338 Lapua Zero Help

[trout-n-salmon]

Problem: I cannot get my rifle to group. I have shot 251 rounds through the rifle (to include break in). I have worked through the below loads and cannot get consistant groups with rifle. There are no consistency to the groups - Some are flat, some are verticle, some start to look like a group then a flier (or two). Most groups are ~1.5"-2" at 100 yards. Occasionally, I get a group inside 1", but cannot get it to repeat. I have tore down and remounted the scope, swapped to different scopes (US Optics and Leupold), still no consistency. I have gotten some great load data with single digit ES/SD which I would expect to shoot well, yet they still are inconsistent. I am beginning to think it is me, but the rest of my rifles will clover leaf at 100 yards. Has anyone had a gun that gives you fits like this? Could it be just a finicky rifle and I have not found the magic load? Any recommendations, besides keep working through it? I have heard that some rifles won't group at 100 Yards but will start grouping at 200 Yards, anyone experience this?


Rifle: Remington 700DM w/ 28" Broughton 5C barrel (1:9.4 twist) W/ 6 port brake (long Shot Rifle Built); Nightforce 5.5-22x-56mm w/ Nightforce Rings on a DE 20 MOA base

Loads:
300 SMK - H1000 88 Grains to 94.5 grains in .5 increments - bullet length 3.680 - 3.650; FED 215M primers

- 300 SMK - Retumbo 92 - 98 grains in .5 increments - bullet length 3.680 - 3.650; FED 215M primers

[Long Trang]

The fact that you 'occasionally get a group inside one inch' means your system is functioning. It is likely those times that whatever is causing your problem is not applicable when you get those tight groups.

Typically, when a shooter has such a problem, it is attributal to shooter error. However, you indicated that the rest of your rifles cloverleaf at 100. Are you accustomed to the 338? Is the rifle comfortable to you to shoot? Is it too long? Too heavy? These are contributing factors which can cause a shooter to blow groups. Have someone you know who can shoot well test the rifle. If they can't group, then you've eliminated the 'shooter error' aspect...then move on to the next likely candidate. The scope.

You said you swapped out scopes and their bases. Did you ensure you had ample torque on the scope systems? (Please don't get upset, remember...you need to cover all possibilities) are you using the scope correctly?

Once you've verified it isn't the shooter nor the scope, then look to the ammo. Some rifles like a certain type of load rather than others. You've tried two. Have you tried standard factory loads? My guess is it is not the ammo. Nevertheless, be thorough.

Finally, the rifle. Are your action screws torqued properly? If not, you may have undue stresses on the barrel. I've personally ran into this problem and it's amazing how bad grouping can be. Are you firing cold bore shots?

Most rifles are well capable of grouping at 100, so your problem appears to be a major one. If you have eliminated all other possibilities, save the rifle, and you can't determine what is wrong with it, I recommend having a qualified gunsmith check it out and look for a defect.

Good luck.

[BountyHunter]

1. Check the bedding. Is it stress free? Does the barrel move slightly when action screws are loosened.

2. Have someone else shoot it and see if it is the headspacing (operator)

Really that should be done first to determine it it is the gun system or you. Then you can eliminate the possibilities with the gun/scope.

3. already mentioned swapping scopes. Try that also.

4. If you are getting 1.5-2 at 100 IT WILL NOT tighten up at longer distances no matter it is said on the internet.

5. Double check brake to make sure not bullets are making contact with it.

BH

[Kevin Cram]

4. If you are getting 1.5-2 at 100 IT WILL NOT tighten up at longer distances no matter it is said on the internet.

Wrong
A 1 1/2" - 2" group isn't good at all but try the load that was giving you the best numbers (SD) on the chronograph and back up to 200 or 300 yards. There's a pretty good chance the bullet isn't stabilizing. Give those heavy 338's a chance settle in. My 338 Chey-Tac will only shoot 3/4" - 1" groups at 100 yards but it will shoot the same size groups at 300 yards. See what that does and let us know. Worse case send it back to Chris and let him know what's going on.

[liltank]

I'm going to throw in the stock option. Is it a factory stock bedded, or an aftermarket? Just wondering if the stock is flexing due to not enough strength in material.

Tank

[Bravo 4]

Originally Posted by trout-n-salmon

Loads:
300 SMK - H1000 88 Grains to 94.5 grains in .5 increments - bullet length 3.680 - 3.650; FED 215M primers

- 300 SMK - Retumbo 92 - 98 grains in .5 increments - bullet length 3.680 - 3.650; FED 215M primers

You have only tried one bullet and two different powders, try a different bullet. Or try seating them longer.

Originally Posted by BountyHunter

4. If you are getting 1.5-2 at 100 IT WILL NOT tighten up at longer distances no matter it is said on the internet.BH

Originally Posted by Kevin Cram

Wrong
A 1 1/2" - 2" group isn't good at all but try the load that was giving you the best numbers (SD) on the chronograph and back up to 200 or 300 yards. There's a pretty good chance the bullet isn't stabilizing. Give those heavy 338's a chance settle in. My 338 Chey-Tac will only shoot 3/4" - 1" groups at 100 yards but it will shoot the same size groups at 300 yards. See what that does and let us know. Worse case send it back to Chris and let him know what's going on.

Kevin, I believe BH means that the bullets will not magically get closer together because the bullet goes to sleep...and he is correct. If the groups are opened at closer range then that amount of damage is done. The groups will not shrink is size, but can in terms of MOA. A gun that shoots 2MOA at 100 yards can be a 1MOA gun at 200 yards if the group doesn't open. But that guns groups will not magically go from 2" at 100 to 1" at 200. No matter what is posted on the internet.

[liltank]

I agree about powder too. Try some IMR powders such as the 7828 or 4831. I have played with Hodgdon and Alliant. I went back to IMR and my groups shrunk and all shots were 3/4" or less with equivalent loads in the aforementioned powders. I am going to give ramshot a try and see if anything is equal or improves. If not, its back to IMR for good.

Tank