Advise on working up test loads

[Skeeter]

I am working up new loads for my 22 BR Norma. I have 400 rounds all prepped and ready. I loaded up 30 rounds last night and used those for barrel break in this morning. Then I started my test loading. I loaded up 30 rounds using two different powders and 5 different powder charge weights for each. I settled on the powder I like and the charge weight, but want to perfect it further using bullet seating depth. All my test fired cases were seated the same at 15 thousands off the lands.

Here's my dilemma. Do I continue to work up my next batch of test loads using my same prepped brass, or should I now use the once fired cases? Using the prepped brass will give me like results in the field (as I'm not planning on fire forming the additional 350 rounds of prepped brass), however, I know the now fire formed 50 pieces of brass is much closer in tolerances to my chamber and should provide the best results.

Suggestions? Thanks

Skeet ???

 

[in2deep]

Since your going to be shooting fireformed brass in competition and it's pretty well been documented that the load commonly changes after fireforming it would seem that final load developement should be done with fired brass.
At closer ranges it may not matter as much but if you do it best the first time I found it saves time and money down the road when you start second guessing the variables and end up repeating everything anyways like I did.
My initial ladder tests fireforming were useful in determining a closer range of load windows and showed useful information to develop the final load.

 

[Skeeter]

I'm sorry, I guess I should have been more clear. The total sum of 400 pieces of brass will be loaded for Prairie Dog hunting. The 50 pieces I have fire formed were from that group. I'm not going to be fire forming the remaining 350 rounds, just use my final load from the test firing on all the pieces.

Since the bulk of my ammo is the 350 pieces prepped (but not fire formed) wondering if I should be tweaking the loads using the newly fire formed or just prepped as that is the bulk of the rounds? Thanks

Skeet

 

[BoydAllen]

Skeet,
How did you come up with your seating depth, and what sort of accuracy are you getting with your best loads?
Boyd

 

[Skeeter]

Hi Boyd,

I basically took some of my knowledge from loading 220 Swift, 22-250 and 6mm BR and applied it to this load. The best group shot was .355 (3 shot group @ 100 yards) using 31.6 grains of Varget, CCR-BR4 primers, 52 gr Sierra MatchKing BTHP's. I was able to replicate the same size group several times, but feel I should be able to shrink this down into the low .2 or .1

Brass is Lapua 6BR Norma run through a custom Redding forming die, then through my Redding FL sizer, pushed through a K&M .224 mandrel, trimmed to 1.557" and very lightly turned to remove high spots, case is run through Redding neck sizing die and bushing to have .002 tension on bullet.

Thanks

Skeet

 

[BoydAllen]

The usual questions....describe the rifle, rest. Are you shooting over flags of some sort? Have you ever tried seating bullets longer than touch? Working up loads at the range is much more efficient. In any case, the accuracy that you already have should be sufficient. One thing...if you are making .22 BR cases by necking down 6 BR cases, it is highly likely that they are not straight, which may be limiting your accuracy to less than it will eventually be with fire formed cases. It looks like you have a good enough load to fend off attacking hordes of prairie dogs. When you return, you will be in a better position to fine tune. Have fun.

 

[Skeeter]

Thanks Boyd,

Gun is a custom made Savage Striker Pistol, McGowen 1:14 twist Barrel w/target crown, Cooper Gen-2 Stock that is pillar bedded and barrel floated, SSS Competition trigger set at 14oz, PT&G Bolt body timed, trued and lapped as well as bolt race way trued, Ferrel Bases & Rings, Vortex Viper PST 6-24 x 50mm scope.

Was shooting off front rest, rear bag, zero wind and 55 degree temp.

I couldn't find any starting info on seating depth for 22 BR Norma, so I started with what my other rifles seem to like. Is there any norm for this round as far as seating long or into the lands? Thanks again.

Skeet

 

[BoydAllen]

So you are shooting a rear grip bolt action pistol, or is it a rifle based on a pistol action? Another thing, without some sort of wind indication devices spaced down range, you really don't know what is going on in front of you. Your I was shooting when there was no wind is pretty typical of what I read from those who don't use some sort of flags. If you want to shoot small, rig something up. They are integral to getting predictable results. Go to a short rang Benchrest match if you can. Consistent small groups require a complete package of equipment and procedures, that are basically mandatory. I find it common that shooters will say that they want to shoot small, but don't want to be bothered with one thing or another that will keep them from their stated goal. These fellows usually do not shoot small aggregates, where every shot is counted. It sounds like you have the makings of a really accurate rig.

 

[Skeeter]

Thanks Boyd,

I have several custom varmint rigs and all of them I have been able to get groups well under .2 in similar conditions. There was no determinable wind Sunday morning as I do have a Kestrel wind gauge, and it read zero at both the bench and at the target and leaves on adjacent trees were not moving. So conditions were right. I think I can shrink it down by testing loads with longer seating depth and switching rear bag. The rig is a pistol with a pistol grip as seen below. Another thing I just noticed was my fired cases are now actually shorter than I started with??? Measured prepped case was 1.557" in length and the fired cases are now 1.475? Seems I have lost some length, possibly due to the sizing and the fire forming of the shoulder/neck junction. This may make it a little iffy in seating the bullets longer as there wont be much of it in the case neck.

 

[BoydAllen]

Nice picture....Back in the day when there was a little pistol benchrest competition, some of the fellows attached a horizontal bar to the bottom of their rear grips, that was designed to track in a rear bag like those commonly used for rifles. My suggestion about some sort of flags stands. Sticks and surveyor's ribbon would not cost much, and will give you a lot more information than you are currently getting from your kestrel. As to your sizing die situation, two things... Are you measuring shoulder bump when you FL size fired cases? Have you measured the shoulder diameter of a formed case, a fired case, and a FL sized case that was fired before sizing? A case getting shorter when it is fired usually happens when the chamber is larger in diameter in the body and some of the neck is pulled down into the shoulder, as the body expands. This is common when fire forming 6PPC cases from .220 Russian, or on the first firing of a case in an AI chamber. Good luck with your project. Let us know about further developments.

 

[Skeeter]

Hi Boyd,

Thanks for the info, I'll take some measurements tonight and let you know the differences. One other thing I did notice was the cases were very sooty and black with carbon on the outside, much more than I usually find when fire forming cases. I was testing loads at 31.4 grains of Varget and could it be the loads were a little under the pressure curve and not expanding enough during the firing and forming process?

I'll certainly take some flags with me this weekend to see if there is anything swirling about while sighting it in ;D

Thanks again for all the great info.

Skeet

 

[dtucker]

Very nice set up. Did you have the barreled action bead blasted and what bolt handle do you have on their?

 

[BoydAllen]

Skeeter,
Once I have fire formed cases in hand, I take my loading gear to the range and do a pressure series, like a sort of 100yd mini ladder test. I pick a day that has easy wind, shoot over flags, and shoot one shot per load on the same target, with .3 gr. increments, shooting carefully and paying attention to the flags. This is done with FL sized cases. Actually, I sometimes run back and forth to the loading bench (8') and reload the same case, to slow myself down, and so that I will not end up with several cases that have been shot a different number of times, than the set that they are a part of, or have been subjected to significantly different pressure. In any case, having picked a seating depth based on previous experience, I keep increasing the load till I feel a little tighter bolt than I like, stop, note the temp., humidity, and load data, and look at the target for some indication of a good powder charge. I look for perhaps 3 shots where the charge increase did not seem to make much difference, a cluster. Then I load the middle charge in that group, and play with seating depth.

 

[Skeeter]

Hi Dan,

The action, recoil lug, barrel, Bolt and Bolt Handle were all Titanium Blasted so they have the exact same finish. The original setup was all polished, but was really hard to get a consistent polishing to match from part to part, so I hand my smith blast the entire thing including the custom SS base. Ken Ferrell made the rings to match. As for the handle, I bought a new SS handle from Kevin Rayhill and then sent it to Bill Hawk to have the custom knob installed.

Here is a closer view of the action.

 

[Skeeter]

Hey Boyd,

Great advice on working up test loads. I do have a compact press and thrower, so I might just follow your routine this Saturday and actually work up the loads at the shooting bench. That way I can make minor adjustments while I witnessing the results of the loads.

I'll follow up again on Saturday when I return from the range. Thanks again

Skeet