Fired my first shots downrange with my new .500 A-Square.

YEE HAW!

All shooting was done at the bench rest at 100 yards, mostly just for load testing, but also trying for some accuracy.

I warmed up with some .22 LRs through my son's CZ 452 to check the chrony—and all was well with the chrony.

Next, I put ten rounds of some mild .458 Lott ammo through the screens to rectify the arthritis:

.458 Lott—BeLL Case—Federal 215 (LRM) Primer—83 Grains VihtaVuori N540 Powder and 500 Grain Woodleigh Soft Point

#1 2,157 fps
#2 2,161
#3 2,151
#4 2,168
#5 2,156
AV 2,159 fps

.458 Lott—BeLL Case—Federal 215 (LRM) Primer—83 Grains VihtaVuori N540 Powder and 500 Grain Woodleigh Solid

#1 2,131 fps
#2 2,170
#3 2,157
#4 2,175
#5 2,164
AV 2,159 fps

Next, I uncased my new baby, screwed on the muzzle brake, jammed a soft foam pad between the Declerator on the buttstock and my shoulder and tried her out:

.500 A-Square—BeLL Case—Federal 215 (LRM) Primer—110 Grains RL-15 Powder and 570 Grain Barnes XLC Coated X-Bullet

#1 2,458 fps
#2 2,462
#3 2,463
#4 2,464
#5 2,474
AV 2,464 fps

.500 A-Square—BeLL Case—Federal 215 (LRM) Primer—110 Grains RL-15 Powder and 600 Grain Woodleigh Solid

#1 2,418 fps
#2 2,423
#3 2,418
#4 2,408
#5 2,418
AV 2,417 fps

.500 A-Square—BeLL Case—Federal 215 (LRM) Primer—110 Grains RL-15 Powder and 600 Grain Woodleigh Protected Point Soft Point

#1 2,375 fps
#2 2,375
#3 2,392
#4 2,370
#5 2,389
AV 2,380 fps

Groups were OFF THE PAPER and my rear express sight has been filed too low! Best I could tell, bullets were hitting 28" low and 18" to the left! But they sure tore up a nice set of grooves in the sand backstop.

I have to do some work here, but what fun!

Hey Mon,
You are using my favorite recipe. 110 grains of RL-15 and the 570 grain XLC. The 570 grain GSC FN is The Solid that is hoarded away for magazine filling. Attaboy! Now go fix those sights.

Yes, RIP, I have you to thank for that suggestion. It seems to be a good, stout load.

I just have to get a new fixed rear sight and file down gradually or get a higher front sight and see what that does. Nothing's easy.

What's the front sight? if it's an NECG, order the partrige(?) and file er down till you get close to the right height, and then get the ball.

what action is she built on?

jeffe

Pictures man we need pictures

How's the recoil with the break and the foam?

Mike

It's the AHR CZ 550 Mag. I posted pics awhile ago at this link:

AHR

I'm going to mike the front sight--it's an NECG fiber optic bead, and see how high it is. I hope it's the lowest. If it isn't, I'm going to have to contact Ed about a new fixed rear blade.

I am surprised that your sights were filed in without being sighted in. That just seems odd.

Have you thorougly tested the rifle for feeding from a full mag, 1/2 full mag, 1 shell in mag, muzzle up, muzzle down, barrel horizontal, etc.?

500 grs.--Me, too on the sights. Seems like they were regulated for a slower load and/or a lighter bullet. Plus, I like a six o'clock hold and that's probably not helping.

Not a big deal though. I'll get it straightened out.

The rifle feeds flawlessly with all tested loads from every angle. Very smooth and positive. BTW, it holds three down and one up.

Sure would be nice if Barnes would make the TSX available in .510/570gr, and while I'm wishing, a .505/565gr, just to be imaginatve.

Since the GSC HV and FN of .510/570gr persuasion are so hard to come by lately, the Barnes XLC and the Woodleigh FMJ "solid" are the best hunting bullets available for the 500 A2. The expansion of the Woodleigh WeldCore soft is too much of a good thing for use in a 500A2 unless you slow it down a bunch, to 500 NE velocity.

quote:

or get a higher front sight

quote:

it's an NECG fiber optic bead, and see how high it is. I hope it's the lowest.

Don't you just need a lower front sight to pull the POI up?

Cheers,
Canuck

Yep,
Bullets hitting 28" LOW and 18" to LEFT at 100 yards:

Lower the front sight height
or
Raise the rear sight height.

Drift the rear sight to the er, uh, RIGHT!

I hope the front sight windage is correct, centered, and there is no canting of sights!

Draw some equilateral triangles and use simple algebra/proportionality to figure out how much the change will be: Need to know the sight radius/distance between front and rear sights.

Yes, Canuck and RIP, you guys are correct. I had it backwards, but I think I know what I meant?!

It's the rear sight that has to go in the direction you want POI to move, and the front sight the opposite direction--so I hope mine's the highest.

God how I miss my scope at times like these!

It would be nice to be able to get GS Custom bullets from a reliable domestic source.

MR,
I knew what you meant and I wasn't going to say anything until Canuck did. Then I found I goofed on my first typing of it too, then edited.

Sounds like a taller driftable rear blade is needed to stick with the current front sight, if it is how you like it, or a change of front sight height and some kind of windage adjustment somewhere.

Give us the sight radius and see who can come up with the correction to compare to your calculation.

quote:

I knew what you meant and I wasn't going to say anything until Canuck did.

I wasn't going to say anything until I saw it in two different posts. Then I thought I'd better mention it just in case a taller front post might have gotten ordered by mistake!

Hopefully the front post isn't the shortest they have, if you decide to attack your problem from the front.

Cheers,
Canuck

Is the ideal long term solution an adjustable rear sight like used on the Weatherby DGR and Safari models. They would appear to have a lot of adjustment and at the same time be immune from sliding from recoil.

Mike

Thanks Canuck, and RIP, too, but I'm a bit slow off the mark so far. I haven't even miked the front sight I have yet.

But I would like to go at it from the front, if possible, since it just might be easier to do that way--if I should ever be so lucky.

I have a table somewhere in some book (or used to have one) that does the math for you and shows how far you need to move a front sight for a given sight radius to move POI a given amount at 100 yds. But I may take you up on your offer Professor RIP.

quote:

Originally posted by Mike375:
Is the ideal long term solution an adjustable rear sight like used on the Weatherby DGR and Safari models. They would appear to have a lot of adjustment and at the same time be immune from sliding from recoil.

Mike

Mike, I haven't seen the adjustable model you mention. But I do generally prefer the fixed ones, with at most one extra flip up blade--once they're properly regulated!

Here is a picture

http://www.hendershots.net/images/gunroom/460c-6.jpg

Although their catalogue, which can be down loaded from their site, has a better picture which is showing the blade as being mounted on a thread.

It might be made by NECG because the front sight on the DGR and Safari sure like NECG.

Mike

MRLEXMA

Thanks for the link to the pics, didn't recall that post.

Excellent looking rifle..

Mike

Okay, I checked my book and there was no table, just a formula:

Distance to move front sight (opposite) or rear sight (same) to achieve desired POI change = (Sight Radius x Desired POI Movement) / Distance to Target (all in inches).

My sight radius is 17 inches, the number of inches of desired vertical impact movement is 28 inches and the distance to the target is 3,600 inches. So, (17 x 28) / 3,600 = 0.132".

My front sight is 0.315" high, the second highest offered by NECG. They offer another lower one at 0.276" and the lowest is 0.256".

0.315 - 0.256 = 0.059". So, with the lowest front sight I can get, I get way too little adjustment.

As best I can tell, a new rear blade will get me 0.090†more height to flat out horizontal, which really doesn’t work for a shallow vee approach. So let’s say I get a new rear blade and file it down to half that, at 0.045†to a nice, shallow but not too shallow vee. That leaves me needing this much from my front sight:

0.132 – 0.045 = 0.087â€

Can’t get it. Can only get 0.059†with the lowest NECG option. Leaves me 0.028†short.

So, maybe I get the new rear set up and cut it down only 0.017†for a much shallower and wider vee? That with the lowest NECG front gets me there, I think.

I’m getting a headache. Somebody please check my math . . .

This may be a simplistic approach, but possibly you could contact Ed and find out what load the rifle was sighted in with? Seems during a past conversation, he stated that he shoots IMR4350 at 110 grains with a 570 grain bullet in the 500 A@ rifles. Good luck and keep us updated on the progress of this as quite possibly someone else can benefit from your discoveries KMule

hell,
stop jacking about with "this might and that might" be enough adjustment

http://www.brownells.com/aspx/NS/GunTech/sight.aspx

jeffe

Great link jeffe. Thanks.

Thanks, jeffe. That's a handy reference. Very helpful.

I'll have to check my barrel's ODs at the front and rear sights, plug in my numbers and see what I get.

MR,
Before doing anything, you need to talk to Ed Plummer about what load these sights are supposedly set up for???

Maybe he would supply some parts no charge???

Thanks RIP and KMuleinAK, but I have already done that long ago.

Ed told me before he shipped the rifle that he used a load with 570 grain Woodleigh softs and H4350 for testing.

I don't know his velocity, but I do know that I don't want to use the 570 grain Woodleigh or any other bullets than the ones in the loads I have already worked up. I also want to keep my velocities in the 2,350-2,450 fps range.

The only thing that threw me a little was that the sights had already been regulated by filing down the rear blade. (Although even with that it's hard to figure how they could be so far off with my loads.) I do intend to contact Ed about swapping out the sights for some that work for me, though. Knowing him, that will not be a problem.

But first I have to do some more measuring and the math!

MR,
O.K.
X = .085"
Y = .132"

Figure about 0.001" left or right will give you 1 inch at 100 yards. I didn't know people would go to such trouble to actually make a table.

Jeffe - thanks a bunch for the link, very helpful although I hope I will not need it on any future projects

Sounds like good fun, I like to use a standing bench for the big bangers................over the bonnet of the cruiser.

I always use the NECG adjustable rear sight available from Brownells.Even on big kickers, one screw and accraglass holds em forever. This way you don't have to solder. They also make sight inserts with different sight heights. Always remember, whether using open sights or a scope. Move the sights in the direction you want the bullet to go. Front sight is opposite.-Rob