I've just started reloading .45 ACP for a Glock pistol. I understand OAL and other measurements but also know there's a way to use my pistol to ensure the rounds feed (or fit) correctly. The last batch I shot at the range about every 3rd-4th round was jamming (failure to feed). Can someone explain precisely how to determine whether or not my reloads will work in my Glock 45? Once I know this I can duplicate this round.

Requirements for correct cycling

1. Properly resized case
2. Correct bullet shape, diameter and weight
3. Correct over all lenght
4. Adequate powder charge
5. pistol that is known to function properly with standard loads
6. So not shoot with a limp wrist.

Assuming you plan everything right you can assemble dummy loads and rack them through the pistol to test the overall length.

If you have a portable press or Lee hand press you can leave some rounds a little long.
Take them to the range and test. If the too long rounds need to be shorter seat them a little deeper with the hand tool.

My experience has been to consult several manuals for a get it close length.
Then I test the OAL by racking rounds through the gun.
I pick a starter load and load 20 then a middle load and load 20.
I run these through the gun before I load a boat load of ammo.

Be sure you have a firm grip and wrist. Limp wristing can cause jamming. I have even had a light grip cause FTF in a 12 ga skeet gun.

quote:

Originally posted by reloTD:
I've just started reloading .45 ACP for a Glock pistol. I understand OAL and other measurements but also know there's a way to use my pistol to ensure the rounds feed (or fit) correctly. The last batch I shot at the range about every 3rd-4th round was jamming (failure to feed). Can someone explain precisely how to determine whether or not my reloads will work in my Glock 45? Once I know this I can duplicate this round.

All of the above plus two more I would like to add

1- Good case gage. I use a Dillon but there are several on the market. On my my 1911 I can use the barrel but the case gage just makes it easier going for large batches.

2- Might as well buy yourself a Lee factory crimp die & bulge buster kit if you use range pickup brass. Sooner or latter your going to get a fired case from a unsupported chambered barrel from the flood of handgun sales from the last few years. I spot checked a lot of rounds from one large reloaded batch of 45acp with my barrel but not 100%. I got sucker punched. My oldest son was in the middle of a match and got one that would not go into battery 100%, had to bump it with the palm of his hand. I was embaresed as heck I front of everyone. Thats when I bought the Dillon gage and 100% of all loaded rounds get checked. The best of reloading dies will not remove the last little bit on the case head from a unsupported chamber.

Forget the case guage, you want the cartridge to fit your chamber not a gauge.
Pull the barrel out of your pistol and "drop" a loaded cartridge in the chamber. It should fall fully into the chamber with the rim just below the hood edge. If you can push the cartridge in further with a little finger pressure check the crimp as recommended. If the crimp is OK the next thing I'd look at is if the bullet ogive is hitting the lands. Color the bullet with a magic marker and do the drop check again, then look for rifling marks on the bullet ogive at the point of full diameter. Failure to run the case fully in the sizing die also can cause trouble. be sure to screw the die in until it makes contact with the shell holder with the ram at TDC then back off a 1/8 - 1/4 turn and lock it in place
Bad or damaged rims from the extractor over a few loading can cause feeding problems too. The most common in my experience is the crimp however.

Thanks. I used a Dillon case gauge to ensure each round fit. It fit even for the rounds that didn't feed in the pistol. The OAL varied somewhat for this batch of rounds although I don't know the cause. What is the variance in OAL that is acceptable (e.g. 0.001")?

quote:

Originally posted by Ol` Joe:
Forget the case guage, you want the cartridge to fit your chamber not a gauge.
Pull the barrel out of your pistol and "drop" a loaded cartridge in the chamber. It should fall fully into the chamber with the rim just below the hood edge. If you can push the cartridge in further with a little finger pressure check the crimp as recommended. If the crimp is OK the next thing I'd look at is if the bullet ogive is hitting the lands. Color the bullet with a magic marker and do the drop check again, then look for rifling marks on the bullet ogive at the point of full diameter. Failure to run the case fully in the sizing die also can cause trouble. be sure to screw the die in until it makes contact with the shell holder with the ram at TDC then back off a 1/8 - 1/4 turn and lock it in place
Bad or damaged rims from the extractor over a few loading can cause feeding problems too. The most common in my experience is the crimp however.

I was getting ready to ask about this.

The KKM barrel for my 21 has a tighter chamber than my Colt Government. My reloads go right through the Colt, the KKM is more finicky.