Difference In Effort To Open And Close Bolt; Federal vs. Hornady Factory Loads.

[Kracken McGraw]

I have a feeling, and it’s really only that, that it’s something to do with the brass. I have right at 800 rounds through the gun. Just encountered this at roughly 750 rounds in, and again only with this one Federal load. Concentrating on the throat and neck area and first 6” or so of the rifling, I clean after each 20 round range session in an effort to keep up with the carbon. Boretech C4 soaks and patches, only an occasional light JB bore paste ( blue ) at about 300 round intervals. Trying to stay away from metal brushes.

I would trust your instincts and just move away from the Federal ammo then.

 

[L.Sherm]

Berger 140's VLD in a saami 6.5 creed (.199) chamber are + or minus 2.93 OAL to the lands i will put money anything 2.80 won't touch the lands

 

[Kracken McGraw]

I’m as curious as a cat. Do the primers on the federal stuff look a lot more flattened compared to other ammo? That might indicate a hot load.

 

[L.Sherm]

A .130 freebore reamer i used for 130 VLD it took 2.86 and a Wyatts 3.0 box to reach the lands in a 6.5 Creed

 

[Turkeytider]

Since you are saying more effort to chamber live round(" no markings on case or bullets"). The extractor/case head could be a fitment issue. Stripping the bolt(just the bolt body) and test chambering a couple of the more difficult to chamber rds.
An ammo checker would probably be the easiest (safest) way for you to check headspace dimensions on a loaded round. Visual comparison and a caliper measurement of headspace is possible with cartridge specific ammo checkers. ( I use Lyman)..

Ammo checker. Might be a good thing to have.

 

[Coyotefurharvester]

Op isn't reloading, having bolt effort issue with ONE brand of factory ammo. If the bolt lugs aren't galling, the ammo checker is likely the cheapest/easiest method to check/measure the difference between the factory rds.

 

[Texas Solo]

I had the same issue with Federal 308 ammo. Bolt would not close period. Hornady, Remington worked fine. Just don't use Federal ammo. Move on.

 

[Turkeytider]

Did a little research and math. If the ogive length for the Federal ( Berger )is longer than the Hornady ( 0.703” vs 0.599” ) , would this possibly explain the difference in effort required to open and close the bolt ? If the answer to that question is “Yes “ , then would it be reasonable for me to expect the same resistance to opening and closing the bolt, regardless of what brand of brass the Berger bullet was loaded into ?

 

[Turkeytider]

I had the same issue with Federal 308 ammo. Bolt would not close period. Hornady, Remington worked fine. Just don't use Federal ammo. Move on.

It’s not so much the Federal brand with which I’m concerned, more so the Berger Hybrid Target bullet. The question is, “ Is it the bullet or the brass that is causing the heavy bolt motion ? “ For example, if the Berger bullet was loaded into Hornady, AAC , or Sig brass, should I necessarily expect the same issue?

 

[Turkeytider]

Op isn't reloading, having bolt effort issue with ONE brand of factory ammo. If the bolt lugs aren't galling, the ammo checker is likely the cheapest/easiest method to check/measure the difference between the factory rds.

One is on the way.

 

[Turkeytider]

I would trust your instincts and just move away from the Federal ammo then.

The confounding factor is that the Federal rounds are the only ones I’ve shot which are loaded with the Berger 140 Hybrid Target. It’s a good bullet.

 

[Coyotefurharvester]

Berger sells that bullet in their ammo line. 2.825 is the max coal, pretty sure Berger knows how to load within SAAMI specs.

 

[ShtrRdy]

It’s not so much the Federal brand with which I’m concerned, more so the Berger Hybrid Target bullet. The question is, “ Is it the bullet or the brass that is causing the heavy bolt motion ? “ For example, if the Berger bullet was loaded into Hornady, AAC , or Sig brass, should I necessarily expect the same issue?

Please revisit post #3. (Pull the bullet on one of tha problem cartridges and see if the new brass case will chamber easily without the bullet)

 

[243winxb]

If the ogive length for the Federal ( Berger )is longer than the Hornady ( 0.703” vs 0.599” ) , would this possibly explain the difference in effort required to open and close the bolt ?

I think you may have fround the problem? Head to ogive?

The case head to ogive may be the issue. It needs measured & compared to the SAAMI standards.
C.I.P. standards may be different?

The 6.5 CM drawing. You may want to measure the factory ammo brass Trim Length, before firing. 1.920" maximum.

 

[243winxb]

Measure the necks outside diameter of loaded rounds. Should not be larger then SAAMI .295"

 

[Kracken McGraw]

Can we see pics of the rounds that have been chambered without being fired?

 

[Turkeytider]

Man, this stuff’s really gettin’ in the weeds! Thanks to everyone, though, for contributing!

Measure the necks outside diameter of loaded rounds. Should not be larger then SAAMI .295"

Will do.

 

[David Milisock]

This reminds me of my wife when our first child was born. She had a baby monitor and it was turned up so loud that I told her to simply move my son into our bedroom so we could at least get, some sleep.

You're shooting factory ammo, there's nothing you can do about it, when you change lot numbers it has a good chance of changing. If it performs well enjoy shooting!

 

[Turkeytider]

This reminds me of my wife when our first child was born. She had a baby monitor and it was turned up so loud that I told her to simply move my son into our bedroom so we could at least get, some sleep.

You're shooting factory ammo, there's nothing you can do about it, when you change lot numbers it has a good chance of changing. If it performs well enjoy shooting!

So far, all the measurements of the rounds appear to be in spec. Just an interesting occurrence, I think, but would still like to know why. I have some of those bullets being hand loaded into Hornady brass , so that may tell me a lot as well.

 

[Turkeytider]

So far, all the measurements of the rounds appear to be in spec. Just an interesting occurrence, I think, but would still like to know why. I have some of those bullets being hand loaded into Hornady brass , so that may tell me a lot as well.

Welp, I may have ( I think probably ) found the cause for the “ snugness “ of the Federal cartridges as compared to the Hornady and AAC cartridges, resulting in the tightness when operating the bolt. At the head of the cartridges, the necks have a different diameter. The Federals measure 0.41 “ while the Hornady and AAC measure 0.40” . Not a lot of difference and both within spec. according to my Lyman ammo checker. That’s the ONLY measurement difference I’ve been able to determine as far as the brass is concerned.
Interestingly, at least for me as a neophyte rifle shooter, I wonder if the tighter fit would result in somewhat higher pressure (? ) . If so, would that be reflected in higher muzzle velocity?