Ruger American doesn't like anything under 160 grain bullets

W

Wendyj

New member
Picked this 7-08 up a few weeks ago and most factory ammo max weight is 140 grains. Since we load for the 7 mag we had some 139 sst, 150 Nosler and some 160 Speers sp. couldn't get to group under 2 inches with the sst. Maybe inch and half with 150 Nosler. The 160 flat base punched less than 1/2 inch. I know the twist is a -9 in this rifle. We had gotten rid of a Remington sps that was a 9.25 twist. Same as the Remington 7 mm mag. The mag shoots pretty much anything from 140 up to 160. Heaviest I've tried in it. I wouldn't think a 1/4 inch on the twist would make that much difference. Loaded all under 40-42 grains of IMR 4350. When I google the Berger bullets they show 140 and 150 for 10 twists or larger. This one is exclusive to hunting so farthest I can get the bullet out is 2.80 or it doesn't fit in the magazine. I tried to single feed a few lighter ones at 2.816 which is all but in the lands. Am getting ready to order some more and was thinking of a 175 grain. Any idea if the twist is the reason it won't handle anything lighter. I don't want the Berbers as they are pricey. Would like a Nosler accubond or Sierra game King. It would be nice to shoot up the 200 139 sst I have but not at 2 inch groups.
 
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I can't IMAGINE a slight increase in twist rate making the rifle unable to throw lighter projectiles accurately. If you've only put 20 or 40 rounds through the rifle, I'D suggest shooting it a bit more, and let things "settle in" on the rifle. If, after 100 - 150 rounds, it still won't group, then perhaps something's going on with it.

I don't shoot 7mm anything, but you might check around for people who do, and ask if they've experienced the problem you're having. I think there's a website/forum for Ruger firearms, so you might make inquiry there, too.
 
Somewhere, there's a written "procedure" for "breaking in" a new rifle barrel, which involves swabbing the barrel between shots or shot groups. For all I know, it may all be just so much superstition, but it might be something to try, also.
 
I clean every shot for first five and every five after until I get about 30 down the pipe. Thanks for the Ruger site. According to the site it's a 9.5 twist. My last Google search said 1-9.
 
Every rifle seems to have its own opinion of what it likes best. A lot of them are pretty similar, but some are just oddballs, for no apparent reason.

Grossly fast or slow twist rate for the bullet can be an explanation for a load shooting poorly, but 2 inch groups with one certain bullet & load and 1/2" with another load, from a sporter class big game rifle isn't a bad barrel. Just a picky one.
 
I finally figured that out in my 308 Savage. If it's not 180 grain bullet it's not going to group. It's only exception is 178 Amax. 10 twist of course.
 
My Tikka T3 lite 25-06. Wouldn't group for anything, multiple loads. Around 55-60 rounds in, all of sudden it comes together. The more I shoot, the better it gets. Tried some earlier loadings that wouldn't group, and they group fine now. I didn't do any break in, except cleaning bore at the end of a session.

Keep shooting it for a bit and see what happens. good luck.
 
It has a 1:9.5 twist, same as Rugers 7 mags and only .25 different from Remington. The twist isn't the problem.

Use this link to calculate. I don't have all the data to plug in for your particular bullet, but just guessing it shows 1:9.5 as ideal and virtually no difference when I ran it at 1:9.25 both with 140 gr bullets.

http://www.bergerbullets.com/twist-rate-calculator/
 
Yes, I wouldn't think.25 would make any difference either. I don't have that many rounds through it so I'll keep shooting and see what it does. I'm going to hunt Saturday in some pretty hilly area. Probably won't get a shot over a hundred yards if even that. I can live with the 160 grain for the weekend. I'm going to take a day or 2 off next week and hunt some tower blinds over food plots that offer 350 yards and I'm going to take the 260 instead. Just don't want to tote it through the mountains Saturday.
 
A quarter turn of twist may not seem to be significant, but the velocity difference between a 7mm Mag and a 7mm-08 PLUS the slight difference in twist could have a very significant difference in the rotational speed and the stability of a longer or shorter projectile.

The indication that the rifle seems to like longer bullets may be an indication that the rifle has a long leade in the throat area of the chamber. Using a shorter projectile in a long throat could cause instability of the projectile and a resulting effect on accuracy.

Try seating the bullet out closer, or using a longer bullet. The Barnes bullets are long for their weight, and may shoot well in your rifle.
 
?

The only bullet I seen you tested below was one 139 grainer. Sounds like you did not try anything but big bullets. Try a couple of factory loads in it first and see what it does.

Sounds like a reloading problem to me.

steve
 
Try different bullets, try flat based bullets, try different powders. Different bullets have different amounts of bearing surface, different ogives, and different hardness of the jacket. Measure the distance to your lands and seat your bullets out to .030" off the lands. Try different primers, smaller cases like standard primers over magnum primers. Try different powders: slow-burning powders like IMR4831 that work well with 7mm Rem Mag may not work well with a 7-08 (it will like faster powders like Varget, IMR3031, and WW748).
 
I haven't used the IMR 4831 in this one. It is what I use in the magnum. I'm using IMR 4350, Varget and h4895. I've got the other powders you listed. Only primer I use is the cci BR-2. I only use magnum primers in the 7 mag. I've tried the 139 sst. 150 Nosler and the flat based 160 Speer. I'll keep plugging away until I find something it shines with. I was just curious if anyone had any experience with this caliber and rifle.
 
Husband took to indoor range today and tried factory 120 and some reloads. Sorry, I don't know how to get these all in one post. Indoor range was only 25 yards. Appears Varget done the best.
 
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Maybe the best for lighter bullets. Bench was only a foot wide so no rear bag. These are all 25 yards. Raining again. Maybe rifle has some hope.
 
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