I shot my 7x65R Lu-Mar over & under today @ lunch. The load is close to what appears to be close to the bulk of available factory; 170-175g @ 2450-2600fps.

I loaded the following:

175g Sierra BTSP
49.0g IMR4350
est velocity @ 2450fps.

At 50 yds both barrels are within 2" and shoot 1" groups. (can be covered with 2.5" circle)

At 100yds both barrels are 4" apart. Amazingly the windage & elevation are almost even. With groups being 45deg. Both groups can be covered with a 6" circle. (when I get home later tonight will post pic of target

My point is, is this about as good as I should expect? Honestly I can live with this level for this gun and the applications I have in mind.

The regulation can be done via the adjustments but 2" here & there sure don't take much movement back at the barrel.

Input appreciatted.

Pete A.

Pete,
I would call that kind of grouping good. We like to use the phrase "Minute of Grapefruit" when talking about double rifles. Your groups most certainly are that good and better.

You didn't say if you used a chronograph on this outing.
When you are finding a load or just seeing how your rifle shoots with the ammo it was regulated for, a chronograph is really the only way to go. You'll save a lot of time and ammo using a chronograph.

I'd work on some loads before I went adjusting the barrels.
Just my opine.

Pete,

If the barrels are shooting 4" apart at 100 yards you might want to increase the velocity. This should pull things in. If you run into pressure problems before you can get the 170-175gr bullest to regulate then drop down to a lighter bullet as you will be able to get the velocity necessary to regulate. Its generally easier to get a lighter bullet to regulate than a heavy one.

Corbin

I think rusty and Corbin are right. The best thing would be to find out what load it was regulated with. That would give you the best starting point. You really do need a chronograph. The chronograph will pay for itself in ammo savings compared to trying to guess it in. I am not saying you can’t eventually find a load that will be “THE LOAD†but it is easier and cheaper with a chronograph. I think your rifle has great potential from the groups you have.
Bill

Here's pic of today's target:

[URL= ][IMG]

I'm favorably impressed with results so far. I don't think I'll 'monkey' with barrel adjustments yet. Try shooting & enjoying more. the bottom barrel trigger pull is huge (easily 10+ lbs). Had a gunsmith recommend I change the way it is placed on rest in front; to try with the forward rest almost back to main receiver block (been placing with fore-end at about half way like I would a bolt gun).

I like the "minute of grapefruit" philosphy. Kinda brings it all into prespective.

Thank you all for any & all input.

Pete A.

I suggest that you get a set of shooting sticks.
If you shoot off a bench, place your hand on the sandbag and cradle the forearm in your hand as if shooting in the field. You should not be "pressing" the rifle/forearm/barrels against the sandbags.

I may be wrong on this, but I think the bottom barrel should be fired first, then the top.

Correct on both counts !

I'd go a lighter bullet first
as well as Chrony the loads.

I haven't seen many 7mm DR's regualated
for a 175gn bullet which is very heavy for calibre.

When trying to find a load for my Merkel 141 8x57JRS I took 4 different bullet weights and loaded 5 rounds of each with 2 different powders using the middle load for each powder type and bullet weight. Shot at individual targets for each load. Most accurate 5 shot (2L,3R) group was with the 200gr (heavy for caliber but what I hoped for) bullet and was I believe (I'm not at home and don't have the target).633. I would think your rifle should shoot far better than what you are getting. My gun IS scoped however which may account for some of it. All my shooting was off the bench with left hand GRIPPING the forearm and back of hand on sandbag which is how I shoot ALL rifles from bench. Barrels were allowed to cool between each pair of shots. Do not have a chrongraph so I only use the book values for velocity. Seems to work for me.

Rusty, It does shoot bottom first & top second. Both barrel hit basically same spot @ 50yd and then thus cross.

500N; I tried 140gs & they would not stay on paper together @ 100yd; 6" apart @ 50yds. I reviewed all the factory ammo spec's and few makers even offer 140g. Majority of loads are in the 170-175g range with some at 150+/-. IMHO 140g have little use in this type of gun; I've got a superly accurate 7x57 for use there. Based on my experience so far I can't see this gun offering 300yd accuracy where a 140g would offer advantage.

I'll try some different shooting postions.

Pete A.

Doubles are like long bows or fly rods, the slighest change in tec. can change POI. and group size. I shot some light loads off the bench, at 50 yards they hit a foot low, then I shot them off hand, they hit right to point of aim. Shoot off of a standing rest, sticks or a good tripod (with a home made flat top to rest only your hand on). Try to hold the gun just as you would off hand
(don't put any down pressure on the hand resting on the sticks, pull back with the front hand just as you would shooting off hand, let it rest lightly on the rest. I would use the same ammo and rerun test, Get the triggers done 3.5 lbs is about right.

JD

Pete

I was thinking more along the lines of 160gns,
not 140gns.

I'm not sure what ammo is available to you
but I'd load up some 160gns

quote:

Originally posted by 500N:
Pete

I was thinking more along the lines of 160gns,
not 140gns.

I'm not sure what ammo is available to you
but I'd load up some 160gns

I bought cases & dies so I'm rolling my own. I'll try them too. Heck any reason to shoot a gun more is a good reason in my book.

Will be a bit before I have more data as we (wife & I) are doing a weekend trip for our 20th wedding anv. So I'll have to let the double sit alone for a couple of days.

Thank all of you for the great tips & ideas.

Pete,
If I read your target right and your subsequent comment as well, your barrels are crossing just past 50 yards with that load of powder. I'd try another six REDUCING the powder load two grains and see what you get. All the advice about ensuring your barrels have a soft support under them (like your hand) is also well taken.


Regards, Tim

Better results!! 48g IMR4350, Receiver resting on front rest not fore-end.

2 3-shot groups; 1.20" & 1.25".

Again groups 45 deg apart with 3.25" ctr's @ 7:30 & 2:30. Total groups size @ 3.65" (I wonder what O.D. of the 'minute of grape fruit" is?). I hope my scriblings on the target don't confuse.

I am encouraged. I'll try @ 47g IMR4350 (should still be 2400fps+/-). As I said before this is all better than I expected at the out set.

[URL= ][IMG]

Obviously, that load seems to group well with each barrel. Comparing it to the first target you posted, the bottom barrel group has not moved. The top barrel group has move to the left and up a bit.

Would it be possible to try another brand of bullet? Do you know what weight of bullet the rifle was regulated with?

If after trying another type of bullet or if the regulation ammo doesn't bring the groups closer, then I'd consider re-regulation.

I still think the best thing would be to find out what it was regulated with at the factorey. The gun should have come with a test target listing the load used.
If you don't have that try contacting the maker.
Hear is a address.
VIA ARTIGLIANI N 11 GARDONEI-25063 ITALY VT , Voice: 011-39-30-8912433 Fax: 011-39-30-8911185
Bill

Pete,
Agree with Bill that you should find out what the maker regulated the barrels with. That can give you a point of departure.

But, the bullet you need to work up a load for is one that you will actually hunt with. That should be one of the premium heads such as Swift A-Frame or, at the minimum, Nosler partition or something premium that welds core and jacket together. NOT Sierra or other ordinary heads that do not hold together.

You will find that the partition bullets, no matter whose, have more velocity in general, due to longer bearing surfaces, just find one that gives you the best group from each barrel and then tweak for the best composite group from both barrels.
Regards, Tim

You answered your own question when you stated you could live with it for the application you intend to use it for..If it suits you then that is all that counts..

I, personally would play with it and see how good it can get and that will be about an inch and a half according to your targets...remember any double will only group as well as the WORST barrel groups..that is what you should strive for.

Most doubles are regulated at a shorter range than 100 meters-usually around 60 or so. I would want a caliber like the 7X65R to shoot into a circle smaller than 6" @ 100 meters - not more than 3" at most.

My 8X60RS SXS generally puts both barrels into less than 3" @ 100 meters with its' regulating load, a 200-grain bullet and 58 grains of RE 22, MV 2450 FPS.......