Bullet Diameter

R

Roland Thunder

New member
I was getting ready to order some plated bullets from Xtreme and I notice that some of their 45acp's are diameter .451 while other are .452. That seems odd that they would have different diameters for the same caliber/weight. They list their 45acp SWC's at .451 and I think the lead ones I have been loading are .452

Any logical reason for this that you know of?
 
Last edited:
The "correct" dia. for JACKETED 45 acp bullets is 0.452". That is because the specified groove diameter of 45 acp barrels is supposed to be 0.452".....and jacketed bullets should be the same dia. as the barrel groove diameter.
This includes both jacketed and plated bullets.

Bare lead bullets should generally be .001" to .002" OVER groove dia. So, for the 45 acp, that would normally be 0.453" to 0.454". Bare lead bullets, at or smaller than groove diameter will skid against the rifling and leave lead in the barrel.

It is possible to shoot plated or jacketed bullets which are slightly undersized, with good results. Bare lead, usually not (but nothing is impossible).

So, as to your bullets, depending on the actual groove diameter of your barrel....the 0.451" dia. plated may work just fine. Your bare lead 0.452" bullets may or may not shoot without leading the barrel. If of a soft enough alloy....and given that the 45 acp is a low pressure round....they just might work. Or, they may lead your barrel badly.

Some bullet manufacturers are sloppy when it comes to quality control issues, such as ensuring that the diameters are correct. When bullets are cast, depending on the exact conditions and alloy used, they can sometimes swell or shrink a bit as they cool. Unless you are getting good results (and no leading) with the cast bullets you have, I'd look for some more like 0.453" in diameter, if I were you. It is possible, though, that your barrel could be slightly undersized - so they may work as is.
 
The shape and length of the bullet can make a difference, too.
For a given weight bullet, sometimes a longer one, like a semi-wadcutter, will
be as accurate as a slightly larger diameter round nose.
 
Greg, I have some .451 poly coated 200gr RN very cheap if you are interested. In my 45 they are not big enough and are extremely inconsistent in velocity and wildly inaccurate. A bullet that is too small by .001 can do some strange things going down a barrel. My target bullet is a .452 "Shooters Bullets" Blackmaxx Coated 200gr SWC bullet that I get at
http://monmouthreloading.com/shop/45-cal-200gr-semi-wad-cutter-coated/

You can slug your barrel to see what size it actually is and get the right sized slug for your gun.

BTW: I am in Suwanee
 
I was under the impression that .451 is the correct diameter for 45 ACP bullets.
Click to expand...

Yep.
.451 for jacketed
.452 for lead
For years and years and years and years and years.

But now there's the newfangled plated and coated and who knows what all else.

And of course there always was the odd duck that went and slugged their barrel so they actually KNEW what diameter bullet they needed...
 
possibly for match barrels

I believe Missouri Bullet Co. Offers lead bullets .001" smaller for .45 and .38 listing these for match barrels. I also agree slugging the barrel may justify one over the other.
 
.451" or .452" plated will work just fine. Berry's generally uses .452", Rainier uses .451", never noticed on bit of difference between them on target or over the chrono.

Lead bullets need to be a bit oversize to prevent leading, but plated bullets work well with either diameter.
 
.451 is acp. .452 is colt. In jacketed bullets the larger diameter bullets are almost always heavier so that they work with the Colt better. Look in your Lyman loading manual and see which caliber takes which bullets. Asking on here gets you two different opinions and you don't know which one is going to be right. Go to a reliable source....
 
45 auto Bullets are often marked .451. 45 colt are often marked .452". I have Xtreme PRN 230's. PM me if you want data on 10.
 
Some bullet makers will send a pack of various size and shape bullets, if you ask.
So ask and see.
Quite often just loading and trying samples is the only way to find out what combination of components works best in a particular gun.
To add to the confusion, powder choices and velocity affect the results, as well as the bullets.
When I was shooting 9mm, it took a lot of fiddling around to finally find the mix that was best.
But it was worth the effort and resulted in a vast improvement on all counts.
It was also quite surprising what turned out best.
Not at all what was expected.
 
I go by the dies, because any bullet larger will be problematic to load. The expander has to match the bullet diameter, and the sizer has to anticipate the larger expander, or the case will gall on the expander plug. The crimp is more flexible by way of adjustment, but you aren't going to get a nice roll crimp on 45 Colt unless the die is sized for the bullet diameter. That's why I use only RCBS Cowboy dies, if available for the caliber I want. On the 45 ACP, I can manage as long as I have Lyman M-die expander and I avoid the Lee Factory Crimp die with its post sizing ring that could resize a lead bullet.
 
Last edited:
If you don't have a Ransom Rest or a 2600 Club card, it is going to be hard to tell a difference between .451" and .452" jacketed or plated bullets in a .45 ACP.

On the other hand, cheap bullets in 9mm P can be a lot of trouble. I have seen more 9mm keyholes in targets than all others put together.
 
Just measured 3 Xtreme PRN 230 gr bullets....
0.4513"
0.4514"
0.4514"

done with Mitutoyo calipers, 3 measurements per bullet averaged.


These shoot well from my XD45 5".
 
Yep.
.451 for jacketed
.452 for lead
For years and years and years and years and years.

But now there's the newfangled plated and coated and who knows what all else.

And of course there always was the odd duck that went and slugged their barrel so they actually KNEW what diameter bullet they needed...
DaleA
Click to expand...
Yep, Yep, Yep. There are tons of "supposed to be" dimensions out there, and you can't know fer sure unless you have facts; measurements. Most factory FMJ or JHP bullets for 45 ACP I've measured runs .451 +/- .0005". Cast lead bullets have run the gamete from .451"-.453". I have PCed some bullets and size them just like I size my nekkid lead (.452" for my 1911s and P90).
 
You must log in or register to reply here.
Back
Top