How long should your barrel be?

Wait…..let’s think this through.

Unfortunately, the rush to use suppressors has led many manufacturers to sell rifles with barrels that are way too short for the calibers they offer.

Some do nothing to warn their customers about the performance loss they will suffer.

They leave you to figure it out and most people do not discover the bad news until after they have purchased the rifle.

2026 will mark our 30th year as a custom rifle builder.

We have never expected our customers to know all the pros and cons to changing barrel length, twist rates, or any other important decision in their rifle build.

That’s our job. That’s why you come to us. We would rather lose a sale than to build a rifle that does not make sense for our customer.

So, let’s take a look at barrel length for a few calibers that are very popular right now.

First, up is the 6.5 PRC.

We are seeing several companies sell 6.5 PRC’s with 18” and 20” barrels in order to make them more attractive to suppressor users.

Did you know you just bought the equivalent of a 6.5 Creedmoor?

Instead of the 2950 fps you are supposed to get, you will get only 2700 to 2750 with most 140ish grain loads.  Hey, that’s about what a 6.5 Creedmoor does with less recoil and three times the barrel life.  Even with a 20” barrel, the 6.5 Creedmoor delivers close to 2630 fps.

Next up, the 300 Win. Mag.

We see a fair number of internally suppressed 300 Win Mags.

They look cool and the suppressor works great.

But, hey, did you know the actual barrel is only 18” long?

Now you have an anemic 30-06.  Is that what you expected?

The same is true for all of the 300 Wins we see with 20” barrels.  You are basically shooting a 30-06 with more recoil, less magazine capacity, and more ammo expense.

Now let’s consider the newest kid on the block, the 7mm Backcountry.

This cartridge does amazingly well out of a short barrel. But even in this case you should pause and think about the tradeoffs.

All of the barrel lengths from 16.5” to 24” work. But, they produce significantly different velocities which leads to different energy, penetration, and wound channel performance.

With the 16.5” barrel the 170-175 grain loads produce about 2815 fps. Pretty amazing from that short of a barrel.

At 20” you get about 3000 fps from these same loads.

All else being equal, the faster bullet creates more hydrostatic shock which results in a larger diameter wound channel. So, when comparing the same cartridge, in this case 7mm Backcountry, the size of your kill zone is larger with the faster moving bullet.

Obviously, penetration will be deeper as well.

A little math might help with this.  

Bullet rpm = (720XVelocity)/Twist Rate.

So, at 2815 fps, we have (720X2815)/8=253,350. At 3000, we get (720X3000)/8=270,000.

Along with the deeper penetration, the extra bullet spin creates a larger, more violent wound channel, thus enlarging the effective kill zone.

Lastly, the shorter flight time for the bullet from the 20” barrel, exposes the bullet to wind for less time. At 600 yards and a 10 mph full value wind, the 20” gun has 2” less wind drift than the 16.5” gun. Not a huge difference, but added to the other differences, this could make all the difference. 

This is really about putting the odds in your favor. With very good shot placement, both barrel lengths should result in an ethical kill. But, what if the shot isn’t so great? If the extra shock destroys a vital organ that the slower bullet leaves intact, that could be the difference between a found animal and a wounded, lost animal. If the extra penetration of the faster bullet results in an exit and a blood trail, while the slower bullet does not exit, that might determine if you find your animal or not.

Is this a 400 yard gun for Whitetail and Mule Deer? Or, do I also need to cover Elk at 600?

For the 400 yard deer rifle, the 16.5” barrel is fine. For the 600+ yard Elk rifle, the 20” barrel would be a much better choice because you need the extra energy and penetration.

These are the right kind of questions to ask before you decide on an extremely short barrel.

When you are thinking about all of this, ask yourself how often you will hunt with your suppressor on the rifle.

I love a suppressor at the range, hunting from a blind, or on hunts that don’t require much walking.

If, however, I plan to do lots of walking, carrying the rifle on a sling or in a pack, I don’t use my suppressor.

I don’t want the additional 6 to 9 inches on the end of my barrel because it makes the rifle more awkward to carry. 

Recoil and noise don’t really bother me in a hunting situation. I just don’t notice them.

At least not enough to make me put up with the suppressor.

Everyone is different and there is really no wrong answer to this. But knowing what works best for you will help determine the cartridge/barrel length combination that helps you to get the most out of your hunting rifle.

How long should your rifle’s barrel be?

Take some time to think about it.

If you end up with some questions, just give us a call or send an email and we will do our best to help.