[Charlie Petty]

Oh boy do we ever… or more commonly now e-mails.

In the current issue of Handloader I have a piece on the effect of barrel length in the .45 ACP. I was able to shoot both 185 and 230 gr. factory ammo in barrels of: 3.6, 4.25, 5.0, 10, 16 and 24 inches.

Interestingly enough the 185 gr. load continued to increase in velocity with each barrel length but the 230 gr. started to slow down between 16 and 24”.

The 24” was especially cool because it was an 03 Springfield that had been rebarreled to .45 ACP.

The piece generated some interest as I hoped it would and I thought it was a fun, if not overly practical, effort.

One correspondent wanted to know what sort of groups I got out of the Springfield at 100 yd. Of course accuracy was mentioned nowhere in the story.

Another wanted to know how +P loads did. Of course I hadn’t shot any of those either. But that sparked the following rant:

I am on the record as opposed to +P handgun loads of any type with the sole exception of the .38 Special. Many years ago I did a pretty thorough cost/benefit analysis of +P ammo that appeared in The American Rifleman under the title, “The Minus of Plus P”.

When it was possible to get loads with the same bullet weight I found that an increase of 5-10% in velocity resulted in a 25% or more increase in recoil and a general decline in accuracy. The exception was the .38 Special where the percentage increase in velocity was greater than the increase in recoil.

Of course that presumes that making bullets go faster is a good thing but that is far from a universal truth. In handguns, accuracy almost always decreases as velocity increases. With the .45 ACP I’ve found that best accuracy- with any bullet weight- is usually around 725-750 fps.

Nor am I a fan of energy as a predictor of success. Maybe it is, but getting a little more does not automatically make a load better.

 

[Snake45]

Another wanted to know how +P loads did. Of course I hadn't shot any of those either. But that sparked the following rant:

I am on the record as opposed to +P handgun loads of any type....

I'm unclear, Charlie. Did "the following rant" come from some reader, or is that from you? :ehsmile:

 

[Tim Burke]

Definitely Charlie's rant.

I'm thinking e-mail makes it a bit more difficult to triage the letters... you can't immediately identify the ones that are written in crayon.

 

[SpecialEd]

Definitely Charlie's rant.

I'm thinking e-mail makes it a bit more difficult to triage the letters... you can't immediately identify the ones that are written in crayon.

"Crayon" ought to be the default font for anyone who can't answer a series of questions when first opening their email program.

 

[William R. Moore]

With due apologies to Charlie, I kinda like 9mm +P. It gets American ammo up to the velocities common in the rest of the world.

I do agree that increasing the velocity while keeping the same bullet might not be real bright. I recall a +P+ round that absolutely shredded the bullet.

 

[JRWnTN]

Interestingly enough the 185 gr. load continued to increase in velocity with each barrel length but the 230 gr. started to slow down between 16 and 24".

If the same type of powder was used for both bullets, typically there's a larger amount of powder for the lighter bullet. Would the larger charge just have more to burn in the longer barrel?

 

[Charlie Petty]

Tim got it... definitely mine. But if he had read the article he might have noticed that I didn't shoot any :evil:

The two cartridges had very different types of powder. You can't tell much by looking, but the ball load looked like some form of Bullseye, but the 185 had a ball type which was probably slower burning.

 

[William R. Moore]

Speaking of crayon......after placing my first ad when I had a shop, the first mail I got was a postcard with "Send Catalog" on it in crayon (so was my address). No return address. Figuring it was a gag by someone I knew, I kept waiting for someone to mention it but no one ever did.

While typing this, comes the dawn: I should have caught a likely suspect at a match and handed him a catalog and the card in front of witnesses.

 

[Charlie Petty]

I recall a +P+ round that absolutely shredded the bullet.

It is generally accepted that a +P load uses the same bullet as the standard pressure load and Mr. Moore has a very important observation. I've seen it in other than 9mm too.

My friend John Hall at the FBI Academy used to say, "expansion is a bonus."

His point was that the first thing a bullet has to do is penetrate enough to hit important structures and it is well established that increasing velocity and decrease penetration.

It seems as if we have conditioned ourselves to revere expansion without really understanding the dynamics of the process.

Now if the bullet is designed for the higher speed that's fine but it seems unlikely that makers would do that and- at least based on observation- that doesn't seem to be the case.

If a standard pressure load is the industry baseline then humping up the velocity may not be a good thing. :?

 

[JRWnTN]

It is generally accepted that a +P load uses the same bullet as the standard pressure load and Mr. Moore has a very important observation. I've seen it in other than 9mm too.
Now if the bullet is designed for the higher speed that's fine but it seems unlikely that makers would do that and- at least based on observation- that doesn't seem to be the case.
...
If a standard pressure load is the industry baseline then humping up the velocity may not be a good thing. :?

We've definitely come a long way in the last 25 years or so. Earlier, magazine articles and other testing seemed to emphasize expansion about all else. Some of the ammo testing only looked at how a bullet performed in 6 inches of gelatin, assuming further penetration was unnecessary or even excessive.

I recall back in the late 1970s-early 80s, there were problems when the same bullets were used in .38 Sp. +P and .357 Mag. At least one company (maybe S&W?) said they used different 125 and/or 158 gr. bullets in the two calibers to optimize results.

A friend and I tried some .38 Spl. in 158 gr. JHPs and found very little expansion in wet newspaper. The 125 gr bullets in that caliber expanded some, but the bullets of either weight in Magnum loads looked like the photos from gun magazines.

I also noticed that the Magnums using 110 gr. bullets didn't have as much recoil as 125's. The factory charts showed the lighter bullets had lower muzzle velocity. I remember one or more writers at the saying the lighter bullets would fragment and penetrate very little if loaded to true Magnum pressure.

 

[William R. Moore]

It is generally accepted that a +P load uses the same bullet as the standard pressure load and Now if the bullet is designed for the higher speed that's fine but it seems unlikely that makers would do that and- at least based on observation- that doesn't seem to be the case.

If a standard pressure load is the industry baseline then humping up the velocity may not be a good thing. :?

That used to be one of the advantages of the 9mm over the .38 Special: there wasn't a 9mm Magnum, so the bullets were designed for the rather narrow velocity window of the 9mm.

Jacking the velocities up to +P levels didn't seem to generally do much more (in the bad old days) than make expansion more probable. On the other hand, there was a definate limit on how much additional velocity insured expansion while slightly reducing penetration within desirable ranges. Too much velocity could cause loss of bullet integrity and severely limit penetration below necessary.

 

[Al Thompson]

The ipso can also be facto too.

I have a bunch of Federal +P+ .38 Special 147 Hydra-shok JHP that refuses to open up in water. :ek:

 

[Charlie Petty]

That's a bit surprising 'cause I shot some into gelatin with decent results .

I qualified with those one time in an airweight J frame... not fun.

 

[HankB]

I'm skeptical of velocity vs. barrel length conclusions based on tests that use different barrels from different manufacturers; you're testing more than just barrel length in that case, and you're not controlling the variables. (To be sure, Charlie's article does say, prominently, "Each and every barrel in the world has its own private mix of dimensions.")

Every now an then you come across a story where someone progressively shortens and recrowns a barrel before chronographing the same lot of ammo through it - those stories make for some interesting reading.

A 10% increase in muzzle velocity for +P ammo doesn't quite equate to a 25% increase in recoil, even if you're computing recoil energy which depends on the square of velocity . . . unless the mass of the additional powder burned ups the recoil momentum enough to gain another couple of percent in recoil energy?

And as for too much velocity causing bullet failure . . . sure, I wouldn't shoot a 150 grain bullet meant for a .30/30 @2200 ft/sec through a .30/.378 at 3400 ft/sec and expect it to perform well on game . . . but +P pistol ammo doesn't come remotely close to that type of velocity increase. If kicking the velocity of a 9mm from 1200 to 1320 (+10%) is going to cause bullet failure, it would seem to be a pretty poor bullet to begin with.

 

[Charlie Petty]

I remember those too and it sure would be a better way except for one thing...

based on the average gunzine pay per article how much would one loose- even if he had all the machine shop gear needed to do it right...?

 

[shep854]

Science, Mr Petty. The pure, simple joy of learning.

Or, you can call it "performance art" and apply for a grant from the NEA.

 

[Tim Burke]

You know, most of those scientists are getting paid from somewhere...

 

[HankB]

Charlie, I thought gunzine writers just wrote an article when they wanted to pay for another African safari, buy a new Lexus 460, or build an addition to their house . . . against that backdrop, buying a barrel and progressively shortening it would cost a relative pittance . . .


:lol:

 

[Charlie Petty]

You would not be the first to question my sanity about my chosen profession but a man's gotta know his limitations...

 

[Daniel Watters]

There is a website that has been doing these inch-by-inch tests. Appropriately, it is named "Ballistics by the Inch".

http://www.ballisticsbytheinch.com/