Anyone having pressure issues with the Remington 700 SPS Tactical AAC in 308 Win? I'm trying to figure out why my nephew's rifle won't shoot well, and got a surprise today.

He reported getting 2 - 6" groups at 100 yards, and I offered to see if I could sort it out. The rail, mounts and scope are pretty top end (Zeiss V6 5-30) so I didn't think that was the issue. Made sure the torque settings were correct for those. Noted that the bedding screws were really overtight, so reset those. Noted the lack of a free floating barrel, and thought that may be part of his issues with accuracy.

So I went to the range with 3 kinds of factory ammo. Black Hills match 175 grain HP, Federal Premium 165 grain Sierra GameKing, Berger Classic Hunter 168 grain classic hunter. I had some of each since I had been tinkering with my own Remington 700 5R and Kimber Mountain Ascent. So I figured I would shoot a few of each and see what it liked.

First shot with the Black Hills and I had difficulty raising the bolt. Sure enough, the primer was extruded noticeably over the firing pin, and there were nice shiny marks on the base of the case. Didn't feel the need to get brave and fire a 2nd one !

Next tried the Bergers and got a 1.5" group for 3 shots. Then tried the Federal and the second shot resulted in a sticky bolt. Case again showed signs of pressure with the bolt face making those shiny marks on the base of the cartridge case. Put that one up as well.

Then shot the Bergers again, this time with a suppressor just to see if it mattered. Got a 3" group this time, and the third shot was again a bolt that was hard to raise. Along with shiny marks on the case.

I told my nephew to take the rifle back and see what they can do for him to get money back or trade in. But don't keep it! Today was a nice cool day in the 50s and I'd sure not want to try my luck when it's hot outside.

By the way, my 5R shoots well under a half inch consistently with Barnes TTSX, Lapua brass, match primers and Varget powder. So I know when it's me not shooting well and when it's the rifle. Plus the pressure signs - scary!!

What would likely be the cause of this high pressure signs? Chamber undersized or what? Thanks for the help in advance.

Three different types of ammo
all too hot? Doubt that part very much.

Has to be the gun.

George

Soot a bullet on a Black Hills round chamber and extract and see if the rifling is engraving on the bullet. Nil leade could see bullets jamming in the rifling and raising pressures to hell. Do the rounds chamber freely?

Tight neck? Measure the neck on an unfired case and one that has been fired to see how they compare. Also may be a short lead as eagle said.

Chambers easily, but that was a great question. Also I cleaned the chamber and bore thoroughly before I shot it. So don’t think it’s a dirty chamber or super short leade.

Hmmm - I can measure the gap to the lands for a couple of bullets and see if that yields any info. Think I’ll give that a try instead of recovering a bullet, which isn’t really feasible at my local range.

Rifle needs to have headspace checked.

Why would recovering a fired bullet help?
Too much guessing; let someone who actually knows something about rifles, evaluate it.

check the bore diameter for the fun of it

No answers ....

Measured the max OAL with stoney point gauge for both my Remington 5R and this AAC. Have had no pressure issues with my 5R, so using that one for comparison. Turns out the OAL is slightly longer in the AAC, so that’s likely not the issue causing high pressure.
Sierra Matchking 168 gr. Hpbt. 2.935 (AAC) vs. 2.930 (5R)
Barnes 165 gr. TTSX 3.012 (AAC) vs. 3.013 (5R)

Measured case neck diameter on fired and unfired cases. Turned out to be almost identical.
Before / after:
Eagle Eye 175 gr. Hpbt precision match. 0.334 / 0.344
Berger 168 gr. Classic hunter. 0.339 / 0.344
Federal Premium 165 gr. Sierra game king 0.338 / 0.345

My 5R has same fired case neck diameter. 0.344

Headspace measurement would be the next logical step, but I will just return the rifle for my nephew to settle up with the dealer. Interesting, though!!

Ummm - could be the bore diameter. Beyond my skills or desire, but that’s a great question.

No answers? You are expecting a diagnosis over the internet; all you get is wild ass guesses. As I said, nothing short of having it inspected by someone who actually can troubleshoot rifles, will give you the magic answer you seek. Like the place that built it.
Oh, excessive headspace does not cause high pressures.

My “no answers” comment refers to my looking for anomalies in the chamber and not finding them. Didn’t expect a diagnosis over the Internet.

This is a great forum with a wealth of experience and expertise. All suggestions or ideas are respectfully appreciated. Really just sharing my experience to see if others had something similar happen. And the bottom line expressed in my first post is that the rifle is to be gotten rid of, rather than cured.

quote:

Originally posted by dpcd:
No answers? You are expecting a diagnosis over the internet; all you get is wild ass guesses. As I said, nothing short of having it inspected by someone who actually can troubleshoot rifles, will give you the magic answer you seek. Like the place that built it.
Oh, excessive headspace does not cause high pressures.

"As I said, nothing short of having it inspected by someone who actually can troubleshoot rifles, will give you the magic answer you seek."


And who might that be, how often do we hear of firearms being returned to the maker or supplier and they don't want a bar of it? If the place that built it knew all the answers they shouldn't have built a dog in the first place. There's plenty of people on this forum far more savvy than many smiths and makers. Again, if anyone is so good they wouldn't produce duds in the first place. What's wrong with their quality control. Remington most certainly don't have a great reputation for it so you are going to ask them!!!!!!

Anything is possible. Our shop got a Remington 700 in Last year in .243 Win for accuracy issues. The barrel was unrifled (smoothbore) and .230 diameter.

quote:

Originally posted by Bobster:
Anything is possible. Our shop got a Remington 700 in Last year in .243 Win for accuracy issues. The barrel was unrifled (smoothbore) and .230 diameter.

Exactly my point, obviously nobody even looks down the barrel of a newly assembled rifle!!!!
Mind you they probably don't know what rifling looks like so no point in looking

Not to dealer, has to go back to mfg.

If it were only Federal ammo I would look closely at that. Federal supplied at least one batch of 308 ammo with case length way over spec.

You may have a defective bolt. Check fp hole for oversize .. also bolt face for perpendicularity and irregularities. Check bolt lugs for roughness or signs of deformation (softness due to heat treat excursion).

"Who might that be?"
There are several members of AR who actually know what to look for in rifles and can perform better QC than the factory can. It will require some detailed inspection; nothing submitted here, so far, is a cause of high pressure. And that inspection must include the ammo as well.
As for the rifle with no rifling; I would have kept that one as a rare collectable to a REM collector.

Yeah it was shooting knuckle balls. The owner sent a 50 yd target that had 10 perfect sideways bullet holes. Would have kept it but was warranty work and had to return to factory. Scary. Remington said they only test 1 in 200 or so, even though all carry Remington REM in an oval proofs. We are QC!

quote:

Originally posted by dpcd:
"Who might that be?"
There are several members of AR who actually know what to look for in rifles and can perform better QC than the factory can. It will require some detailed inspection; nothing submitted here, so far, is a cause of high pressure. And that inspection must include the ammo as well.
As for the rifle with no rifling; I would have kept that one as a rare collectable to a REM collector.

quote:

Originally posted by dpcd:
"Who might that be?"
There are several members of AR who actually know what to look for in rifles and can perform better QC than the factory can. It will require some detailed inspection; nothing submitted here, so far, is a cause of high pressure. And that inspection must include the ammo as well.
As for the rifle with no rifling; I would have kept that one as a rare collectable to a REM collector.

dpcd I may have misunderstood what you initially posted and took it as a bit of a put down of the talents of AR members who are offering advice, much of it will be from personal experience of various factors that can cause high pressures.
After all you did say "As I said, nothing short of having it inspected by someone who actually can troubleshoot rifles, will give you the magic answer you seek. Like the place that built it."

I took it from that statement that you were inferring the OP was wasting his time expecting to find a solution from fellow AR members and that the rifle in question should go back to Remington. Did I get that wrong?

Bolt hard to open and bright marks on ctg head not necessarily pressure .... esp since he has the same symptoms with 3 different brands of ammo. The only thing that would account for high pressure with 3 different brands of ammo would be tight bore or tight spots in bore ...

Eagle, sorry; I type faster than I think; I am saying three things;
1: No amount of guessing on the internet is going to fix that rifle. Shotgunning out potential causes is good for discussion, but none of them will pinpoint the problem. So, all this is just an exercise in words until someone can look at it. I do this kind of troubleshooting at least once a week and it can't be done by telepathy. (Ok, sometimes it can but not in this case.) On the actual rifle. In no way would I disparage an AR member, but if the OP wants his rifle fixed, it won't be on the keyboard.
2: There are definitely a few AR members who can diagnose what is really wrong, IF they can physically inspect it.
3: When I said, "Like the place that built it", that was not well thought out; I was thinking about custom rifles and not necessarily the Remington factory. So, my fault for a less than well thought out statement.

Russ,
The worst of the bunch was the Black Hills ammo, though there were some symptoms with all three. For that "match grade" ammo, the results were (1) bolt very hard to open; (2) bright ejector marks on the face of the cartridge; (3) notable flowing back of the primer over the firing pin, to the extent that the crater was visibly raised above the primer and could be felt with your finger! That's why I didn't elect to fire even a second round of that ammo.

In reloading, you don't always get clear signs of higher pressure, but when you do, those warrant backing off the load involved. That's been my experience over 50 + years of doing this, with occasional exciting mistakes !! So when I get these indications from factory ammo, and three different brands, I am indeed puzzled and am putting the anomaly on the rifle.

Also, here's what Hodgdon has on their website, regarding signs of high pressure in reloading.
"These signs include very flat primers, slightly cratered primers, ejector marks on the case head, and stiff extraction. All these case head signs indicate high pressure, and loads should be reduced until these signs disappear."

Try to take some fired, not sized brass and try to insert a bullet into the neck, normally if it won't go there is a tight neck problem. If all else fails, do a chamber cast.