Home Forums Hunting & Shooting Ask The Gunwriters Went to work with a recoil calculator...

My go-to rifle is a Vanguard 300 Win. Mag. With scope, ammo and Harris bipod, probably weighs in around 9 lb or so.

I changed over to Federal w/Barnes 130 TTSX couple years back, and noticed a considerable difference in recoil. Certainly took the edge off a dozen rounds off a bench.

Just read an article by Dick Metcalf in Rifle Shooter about recoil, how to calculate, etc.

Got me to wonderin' just how significant is bullet weight a factor. I found an online calculator, and then went to Hodgdon's online reloading data to fill in the blanks. Went with reasonably similar bullets, IMR 4350 for consistency and maximum load data.

Online version...

http://www.shooterscalculator.com/recoil-calculator.php

Results, using 9 lbs weight:

130 gr. - 3466 fps - 74.0 gr. = 23.73 ft.lbf Recoil Energy
150 gr. - 3254 fps - 74.0 gr. = 25.95
165 gr. - 3142 fps - 73.3 gr. = 27.60
180 gr. - 2974 fps - 71.0 gr. = 27.93
200 gr. - 2860 fps - 69.5 gr. = 29.79

Dropping from arguably standard 180 gr. bullets down to 130s reduces recoil by about 20%.

That's pretty significant, and all things being equal gun-wise, about the difference between the 300 Win. Mag. and a 30.06.

Even switching to 150s can take some bite out of a rifle.

With the quality of bullets being what it is these days, particularly with monoliths, this suggests that, if recoil is becoming a factor with one's rifle, as it can with age, particularly in the realm of 7mm or .308 calibers, a simple and certainly a lot less expensive solution than buying another rifle, is to drop down in bullet weight.

Of course, if dangerous game is on the menu, that's another topic. But for elk, and even moose, and probably a long list of African plains game, can't see a downside. And there's the added benefit of a little flatter shooting weapon out to 400 yards, too, beyond which sidewind comes into play.

For some people, a .300 magnum can be right on the edge of tolerance regarding recoil. But maybe it doesn't have to be nearly so?

FWIW.

For those that work in Excel and would want to calculate free recoil without being on line it can be easily done by placing the enclosed formula in column E on a worksheet (just copy and paste, then use auto-fill to spread it down the column).

= (((A2*B2+4000*C2)/7000 )^2)/(D2* 64.348)

A = bullet weight in grains
B = velocity in FPS
C = Charge weight in grains
D = gun weight in pounds
E = Free recoil (product of equation above)

Note 1: Since Row 1 was used for headers the first row with calculations is Row 2 (hence cell reference A2, B2, etc.)

Note 2: The 4000 constant for the velocity of gas is from the NRA Fact Book (1988). For decades I�d used the 4700 figure (which is used in most ballistic books), but have recently modified the formula to reflect that data. The NRA Fact Book (1988) gives the following estimates for p. For small arms, the gas velocity is about 4000 fps for smokeless powder and about 2000 for blackpowder. For cannons 4700 is used. Other references give only the 4700 fps figure.

Here's another. I like the felt recoil explaination below the calculator:

http://www.handloads.com/calc/recoil.asp

Here's the thing about this...

In all the years of reading about recoil, and solutions to mitigate it, I can't recall ever coming across reducing bullet weight.

New stock, new fangled recoil pads, counter weights built into stocks, new rifle, heavier rifle, shoulder pads, and the latest one being reduced loads. One thing in common with most of these suggestions is that, to one degree or another, they cost more money...in some cases, a lot more money.

Certainly with the rising popularity of light weight rifles, recoil becomes even more of a potential issue, particularly with magnum calibers. Knock a couple pounds off in the afore mentioned calculator, and watch felt recoil jump! I know from experience that, even with a Limbsaver installed, a T3 in .300 WSM off a bench still generates a fairly sharp bite.

While nobody really remembers how hard a rifle kicked in the moment of truth out in the field, prerequisite practice at the range is another matter entirely. It's here where flinching develops, and hunters can become gun-shy, which in turn can seriously affect their accuracy in the woods when it really counts.

Using the calculator, it becomes quickly apparent that a combination of mildly reducing a load and using a lighter bullet can even further mitigate a substantial amount of recoil.

All that said, one still has to think about the game one is after. A 130 gr. cup & core bullet, out the tube of a .300 Magnum sizzling along at 3400 + fps probably isn't ideal for 200 lb whitetails, as it has a good chance of splattering into little pieces on impact. A better option probably would be something like Fusion 150s, the quality of which are arguably suitable for pretty much anything short of big bears.

I'm old enough to remember the days when 180 grain bullets for the likes of .303 Brits, 30.06 and .300 Win. Mags were basically a given for pretty much everything. Wasn't something anyone even bothered to debate.

But that's just not the case any more.

And of course, we all know some guys would rather chew their arm off at the shoulder than, Gods of hunting forbid, admit that...yes, often due to getting older...recoil is for some damned reason becoming a bit of an issue.

For them, this solution offers an out without having to explain to anyone the real reason behind it.

I would be Intrested to hear the logic behind this statement

From everything I've read, cup & core bullets and relatively extreme speed don't work that well, as they can quite literally blow to pieces on impact, particularly with bone.

Personally witnessed an occasion in which my hunting partner...who handloaded, usually to maximum heat...smacked a small whitetail deer in the lower neck with an 80 gr. Hornady out of a 6mm at about 80 yards. Basically zero penetration, but wiped out a remarkably big section of flesh just below the hide. Was enough to still kill it, but we had to spend some time finding it. Bullet shattered.

Wouldn't have happened with a quality bonded bullet...something that was still in its birth stages of development way back then in the early '80s.

Yes, 80 grains 6mm is somewhat lighter than 130 gr. .308, but my understanding is that the dynamics are somewhat the same.

And I've killed numerous deer, most DRT, with 117 gr. Sierras pushing 3000 fps from a 25.06.

Beyond 3000 fps, I'm of the opinion that better quality bonded bullets that reliably expand and hold together are in order.

Bad bullets happen, Just like anything else some fail. Below are pics of a 120 gr Hornady .257(25.06) from the same time frame. Recovered from a buck at 185 yrds. Velocity was 2900.







As your buddy, something happened. Called maufacturing failure. I have also pushed Cup and Core bullets past 3100+ on many occasions and had no failures. Not saying you are wrong, just fail to see the velocity cutoff point.

I've seen similar failures with my 25.06. Separated, cores torn in half. But still got the job done because they penetrated far enough first.

What's the magic cutoff number? Hell if I know the exact answer to that, but from what I can gather, failures increase with speed. And also, I believe, with relatively light for caliber bullets. Sectional density and all that stuff.

Too many factors involved to write off failures simply to manufacturing process. The faster they move, the harder the impact, the greater the stresses upon the bullet, the greater the chance for failure.

Which is why, first "core locked", and then later on bonded and monolithic bullets came about, and have changed...for the better...the way we might approach the subject of bullet weight.

The 130 TSX turned my -06 into a kitten, and we plan to run the 110TTSX soon, just to see what it does.

Overall, it makes an -06 into a 243, so I've just been running that instead.

Bullet weight makes a huge difference in felt recoil.

Bullet weight indeed makes a huge difference ... and with todays monolithics, performance need not suffer either.
Cheers...
Con