Strange issue

[linksmechanic]

I am reloading for a .308 ltr with lapua brass, 155 bergers, fed gm210's and 46.5 grains of varget. Now I know I'm close to max. Here's the issue about every other to every 2 rounds are hard to eject. The ones that are easy there is no extractor marks or any other pressure signs. The ones that are hard the entire case head is shiny, not just an extractor mark. there is also brass color on the bolt face. What's strange about this also is that I just bought the rifle new and it had alot of brass color on the bolt face right out of the box. Any ideas? I've checked my powder measure and the simple things. i have no blown primers or pierced primers. Very strange to me.

 

[esshup]

How does the fps from your gun correspond to the listed fps for that load?

 

[J E Custom]

I would look at the case neck length compared to the neck length in the chamber.

Some rifles have short necks and if the brass is to long it will raise pressures.

One way to check this is to take one of the cases with pressure signs and try placing
the bullet of a loaded round in it. If it's tight or wont go it is because the short neck
chamber tends to crimp the case neck at the mouth.

The way to fix this problem is to deepen the neck of the chamber or trim the brass
until this problem goes away.

Also if you have a tight neck chamber you may have to neck turn all of your brass.

Just a thought

J E CUSTOM

 

[Kiwi Nate]

46 grains of Varget is a mild load- have had a run of .308's through the workshop of late and all reach absolute max (but still OK) at 50 grains compressed with mild pressures at around 48 grains. That said, All were Remingtons which have a freebore of 100 thou. On the other hand, Varget is very consistent, extremely temperature stable and not prone to sudden spiking when used in low capacity cartridges.

Sometimes, a rifle will have a minimum throat- saw that on an A-Bolt a while back. The throat was too short- even by SAAMI standards. With factory .270 Win ammo, the bolt locked up every now and then.

Regardless, I am constantly being proven wrong by other factors. One of these factors would be seating depth. If you have micalculated the COAL and the bullet is jammed hard in the lands, it will casue pressure spikes and stiff extraction with near max listed loads- every couple of shots. I just had a hunting client arrive with such a load- had his seating die set up for Nosler BT's but loaded a batch of Partitions for the hunt.

Something is definitely wroong and as esshup said, you need a chrony as an aid to pressure/ velocity. It may sound silly but you would be surprised how many times people get caught out by decanting powder into a more user friendly container but then get the labelling mixed up- especially if the label is on the lid. Might pay to double check that.

Someone else mentioned your brass- if it is too long, it will pinch the bullet and trap it in the chamber.

Good luck, if it is human error- you will probably kick yourself, its always the simplest things we overlook. I just had a client wanting to show off his new Sendero to me. He wanted me to look at the bedding block and give it the once over which I did, shaped it here and there, after which I re-assembled the rifle, gave it back to him and continued my tasks for the day. I always make a point of checking that the mag box is not pinching when I re-assemble a Rem but in this case, not only did I fail to check it, I mis-aligned it- idiot. Luckily the client noticed it when he got home. He visited me today and gave me heaps of s---t.

 

[trueblue]

My guess would be your brass is a bit long for the chamber. Check your brass length on the ones that don't show pressure signs, and compare that to the ones that do show pressure signs. At 46.5gr you are close to max as far as quickload is concerned, but from what you have discribed it seems to be more of a brass length problem, but also verify your ogive measurement.
Let us know what you find, so we can all learn from it.

 

[johnnyk]

Sounds to me like the brass wasn't all trimmed to the same OAL. I set my trim-to length .010" shorter than the OAL (2.015" in the .308Win) and check each time. JohnnyK.

 

[linksmechanic]

Thanks guys. Without more testing on the range let me give some more info. The bullets are way off the lands. I was using these cartridges in a tc icon with a box magazine and I know they are quite a ways off the lands which i will correct on the next reloading. This load was super mild in the t/c so I was surprised to see the heavy bolt lift in the ltr. Also the primers appear to be flattened on every round shot out of the ltr. The same bullets shot out of the T/c are not. you can tell the entire case head is being forced into the bolt face and the primers are rough looking do to the finish on the bolt face. None of these issues are apparent on 25 rounds shot out of the t/C icon. I gotta tell you this is super frustrating. I bought the gun in a whim. It is brand new with a 40x trigger which is strange. I bought it as a quick backpack/brush guns and now I have to screw with it. The brass was all trimmed to the proper lenght before loading. The only thing I notice on the necks is slight ding from extracting the rounds. I will check my freebore tonight and post results. The thing shot real nice with some junk white box winchester ammo and had no sticky bolt issues. I wonder if this thing has a tight chamber or neck? Thanks for the help.

 

[acloco]

I am reloading for a .308 ltr with lapua brass, 155 bergers, fed gm210's and 46.5 grains of varget. Now I know I'm close to max. Here's the issue about every other to every 2 rounds are hard to eject. The ones that are easy there is no extractor marks or any other pressure signs. The ones that are hard the entire case head is shiny, not just an extractor mark. there is also brass color on the bolt face. What's strange about this also is that I just bought the rifle new and it had alot of brass color on the bolt face right out of the box. Any ideas? I've checked my powder measure and the simple things. i have no blown primers or pierced primers. Very strange to me.

You have another LTR that has headspace and/or bolt issues. I have personally seen TWO of these in the last 6 months. Advised both owners to send back to Remington.

On each rifle, only one lug of the bolt was contacting the receiver. (easy to verify with a black sharpie).

One of the rifles had been shot by the owner with the exact issue as yours...but the all of the cases were like yours.