I have a sporterized Swedish Mauser in 6.5X55 that shoots minute-of-angle or better at 100 yards, but at 200 yards the groups spread out to four or five inches. At 300 yards it's 10 inches. I suspect a bullet stabilization problem.

This is a barrel I purchased in the white through SARCO about 10 years ago. I believe it came from the Mauser factory which means it probably has whatever rate of twist was standard for Swedes. It was 23 inches long, but I had it cut down to 21 inches to get rid of that stepped-down portion near the muzzle. A quality gunsmith (Harry Lawson Gunsmithing in Tucson) cut, re-crowned and fitted the barrel, and I glass-bedded it into one of Lawson's 90% inletted stocks.

I've shot various factory and handloads through it. All bullets have been between 129 and 143 grains and spitzer types, no round nose. All factory loads have been of the lawyer-approved variety which means muzzle velocitys around 2600 fps. All of my handloads were near the middle of the min-max range shown in reloading manuals. Today's fiasco was with 140-gr. Hi-Shok soft points.

Which direction should I go to extend bullet stability out to 200 and 300 yards? More velocity? Lighter bullets?

I'd put this gun back in the safe and give up on it, but I want to give it one more try. Seems like any rifle that is sub-moa at 100 yards is wanting to be a shooter if I can just learn how to work with it.

as much as you like to hear this, it could be human error. could also be the rest you have and not being stable enough. i hope you are not shooting off a bi-pod as sometimes they cause erratic shooting and accuracy varies between soft and hard ground with a bi-pod.

if the bullet stability is really the problem its probably best to try a lighter bullet, as it would only get worse the heavier the bullet you used

This may be a silly question ...

What were the wind conditions at the range? If the groups are horizontally dispersing it could be a crosswind.

Just a thought.

Well if it's indeed a Swede barrel it will have a very fast twist. The Swede military round shot a pretty heavey for caliber bullet. So you are definately stablizing those lighter bullets. I would think the 140's would shoot. If you're on a commercial action you could zip the velocity up safely. You might try that and a heavier bullet. I just think you haven't found what your barrel likes yet.

Thanks for suggestions. I only wish it really were a commercial action. The action is an old military job from Mauser Obendorf. Not the best choice for building a sporter, but that used military rifle for $129 and new barrel from Mauser for looked like bargains to someone who hadn't yet tried sporterizing a rifle. It's now about 10 years and $400 later, and I'm still trying to get it to shoot.

If human error or poor rest were the problem, I would expect problems at 100 yards. But it shoots beautifully at 100 yards.

The wind theory was a good one, but today's winds were weak and insignificant. In between shots with the Swede at 200 yards, I was shooting a 1 1/2 inch group at 200 with a 7MM SAUM.

About 2 years into owning the gun, I had a shoot-off between the Swede and two pre-'64 Model 70s to determine which would be taken on an antelope hunt. The Model 70s were a 30.06 and a .270. The Winchesters tied for accuracy with each giving me 4-inch groups at 300 yards. The Swede was the best of the three at 100 yards but spread out to 10 inches at 300. And yes, I was shooting off a bi-pod that time, but not today.

The problem clearly stems from bullets starting to veer off course in random directions somewhere between 100 and 200 yards. I just don't know why it's happening.

quote:

I was shooting a 1 1/2 inch group at 200 with a 7MM SAUM.

thats pretty good going

when you are shooting 300yards, and problems with the rest etc are 3x worse than @ 100yards. but since you can shoot decent groups with your 7mm saum its possibly a bullet/powder/primer combination. what is the power of your scope?

anyway some rifles dont hold there accuracy, and some really dont like bi-pods. thats the theory anyway

I think it is a bullet stabilization problem. Possible solutions are:

1. Lighter bullet.
2. Higher velocity (if your gun can safely take the pressure).
3. Shorter bullet (i.e., roundnose).

Hey Audsley, What kind of scope do you have on it and what Power is it?

Some thoughts for you:
twist is 1 in 7.87" so heavy bullets are fine, I've only heard of bad things happening to very light varmint type bullets in those barrels.

Do you have a chronograph? You say that you're using middle of the road data, but pay attention to the barrel length that data was developed for. If it was for performance in the original 29" tube, you may be much much lower in velocity. Clock the loads and find out.

Pay attention too to seating depth, as the military barrels have very long throats origninally cut for 156gr roundnose bullets. One of the devices for checking bullet-to-lands distance is invaluable. I was once told (and it has held true for me) "if it'll fit in the mag, it'll feed in a Swede"


Hope this helps
Eric

heavier bullet and more powder (MV) and it will go away. that twist is extremely fast,..and you really need a longer bearing surface and a heavier charge to creat an RPM that it will run with. Look for something in the 2800-2850fps range and I bet you will see it settle in.

You didn't mention the bullet types and I've found that some rifles will not shoot boat tail bullets as well as flat base. I'd try a flat base and probably heavier, then crank up the powder. Nate

Thanks, guys. That gives me some things to work on. I'll work up some higher velocity handloads with flat base bullets and see what happens. I hope 2800 fps at 140 grains doesn't set back the receiver.

the idea that it could be lack of stabilization is frankly, rediculous.

The swede has a very fast twist designed to stabilize 160gr bullets.

Building a sporter on an Oby-swede? not my choice, but...

What specific bullets are you using?
My swede doesn't like thin jacketed bullets and in general I load to fit the magazine to reduce the jump to the rifling as much as possible.

I think on any mauser swede barrel you will have a tough time making ANYTHING touch the rifling including the L-O-N-G 160gr RN's

Remember also that the two factors for wind drift are wind speed and bullet velocity.

What loads were you shooting in that 7mmSAUM?
120's at 3400? IF your SAUM loads were significantly faster than your swede loads
say 600-800fps is not out of reason, ther'd be a pretty big difference in wind drift.

AllanD

Two people have asked about the power of the scope. It's a 2x7 Redfield cranked up to 7x.

On the 7MM SAUM, which is the "control" rifle that tells us neither wind nor operator error was a factor, I was shooting a 4.5 x 14 Weaver Tactical. A few years back when I was shooting the Swede along with the two pre-64 Winchesters, the 30.06 Winchester was wearing the Weaver tactical, the .270 Winchester had a 3x9 Leupold Vari-X II and the Swede had a 3x9 B&L Elite 3200. I got the same results then. I believe any scope I've used on the Swede is more than adequate to shoot much tighter groups at 200 and 300 yards.

It's apparent that bullet stabilization is the issue. I'm wondering if the 21-inch barrel is the source of the stabilization problem and whether it can be overcome with higher velocity.

quote:

Originally posted by audsley:
Two people have asked about the power of the scope. It's a 2x7 Redfield cranked up to 7x.
... I believe any scope I've used on the Swede is more than adequate to shoot much tighter groups at 200 and 300 yards...

Hey Audsley, As long as you "believe that", there is no real use for any of us to confuse you with reality.

Best of luck to you.

You mean five-inch groups is the best I should expect at 200 yards?

Silly question ...

Parallex?

I have the had the same thing happen on a couple of occasions. The problem turned out to be scope parallax. Check that first.

Jim

.

quote:

Originally posted by audsley:
You mean five-inch groups is the best I should expect at 200 yards?

No, you should be able to do much better.

quote:

Originally posted by Gaviidae_Esq.:
Silly question ...

Parallex?

Not silly at all. Both you and Jim "may" have nailed it. Or, it could be..... other things.

There are a lot of variables at play here. If it has a fast twist, heavier bullets will help with that. More velocity...not necessarily. Factory/surplus ammo...could come into play. Parallax difference between 100 yds and 200 yds...yup, that would be a big factor. Most scopes are set to 0 parallax at 100 yds. A scope with an adjustable front ocular would help that a bunch.

If you reload, try this load for a 140 grain BT bullet..37.8 grains of IMR-4895. This load shoots really good for me. Norma brass and Remington primers. Case should be trimmed to 2.150" OAL of loaded round 3.062" Rifle this load was used in was a Swede carbine with an 18" barrel with a 1-7 1/2 twist rate.

Make sure bases on scope are screwed on tight, rings are tight, and bedding screws are tight.

Good luck.