VLD Seating Depth

[brant89]

I recently bought a Savage 12LRP in 260 Rem and have been thoroughly disappointed with it until I saw the first glimpse of hope today. I started out with Lapua brass, IMR4831 (availability), topped off with a 140gr AMAX and set off by a CCI 250 primer and could not get good velocities with that powder (not uncommon) and could no longer find that bullet in stock. So I started from scratch with IMR 4350 and Berger 140gr Hunting VLD's and got excellent velocities (+2800fps) but poor accuracy regardless of charge weight (about 1-1.5MOA) when seated about 0.010 off the lands. So I decided to reduce my charge and find the optimal seating depth per Bergers recommendations. Well folks, the proof is in the pudding. Here are two of the groups I shot today showing what a huge difference seating depth can make.

 

[brant89]

Couldn't get both pictures in the same post from my iphone.

 

[BrentM]

Yep, nice work. I personally have not had much luck with seating close to the lands.

 

[brant89]

I just hope that my groups remain tight as I increase powder charge since I'm sure my velocity is rather low with only 39.0 gr of 4350. Just need some time at the reloading bench and some nice weather to finally button up these loads.

 

[Mikecr]

What you're seeing is that seating depth is prerequisite to all else really.
Powder will be a fine tune from here.
Good job

 

[Engineering101]

brant89

Attached is pic of a group my buddy shot with his Savage LRP 260 Rem. (I have the same rifle.) The group was 5 shots, 200 yards, 0.375" center to center. The load, 40.9 grains, Varget running 3,034 fps. It does take some tuning to get the best out of these rifles but their best is pretty good.

 

[Engineering101]

Oops, forgot to mention the bullet was 108 grain Lapua Scenar

 

[brant89]

Well, as I had feared, my groups opened up as charge weight increased. I guess the next step is to load some more at 39.0 gr and see if my groups tighten back up or not. I'm seriously regretting buying this rifle.

 

[Engineering101]

brant89

If it turns out that you got a lemon you could pull the barrel and throw on just about anything you want - that is the nice thing about Savages. There are several outfits that make prefit Savage barrels including for large shank rifles which the LRP is. The basic platform is very good with the HS precision stock and target action with target accutrigger and DBM. I trade barrels on mine depending on what I'm doing from 270 WSM and the 260 Rem. I do have to swap barrels, bolt heads and magazines but that takes about 15 minutes once you have done it once or twice. You do need a barrel vice and a barrel nut wrench along with go and nogo gages to set headspace but having the capability to swap to whatever you want is pretty nice. I think my next barrel is going to be in 22-250 Rem.

 

[brant89]

Well if the 39.0 gr doesn't shoot this time around I think I'd like to find someone in the southern michigan/ tri-state area with a 260,308, etc that shoots sub-MOA to make sure it isn't just me. I like to think that it's just the rifle since my 12FCV in .223 shoots 1/4 MOA past 200yds and about 1/2 MOA out to 700 (calm conditions of course). But it's a very different cartridge too. I used to have a sporter weight .300wm that would hold 1/2 MOA at 200yds so I like to think that it isn't a recoil issue, but idk, I'm starting to lose confidence in myself over this. I've been through 300 amax and nearly 200 Bergers trying to find a decent load.

On a lighter note, I am also an engineer. Just thought it was an interesting coincidence.

 

[benchracer]

Well, as I had feared, my groups opened up as charge weight increased. I guess the next step is to load some more at 39.0 gr and see if my groups tighten back up or not. I'm seriously regretting buying this rifle.

I am a bit unclear regarding what you are saying here. Are you saying you tested all the way to max without finding a higher accuracy node? Or are you simply saying that an increase in the powder charge made groups open up?

Chrono data would be helpful here. At your stated powder charge, you should be around 2600 or so. Your next node should show up around 2700ish.

 

[brant89]

After playing with seating depth at 39.0 gr I loaded three rounds each in .3 gr increments and shot each at separate dots at 200yds, allowing the barrel to cool between shot strings. This gave me two touching and one flier at 39.3, 39.6, and 41.7. There were also a couple other groups that would group two fairly close and send one flier. In my previous load development with this rifle shooting 5 shot groups it would consistently shoot 3&2 groups showing two separate POI at any distance in a totally random order. I have been very careful when adjusting parallax and making sure I have a consistent cheek weld from one shot to the next. So far I have made sure that the tang and barrel are fully floated and I have bedded the recoil lug but no bueno. I also removed the scope and remounted it as well as making sure the action screws were to the proper spec. Still the same issue. I'm going to shoot a couple 5 shot groups tomorrow at the 39.0 gr charge weight and see what I get.

 

[brant89]

I will chrono the loads tomorrow as well but I would expect to see around 2600 as well. I do know that 41.6 (near max) gives me about 2800fps.

 

[1kbong]

i have found that seating depth is really critical for berger bullets. Not so much hornady bullets. The recommended o.a.l. for hornady seems to be spot on for depth. Also to get off subject a little bit. I am looking for reloading data for the 140gr. berger long range bt target bullet in .264. 6.5mm. I cant find anything. Any help would be appreciated.