24hourcampfire.com
24hourcampfire.com
-->
Previous Thread
Next Thread
Print Thread
Hop To
Joined: Jul 2008
Posts: 37
D
Campfire Greenhorn
OP Offline
Campfire Greenhorn
D
Joined: Jul 2008
Posts: 37
I wanted to try out a combo gun for a while so I picked up a MP94 at Bud's for $475. I read all the way through this forum and others to find out how to get it shooting where I wanted. It is 12G over 30-06 and at 50 yards with iron sights the rifle barrel hit 10" lower than a rifled slug, with a scope the variance changed to 17" lower than a slug at 50 yards. The difference here is the difference between the height over bore of the irons verse a scope. It is impossible to have both barrels hit same point of aim with 2 different height sighting systems.

Next step was to determine which slug and which rifle load to use. I bought every different slug I could find and found out they all hit within 2" difference at 50 yards, so I picked a Winchester 1oz at 1600 fps. The rifle shot best with a handload of H4350 and a 180 Hornady spitzer. If I let the barrel cool all the way between shots I could put 3 shots into about an inch at 100 yards.

And the most important thing- the gun shot both barrels to the same windage, thankfully, cause that would not be easy to correct. I wanted the slugs to print between 1-2" hi at 50 yards and the rifle to be on at 100 to maybe 1" hi. I would not be shooting much past 100 with the rifle and not past 60 with a slug. So I checked the rifle at 50 with a zero at 100 and at 50 it printed .5" low. So there is my goal - shoot both barrels at 50 yards and have the slugs hit 1-2" hi and the rifle to be .5" low to dead on (at 50 yards).

I decided most of my shooting would be with a scope so I would have to accept a larger dispersion between barrels with the iron sights.

Now, the barrels were hitting 17" apart at 50, so I needed to make up between 15-16". I started by removing the wedge pin between the barrels. It came out easy as there was no tension at all on it. It was not wedging anything, just taking up space. So I called USSG and ordered some new wedges. I figured their gunsmith was probably an idiot ( and I was right) so I ordered 3 wedges. I gave them the exact dispersion between barrels and the size of the current wedge. I said send me what they thought I needed, then send me 2 more wedges even bigger. They wound up sending me 2 wedges smaller than my current wedge and one wedge slightly larger but way smaller than I needed. Total waste of time.

So i decided to cut some shim stock from a stainless steel shim kit I got from Brownells. I just cut it to fit the flats between the barrels where the wedge goes. Trial and error determined that .025" of shims in conjunction with the original wedge worked perfectly. And when all assembled you could not see the shims at all. The rifle barrel now hit dead on at 100 yards, about .5" low at 50 and the slugs hit 1" hi at 50 yards. I am ready to hunt!

The shimming process did not change the windage and both barrels still printed with the same windage. The shimming did make the rifle barrel much more sensitive to temperature, probably due to the greater stress it was under. But if I waited till it was cool between shots, they all hit very close.

Last edited by dieselten; 11/16/13.
GB1

Joined: Dec 2006
Posts: 28,172
Campfire Ranger
Offline
Campfire Ranger
Joined: Dec 2006
Posts: 28,172
Great job!

Now...for the triggers. wink


Hunt with Class and Classics

Religion: A founder of The Church of Spray and Pray

Acquit v. t. To render a judgment in a murder case in San Francisco... EQUAL, adj. As bad as something else. Ambrose Bierce “The Devil's Dictionary”







Joined: Jul 2008
Posts: 37
D
Campfire Greenhorn
OP Offline
Campfire Greenhorn
D
Joined: Jul 2008
Posts: 37
You are right! Mine measure 7.5 and 9 pounds. But you get used to it. When the gun was new, it took 2 men and a pry bar to break it open. After 150 rounds it is way way better.

Joined: Dec 2002
Posts: 32,235
Likes: 1
Campfire 'Bwana
Offline
Campfire 'Bwana
Joined: Dec 2002
Posts: 32,235
Likes: 1
Dieselten as in Thomas The Tank Engine's Dieselten?

Jeff

Joined: Jul 2008
Posts: 37
D
Campfire Greenhorn
OP Offline
Campfire Greenhorn
D
Joined: Jul 2008
Posts: 37
Originally Posted by 260Remguy
Dieselten as in Thomas The Tank Engine's Dieselten?

Jeff


Yup. You are only the second guy to ever get that

IC B2

Joined: Sep 2013
Posts: 2
M
New Member
Offline
New Member
M
Joined: Sep 2013
Posts: 2
Interesting post. I have one in 20/22WMR. I went for a red dot sighted in at 100 for the rifle. I haven't tried a slug in the twenty but my pattern with #4 lead shot is okay at this setting. Thats at twenty meters.


Moderated by  RickBin 

Link Copied to Clipboard
AX24

416 members (10gaugemag, 10gaugeman, 1beaver_shooter, 007FJ, 12344mag, 06hunter59, 52 invisible), 2,498 guests, and 1,174 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums81
Topics1,193,645
Posts18,512,528
Members74,010
Most Online11,491
Jul 7th, 2023


 


Fish & Game Departments | Solunar Tables | Mission Statement | Privacy Policy | Contact Us | DMCA
Hunting | Fishing | Camping | Backpacking | Reloading | Campfire Forums | Gear Shop
Copyright © 2000-2024 24hourcampfire.com, Inc. All Rights Reserved.



Powered by UBB.threads™ PHP Forum Software 7.7.5
(Release build 20201027)
Responsive Width:

PHP: 7.3.33 Page Time: 0.072s Queries: 26 (0.007s) Memory: 0.8191 MB (Peak: 0.8610 MB) Data Comp: Zlib Server Time: 2024-05-15 04:03:14 UTC
Valid HTML 5 and Valid CSS