Shoulder question

[Wjro]

Reloading for bolt action 50 bmg. Using once fired brass from Hornady Amax 750 fired from that rifle. Ran it through Lee collet die which sized the neck just fine. Tried to chamber it, uncomfortably tight. So I got to measuring. All I can find is that where the shoulder meets the body on all the fired brass, including one's I didn't run through collet die, is about .008 to .010 wider than on unfired or full length resized brass where the shoulder meets the body.

So I set full length sizing die 3 turns out and started working my way down. It won't chamber easily until it's about 1/4 turns past die-shellholder contact. It measures about .004 longer, with comparator, than totally full length resized, where I went about 1/2 turn past contact.

So I'm confused. I thought fire-formed brass should fit with neck sizing, at least once or twice. Anyone have thoughts/suggestions?

 

[dcloco]

Not always. Depends on the chamber cut, the brass, load, and pressure generated.

 

[Mk-211]

What kind of 50 BMG rifle do you have?

Yes, you should be able to neck size a couple times and then you'll need to full length size the brass. You'll also have to trim the brass back to 3.90" after full length sizing them.

If you're going for accuracy, you'll need to full length size your brass every time you reload it. If you're just neck sizing, how far down the neck did you adjust the die for? I have a dedicated neck sizing die for my press (RCBS) and adjust it to about 1/16th of an inch above the bottom of the neck.

What kind of projos are you loading, AMAX, ball, AP...

 

[Walkalong]

Just full length size the cases and save the headache.

 

[Wjro]

Thank you for your replies! Rifle is an AX 50. Brass is from Hornady AMAX 750, loading AMAX 750s. Am definately interested in accuracy, just trying to extend brass life. I think the brass stretches about .008 from factory Hornady. But full length resized is about .008 shorter than factory Hornady. So that'd be a stretch of .016.

What's weird, to me at least, is when I examine the brass after firing, the shoulder/body junction is wider by about .008 so that when I put the comparator on it, you can see the difference.

FLRS makes them chamber easily, but I'm thinking I won't get too many firings out of them. Unless my comparator readings are screwy due to the change in diameter at shoulder/body. I can cram the bolt down on neck sized only, but it is very stiff.

 

[Mk-211]

One of the things that you can do is to rotate the brass, size it and the turn the brass 180° and then size it again.

I know it sounds weird but when it comes to .50 brass, it's something that reloaders have been doing for years.

Another way to help extend brass life is to anneal the brass. Some guys do it every firing, some every 2-3 firings.

Depending on how hot you're reloading your rounds can help extend the brass life. I usually use 215 grs of powder for my loads, that will get any bullet well past 1000 yards easy. It doesn't beat me up, the brass or my rifle (AR-50).

 

[H&R Glock]

(My) LAR has a tight chamber and I had to FL size all my brass. Brass that was shot in my buddie's custom 50 caliber would not chamber in my gun even if I FL sized it. (it was blown out in all directions)
I don't think the 50 BMG ever had a standardized chamber specification when I was reloading same. I only shot 205 grains of IMR-5010 under every type of bullet available. It always poked holes on the paper target at 200 yards.
You may also have a tight chamber.

 

[Mk-211]

The issue with your LAR and your friends custom rifle might've been in the neck area. If he had a match chamber, he might've had to turn the necks on his brass.

If he did, that would be a reason why it wouldn't chamber in your rifle. It would also make it seem that it blew out in all directions.

 

[Wjro]

One of the things that you can do is to rotate the brass, size it and the turn the brass 180° and then size it again.

I know it sounds weird but when it comes to .50 brass, it's something that reloaders have been doing for years.

Another way to help extend brass life is to anneal the brass. Some guys do it every firing, some every 2-3 firings.

Depending on how hot you're reloading your rounds can help extend the brass life. I usually use 215 grs of powder for my loads, that will get any bullet well past 1000 yards easy. It doesn't beat me up, the brass or my rifle (AR-50).

I was trying to reproduce the numbers from the factory Hornady ammo so I could shoot either with same POI. I called Hodgdon and verified that 233 grains of H50 was the max with 750s, they verified that it was. I chrony'd the factory AMAX at avg MV 2611 fps. So I started at 214 grains and went in increments of 214/220/224, with my highest being at 227.5, which QL said should give me about he same MV and it fell on a calculated node. In thinking about what you said, I went back and checked the fit of the unsized brass in groups each of the firings...227.5 was the worst, and each lower increment was a little better. My numbers at 227.5 averaged close to the same MV, but something was off because my ES and SD were too big. But I was getting a little beat up by that point so that might have been part of it. IDK, I'll try the 180 turn with the die out a little more and see if that helps.

 

[Mk-211]

What type of case lube are you using? When it comes to 50 BMG, the two standards are Imperial and Unique.

Also, when loading the AMAX, what are you using as a overall loaded length? If you're using 5.45" you'll need to do some adjusting. With the AMAX as long as they are, they get stuffed in the case pretty deep. This can raise the pressure of the loaded rounds.

You can try using a marker and run it around one of the AMAX projos. Seat it in the case further out until you see rifling marks on it. From there you can back off 10-30 thousandths and see what type of results you get.

 

[edwardware]

. . . but I'm thinking I won't get too many firings out of them.

That's entirely dependant on how far you're moving the shoulder back, and possibly reducing other case dimensions. If total sizing reduction is minimal, then they'll reload many cycles.

With brass that expensive, you might want a custom sizer. . .

 

[Wjro]

What type of case lube are you using? When it comes to 50 BMG, the two standards are Imperial and Unique.

Also, when loading the AMAX, what are you using as a overall loaded length? If you're using 5.45" you'll need to do some adjusting. With the AMAX as long as they are, they get stuffed in the case pretty deep. This can raise the pressure of the loaded rounds.

You can try using a marker and run it around one of the AMAX projos. Seat it in the case further out until you see rifling marks on it. From there you can back off 10-30 thousandths and see what type of results you get.

Lube is imperial. Fir the ones I made I comparator-matched the COAL. There's about 0.5" jump at factory COAL, but they shoot well especially given I'm still learning how to effectively manage the recoil. I mocked up a round where the jump would be 0.05 or so and they fit in the magazine, but it only leaves a little bit of bullet in neck. Looks bizarre too.

 

[Wjro]

That's entirely dependant on how far you're moving the shoulder back, and possibly reducing other case dimensions. If total sizing reduction is minimal, then they'll reload many cycles.

With brass that expensive, you might want a custom sizer. . .

Yes, I was kicking around getting one made from a chamber cast given the fire formed brass doesn't fit so well.

 

[edwardware]

Yes, I was kicking around getting one made from a chamber cast given the fire formed brass doesn't fit so well.

Not a cast. . . a sample of 3-5 fired cases.

I'm still learning how to effectively manage the recoil.

Yeah, I'll bet. I'm still mid-learning curve on my .375H&H.

 

[Mk-211]

I forgot that you're fighting a magazine restriction on overall length. If you want to play with longer lengths, you'll need to load them one at a time into your chamber.

That will help you find the potential accuracy of your rifle. It's a lot of money restricting AMAX to mag length.

 

[Walkalong]

I think the brass stretches about .008 from factory Hornady. But full length resized is about .008 shorter than factory Hornady. So that'd be a stretch of .016.

Don't screw the die down all the way.

 

[Mk-211]

Another option is to check out companies that make turned solids for 50 BMG. Lehigh Bullets makes a 650gr brass solid that should fit your mag when loaded to the cannelure.

I would use a light crimp just to keep the bullets from pulling out of the case from recoil.

 

[243winxb]

Fired brass may not chamber if, the chamber is oval or if the bolt face is not square to the chamber.

Put an index mark on the case head, fire , extract, try to chamber case again without turning. If it goes back in, remove, turn 1/4 turn, try to chamber.

 

[243winxb]

Lee collet die

May not size the case mouth fully. So Lee said. https://support.leeprecision.net/en/knowledgebase/article/updated-collet-neck-sizing-dies

As said, just fl size. Good neck tension is needed. May not get it with Lee collet.