Factory ammo hard to chamber

[Grizzlypeg]

So I treated myself to two boxes of Federal Premium Barnes Ttx 165 grain 300 wsm ammunition. The bolt is hard to close. I fired 5 rounds, accuracy is excellent. No signs of over pressure, or difficulty opening the bolt.

I used a comparator, and the unfired federal ammo measured out at 3.033". After firing, they are shorter, 3.029. and coincidentally, my hand loads that chamber just right are 3.029".

Should I contact Federal, or just put up with the hard closing bolt? Gun is a Sako A7.

 

[PlinkerFrog]

This summer there was a kid at the range who could not close the bolt on some cartridges from a new a box of hornady ELD match 6.5CM. We tried them in mine and I was also unable to close my bolt. Visually comparing with an OK one, there was no difference perceivable but we had no measuring tools on site to check properly. We told him to bring them back to the store. Someone told me that he had no problem exchanging them but I do not know what was the issue.

I was surprised ELD match is kind of in the high tier of ammo price/quality. Can you imagine you buy a box of ammo for 60$ you go hunting and the bolt doesn't close on the shell.....

In your boxes, are they all hard to close? Personally if it closes and the accuracy is excellent and there is no ejection issues, I would just shoot them. They are probably toward the max saami length and your chamber toward the min saami length.

 

[Potashminer]

OP - SAAMi does not specify an absolute length for either ammo or a chamber - they give a "range" - go here - SAAMI.org - https://saami.org/wp-content/upload...rfire-Rifle-Approved-2-10-2025-2026-04-27.pdf - page 113 is 300 Winchester Short Mag - upper part of the page is the drawing for the ammo; the lower part of the page is the drawing for the chamber. You will see that SAAMI specs minimum as 2.560" and Maximum as 2.860" on the cartridge - from case base to bullet tip - no clue where on a 300 WSM that you got 3.029" - but that is way longer than SAAMI spec - chances good the ammo that you bought is in spec - so returning what you bought is probably going to get you told it is within spec. Unless you have something different than 300 WSM; unless you measured to some different place. But at the link that I posted you will find most all centerfires that SAAMI has accepted, as of the date of that document.

 

[Deathrawt]

Maybe the oal on the factory ammo is too long for your chamber?
Does the fired brass go back in and chamber ok?
If you have a press and dies maybe push the bullet down a hair and see if it chambers better

 

[Grizzlypeg]

OP - SAAMi does not specify an absolute length for either ammo or a chamber - they give a "range" - go here - SAAMI.org - https://saami.org/wp-content/upload...rfire-Rifle-Approved-2-10-2025-2026-04-27.pdf - page 113 is 300 Winchester Short Mag - upper part of the page is the drawing for the ammo; the lower part of the page is the drawing for the chamber. You will see that SAAMI specs minimum as 2.560" and Maximum as 2.860" on the cartridge - from case base to bullet tip - no clue where on a 300 WSM that you got 3.029" - but that is way longer than SAAMI spec - chances good the ammo that you bought is in spec - so returning what you bought is probably going to get you told it is within spec. Unless you have something different than 300 WSM; unless you measured to some different place. But at the link that I posted you will find most all centerfires that SAAMI has accepted, as of the date of that document.

Those numbers are only good for comparison, not absolute, because they include the length of the shoulder comparator. They are shoulder to base using what is supposed to be the correct size shoulder gauge for 300 wsm. I'm sure you alread know this but I use them for setting up dies to only bump the shoulder .003 for instance. In this case they are telling me the manufactured ammo is longer at the shoulder than what comes out of the gun, or what I get when I full length size, die contacting the shell base.

It might just be a matter of a chamber cut at closer to one extreme of spec and ammo closer to the other end of spec. A slightly unhappy pairing.

 

[Thunderhog]

So I treated myself to two boxes of Federal Premium Barnes Ttx 165 grain 300 wsm ammunition. The bolt is hard to close. I fired 5 rounds, accuracy is excellent. No signs of over pressure, or difficulty opening the bolt.

I used a comparator, and the unfired federal ammo measured out at 3.033". After firing, they are shorter, 3.029. and coincidentally, my hand loads that chamber just right are 3.029".

Should I contact Federal, or just put up with the hard closing bolt? Gun is a Sako A7.

This is actually a very common issue with Federal factory ammunition. After firing they fit fine, eject okay, and can be reloaded. Don't waste your time with Federal, some rifles have different or tighter chambers, or even different throat tolerances. I doubt Federal would do squat.....

I just shoot them, so the bolt closes a little stiff, you will get used to this with Federal ammo........

 

[Duramax6.6]

This subject is why you always cycle all the ammo you’re taking on a hunting trip through the intended rifle you’re using.
The range or competition or hunting trip are not the places to discover these symptoms.