Bolt jams 30-06 possible causes?

[Tinybear]

Was out today doing some zero confirmation/barrel seasoning and decided while I was going to the range I May as well send a few rounds through my Savage Axis II precision (30-06) and test some different ammo’s.

Well sent down 20 rounds of Hornandy white tail 180g. And it cycles fine but groupings were piss poor around 1.5-2”.

Then I loaded up some Nosler 165 grain ballistic tip ammo. Wow this stuff was dead on with great 3/4” groups. BUT!!!!! my god every round had me nearly having to beat the bolt open to extract the round. It would load fine and extract unfired rounds fine. But once fired the bolt was Jammed, you could lift the bolt like normal but could not pull the bolt back without excessive force.

Unfortunately didn’t have any other ammo with me to try after that nosler. I suspect the ammo was at fault being as the Hornady stuff function fine right before but figured I’d get a consensus here as well.

The brass looked fine after extracted and to the naked eye looked no different than the fired Hornady brass. I kept the hornady brass and tossed the Noslar stuff (Probly should have kept it to take some measurements with some calibers in hindsight).

 

[guntech]

I believe the ammo is at fault... maybe just a bit hot in your rifle. Hard extraction is the first indication of excessive pressure.

 

[bearhunter]

Did you measure the length of your fired brass, before and after shooting?

This can happen if your cases are right on what your chamber will accept, but the last bit of stretching will be enough to cause difficult opening and extraction.

What do the primers look like after firing?

 

[Grey_Wolf]

It's too hot for your gun. Stop shooting it. Had happen with an old Voere 6.5x55 - Nosler and Hornady premium ammo was too hot for it

 

[Dave_D]

Another vote for hot ammo.
My savage axis ii (762x39) had similar results with norinco red box ammo.

 

[OldDude]

Are there any marks on the head of the fired cacses? That would be another sign of high pressure.

I had some factory Hornady rounds that, on about half the rounds, left an imprint of the ejector pin's hole in the brass.

 

[Lastgun]

What were the weather conditions...Warmish ammo in hot ambient temperatures and sitting in the hot sun can become HOT ammo in a hurry.

 

[Dave_D]

Are there any marks on the head of the fired cacses? That would be another sign of high pressure.

I had some factory Hornady rounds that, on about half the rounds, left an imprint of the ejector pin's hole in the brass.

Another vote for hot ammo.
My savage axis ii (762x39) had similar results with norinco red box ammo.

Further addition to my post. It was flattening the primers. Was another sign

 

[Potashminer]

https://www.canadiangunnutz.com/forum/threads/a-cautionary-tale.2230590/#post-18569081

I do not know how modern ammo makers can set ONE COAL length on their ammo that will fit into "every" rifle of that chambering - given the variability in throat length that exists. I had thought much of the variability had been eliminated by CNC and "modern" manufacturing methods, but that might be the issue that you are describing here? If a load is worked up and tested for pressure and velocity in one chamber with .030" bullet jump, one is going to get different results in another rifle that has .020" of that bullet jammed into the rifling, with the same loading.

 

[fingers284]

I do not know how modern ammo makers can set ONE COAL length on their ammo that will fit into "every" rifle of that chambering - given the variability in throat length that exists

That is what SAAMI specs are mandated for, commercial ammo is supposed to meet their min standards. I think gun manuf try to have their chamberings cut to the same standard so they accept SAAMi ammo but play with throating & free-bore to their own preference.

 

[remington jim]

Was out today doing some zero confirmation/barrel seasoning and decided while I was going to the range I May as well send a few rounds through my Savage Axis II precision (30-06) and test some different ammo’s.

Well sent down 20 rounds of Hornandy white tail 180g. And it cycles fine but groupings were piss poor around 1.5-2”.

Then I loaded up some Nosler 165 grain ballistic tip ammo. Wow this stuff was dead on with great 3/4” groups. BUT!!!!! my god every round had me nearly having to beat the bolt open to extract the round. It would load fine and extract unfired rounds fine. But once fired the bolt was Jammed, you could lift the bolt like normal but could not pull the bolt back without excessive force.

Unfortunately didn’t have any other ammo with me to try after that nosler. I suspect the ammo was at fault being as the Hornady stuff function fine right before but figured I’d get a consensus here as well.

The brass looked fine after extracted and to the naked eye looked no different than the fired Hornady brass. I kept the hornady brass and tossed the Noslar stuff (Probly should have kept it to take some measurements with some calibers in hindsight).

Over PRESSURED ! The Nosler was factory ammo ?

 

[Dogleg]

Ammo pressure testing has a complicated formula involveing max average pressure, variability of the pressure and such to come up with a small possible percentage that is over pressure but in a range where nobody gets hurt.
Although it seems funny to say, the OPs experience is the system working. Just quit doing it.
A similar situation exists with pressure tested handload data. When the average pressure given is below Sammi its not because they are being cautious, its because the math says thats as far as they can go while staying in the good boy zone of a certain percentage hitting between max spec and proof load. Of sure theres the loads that ran out of case room before they made pressure but thats a story for another day.

 

[Tinybear]

Wow thanks.

So to answer some of the questions.

The ammo was 100% factory ammo as I’m not reloading YET. Purchased it online from a site sponsor received it the night before I went and shot it. The day was very hot (35* with the humidity) and ammo was locked up in my truck for 8hours before I went shooting (hind sight wasent the best idea I suppose).

I didn’t keep any of the brass that was jamming (again hindsight that was dumb). But inspecting it while there it and the primer didn’t look any different to me than the fired brass from Hornady that functioned flawlessly on the same day (just with poor groupings)

The rifle is also fairly new with now only 140 rounds down the pipe.

I don’t have any more of that particular round but do have 40 rounds of Noslar Ballistic tip 180g I’m hesitant to try now. All other ammo’s I have fed this rifle functioned fine, Remington core lock 150g,165g and 180g, Hornady American white tail 180g, Hornady precision hunter ELDx 178g

Hoping to hit the range next week again and will go back out with some of the Hornady precision hunter and maybe try one of the Noslar 180g rounds and a couple PPU rounds made for the M1 garand.

 

[DGY]

The fact that the ammo was in the car for that long m(could have been well over 40*c in there) would make a difference for sure!
Try the same ammo in the same rifle under normal temps and you will most likely be fine!

 

[SuperCub]

I have taken ammo to the range in small cooler with freezer packs to keep it closer to the temps it would be used at in the fall.

 

[Mogulrider]

Most likely hot ammo.