10 fcp hs precision problem: shifting poi!

I did a few searches and didn't get any results, so I thought I would try a new thread.

I have a 10 fcp hs w/ nightforce f1 scope. Since new, I only have around 150 rounds through it- Black hills 175 smk. I have had a reoccurring shift in poi. I will get the rifle zero'd and then the poi will start to drop after 20 rds (slow fire). I will adjust, and adjust again. It still groups the shots, just gets lower as the gun heats up (sometimes up to 3 in. at 100 yds.) a gunsmith checked all tourque settings, no unusual wear on action, headspaced ok, bbl nut tight, borescoped bbl and nothing obvious. free floating at the bbl. Very frustrating!!! I sent the scope back to nightforce and they checked everything on the scope (awesome attention to my situation), but nothing wrong with scope. I called Savage, but the CS rep was not knowledgable enough to help. HIs only answer was " you can send it in, but we can only fire 10 rounds to recreate problem." Anyone else seen this problem? Any help would be appreciated.

sidenote: My first batch of hand loads had a fit problem. specs were correct, but couldn't close bolt on some, others could't extract without a lot of force on bolt. I've seen a thread on this issue, but didn't know if it is relevant to my problem.

You said: sidenote: My first batch of hand loads had a fit problem. specs were correct, but couldn't close bolt on some, others couldn't extract without a lot of force on bolt. I've seen a thread on this issue, but didn't know if it is relevant to my problem.

And my response to that would be a "Yeah for sure maybe". Ummm.....you definitely have a brass sizing issue if you can't close the bolt on your handloads, and\or you can't extract the cartridge (I'm assuming a non-fired reload) once you chamber the round. OR....you have the OAL seated to long and your jamming the bullet into the lands when you chamber the round (which can create a dangerous initial high pressure situation) OR your brass isn't trimmed to the proper length, and this could also create a dangerous initial high pressure situation.

So....after all of that, are you full-length sizing your brass? If so, have you tried just chambering your brass only (no primer or bullet loaded in it) into the chamber? If your F\L sizing die is set properly, your brass (once sized...and then trimmed to length...and trimmed after sizing) should "slide" right in and out of the rifle's chamber.

Check your brass sizing and post your results.

Dave

PS: Have you ever cleaned your bore with a quality copper remover solvent such as Wipe Out? I find that "new" barrels will copper up fast until they get "broken in" and the chamber marks get worked out.

When barrels are made they have a natural "bend" in them. The bend is then corrected to make the barrel straight. When the barrel is heated up through repeated firing the barrel returns back to its natural bend or "happy spot". The barrel will always shift back to origional POI after it cools. If you use the barrel to fire a few rounds here and there it will be okay. If you use it for matches and fire strings of ammunition you will notice the shift.

This is what seperates "select" match barrels from the other match barrels. The selects are the straightest barrels that when checked for runout/straightness are within spec and do not need to be corrected. Thus the barrel is already in its "happy spot". Factory tubes are usually just mass produced and screwed on. You could talk to savage about the issue. Maybe they would be willing to swap out the tube if the 10 rounds they fire are able to produce the results your getting. Ask them what there procedure is for the 10 rounds. If its fire, wait 5 minutes, fire again then chances are you'll be SOL as they wont see anything wrong.

This is just my .02 cents on your issue. I have the same rifle as you and the factory tube would shift as well. Mine would move up and left.

You mentioned altering POI after 20 rds. Does that mean after every 20rd box of ammo? All the same lot or different? How big is the group?
Vertical stringing on a new gun might be from weak strike/varying ignition, maybe look at firing pin, firing pin spring(if you are convinced it is not the ammo, the scope or other barrel/action issues).

Barrel completely floated? Tang floated? Front scope base screw not too long? Just covering the obvious here.

The barrel is free floating, but I'm not sure about the tang. Are we talking about the rear of the action, just under the safety? The front screw on the nightforce 1 piece base seemed to tighten before bottoming out, and the gunsmith took it out and checked it (i'm assuming that was what he was looking for). He is the one who cut my barel down to 20" and recrowned it. They work on AI, and HS Precision rifles, so I trust him on the basics. I haven't cleaned the barrel yet- a lot of people seem to think you shouldn't clean till accuracy falls off.

140 of the 150 rds fired were all factory ammo, and I was chronographing the first batch ( all within 30 fps) so I can't blame the ammo. The strange thing is that the groups were tight (< 1in.), but drifting down after a while. As far as the barrel goes, I don't know if they could recreate in only 10 rds. Is there a contact at Savage that Could address this problem correctly?

Dave- Sorry I didn't give more detail on the reloading, but I didn't think it was relevant. The case trim length, and COL, were good. I tried neck sizing that first batch, and I don't think I got down to the shoulder. On the 2nd try, I turned down until I was getting the brass to fit. The reloads fit better now- But not perfect! I f/l resized a box and they seem to feed normal. When I feed and extract the unfired rounds, I am getting a horizontal scratch on the bullet (reloads, not factory). I have yet to try the 2nd batch.

Thanks for the help guys!

Quote:

---

Originally Posted by COrubi06

I haven't cleaned the barrel yet- a lot of people seem to think you shouldn't clean till accuracy falls off.

---

For barrel break in I'll have to agree to disagree. Especially if your going for maximum accuracy, repeatability, barrel life span. You want that barrel as clean as possible during break-in, with nothing extra in the barrel increasing pressure on the rifling as the round travels the barrel. Hopefully each round takes off the minimum amount of metal as it passes through the barrel. The consecutive passes of a round down a clean barrel maximizes the polish of the rifling. If its not clean the fit and finish of a broken in barrel will not be as good. By not cleaning you have also left compounds in the barrel that are even now etching it. The metallic fragments still embedded within the rifling are preventing a even polishing of the barrel by the exiting round. Just my 2 cents worth... below is how my grandfather taught me how to clean rifles, though he always used old bamboo fishing poles for his rods.

I would recommend the following cleaning steps. I also suggest the use of a bore guide when cleaning especially if your going for a precision gun. Barrel down, remove bolt, insert bore guide, put empty-clean-dry soda bottle over the barrel to catch splatters. Using the largest possible/stiffest covered rod, do not use bare metal or segmented rods. Carbon fiber or nylon covered rods the ticket, you do not want to scratch the barrel. Load an correctly sized nylon brush for your caliber with Hops #9, push it all the way though so the brush exits the barrel. Pull the rod out so the brush exits rifling and is into the chamber. Repeat 5x, let sit for 15 minutes. Using a patches with a nice quality jigger, (don't use lopped patch holders) swab your barrel, the jigger should not comply exit the barrel as I'm sure you know. Once you see the tip of it sticking out, retract and replace the patch. Do this for 5-7x patches laying out the patches in order of use, normally the 5-7th patch would be a light grey.

You are going for functional clean, as compared to "white glove" clean. You do not want to use any harsh cleaners as they can eat your barrel. You do not want to remove and submerge your barrel in a "vat" of cleaning solution, nor stand it on end and fill the entire barrel with cleaner. You want to remove carbon and copper build-up and insure the even wear in of your barrel. I would clean every 5 rounds for the first 50 and every 10 till the first 100. After that you should clean after every use to insure even wear. I personally do not like to use wire brushes. I'll use a stiff nylon to hit trouble spots within the barrel itself. The barrel guide and max size covered rod that you can get to fit in your barrel, help keep metal on metal scraping in your barrel from your cleaning tools to an absolute minimum. Not to mention use of a barrel guide helps keep anything from running down into your action.

Do we have anyone from Savage on this site? It would be nice if they jumped in with some suggestions on how to get this fixed.

Quote:

---

Originally Posted by COrubi06

Do we have anyone from Savage on this site? It would be nice if they jumped in with some suggestions on how to get this fixed.

---

Haven't seen anybody from Savage on here before that I can remember, but I've only been here off and on for the last 5 1/2 years. There might be someone who has been on here during one of my periods when I was away.

Quote:

---

Originally Posted by COrubi06

He is the one who cut my barel down to 20" and recrowned it.

---

If you cut the barrel, you can call Savage all you want, they will not "fix" something that has been modified.

I don't clean until accuracy falls off. HOWEVER, only once I get a barrel smoothed out(if it needs it)
I live in the desert...What humidity? So using ammonia is fine. In all honesty, provided you get it all out, it is fine anywhere. Ammonia doesn't magically eat steel, but it does LOVE water; creating rust.

If you full length size it and it fits, it sounds like you have soft brass/high pressure, or a slightly large chamber. Another part that concerns me is the "I tried neck sizing that first batch, and I don't think I got down to the shoulder". Also sounds like you are unsure how to, or didn't read the directions on setting-up your dies.