Way over spec 6.5 creed brass once fired 1.1935 to 1.945 oal

[Savagehunter]

I have never reloaded for an AR rifle before. I traded for an Aero m5 upper and lower 20 in barrel 6.5 creedmoor. I loaded up some of my prepped hornady brass with 123 gr noslers and some imr4064 I had as I didn't really want to use my rl17 or h4350 for this rifle. I went up in .5 gr increments and topped out at like 2700 fps. Everything fired fine no pressure signs they all cycled and the upper 2 loads grouped pretty well. Bullets were loaded just shy of mag length. No problem right. Well this was prior to covid fast forward til tonight I decided to mess with this rifle again just because. I had tumbled the 35 brass and and started to prep them. When I measured overall length they are way long like way way long 1.935 to 1.945 something seems wrong and any ideas ?? And do you think it is safe to trim these brass down and fire the rifle again?

 

[Savagehunter]

I just checked the dummy round I made for this gun and oal of the brass unfired was 1.912

 

[venatic]

You need to check your brass with head space gauge. Your chamber maybe a little long

 

[Savagehunter]

I have checked the shoulder measurement with comparator and they are a little longer than my bolt guns but I'm talking a few thousandths not enough to explain the superlong neck on this brass

 

[Old Navy]

That is a lot of growth in one firing. I have you same shooter and after 8 firings on my Lapua brass most all are 1.912 or less.

 

[Savagehunter]

I measured them all longest

 

[Savagehunter]

Shortest

 

[Savagehunter]

Longest

 

[Savagehunter]

Shortest

 

[Savagehunter]

This was unsorted brass just full sized trimmed chamfered and loaded . The longest weighs 5 grains more than the shortest

 

[PRR1957]

Possibly stretching the case neck during resizing if your using a conventional sizing die when the neck sizing button when it is pulled through the neck. Try lubing the inside of the case neck prior to resizing. I use RCBS Case Lube 2 on a nylon bore brush run through the case neck wiping off any lube that gets on the out side of the case neck then lay the case on the lube pad if full length resizing. If just neck resizing, I’ll toss the case in a bowl. I’ll also remove the neck sizing button to wipe off the lube build up after about ever twenty or so cases run through the die. After resizing, I’ll run the cases through fresh corn cob in my second tumbler to clean out the case lube. In my experience with this method, it reduces case neck stretch greatly, and reduces brass build up on the neck sizing button and galling of both the neck sizing button and the inside of the case neck. Some people use a dry lube like Imperial Dry Neck Lube sold by Redding. Personally I like using a wet lube as it removes some of the carbon from building up on the inside of the case neck. To each their own.

 

[Savagehunter]

Redding bushing full size with button removed .289 bushing. No pull on neck

 

[JohnKielly]

How does the unsized shoulder length compare with your other rifle?

 

[243winxb]

I loaded up some of my prepped hornady brass

This was unsorted brass just full sized trimmed chamfered and loaded

The 1 photo shows 1.957" . Thats .037" over maximum trim length? Something is very wrong, maybe me?

 

[Savagehunter]

Unfired shoulder measurement 1.530

 

[Savagehunter]

This brass is the same brass i have been using in my bolt guns for 3 or 4 years. Some of that brass has 6 firings on it. No issues. I have a go/nogo for my bolt actions can I try the nogo and see if it goes into battery ? I'm super confused because the shoulder being good but the neck being that long.

 

[Park ranger]

Check your calipers are out of wack. Can’t hurt.

 

[rogina]

The 1 photo shows 1.957" . Thats .037" over maximum trim length? Something is very wrong, maybe me? View attachment 1268466

Maybe, check your caliper?

 

[Savagehunter]

I actually changed calipers for the pics just for that reason I also used a dial mitutoyo that I have. I will be running the go no go up in this puppy before I shoot it again and I'm going to go shoot a single round at the 2700 fps load to check growth

 

[Webster]

I have never reloaded for an AR rifle before. I traded for an Aero m5 upper and lower 20 in barrel 6.5 creedmoor. I loaded up some of my prepped hornady brass with 123 gr noslers and some imr4064 I had as I didn't really want to use my rl17 or h4350 for this rifle. I went up in .5 gr increments and topped out at like 2700 fps. Everything fired fine no pressure signs they all cycled and the upper 2 loads grouped pretty well. Bullets were loaded just shy of mag length. No problem right. Well this was prior to covid fast forward til tonight I decided to mess with this rifle again just because. I had tumbled the 35 brass and and started to prep them. When I measured overall length they are way long like way way long 1.935 to 1.945 something seems wrong and any ideas ?? And do you think it is safe to trim these brass down and fire the rifle again?

If they chamber easily, fire and eject is there really a problem. Like someone said mayber your chamber was cut a little deeper. In a sense you may have a mini wild cat with the head to shoulder distance a little longer than normal. You measured the overall length, what's the head to shoulder distance with a bump gauge comparing a new unfired case or a case fired in a different rifle to the AR?