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7x57r drilling
45calmuzzleloader
Member Posts: 22 ✭✭
I just purchased a JP Sauer & Sohn 12/70 x 7x57r model 3000 drilling. I have some Prvi Partizan factory 139 grain ammo. It shoots 4.5" high at 100 yards with the open sights. Can anyone tell me what weight/speed bullet the sights are regulated for and at what distance?
Comments
Charles W. Mathews ballistics tables.
As Sauer Drilling's are likely to be special order, made on a custom basis. The guy that bought it, could have specified. That the rifle sight be regulated, for a non standard bullet weight. Only way for you to find out. is to buy all the available bullet weights. And fire them all at 100 yds. As I said above though, IMHO it's likely to be the 156 Norma Oryx, as referenced above.
https://www.norma.cc/us/Products/Hunting/7x57-R-Mauser/
Just a little food for thought:
Here is the link to the Privi Partizan ballistics page for the 173 grain SP ammunition:
https://www.prvipartizan.com/search_rb.php?id=A-090
Note that the sight in distance is 150 meters. Also note that the velocity is substantially reduced from the CIP standard.
Besides working with the ammunition to achieve your goals, there is also the possibility that you can replace the front sight bead with a new one which is taller. This will force the muzzle down and accomplish what you want without trying to balance the ammunition. The replacement sights are available from New England Custom Guns:
https://www.newenglandcustomgun.com/Gun_Services/Front_Sights.asp
You can call them for assistance in selecting the proper bead and height. IIRC you tap the original sight forward towards the muzzle then tap the new one in from the front to the rear. Ask them for guidance or maybe even send it off to them for fitting.
Best.
Best.
on your intended target. A drilling rifle barrel will shoot away from its two upper shot barrels. That is down.
How much so depends upon vibration motion direction at the exact moment the bullet leaves the barrel, and that is velocity .. I have found 120 gr ballistic tip 7mm to be very effective in terminal results mushroom upset and trajectory. I would try that weight range and adjust the velocity to achieve regulation. It requires tuning by slight velocity changes, and sometimes you go too far in the wrong direction (tuning) .
Keep in mind that bullet performance must
be considered as well as where it strikes . You did not mention a scope, if so
then bring the scope to a setting to match the iron sights.
Having satisfied that , begin with brenneke slugs on the more open choke of the
12 gauge barrels and achieve both rifle and (reasonable )slug regulation .....now you have
a drilling!
game and distance you intend on hunting and pick a bullet to match those needs.
A drilling is very accurate due to a triangulated stiffness of three barrel design, yet
it does react to bullet travel barrel vibrations. The reactions will normally be in the
vertical plane of shot placement. Most drillings have little to no iron sight adjustment
with the exception of apeture sights. And such start "tuning" by bench shooting with
handloads to obtain a result of bullet placement within the velocity desired.
Next adjust your scope (if equipped) by provision of see thru mount to coincide
with the now regulated iron sights. Having achieved this now move on to slugs.
Usually a more open choke will give best results but not always , experiment and
consider which of the two triggers you prefer as a slug. This in effect gives you a
double rifle capability with one trigger for the rifle (of the same/selector)
and the other for a slug. You may even achieve good results with slugs in both
barrels, although the optimun set up is one rifle,one slug, one shot barrel.
Obtain a scope case shoulder strap and carry and hunt with your drilling in
iron sight mode and attach the scope when a longer shot is presented.
Brenneke make a large assortment of 12 ga slugs , 16 gauge slugs are available
but I advise reducing the load of drillings made prior to 1950 . One other
tip //removing a original style brenneke slug (wad screw attached ) and sanding down
the helical rifling to match the choke perfectly and reducing the charge or substituting
7625 powder load is a great way to tune a pre war
drilling. And please refer to drilling as "dry-ling" the correct pronunciation
for german "3" , the only thing you will be drilling is game!
cartridge. I have found good results with 4895 powder filling the cartridge to a
perfect level and there is a wide variety of
bullets. As a drilling, you have room for overall cartridge length not
restrained by magazine length . Allowing you to seat long ballistic bullets out
to the rifling.
as you work with loads keep in mind you have other options for lowering bullet
impact. The front sight usually can be tapped out of its dovetail . allowing you to
replace with a higher sight (file down as you shoot) or on original front sight ( stand up
flat blade I assume) extend its height by adding epoxy( jb weld with black dye, )and again file down as you shoot..
The epoxy can be removed later if desired.
The rear leaf a pop up i assume is held in with a simple cross pin, you can easily remove and replace
with a blade allowing you to file the slot lower. all of this requires competent gunsmithing but not a high degree of effort. the amount of front sight height added
is very little to lower impact from 4 inch to 1 inch @ 100 yards .
A competent gunsmith can even calculate the front sight height required and come very close
to the alteration ,allowing for final tuning at the range.
as for turkey hunting , I have taken many a coyote ( out of shotgun range) with the rifle barrel of a drilling that came to my turkey decoy set up and thus help protect the flock.