Ladder test ???

[JeffP40]

Ditch the sled and use a good front and back bag set up. Shoot for groups at 100 or 200 yds. Take the best and do another ladder at 500 and see what happens. I'll bet your groups improve tieh the bags. Then your ladder may tell you something.

 

[jsthntn247]

Those targets got me drunk trying to read them. You got too many things going on at once. What powder charge and bullet has been the best so far. All 7mags I've had in the past liked the 168 with 65 grains of re 22..

 

[tstarky]

The rifle seems to favor Berger VLD 168gr. with 64 grains of re 22. The Sierra 175 grain looks promising also. See the group vertical maximum chart. It is in inches. The Berger 168gr. vertical max for the 3 round group is 4.2" at 500 yards. I would like to see 2". The Sierra 175 vertical max for the 3 round group is 9.2" at 500 yards. Also note that the feet per second charts show fairly stable velocities. These are indicators that we are on track to find the "magic" bullet/powder combination.

I installed the B&C stock last night and am waiting for the bedding that I added to cure. It has a aluminum integral bedding block and a raised area near the front of the stock where the barrel is. The barrel/action assembly sat on the rear piller (at the action) and the barrel sat on the raised area near the front of the stock. There was a gap between the front pillar (front trigger gaurd/action bolt area) bedding area and the action. When I began to tightened down the 2 action bolts the presure began bowing the barrel/action assembly and/or the stock.
I removed some of the stock material from the front area to lower the action and close the gap. I was carefull to insure that the rest of the barrel stayed free floating. The gap shrank but there still was a small gap left. I then bedded using Acruglass at the piller areas where the action seats to the stock. I will see how it shoots and if not satisfied I intend to remove the raised area near the front of the stock wher the barrel rides, free floating the barrel the entire length.
Does anyone have any comments or opinions about this raised area near the front to the stock where the barrel rides. I have seen it on the B&C and the stock Remington XCRII stocks. Why is it there?

I will continue testing this weekend with some other powder bullet combinations and 5 shot groups of the promising combinations noted in this post.

BTW
The Berger 168g VLD hunting bullet has a hollow point and they are finding that this round is opening up in flight. They are redesigning to fatten the narrow missle like projectile. I ran into Carl recently at the Ben Avery range testing these new bullets and am looking forward to the results.

 

[DMP25-06]

I think that you will have great difficulty in trying to free-float the barrel in your Bell & Carlson Alaskan II stock , as it is designed to have an upward pressure point at the fore-end under the barrel . Read the note beneath the description of the Alaskan II in MIDWAY USA website .

When you tighten your action screws to the proper torque , it will cause the fore-end to raise up to contact the barrel , just forward of the front sling stud .
Call Bell & Carlson to verify if what I say is correct .

I have a Weatherby Mark V , mounted in a B & C Medalist stock , that had the very same problem . The stock is made with 2 aluminum arms that are part of the bedding block system , and these arms extend full-length forward of the recoil lug area , one along each side of the stock .
When the action screws are tightened , the arms are leveraged upward , to create a pressure point under the barrel . This was quoted , and explained , to me by Bell & Carlson customer service .
In order to free-float my barrel , I had to cut these 2 arms , just forward of the recoil lug , removing a 1/4" section out of each rail , then repaired the stock using Marine-Tex epoxy .
Problem eliminated , barrel now free-floats , and accuracy greatly improved .

By the way , I have a Remington Sendero 7MM Rem. Mag. that shoots very well using 162 gr. A-MAX bullets , Fed.215 primers , H4831 powder , and Winchester brass . 26" factory barrel @ 3020 F.P.S.

GOOD LUCK .

 

[tstarky]

Thanks for the information DMP25-06. I was able to free float the barrel using Gunline tool's Barrel Bedding Tool in 3/4". Midway USA sells them. And I bedded the action areas using AcraGlas.

A few weeks ago, after the bedding job, I went on a long range shooting clinic offered by HellsgateTactical.com. I had not delveloped the load for this rifle yet so I used Winchested 150gr factory ammo figuring that I could at least gain some techique pointers and have some brass to reload.

It was a windy day. I was able to hit a 9" round target 853yards away 20% of the time. I thing we have experianced an improvement in accuracy. After my next test usingf 5 round groups I will know which bullet/powder combo she likes.

 

[tstarky]

Re: Ladder test ???- now sub MOA shooters

Eureka!
After finding the best bullet and powder combos and then performing a 5 group jump test (incrementing jump .030 each step, ranging from .010 to .130) we have a pair of sub MOA, @100 yards, rifles now.

These are factory barreled rifles.
The Remington 700 7MM RM loves the Berger 168 VLD hunter with 65gr of RE22. The bullet jump is .010.

The Remington 700 30-06 is happy with Sierra Spitzer's 180gr and 58.3 grains of H4831SC powder. The bullet jump is .130.

I will be performing a finer jump test of .002 increments, ranging .040 (+-.020 sans jamb) over the next few weeks with hopes of shrinking the consistant sub MOA groups.

Also noteworthy is that we added an adjustable Muzzle break to the 30-06. The group size shrank about 40%! Got it from Brownels Blue, .660" : ADJUSTABLE MUZZLE BRAKE | Brownells
We did not have time to optimize the adjustment setting but will be performing that fine tuning after the completion of the jump test.

 

[tstarky]

Here is the first group just after rifle was purchased and the last group as of 12/4/12