Relined drilling

[mart]

I have a Franz Jaeger hammer drilling in 16x16x222 Rimmed. Nice little gun but it was relined from 8x57R at some point prior to my ownership. It has been frustrating to get it to shoot to the sights, scope included. I run out of elevation before I can get close to a zero. Then it dawned on me today. Perhaps I should be trying to emulate the velocity of the slower 8x57R instead of the higher 222 speeds. Now I'm considering cast and jacketed bullet loads in the 2000 fps range as a possible option to get it shooting to a zero. I'd be happy if I could get it zeroed at 100 yards with both the scope and iron sights.

Changing bullet weights has not helped enough to get to a usable zero. I'm hoping changing velocity will bring it back in line with the sights. Windage is fine. Elevation is the issue.

Any thoughts would be appreciated. Am I off course? Do think this plan may work? Thanks.

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[Diz]

mart,

I am not the drilling expert but I will make a few comments about your problem. I am guessing from your comment that it is shooting low and I wonder if most of the problem is caused by the much lighter bullet and not so much the velocity. You may have a hard time equaling the recoil impulse of the heavier bullet. Possibly try a heavier bullet along with the lower velocity. A quick rifling twist would help stabilize heavy for caliber bullets so you may want to check that. Adjusting the height of the front sight would be another option but tinkering with the claw mounts could be complicated. I am sure people way more knowledgeable than me will come in.

A fine looking drilling by the way.

Good luck, Diz

[sharps4590]

I think you're on the right track. Ordinarily slower/heavier shoots higher, as Diz opined. Only one way to find out. I have a Franz Jaeger in 16 X 16 over 9X57R quite similar to yours. Nice pieces.

[mike ford]

Mart,
This may be a problem for you. While recognizing that the owner can do what he wants with his own property, this drilling illustrates why rechambering/ relining drilling barrels is generally a bad idea( with limited exceptions such as from "D" to "Norm." chamber in 9.3x72R). In my opinion, Diz has correctly identified the source of your problem as the difference in recoil impulse between a 50gr bullet and 196 gr. one. There is one possibility of a simple fix, before we get to the difficult ones. The procedure for mounting a scope in claw mounts includes centering the reticle and adjusting the elevation of the rear mount, by milling it to the correct height as determined by "bore sighting". At this point, it wouldn't make any difference what the caliber was. After fitting the rear mount( the front would have been fitted prior to bore sighting), taking the scope apart, soldering the tube/mounts together, blueing the tube, and reassembling the scope; the rifle would have been zeroed by shooting on a target. Now, here is the possible easy fix, some time ago, Axel posted a procedure for adjusting this type scope. As I recall, this included resetting the adjustment ring to "zero" after sighting in. There is an outside chance that the scope actually has enough adjustment to allow sighting in, but just seems not to. I suggest you search this forum and find Axel's description of the procedures. A close reading of the procedure may reveal what you need to do, indeed if it is possible. This theory depends on the 222 barrel having been installed concentric with the 8mm barrel, so the bore sighting would be the same. This is not by any means a "sure thing". If this "fix" fails, you are left with either re-regulating the barrel (not a real possibility), or reworking the rear mount. The mounts have what is known as " mit support" which means windage adjustment. The rear mount is in two pieces, the bottom part of which could be replaced with a taller one. The difficulties with this include finding one in the first place, that will fit at the top, is tall enough to allow room to mill new "hooks" after re-boresighting. Then it would have to be re-fit, by someone( such as New England Custom Guns) experienced with claw mounts. It would be highly recommended to replace the "slider" at the same time to allow proper fitting. This would be expensive. Another, less expensive, but less "elegant" solution would be to mill the bottom part of the rear mount in two with a thin "slitting blade", and hard solder a spacer between the two pieces; thick enough to allow the adjustment available in the scope to be sufficient for sighting in. This solution would utilize the existing parts and fit up of the hooks, but would require refinishing only the modified part. Any competent gunsmith could do this work. Good luck.
Mike

[mart]

Thanks guys for the insight. It is actually shooting very high. Almost a foot at 100 yards. I've tried bullet weights from 40 to 60 grains and while they vary slightly in POI it is not enough.

To give you some history. The gun came to me in a trade with one of my gun buddies. I doubt he knew it was relined. He picked it up 20 years ago at a Texas gun show. He had a very eclectic collection of high end guns. I ribbed him several times about trading me a lemon. It really isn't and I know he never fired it. It shoots most loads extremely well. One inch groups are very common though they impact high. He passed away suddenly last month. I miss him greatly. We worked together and he was the only guy I've ever worked with who could speak gun on the same level. Everyone else's eyes, (even the ones who thought they were gun nuts) would just glass over when he and I started discussing classic firearms.

The "less elegant" solution of adding height to the existing mounts will be my likely recourse should my attempts with slower loads fail to bring me closer to zero. I have a Husqvarna 46 9.3x57 with a similar problem and had already considered a similar solution. It has claw mounts on the gun and I fitted a set to the gun but they need to be reworked to bring that one down to a good zero. I don't know why I didn't consider that option for the drilling.

[mike ford]

Mart,
Be sure and read Axel's comments I mentioned before you do anything else. I just re-read them, and your answer may very well be there. Look on page 9 of 31 of General Discussion, the thread title is "Hensoldt Scope", and is the last one on page 9.
Mike

[mart]

Thanks Mike. I will try that first.

[Diz]

mart,

I mistook your comment about elevation to mean shooting low. Heavier / slower bullets are unlikely to help you if it is shooting high. Mike's suggestion about Axel's thread may help, other wise cutting and lowering the rear mount will be necessary. I am not sure how tight the front claw is but maybe you could slip a shim between it and the rib but I doubt if you will be able to get a foot of elevation out of it. Try Axel's fix first.

Thanks, Diz

[mike ford]

Diz,
I thought he meant it was shooting low also. He could raise the front a little by widening the dovetail in the front saddle, then shim under the foot plate. It would take careful calculations, you can't widen the dovetail much and must do it on both sides, so it comes straight up.
Mike

[CoyoteJoe]

Just guessing by the photo that the mounts are about 6" apart it would only be necessary to shim the front up about .020" to lower the point of impact by one foot at 100 yards.

[mike ford]

CoyoteJoe,
I think you are right, but I think it would be less stressful to mill the rear base "in two" with about a .025" slitting saw, then hard solder it back together. That should get him on the other side of the zero point( i.e. bracket it) and get it to zero with scope adjustments. Of course, this is only if Axel's tip doesn't help him.
Mike

[Diz]

Leatherman, stopped by your table at Dixon's on Friday but you were busy with a saucy looking lady in bright red pants and who am I to interrupt! Also, saw your arm in a sling and hope it's not too bad. Thanks, Diz

[mike ford]

Mart,
Did you get a chance, last weekend, to try Axel's advice in sighting it end?
Mike

[CoyoteJoe]

CoyoteJoe,
I think you are right, but I think it would be less stressful to mill the rear base "in two" with about a .025" slitting saw, then hard solder it back together. That should get him on the other side of the zero point( i.e. bracket it) and get it to zero with scope adjustments. Of course, this is only if Axel's tip doesn't help him.
Mike

Yep, that would work.

[Leatherman]

Diz , you should have interrupted , that was my saucy wife. I dislocated my shoulder the second day of my African hunt 3 weeks ago. Good story but made for a painful two weeks of hunting. Going to write up a Hubertus article about my hunt with my cape gun and a Hereen single shot in Africa.