Interesting day at the range (over pressure)

[Jayph]

So I had a moment of weakness in the last SFRC sale and bought a Savage 10 TR. I had a chance to grab a pair of boxes of nolser 175gr bthp match ammo and try it out tonight. I was getting signs of over pressure that I have never seen before with factory ammo.

Box 1 had 2 of 3 rounds blow out the primer with the third having heavy scorching.
Box 2 had 3 of 3 with cratered primers but none blew out

Some rounds had some resistance in chambering some were fine. Accuracy was around 1.3" CTC and 1.5 CTC which was weird with the pressure problems since most issues I googled just now complained of erratic accuracy when experiencing the same thing. My brain is telling me that it's either a bad lot of factory ammo or a throat that is too short, but this is all new to me. I never even seen issues like this when approaching max loads reloading. Obviously I shut it down after the 6 rounds.

My plan of attack
1 email photos and info to nosler in the morning
2 Grab a box of 155-168gr match ammo and see if problem persists
3 if problem persists take gun to gunsmith to check headspace and throat

Any advice, thoughts, info would be appreciated if I should do anything different than above. I have never ran into a problem like this before. This gun has been cursed since the beginning from savage not including the rail and now this.

Thanks

Jason

 

[duncansuds]

I have had this happen with Remington corelokt, you may have a snug chamber that is very sensitive to OAL. Try a different brand. Be careful, wear glasses. If you have access to a gunsmith with gauges, try that first, but I wouldn't be too scared of it. Measure the remaining shells and see if they are a little long.

 

[358 BLR]

So I had a moment of weakness in the last SFRC sale and bought a Savage 10 TR. I had a chance to grab a pair of boxes of nolser 175gr bthp match ammo and try it out tonight. I was getting signs of over pressure that I have never seen before with factory ammo.

Box 1 had 2 of 3 rounds blow out the primer with the third having heavy scorching.
Box 2 had 3 of 3 with cratered primers but none blew out

Some rounds had some resistance in chambering some were fine. Accuracy was around 1.3" CTC and 1.5 CTC which was weird with the pressure problems since most issues I googled just now complained of erratic accuracy when experiencing the same thing. My brain is telling me that it's either a bad lot of factory ammo or a throat that is too short, but this is all new to me. I never even seen issues like this when approaching max loads reloading. Obviously I shut it down after the 6 rounds.

My plan of attack
1 email photos and info to nosler in the morning
2 Grab a box of 155-168gr match ammo and see if problem persists
3 if problem persists take gun to gunsmith to check headspace and throat

Any advice, thoughts, info would be appreciated if I should do anything different than above. I have never ran into a problem like this before. This gun has been cursed since the beginning from savage not including the rail and now this.

Thanks

Jason

Funny you should mention this, Jason, I bought some "Nosler Match Grade 168gr HPBT" and when I tried to chamber them, I too had a hard time closing the bolt.
So I got the required components to use my Hornady Lock and Load OAL gauge (basically I needed the .308 modified case and the comparator set) and do some testing.
I used a Hornady 175 gr A-Max bullet to determine the length where the bullet would be contacting the barrel rifling, then used the comparator to see if the Nosler's were longer
then that and they were. So even though the "Nosler Match Grade 168gr HPBT" have a COAL less then 2.81 inches, the ogive of these bullets is so far forward that they contact
the rifling - well, on the Savage 10TR they do.
When I had a hard time closing the bolt on my Savage 10TR, I refused to use these bullets as I suspected that they might be making contact with the lands and I was right.
No more Nosler Match Grade cartridges for this cowboy...

 

[thump_rrr]

If my 10TR is any indication you are jamming the bullets into the lands.
In my Savage 10 BA my 180gr SMKs seated at 2.800 were jamming into the lands of the 10T|R
My 175gr SMK's seated to 2.800 were only 0.010" off the lands in the 10TR.
My 168gr SMK's seated to 2.800" were 0.022" off the lands in the 10TR.
Depending on the profile of the bullet you may or may not be jamming.
I would try 168gr FGMM if you don't reload.

I suspect that since they were marketing to the LE crowd they went with the assumption that 168gr and 175gr FGMM would be the cartridges of choice so they set the rifle up to get the best accuracy with FGMM.