Tell Me Whats Wrong

[918v]

The 1.260 rounds fit the mag of my SA 911 and chambered, but they were a little shorter after cambering Two times.

Take the barrel out. Drop the round in the barrel. If the back of the case portrudes past the barrel hood, the OAL is too long. Reduce the OAL until the back of the case sits flush with the end of the barrel hood.

 

[rcmodel]

what would cause the the OAL to be shorter after chambering two times then?

What I said in post #24.

I think seating shorter will increase neck tension and may feed better without beating them into the feed ramp.

The point I was trying to make is, the bullets are already bulging out the sides of the cases, so he already has all the neck tension possible at that seating depth.
The only way to increase it now is to put more bullet shank inside the case to provide more surface area / friction with the case wall.

rc

 

[LiveLife]

rcmodel, I think we are on the same page, but talking about different things.

This is the guy with the bulged bullet base on his case in the first post.

He didn't say bulged base, just expansion of brass below the bullet.

Originally Posted by rcmodel
If it removed the bulge on the .45 ACP round in the picture?
It would also squish the bullet base undersize for the bore.

and would also lower case tension on the bullet contributing to setback upon chambering.

The 1.260 rounds fit the mag of my SA 911 and chambered, but they were a little shorter after cambering Two times.

I took that he chambered twice "without firing" and OAL length decreased, thus my comment for bullet being seated deeper into the case from the slide pushing the bullet deeper against the ramp/chamber during chambering. If the bullet moved in the case neck, then he doesn't have enough neck tension to hold the bullet.

I wasn't commenting on if he "fired twice" and OAL length decreased.

Sorry for the confusion. Maybe OP/cvo can explain whether he just chambered twice without firing.

 

[joneb]

Tell Me Whats Wrong

The round looks fine to me with the exception of the COL. I'm pretty sure it would be to long for my Colt 70 ser. chamber, and if I let the slide chamber that round the slide would not go into battery and/or the bullet would get set deeper in the case.

jibjab...I still think the managment should make that a "Sticky"....Then I wouldn't have to keep asking Walkalong for a copy of it everytime I lose it...

I have it bookmarked from THR and TFL and I always have trouble finding the darn thing.

If the bulge bothers you, try a Lee CARBIDE FCD.

That's how I know what grain bullet is in there

 

[cvo]

I chambered it twice without firing and I lost a small amount of OAL, from 1.260 to 1.251.

Previous I also stated that I hadn't neck crimped the rounds.

 

[Skip_a_roo]

If your bullet moves after chambering, you need to use a taper crimp on it. Your bullet is too long. After chambering, look at the front of the driving band. Does it have any marks on it? Take the barrel out of the firearm, drop a loaded round in the chamber. It should seat without being pushed in. If you have to push it to have the case head flush with the chamber end of the barrel, your OAL is too long.

If it were me, I would use an OAL that only left about 1/32" of the straight part of the bullet exposed. That may mean that the OAL is in the 1.200" range. If so, check your recipe to see what the minimum OAL is for that bullet and powder. Makes a big difference.

Hope this helps.

 

[LiveLife]

I think seating shorter will increase neck tension and may feed better without beating them into the feed ramp.

The point I was trying to make is, the bullets are already bulging out the sides of the cases, so he already has all the neck tension possible at that seating depth.

The only way to increase it now is to put more bullet shank inside the case to provide more surface area / friction with the case wall.

Yes, I agree.

I chambered it twice without firing and I lost a small amount of OAL, from 1.260 to 1.251.

cvo, is the OAL decreasing when you hand chamber the round because the front of the bullet is hitting the chamber/rifling/ramp of the barrel? Can you see any mark or deformation on the nose of the bullet?

 

[cvo]

I am going to set the rounds at 1.230 like recommended in the Hornady manual and crimp them. The round I pictured had no primer or powder in it.

 

[joneb]

Crimp to only remove the bell. If you want the tolerences. They are .469" to .472". No more/no less.

Measure a little below (say 1/8") the case mouth and then at the case mouth. The case mouth should be at or slightly below (.001 to .002) what it measures 1/8" down from the case mouth.

Do have any factory ammo ? See what they did.

Does it pass the chamber test?

Well does it?

 

[1SOW]

He may have been referring to that "long" round.

If you chamber it and it's a little long the slide will hammer it in a 'little'.

 

[cvo]

Yes the long round (1.260) does chamber, but with a little drag. But the 1.230 is like butter when chambering, so I will start out with this OAL.

BTW, the Hornady book calls for this OAL with the particular bullet and powder.