Home Forums Reloading Big Game Rifles Horizontal groups

I have run into an issue that I can’t figure out. Unexplainable horizontal groups. Like, 8” wide, 2” tall. Here’s the skinny.

Shooting a Henry X in 45-70 with Silencerco Hybrid 45. I’m developing loads for it and have one load (350 gr Berrys plated) that shoots 1.5” at its worst and .88”. 4 shot groups at its best. Very happy with this load!

I’m loading some 410 grain Hornady Sub-X, trying to get a good subsonic load. Every load from 1050 fps down to 900 fps is shooting a horizontal group of up to 8” with a vertical spread of about 2”.

First, it ain’t me. It’s not the sandbag rest. Its not wind either bc I’m shooting at an indoor 100 yard range.

I can shoot. So, It’s not me. I usually take 3 guns to the range to do load development. This day it’s a 300 win mag and a 7 mag. I’m getting 1.5” down to .6” with them. I know when I pull a shot, so it’s not user error. Also, the subsonic loads have very little recoil, so it’s not flinch induced.

Why would a gun spread bullets out in a horizontal group when all the variables are consistent with tight groups on other guns?

That may have come off a bit cocky! I can mess up a good group as good as anyone, but, I’m usually aware of it.

All my subsonic loads in this gun are shooting horizontal, none of the supersonic, harder recoiling rounds have this problem.

I would suspect the scope or the scope mount. Check the rear bell focus ring if your scope has that. A loose rear bell will cause your problem. Remove the scope and check the base(s) for security. If that's good set the scope vertically on a hand mirror with the magnification on the lowest setting. Adjust the windage and elevation so the reticle is over the image of the reticle (you'll see two reticles if the reticle isn't centered). Hold the rear of the scope in one hand and smack the ocular end into your other palm and then check for movement of the reticle with the mirror. If the reticle moves your scope is not holding zero.

Sounds like a bullet stabilization problem. A 410gr bullet at 900fps probably isn't spinning fast enough to stabilize

Dave. I suspected the scope too, but the full power loads shoot great. It’s a good scope. Leupold VX-R in Talley mounts.

Ok. Before I hit post, I went to look at the gun. Dang scope is loose. You gotta be kidding me. The bases worked themselves lloose. No wonder my groups got progressively worse.

This is very good news. I was getting frustrated with the poor performance. Now, the horizontal string makes more sense.

Before putting it back together, make sure the screws are not bottoming out on the barrel threads or anything like that. Degrease everything and then use blue loctite this time... Shouldn't have anymore issues that way.

Thanks. I did pretty much exactly that. Cleaned it up, cleaned out the threads and put some red locktite on it.

On a more positive note, I wasn’t expecting a lever gun to produce such great accuracy. I was expecting 4-5” groups. Shooting cheap Berrys plated bullets at 1” is a huge bonus surprise. Reduced recoil load of 40 gr H4198 is very pleasant to shoot. Have not chrono’d that load yet.

Just loaded up more 410 gr Sub-X bullets to test accuracy, again. I got 1050 fps the first time with 14.5 gr of Unique. No filler, just powder and air. Yeah, it concerned me at first, but apparently, it’s a very common powder for reduced velocity 45-70 loads.

Red? As in stud and bearing mount?

Red as in high strength (loctite 271 probably) stuff that should not be used on scope mount screws!!!!! That is a permanent thread locker and requires heat to loosen up. Asking for trouble, using it on any part on your gun. I'd use clear finger nail polish before using red loctite..

Not to worry about red loctite. Holding a hot soldering iron tip on the screws for 2 min will break the bond.

Yes, red. It’s all I had. I have used it on gun parts from gas block set screws, muzzle devices and scope base screws. Like someone mentioned, a heat gun will take care of it if I change my mind. Use with caution, but it can be used.

Yes. Scope mounting issue. One thinks things will always stay tight, but that's a fallacy.

Yeah, that is unnecessary. When he goes to sell it and the new owner can't get them off, its always an issue. Just use blue.. For fuggs sake..

None of mine come loose. You stupid fu cks that can't do schidt shoudln't be working on a stick horse..

I have always found that experience trumps internet opinions.

This was 100% operator error. I know what I did now. I had two mounting options, a pic rail and Talley mounts. I was going back and forth between the two and didn’t torque them down properly since I wasn’t sure if this is what I was going with.

Another lesson learned through failure.

Interestingly enough, red locktite has been my go-to since before Al Gore invented the internet. Can’t tell you how dismayed I am to learn that it’s not acceptable.

No dog in the Loctite picks, but I have used clear nail polish for years and so far I haven't had any issues.

Glad you sorted out the issue and are back on top.