fine tune this .308

[thomis]

Finally had a chance to stretch out to 100 meters last evening with my new Savage Model 14 Classic .308 Win.
Some background info:
Two weeks ago; When I received the gun and before I mounted the scope, I removed the stock, seated the recoil lug and bbl by pointing the bbl up and lightly tapping the butt of the stock, then replaced the stock screws. I mounted the scope (Warne bases, Leup rings, Leup vxII 3-9X40). I then took 14 shots across the chronograph to check some hand-loads and to put it on paper at 35 yards. I posted those results in this thread.

Results from last evening:
All handloads were varying measures of IMR 4064 behind a Hornady 150 BTSP.
My first group was about 7" using 45 grains. Something clearly wrong. After cool down, I shot 4 more. This time using 42 grains. Groups were a little tighter but still way off. I let my spotter shoot to see if it was me. His results were the same. Let it cool down for 20 minutes.
Next, loaded some factory Remington Core Lokts and shot a little better, a 4" group. It got me thinking.. Across the chronograph, the Rem factory loads were similar in velocity to the loads closest to max charge so I decided to try the max charge loads. Groups tightened significantly. Group size was less than 1.75". I thought I had it nailed that it liked the max loads so I shot a volley of 44 grain loads to prove my theory, fully expecting the groups to open up. That group was .75". Now confused but happy, I loaded one more time and fired one last volley of 43 grain loads. Another .75" group.

What I gather from this is that I should concentrate on a load around the 43 - 44 grain mark.

I have not cleaned the bore yet, and I plan to do so before I return to the range.

Can you spot something I'm missing or have any further advice? I'm expecting a lot from this rifle and caliber.

 

[USSR]

Something bad happening mechanically with your rifle. You don't go from a 7" group with 45 grains of powder, to a .75" group using 44 grains of powder.

 

[dakotasin]

agreed - there is an issue somewhere. i have yet to have a 1 grain difference in powder charge make a gun go from 4" or 7" down to sub moa.

suggest you make sure everything that needs to be tight is tight, everything that needs to be snug is only snug, and check over the bedding and barrel channel.

what were chrony readings?

also, last night i shot a sporting rifle match using a 257 roberts. by the end of the match the barrel was hot enough to melt rubber. my poi and group size remained constant. all that to say i doubt barrel heat is a contributing factor in groups going from 7 moa to sub moa...

 

[thomis]

When I received the gun and before I mounted the scope, I removed the stock, seated the recoil lug and bbl by pointing the bbl up and lightly tapping the butt of the stock, then replaced the stock screws.

The mounts and rings were checked prior to the range trip. The only other centerfire rifle I have called my own, was given to me used. So I never got a chance to "break it in". I'm just wondering if there was something in the bore that could have been left over from the factory that needed shot out or something like that.

At this point, all I can do is make a few more range trips until I get everything figured out.

I'm careful of over-heating the barrel because <the other rifle mentioned above> is a Rem Mohawk 600 with a 16" bbl. After two shots, the shots begin to walk badly and the thin bbl gets super hot. It is not meant to be a benchrest rifle, but a carried hunting rifle. Because of my experience with this, I'm in the habit of letting the bbl cool.

 

[sonier]

sounds like a shooter problem not the gun, i dont see why the gun would be that off, maybe you were prone shooting and the muzzle was to close to the ground i dont know, id revisit the 44 grain loadings and try again.

 

[Andrew Wyatt]

post pics of the groups if you can. were they stringing vertically a whole bunch?

 

[Al Thompson]

Agree that the powder has little to do with your results. It almost sounds like your rifle had a burr in the barrel or your scope had an internal issue that fixed itself. If I were you, I'd "box" the scope (15 clicks up, fire a group, 15 clicks right, fire a group, 15 clicks down etc., till you end up back at your zero) so you know the scope's OK.

Interesting problem...

 

[Zak Smith]

A good match quality barrel should not have its POI wander when it gets hot. POI drift due to temperature can also be due to the action warping or a stock/bedding issue. If this is all sorted out there should be basically no drift. I regularly shoot my barrels until they are too hot to grab and the POI does not wander.

 

[APIT50]

Muzzle crown issue????

 

[dakotasin]

go to the range and test out the same loads again. also as suggested run a box test w/ your scope - i suggest you do this w/ factory ammo as a time saver, but you can do it w/ handloads.

check your action screws to make sure they are snug. if they are crazy tight, back them off some as they may be stressing stuff. i've always run them just tight enough so they don't back out - it is not their job to handle recoil. if they are loose, snug 'em up a bit.

if you have cleaned the barrel, shoot 2 or 3 fouling shots thru it before you do anything else.

it is entirely possible that your initial shots just seated everything and nothing more.

i do not think it is a crown issue because of the consistency of the accurate loads.

 

[thomis]

A good match quality barrel should not have its POI wander when it gets hot.

Zak, comment noted. I would not have thought that. But my rifle does not have the match quality bbl, it is basically a pretty hunting rifle.

Someone here that I work with said I should be happy with the .75" groups from a factory rifle but I want to be able to tack drive at 300 yards so I want to see half inch, one-hole groups from this rifle.

 

[Zak Smith]

Once the reason for the huge groups is figured out, my best bet would be to try Varget and the 175 or 168 SMK in some good brass. Generally if that load doesn't work very little else would either.

 

[thomis]

The only thing stopping me from trying one of the popular SMK type bullets is that they are not approved for hunting. I plan to use this as my main go-to deer rifle so no point in even trying the SMK's if I won't be using them in the field.

 

[larbhills]

I would like to see if your groups were stringing in one direction or if they were a dispersed group.

 

[thomis]

I didn't taken pictures of the groups but they were indeed evenly dispersed. No stringing patterns were noted. I will take pictures my next trip to the range. It will be in about two weeks.

 

[WNTFW]

"The only thing stopping me from trying one of the popular SMK type bullets is that they are not approved for hunting. I plan to use this as my main go-to deer rifle so no point in even trying the SMK's if I won't be using them in the field."

What Zak is advising is to prove the rifle can shoot well. If you can get it to shoot well with SMK you can get a SGK that should match the performance. It you cant get it to shoot well with anything then you have to look at the rifle or your shooting, as a system.

Zak obviously get results. I would venture to say he does so by isolating multiple problems into singular problems.

 

[USSR]

The only thing stopping me from trying one of the popular SMK type bullets is that they are not approved for hunting. I plan to use this as my main go-to deer rifle so no point in even trying the SMK's if I won't be using them in the field.

If you want a match bullet that doubles as an excellent deer hunting bullet, I would suggest the Hornady 178gr Amax bullet.

Don