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WyattCE
About a month ago, I finally had the chance to shoot my first hand loads in this caliber (.338 Remington Ultra Magnum).

I bought the bullets from Lost River Ballistics (J40 target bullets @ 250 gr).

IMR 4350 (I forget the exact amount of powder I used at the moment, but I know it was roughly in the middle of what my load guide suggested). If you think this might be the problem, I can go dig up the boxes I put the ammo in (I mark the load on the boxes when I do my hand loads).

I also Moly coated the bullets (not going to do this next time as it added about 1.5 gr to the bullet weight). I might still use the moly paste in the barrel, but I'm not going to coat the bullets.

I was shooting at 475 yards. But I completely missed the target each and every time. My spotter was telling me I was several feet off and it was all over the place, some left, some right, and some high, but none low at this point.

I couldn't figure out what was going on. So I took the rifle to a 100 yard range and continued with the same hand loads. At 100 yards I was again all over the place in about a 3.5 foot diameter.

Curious, I started shooting some 250 gr Remington Manufactured rounds. I was accurate at 100 yards with those. My group of 5 was about a 3/4 inch.

Anyone have any ideas as to what I could be doing wrong with my hand loads? I've been hand loading my .220 Swift for about 2 years now and I have never had any real problems with that. I used the same technique on the .338 RUM and this happens. I just don't get it. Any advice would be more than appreciated.

Thanks
Rob01
What barrel twist does LRB recommend for that bullet? You might have the wrong twist and throwing rounds because they aren't stable. Sounds strange that they were that far off though
One Round Down
In your post you said that your groups at 100yds were 3.5 "feet" in diameter!! Feet!! I hope you mean 3.5 inches!!! 3.5 feet indicates a SERIOUS issue. I would take Rob01's suggestion and check out the require barrel twist for that particular bullet. From there, I would check the reloading supplies that you used in creating these loads (powder and primers) to make sure something is not running afoul there.

I have heard of moly causing some unusual results in terms of inconsistency and the occassional flyer, but not 3.5 foot groups at 100yds. I doubt very seriously that it is the moly coating that is causing your problem.

Let us know what you find out. Also, you may want to pull apart one of those loaded rounds to check them out for discrepancies. It couldn't hurt to take a look anyway.

Good Luck.
ORD Out...
J Schulze
Did you prep the barrel with moly grease? Do you have correct twist rate for those LRB?

I would put my money on it being the twist combined with non prepped bore.
WyattCE
The information on Lost River Ballistic's web site states the minimum required twist rate is 1:10 which is exactly what my barrel is supposed to be.
The rifle is a Model 700 LSS. According to Remington's website, the twist rate is 1:10.

And yes, I did say 3.5 feet at 100 yards. That's why this scared me as much as it did. I had to staple several targets side by side so I could see where the bullets were hitting.

I just got two new boxes of bullets from LRB's today. I'm going to load them tomorrow and take them out to the range on Saturday.

I am not going to moly coat these rounds, and I am going to clean the barrel to the best of my ability to get as much of the moly paste out of it that I used before.

So here's what I got.
.338 Rem Ultra Mag
J40 Match Bullets from LRB. 250 gr BC = 0.770
Model 700 LSS with a 26" barrel and a 1:10 twist rate.

I was planning on using IMR 4350.
Should I use something different?
What amount of powder do you suggest?
I would like to keep the amount of powder on the light side, seeing as I'm having problems. I don't want to run a higher risk by using a heavy powder load.

Edited to add:
I used moly grease on the barrel when I first bought it. But have not used it since. So I had about 100 rounds of Remington brand rounds through it without regreasing it before I started using my Moly coated hand loads. I also cleaned the barrel a lot during this time as it was the break in period on the barrel. So I believe that most, if not all, of the grease had been removed by the time I got to my hand loads.
samuraiwarrior
It sounds like a loose scope or mount ,but if you put 5 rem factory rounds down range with good accuracy it would lean away from that.Unless of course the reloads were loaded hot.And heavy recoil is bouncing your scope around.Maybe double check your mount and optics if it continues,try other factory ammo before continuing to use your reloads.
WyattCE
QUOTE
samuraiwarrior:
It sounds like a loose scope or mount ,but if you put 5 rem factory rounds down range with good accuracy it would lean away from that.Unless of course the reloads were loaded hot.And heavy recoil is bouncing your scope around.Maybe double check your mount and optics if it continues,try other factory ammo before continuing to use your reloads.
I'll try this. I didn't even think about this due to the fact that I did put 5 factory rounds downrange with reasonable accuracy. But it kinda makes sense. As I could see a loose mount causing my spray downrange.
It's a Leupold scope, so I don't think it's that. But there is a very good chance that it could be the mounts. I was never really happy with them.
J Schulze
why are you using such a fast powder? Hodgdon has 338 Rum Data available.
WyattCE
QUOTE
J Schulze:
why are you using such a fast powder? Hodgdon has 338 Rum Data available.
Simply because it was the only thing in the loading manual that my local gunshop also carried.

Looking up Hodgdon now.
WyattCE
I didn't have to go into work today due to icy roads (wimps), so I took the rifle back to the range.

At first I went through the last 17 rounds of factory ammo I had. I started off with reasonable groups, but the groups were about 1 inch to the left. So I just adjusted the cross hairs for that one.

Then I went ahead and moved to the hand loads I did last night. With the hand loads I was shooting about an inch high. But I was getting great groups (for my skill level anyway). I was getting roughly half inch groups. I started getting 3/4 inch groups later, but that was due to fatigue and the fact that I need a muzzle brake on that rifle.

So I didn't have any problems this time. It must have just been that one set of hand loads. Yet, I still don't know what it was! Could it have been the powder? A bad can of powder or maybe it even got contaminated somehow when I was load? This is the only thing I can think of. Unless maybe it did have something to do with the moly coating. But I find that one hard to believe.

As I stated before. I just started doing hand loads with this round. Next time I will try Hodgdon as it was suggested.

I appreciate the advice here guys. I just wish I knew what went wrong so I won't repeat it again.
J Schulze
Wyatt also try the 300 gr SMK. higher BC actual use from LRH.com has it at .8 BC. When I get a chance to build one it will be a rem 700 LA, Lothar barrel, Opsinc break and will use 300 SMK only probably.
WyattCE
QUOTE
J Schulze:
Wyatt also try the 300 gr SMK. higher BC actual use from LRH.com has it at .8 BC. When I get a chance to build one it will be a rem 700 LA, Lothar barrel, Opsinc break and will use 300 SMK  only probably.
I'd like to have Celt build one in .338 RUM for me (his LRP-2). But at the moment, I need to start setting aside money for it, and I'm not even sure if he's taking orders yet. If I'm not mistaken, his website says he's still waiting on his FFL.
But that's not a concern for me yet. It'll be a year or so before I have the funds needed (just finished grad school and am job hunting at the moment).
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