I have historically sighted my big bore guns at 110 yards.

The gun has normally been an AHR CZ 375. It has had a trijicon 1-4 green post and a swarovski Z6 1-6 illuminated.

I have also sighted in a sako 9.3x62 with a trijicon red post on 3x9 scope.

Recent I sighted in a Ruger 375 with a nikon 1x4 scope.

The groups have been okay - I have moved on to shooting the gong and getting more real world practice.

Now the issue - I think all of these big bores are very accurate rifles. My sighting in has been poor at best.

The issue I have had with the trijicon and the swarovski scope is that at 110 yards the magnification and reticle were not well suited for accurate aiming. I don't clamp the gun with a lead sledge but shoot of a shooting bag.

Anyone else have this issues of trying to sight in a large bore rifle with a relatively low magnification scope. I just think I am aiming at different points of impact as at 110 yards with either a trijicon post or swarovski illuminated reticle I cannot exactly pin point the bullseye on the sighting target.

Last week on the ruger I sighted in at 50 yards. This was driven by the Florida heat where I was too lazy to walk 110 yards to set up the target and go check it (I left my crappy spotting scope at home). At 50 yards I was getting one hole groups as I could see the bullseye much better.

I am assuming I have just been sighting in poorly - anyone have any suggestions/tricks of the trade.

I don't think this has an impact on accuracy for hunting purposes but my gut is I have really accurate rifles in my big bore collection.

Mike

I got around this by using those large 1" diameter fluro orange stickies you buy from stationary shops. I put those over the bullseye on my targets, they stand out proud and are easy to see.
I also use them as my aiming point when working up loads, the centre is easy to make out at 100yrds.
Hope this helps.

Cheers.

My favorite 375H&H is a Win Model 70 SS Classic with a David Miller laminated stock and a Leupold 1.5 VXIII scope in Warne mounts. I sighted it in at 100yds on a Target of a cardboard sheet from a computer paper box I used to get from my place of employement. I was shooting of a home made folding bench I could put in my car. I sat on a folding stool. My best group was shot with 20 shots with no barrel cooling at all, just the time it took to shoot 3 carefully aimed shots and then reload 3 rounds (the rifle only holds 3 rounds because the stock is narrower thru the magazine area and I had to cut top of box off to fit ). The resulting group of 20 shots measures approximately .72. Bullet was a 260 grain Nosler Partition in front of 75 grains of IMR4350 which at the time was my standard load for Africa and I took lots of game with it. Group was 1 1/4" above center of 2" computer printed square on a piece of PC Paper I stuck on the cardboard. I sighted that rifle in 1998 and made 5 trips to Africa with it and have never done anything but check zero each time. I even shot an elephant with it with 300gr Woodleighs and they shot to almost the exact same place so I didn't change a thing. That's probably the most accurate big bore in my collection. It is fully (from tang to forearm tip) glass bedded. Incidentally I just go up in the mountains and find a safe draw to set up in and measure off 100yds and have at it. I prefer a narrow draw or ravine to keep down crosswinds.

Mike……

I have been shooting and working with big bores for 20 years now and more. While I have done some shooting at longer ranges to check the sights where they may hit at 100 or so, I have always sighted in at 50 yards. Taking into account the low power scopes used, normal
1X4 or 1X5 sometimes 1X6, I promise you that you can see better at 50 and sight in tighter at 50 than you can at 100…. You just plain can hold and see better at 50, rather than 100 with these scopes, and of course my eyes too………..

What are big bore rifles designed to do? Big dangerous game, 95% of the time. One does not shoot Dangerous Game at 100 yards………. 50 yards is LONG RANGE to be shooting Dangerous Game….

Lets say for instance you have a trauma inflicting bullet, soft or CEB Raptor, and matching solid. I will sight the soft or Raptor now to anything from 1/2 to 1.5 inches high at 50. Then check the solid. Normally the solid will be from center to 1 inch high. If High,and Raptor hi then drop to about 1 inch high with the Raptor and solid will be just below. With this, even taking a 100 yard shot to 150 yards with a big bore, depending on velocity, just aim and shoot.

Last year I had a big mission for a 458 B&M using a 250 gr Raptor at 2900 fps for all plains game from impala to zebra, 420 Raptor 2250 for buffalo, and 450 #13 Solid at 2225 for hippo, elephant, second shots on buffalo. 250 Raptor at 1.25 inches high, 420 Raptor 1 inch high, and 450 Solid center. With this setup I shot the 250s anything from 17 yard hippo brain shot (100 yds from the water) to zebra/wildebeast at 150 yards. Buffalo at 35 yards with the 420, and 450 #13 Solids from 12 yards on elephant to 25 yards on other things. I never looked at POI at 100 yards before leaving, never changed the sights, never anything except point and shoot at all ranges dead on........

Now if using a rat caliber like 375 caliber, and was planning on shooting further than 200 yards, then one might want to check POI at 100 yards, go something like 1.5 inches high at 100 and go hunting, dead on at 200, and normally 10-12 low at 300......

On real calibers for DG, no need to ever do anything beyond 50 yards.........

Michael

Use a relative large center bull to aim at, and you will be fine.

The target above is of our 416 Rigby Improved, with a 1.5-5 Leupold scope.

The load was 105 grains of H4350, which shot well in my 416 Weatherby.

We just finished the rifle, and after sighting it in, I loaded 3 rounds of 400 grains of Trophy Bonded Bear Claw bullets and fired them.

When I looked through the spotting scope, I saw them all cutting each other.

I took the same empties, and loaded them again with Barnes 400 grains Super Solids.

I fired them at the same target.

The result is as you see above.

I stopped load development on that rifle, and that is the only load I have ever used in it on safari.

A large bull also helps with sighting in peep sights.

I have a Springfield M1A National Match, and I can shoot one ragged hole groups with it on the same targets.

Fifty yard sighting in works well. The Federal website has charts for their ammunition showing the points of impact, with the differential between 50 and 100 yards for our calibers one-tenth of an inch. This is just fine for large game usually taken at no greater distance.

Thanks guys - some very informative tips.

I only hunt with one rifle - my AHR CZ 375 H&H. All other rifles I own are are for all practical purposes show pieces.

I may start using some other guns in the near future to hunt. I need to hunt with the VC double and the sako 9.3x62 and the ruger 375.

Going to Alaska with Biebs for Moose in sept - talking the 375 (its with Wayne getting all fixed up for Alaska).

I may have to shoot at 200 yards - so I want to get the gun sighted right - will have the swarovski 1x6 scope on it.

I think I am going to sight it in at 50 yards - move it to 100 yards - then 200. Finally set the gong at 200 and whack away.

Any recommendations on factor loads and bullets for Moose. I have 300 grain swift aframes - am running low on 300 grain barnes. Both federal.

Thanks,

Mike

You might try re focusing your scopes to make sure you are getting a crisp, clear sight picture of your target at that distance. Also, you might try sighting in without illumination. A nice black reticule generally will give a better contrast on a target than a lighted reticule during bright daylight.

I agree with Blacktailer, you have not focused your scope..I use mostly 3X Leupolds, on my 9.3x62 and up. I don't want much magnification on DG animals, The lower power should be clear as a bell from 10 yards to 1000 yards, they just don't magnify as much. Also for offhand shooting the lower the power the better I shoot, who wants their natural wiggle magnified by any amount, go figure a 10X magnifies your wiggle by 10 times and the results are you grab at the trigger as it bounces by the target!

I don't consider a .375 to be a big bore. If I am hunting dangerous game with a .375, it will be one of the cats. For that, I would sight-in the rifle in the field, depending on the distance to the blind, or if not hunting from a blind, at 100 yards.

If I am using a .375 for plains game, which I have often done, I sight it in at 200 yards.

I use low end variables on my .375s, 1.25-4x or 1.5-6x, and these have been fine, both at the range and in the field.

For larger medium (.416) or big (.458+) bores, I sight them in to hit the top of the aiming point at 50 yards, with iron sights, or low power fixed scopes, such as the excellent 2.5x Leupold, or low end variables, typically 1.25-4x.

I like the sighting-in targets with the orange squares. Much better than black bulls-eyes for sighting-in a scoped rifle. The bulls-eye targets are fine for irons.

Clearly, it is your aiming point that is the issue. If you continue to have problems after increasing the size of the bull, try this.

Use a square, yes, square aiming point and don't aim for the center. Put the cross-hairs along the edges of the square -- you have four aiming points. It is more precise than trying to find the center of anything.

I sight all my big game rifles in 3" high at 100 yards, that will be 4 inches high at 200 and on at 275 to 300 depending on the caliber.

It's about the oldest accepted way to sight in rifles that I know of..Jack O'Connor said so, and he was the best rifle shot I have ever known and I've known a lot of good shots. I went with Jacks advise on that issue when I was a kid, and have never seen any reason to change.