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I am definitely contacting Savage tomorrow.
I did the swab in the barrel about 20 times and it is an 11" twist. I think I even called about this back in March before I bought it because they list 2 different 7-08's on the savage website with diff sku #'s.
Thanks for the help on this, you all definitely know your stuff.
Swap the scopes and use the known good scope and see what it does. Many possibilities covered already. I have an 11FL that drove me nuts. Four inch groups with handloads that shot an inch and a quarter in a handi rifle. I shortened the base screws and action screws, floated the barrel, changed scopes, inspected the crown, etc. Turns out that my problem was the bolt handle cut-out was off. The stock started out as a right hand stock and they filled the original slot and cut a new one on the left side. Unfortunately, it was almost a quarter inch too far back. The bolt handle was binding against the front of the cut out. I found it only because my buddy put a rattle can paint job on the stock and I finally noticed the paint was rubbed off at the cut-out. I filed out the slot and that dog became a .75 shooter.
You may also want to try a slower moving projectile. It helped my with my 30-06. I slowed the bullet down a few hundred FPS and my groups tightened up 3-4 times. Its now shooting .345" groups at 100 yards for me.
If the twist being too slow is the problem, I think slowing the velocity down would only make it worse.
I think. ???
I called Savage 10 minutes ago and explained the situation, gave them the serial number, etc... The service rep said my options were to send it in and they will look it over and see why it is inaccurate and fix any problems, and they would send a target with the ammunition they used to test fire it. I asked if he could tell me the twist rate and guess what, it has an 11-1/2" rate of twist. They said the gun was made in 2010 and probably in the (Davidson's)warehouse for a while and since it was sold to them and resold to me they couldnt do a rebarrel under warranty.
So then I called Davidsons and asked if they could tell me the rate of twist on the gun. 1 in 9-1/2" twist. Wrong. Davidsons is manning up, taking the gun back, having Savage re-barrel it to 1 in 9-1/2 and shipping it back. I'm figuring I'll have it back by next deer season. Anyway Im happy with the outcome, could've been worse.
I'd at least try a few 120's before you send it back.
+1Quote:
Originally Posted by keeki
Faster twist for heavier bullet. the heavier you go the slower. so slow down a lighter bullet to achieve the speed of the heavy one. There is a table on http://www.riflebarrels.com/products...wist_rates.htm that may help.
to stabilize a long bullet, it has to turn at a higher rpm than a short bullet. the faster it is moving, the higher the rpm.
He might be shooting to light of a round in to fast of a twist
Cmorsch, with all due respect, I think your logic is faulty here. Bullet stability is a complicated product of bullet diameter, length, speed, and rate of rotation. You are changing two variables - speed, and length of bullet (lighter). Any gains in stability in this case will be due to using a shorter projectile, not from SLOWING DOWN a shorter projectile. In other words, slowing down a shorter bullet just for the sake of matching the velocity of a longer bullet, is not going to make the shorter bullet more stable in flight.Quote:
Originally Posted by cmorsch
Over-rotation of any bullet (too much velocity for a given twist) can make it slightly less accurate than if it was within its optimum RPM's, and in extreme cases can actually make the bullet disintegrate in flight, but it will remain stable (spinning on its axis) up to that point.
The problem the OP is having is on the opposite end of this spectrum. Keep in mind that bullet stability and accuracy are separate issues. Stability can and does ultimately affect accuracy, but there are a host of other factors that affect accuracy. Stability is required for the bullet to remain spinning on its axis, or else it begins to tumble in flight. Slowing a given bullet down if it is already on the verge of instability, will only make the condition worse, resulting in key holing and very poor grouping, which are problems the OP is already having.
Shooting a shorter, lighter bullet at HIGHER velocity, such as a 120 gr in this case, should improve stability, and accuracy in this case, and is something that has been mentioned many times throughout the course of this post. Apparently the OP does not want to do this, as he has not responded to these suggestions yet. That is understandable if he only wants to use 140gr bullets, but the only thing that would help in that case would be to push them faster, which would require handloading, and may push the envelope of safety pressure-wise.
+1
Barrel-nut I am following what you're saying. I didn't plan on using any ammo lighter than the 140 range, I want the gun for deer hunting and at a range no greater than 150-200 yards, most shots I take are between 50-85 yards and rarely a long shot on an exceptional animal(big buck).
My long time deer rifle is a Remington 7600 308, a pump action by the way. I use 150 grain Remington Core-Lokt off the shelf ammunition. Before that I used a Rem 760 in 30-06, again 150 grain ammo nearly identical performance, the later rifle was retired after three generations hunted with it. So 140 is as low as I want to go, I could use less since I hunt over farmland and not woods, I agree it's worth looking into but I want to stick with what works for me. I know what the 308/30-06 150 is capable of and the ballistics are similar to 7-08 140's so thats where I want to stay.
I did use Hornady Superformance GMX 139 Gr which have a velocity of 2910fps, about 110 fps faster than the Winchester 140 Gr Ballistic Silvertip, and the groups were larger than any other slower ammo and the bullets were key-holing the target.
I was wondering if a BoatTail bullet would make a difference in accuracy in the 1 in 11.5" barrel.
the boattail is longer which requires more twist. The longer the bullet the more the twist, so you could probably stabilize a 140gr round nose, but who wants to do that
I appreciate the advise as far as hands loads and lower grain bullets and for some it works fine. I dont load or reload rifle ammo but I can understand and benefit of creating custom loads for ones gun and the satisfaction of making the optimal round for your gun. At one time I loaded shotgun shells when I was skeet and trap shooting and I developed my own load for each that I was quite proud of. So for those that offered their advice in that regard I thank you but I am currently limited to what the store shelf has in stock.
I am hoping that the problem will be resolved when the 1 in 9.5" twist barrel is put on the gun.
" I am hoping that the problem will be resolved when the 1 in 9.5" twist barrel is put on the gun. "
Good decision you will not regret.
Again, as I explained in post #17, the reason the 139 gr GMX didn't stabilize well is that it is VERY long for its weight due to its lead-free construction. Remember, stability is dependent on velocity, bullet diameter, bullet length, and barrel twist. A short 140 gr bullet like the Core-lokt is easier to stabilize, even though it's moving slightly slower. If you could push the core-lokt a couple hundred FPS faster, it just might give you the results you want, but I doubt that could be done safely pressure-wise.
I agree completely about the 30-06 150 Core-lokts working very well in Remington rifles. They are as accurate as any other factory ammo, and better than most. The terminal effects are devastating too.
The rifle returned from Savage last week with a new 1-9.5 twist barrel. I checked it with the swab down the barrel, at the gunshop, just to be sure.
Unfortunately, when I opened the box and took out the gun the first thing I notice is a gouge in the forearm near the magazine well. Upon further inspection I found a dent near the pistol grip and the checkering on the bottom of the forearm was flattened like it was scraped across a table edge. There was also the residue of the savage logo sticker on the stock which had collected dust. I took that sticker off my gun and cleaned the residue off with Rem oil, and oiled and cleaned the entire gun. This gun was covered in dust.
So, to make it short, I am now returning the stock to Savage for a replacement. I dont know what is going on with Savage or Davidsons but this is ridiculous.
So they gave you someone else's stock?
Does the serial number match your original serial? Maybe they sent you the wrong gun all together.
The serial number matches, the stock was beat up somehow. Savage said they no longer make or have a stock like the one that was on the gun, the stock has been redesigned and the replacement they have is different from the original.
Sorry, haven't looked at this posting in a while. Yes, I handload and haven't used factory ammunition in many years. Off hand, I don't know of a source for 120 gr factory loads.Quote:
Originally Posted by barrel-nut
Sav101 , I'm not familiar w/ your particular stock configuration. But, you might find a replacement at Numrich arms. Nice to hear Davidsons backed you up even if Savage wouldn't. Sorry you had such a hassle getting it all resolved.
If you removed the barreled action from the stock (say, to adjust the Accu-Trigger), be sure you re-installed it using the proper procedure:
Drop the barreled action into the stock.
Start the action screws just far enough to catch threads; be sure you have the screws properly oriented (they are not the same length).
Holding the barreled action in the stock with your left hand, lift the rifle out of the rifle vice (or rest) so that the muzzle is pointing up and the butt plate is on the bench.
Apply moderate pressure on the barrel so as to force it aft (toward the butt plate).
Tighten the front action screw to about 30 in-lb.
Tighten the rear action screw to about 20 in-lb.
Now check that the barrel is free floating, and then check that the tang is free floating. Savage usually does a good job floating the barrel, but it is not uncommon that some relief of the stock may be needed to fully float the tang.
If you have to remove the barreled action to open either the barrel channel or the tang relief, re-install using the above procedure.