference any ways, ha.

I circle back around to in the end I just didn't want to suffer through a magnum recoil for very little velocity return compared to a more pleasant standard cartridge.
I hoped that QL was an easy option for "guessing" the effect of barrel length.

 

[mikecr]

You should buy it

 

[mdbruce]

I already have it

 

[potatojudge]

As you know, many variables here including the unpredictable "fast" vs "slow" barrel.

You can get empiric data from the Specialty Pistols group since they run 14-20 inch barrels in all classes of cartridges including big magnums.

The only way to be reasonably certain what you'll end up with is to buy a gun already built with known load and chrono data and hope your components are comparable. Otherwise, be willing to push a barrel and if it's not giving you what you think is possible sell it and try again with a new blank. At 200 rounds per barrel to see how the speed settles out, that's a long road. This would be hard to do without charging the case and seating bullets at the range.

The recommendation of finding a terminal velocity floor and matching it to bullet and game is a good one, because after 300 yards you need to know your distance and drop for a shot on game anyway, magnum or no. 1800fps was the standard, now there are bullets you can rely on to expand down to 1300 or less. Some target bullets have been found to perform on game extremely well at these lower velocities, but you have to be very selective doing this.

I don't know that anybody has shown that a light or heavy bullet takes greater advantage of a short barrel. Lots of guys are hunting with 14 inch 7-08s running 120s and others run 160 grains or heavier, and all can be successful.

Another option that was recommended to me by a champion IMHSA shooter is to have a load for 100 yards and another for long range. His 100 yard data was usually a small amount of a pistol powder and long range load was traditional data. This gets you trigger time with low recoil and you can spend your recoil tolerance capital on getting dope at longer ranges.

Sorry if this isn't a direct answer to your QL question, but I think it is what needs to be considered in choosing a barrel length and chambering.

The obvious answer, as you know, is to get a 284 Winchester.