How do you check your 45acp for COAL?

[inkd_dad]

Started reloading for my new SA Loaded 1911. I understand that the 45 acp headspaces off of the case mouth. I cast some LEE 452-228 228gr RN bullets this evening. Could not find specific data for this round in regards to COAL. There were other similar rounds recommending between 1.250 - 1.272.

So I took my barrel out of my 1911 and started experimenting with different over-all lengths. The ogive contacted the rifling on everything above 1.210. Once I seated to 1.210 the case mouth struck first. So my question is am I checking this incorrectly or do I really need to seat these at 1.210? Does the case mouth NEED to contact the lip of the rifling to operate correctly? Is it safe to headspace off of the bullet?

I am worried about finding a safe starting powder load (cannot find a similar bullet shape that is seated this far). Any help is appreciated!

 

[chris in va]

No that's about right. You want to hear the CLINK of the case mouth making contact.

Now here's another way to look at things.



1.21 does sound a bit short. I also load the same bullet, but my OAL IS 1.23 for my CZ. The ogive on this mold is very gradual and doesn't follow the normal 230gr FMJ profile. They need to be loaded shorter than normal.

 

[Swampman]

Would it be possible for you to take and post measurements across the case mouths of a couple of loaded, crimped rounds?

 

[bluekouki86]

I'm loading 200gr .452 lead RN at 1.170. 5.4 gr of win 231 works well for me. With those bullets I had to seat to that depth to keep the bullet out of the rifling. I think you'll be ok.

 

[inkd_dad]

My case mouth width at the taper is .470, my bullet width as it enters the case mouth is .4515.

Thanks!

 

[inkd_dad]

Chris,

That very image of the four chamberings got me thinking that I may not want to be trying to have the case mouth strike the lip (first image you provided), but I may want to shoot for the third image (headspacing off of bullet ogive).

Here is a completed cartridge COAL 1.210



Here is one that was set to 1.250 and then chambered (please note rifling grooves)

 

[inkd_dad]

bluekouki86,

Thanks for your feedback, I was looking for some others real life applications in this situation. I will start low and run a .1 grain ladder as I build up.

 

[Rico567]

I just drop them in a Midway loaded round gauge, set flat on the bench; if the case head doesn't stick up, it's good to go. If I'm looking for a specific length, I check with calipers.....

 

[Jesse Heywood]

I just drop them in a Midway loaded round gauge, set flat on the bench; if the case head doesn't stick up, it's good to go. If I'm looking for a specific length, I check with calipers.....

In most cases that will work. But not all chambers are the same, and the geometry of bullet ogives can cause issues that will pass the gauge but not clear the lands.

It always pays to do the plunk test. Here's a link to the thread. http://www.thehighroad.org/showthread.php?t=506678
There's a lot more to it than the first graphic, and you need to read the whole thread to get the most out of it.

 

[Rico567]

"Jesse Heywood" says: "It always pays to do the plunk test."

I am well aware of the plunk test. I have gotten along reloading for 50 years without resorting to it, and feel that -at least for my reloading- it's unnecessary.

I also tend to believe that the word "always" is almost "always" unjustified. Like "never."

 

[steve4102]

I still see the flare on those completed rounds. Leaving the flare can give false readings when checking max OAL. What does your crimp measure?

 

[243winxb]

Measure on the bullet right in front of the case mouth. The Lee needs to measure .450" If larger in diameter, seat the bullets deeper, shorter COL. It is possible to have the lead bullet contact the rifling. This removes end play for a more accurate load. But chambering may not be 100% reliable. Home cast bullets need to be sized to at least .452" no larger & at times .451" is better. Depends on the firearm.

 

[bluekouki86]

bluekouki86,

Thanks for your feedback, I was looking for some others real life applications in this situation. I will start low and run a .1 grain ladder as I build up.

The 500 rounds I loaded and shot this weekend were pretty "real world". Happy loading and good luck.

 

[243winxb]

I measure a lswc col this way for my Gold Cup. Just touching the rifling. "] [/URL]

 

[inkd_dad]

The 500 rounds I loaded and shot this weekend were pretty "real world". Happy loading and good luck.

bluekouki86,

Looking back the sentence structure used could be read as somewhat dismissive. I was trying to convey my appreciation for your real world experiences, not stating that your info was not such. Sorry for the confusion!

Jay

 

[inkd_dad]

I measure a lswc col this way for my Gold Cup. Just touching the rifling. "] [/URL]

243winxb,

Thank you for the visual. So you are resting the shoulder of the bullet on the rifling and then setting your distance from that? Does this round sit flush with your barrel hood? Thanks!

 

[inkd_dad]

In most cases that will work. But not all chambers are the same, and the geometry of bullet ogives can cause issues that will pass the gauge but not clear the lands.

It always pays to do the plunk test. Here's a link to the thread. http://www.thehighroad.org/showthread.php?t=506678
There's a lot more to it than the first graphic, and you need to read the whole thread to get the most out of it.

Thank you very much for that link! Will research this evening.

 

[inkd_dad]

I still see the flare on those completed rounds. Leaving the flare can give false readings when checking max OAL. What does your crimp measure?

My crimp measures .470 on average. I believe I measured this one for another reply and it was .470. It does vary with different cases throughout the reloading process due to slightly different case lengths. Because I do not trim my cases (periodic case length check) the LEE Taper crimp die does not always apply the same crimp due to case length. Separate subject, but am interested in your thoughts on this as well.

 

[noylj]

There's no coal in my .45s, so I have never had to check.
COL (Cartridge Overall Length) is measured from the bullet meplat to the case head, unless you have a bushing to measure off the ogive of the bullet.

 

[bluekouki86]

bluekouki86,

Looking back the sentence structure used could be read as somewhat dismissive. I was trying to convey my appreciation for your real world experiences, not stating that your info was not such. Sorry for the confusion!

Jay

Sorry inkd dad, I took that the wrong way. This internet stuff is hard to convey attitude and can be misleading. Major apologies!

 

[7mmb]

The way I've come to a COAL with round nose bullets in 45 Auto is by measuring the diameter of the bullet at the case mouth. The diameter of the shank of the bullet should be .451". While incrementally seating the bullet and measuring the diameter at the case mouth when the diameter drops to .450" the entire shank is seated in the case and it will chamber in any 45 Auto barrel. The Xtreme plated RNs I've loaded this way come in right at 1.265" and function flawlessly and are very accurate.

45 Auto, like all rimless pistol cartridges, must headspace off of the case mouth. Don't seat the bullets so long that they engage the rifling. Not only will you have incorrect headspace but if you did manage to get the pistol into battery and fire the round you likely will have excessive pressure.

An easy way to check your seating depth is to measure the length of the bullets you are loading and subtract it from the COAL. This well give you the distance from the case head to the base of the seated bullet. If you can compare another bullet of similar weight with a known published COAL you can tell if you have a similar seating depth and can tell if you need to load your bullets a little lighter than the other bullet if you are seating deeper or can use the same weight of powder if the seating depth is the same.

 

[Swampman]

Originally posted by: Rico567

I am well aware of the plunk test. I have gotten along reloading for 50 years without resorting to it, and feel that -at least for my reloading-it's unnecessary.

Ummm... The plunk test isn't something that one "resorts to"it's simply the best way of ensuring that the loaded rounds are a perfect fit for your particular pistol.

After all, what are these rounds destined to be fired in, a "Midway loaded round gauge" or your pistol?
All Jesse Heywood was trying to say was that while the gauge is good, it's not foolproof. It's quite possible to have rounds that "gauge" perfectly, but that won't function through a pistol with an extremely short leade or tight match chamber.

I've been loading for 38 years, and while I own quite a few gauges, I've never found it necessary to "resort" to buying a "one size fits all" gauge for my semi auto handguns when they already come with a free one, custom made for the weapon.

@ inkd_dad
While you're likely to get the best reliability if you headspace purely off the case mouth, I'm betting from the bullets used that these rounds probably aren't meant for self defense use.
If they are, in fact, pure target loads, play with your COAL a bit and test for optimal accuracy combined with acceptable reliability.
My cast 230 grain round nose target loads are seated so as to just barely kiss the rifleing. Back when I used to industriously clean all of the Alox off, I'd go 5000 rounds between cleanings with near 100% reliability.
Now that I've gotten lazy and started leaving it on, I've found that I start to get some failures to fully chamber after about 1200, especially in cold weather.

Even though I can't really tell much difference in accuracy between the loads that touch the lands and those that don't without using sandbags. I'll keep loading to the lands because I like to know it's ME when I miss and not my ammo.

I'll also keep leaving the lube on my bullets because cleaning it off is time consuming, messy and boring. Plus, I'm lazy and it takes a lot less time and effort to push a rag soaked with carb cleaner through my bore every thousand rounds or so than it does to remove the lube from 1000 loaded rounds.