New brass

[Gater]

I Rebarreled a savage .223 with a quality barrel bedding is tight as bark on a tree I loaded up 50 80.5 Bergers 24.8 grains Varget shooting 2800fps bass has never been fired Lapua seated .005 jump at 200 yds I would get 3 tight two would end up high. How much will the brass being never fired affect accuracy? Thanks guys

 

[lazyMlazyK]

I can't speak to your brass question, but have you checked scope ring and base screws?

 

[Gater]

I can't speak to your brass question, but have you checked scope ring and base screws?

I thought that all that was good but it doesn’t hurt to double check also I did go to a different scope. Thanks

 

[Coyotefurharvester]

Probably not "one thing", new brass is just part of the equation.

 

[Ned Ludd]

I have used prepped virgin Lapua .223 Rem brass in F-Class matches on numerous occasions. If it is properly prepared, virgin brass can shoot very, very well. I have noticed over the years that the neck tension (interference fit) with Lapua brass straight out of the box can be all over the map. I size .223 Rem Lapua brass first using a FL die with a 0.246" or 0.247" bushing. Then the necks are opened back up and the desired neck tension set with a 0.2225" mandrel (i.e. 0.0015" under bullet diameter). Sizing the necks first with a bushing that is slightly smaller than I would use if it were to be the sole neck sizing step to yield approximately .002" neck tension (i.e. 0.246" instead of 0.248") allows the mandrel to do work on every piece of brass, even the pieces that have slightly larger diameter necks than the others. Spring-back of the brass following withdrawal of the mandrel that is .0015" under bullet diameter yields very close to .002" neck tension. If the bushing die has already been properly adjusted to bump the shoulders of fire-formed brass for a given rifle/chamber by .0015" to .002", it will not move the shoulders of virgin Lapua brass back at all (i.e. base-to-shoulder measurement, BTS).

There is another consideration to using full pressure loads in virgin Lapua brass that also stems from the BTS measurement straight out of the box. In my hands, the BTS dimension of virgin Lapua .223 Rem brass may be as much as .006" to .008" shorter than it will be after the first firing. Brass that is relatively short in the BTS dimension can promote blown primers with full-pressure loads because the case is driven forward by the firing pin strike, yielding a bit more headspace as the cartridge fires. Apparently, this action can help to promote blown primers with full pressure loads in virgin brass. I have observed this happening with both .223 Rem and .308 Win Palma brass from Lapua. To be fair, the frequency of this is not high...maybe a piece here and there. Unfortunately, a blown primer in virgin brass usually means the primer pocket is toasted and the case no longer useable. One obvious solution is simply not to run full-pressure loads in prepped virgin brass.

Once virgin brass has been fire-formed and the shoulder bumped .0015" to .002" during the next re-sizing step, in my hands it is usually necessary to drop the charge weight by anywhere from about 0.1 to 0.3 gr to re-create the velocity obtained with the virgin brass. Presumably this stems from a certain amount of energy from the powder being necessary to expand the virgin case and push the shoulder forward. In any event, it is usually very easy to reproduce the original velocity of the load as worked up in virgin brass, which will typically also reproduce the performance of the original load, or at least provide a very good starting point for re-working the load in fire-formed brass.

 

[lazyMlazyK]

Once virgin brass has been fire-formed and the shoulder bumped .0015" to .002" during the next re-sizing step, in my hands it is usually necessary to drop the charge weight by anywhere from about 0.1 to 0.3 gr to re-create the velocity obtained with the virgin brass. Presumably this stems from a certain amount of energy from the powder being necessary to expand the virgin case and push the shoulder forward.

I've heard similar things in the past, and I just can't wrap my head around it. In my mind, it goes like this - say the charge used in the virgin brass is 20gr. Fire the round, you gain a slight amount of volume in the case due to the shoulders being formed to your chamber. To increase the pressure and velocity upon the 2nd loading of the case, in my head, one should need to increase the powder charge, maybe to 20.2gr, to make up for the slight increase in case volume.

From what I've read, it doesn't work this way, and I have no way to determine actual case pressures.

 

[barefooter56]

I Rebarreled a savage .223 with a quality barrel bedding is tight as bark on a tree I loaded up 50 80.5 Bergers 24.8 grains Varget shooting 2800fps bass has never been fired Lapua seated .005 jump at 200 yds I would get 3 tight two would end up high. How much will the brass being never fired affect accuracy? Thanks guys

Did you start out with a clean barrel when you shot this group?

 

[jelenko]

I Rebarreled a savage .223 with a quality barrel bedding is tight as bark on a tree I loaded up 50 80.5 Bergers 24.8 grains Varget shooting 2800fps bass has never been fired Lapua seated .005 jump at 200 yds I would get 3 tight two would end up high. How much will the brass being never fired affect accuracy? Thanks guys

Is that a known good load? And, just to confirm, the new barrel is the same length and chamber as the factory one?

 

[M-61]

No clue.
However it will happen only once.
So unless you plan on loading and shooting’unfired’ brass, I wouldn’t give it too much thought.

 

[Ned Ludd]

I've heard similar things in the past, and I just can't wrap my head around it. In my mind, it goes like this - say the charge used in the virgin brass is 20gr. Fire the round, you gain a slight amount of volume in the case due to the shoulders being formed to your chamber. To increase the pressure and velocity upon the 2nd loading of the case, in my head, one should need to increase the powder charge, maybe to 20.2gr, to make up for the slight increase in case volume.

From what I've read, it doesn't work this way, and I have no way to determine actual case pressures.

I can only tell you that in my hands, the charge weight necessary to maintain the original velocity of a load in virgin brass once it has been fire-formed is always slightly lower than it was in virgin brass. Yes, the case volume increases slightly upon fire-forming. However, if you play around with case volume inputs in a reloading program such as QuickLoad or GRT, the predictions are that relatively minor changes in case volume don't have a huge effect on velocity. The effect will obviously not be zero, but it isn't huge either. Obviously, the more generous the chamber specs, the larger the difference in case volume before/after fire-forming, thus a greater potential effect on charge weight and velocity in subsequent firings.

It is clear that a certain amount of energy that derives from combustion of the powder must go into expanding the brass to fit the chamber, rather than pushing the bullet; i.e. increasing velocity. Whether that is the sole reason it seems to take slightly less powder in fire-formed brass to obtain the same velocity as with virgin brass, I can't state with any certainty. I could imagine there could be other contributing factors. For example, how quickly/well the neck seals to the chamber during the initial stages of ignition could vary between virgin and fire-formed brass. The good news is that we really don't have to understand the exact mechanism by which this might occur (even though many of us reloaders would like to), because the effect of fire-forming brass on charge weight and velocity can be tested with a relatively minor effort.

 

[KMart]

No clue.
However it will happen only once.
So unless you plan on loading and shooting’unfired’ brass, I wouldn’t give it too much thought.

I think there is something to it. Have you noticed how well everybody's rifle shoots when they are fireforming brass, 6br to dasher , for instance.
Some take it to shoot prairie dogs. Others shoot it in match that isn't that important to them. And it all seems to shoot well.

 

[M-61]

Yes there is something to it, however I noticed your two choices.
I’ll add my best one. 30BR. It doesn’t seem to care at all. A few years ago I got hooked on the 30br
Have to fire form and there isn’t really any kind of shortage at the time. But none the less I pulled lots of 30 carbine bullets. WW2 vintage. 100 yards. Hoping to hit the paper which was large. 5 shot groups. Figured I’d be done in no time.
First group I have 3 touching. I slow down and start again still figuring this was a fluke. I fired lots of 5 shot groups that day. Don’t know the number of clover leafs I shot but it was amazing to me.
Who knew? Some cartridges are real naturals.
Some were never meant to be.

 

[Gater]

The barrel is the same length and diameter the old one was a 1-7.7 this one is a 1-7 both barrels made by the same company the old one shot great but started opening up at 200 from holes in holes to about and inch so I put the new barre on and started with unfired blue box Lapua brass. Shot one round cleaned it shot another cleaned it shot five cleaned it it was cleaning up fast so I fired a total of 50 so am going back check scope mount tension on the stock i necked sized the brass checked the length they look good. Also backing load off to 24 gr varget same jump and see how it goes Thanks again for the help have been reloading for a long time some times ya just need to step back and say wtf

 

[Ray123]

Unfired brass has shot some excellent groups, when shooting a bullet the barrel likes, even better than the same brass reloaded in the ssme chamber. I have been shooting unfired & primed LC brass, some dirty (and some polished off) on the outside from bullet sealant, in a variety of 308's bolts & AR 10s plus 100 Nato primed brass from turkey, with a slightly smaller capacity than LC brass. Shot as an experiment crap unfired brass, cheap surplus powder, and 748, h380 and old powder on hand. With the bullets the 3 AR 10 barrels liked, they 5 shot groups were .3" to .6" Many were in the 1" range with crap primed Mil-Spec brass. In the heavy bolt gun in 308 this crap LC primed brass printed nice tiny groups about a tenth or so, larger than the Lapua brass previously fired in that rifle firing the same match bullets. My dasher shot unfired new Alpha brass into tiny groups with 13 different loads and match bullets.
No special attention to the 308 loads just loaded in a Dillon progressive and fired, except cleaning the tar specks of some and firing some really dirty...it the barrel liked the bullet it shot good groups. If shooting in competition or your best effort in some shooting sport go with the best components and the prep you desire...but for general use and steel shooting with friends, LC does pretty well. One of the most continuous accurate bullets across 3 AR 10s and 2 bolt guns with a variety of twists and chambers with crap brass was a 15 cent (bought in quantity) Speer 130 gr Vatmint bullet, shooting .3" and .4" 5 shot groups back to back in one 18" AR10 and around .5" 5 shot groups in the other AR 10s...also liked was the 168 Speer match across a wide range of 308's...one AR 10 18" 10 twist put 10 shots into .970" with primed LC brass ...never before fired.
So is large or double grouping a fault of unfired brass in your chamber an issue, most of the time probably not...but your barrel may have a different opinion.

 

[K22]

I've never had virgin brass cause any significant change in precision that I could detect.

I full size all new cases before firing with a zero-shoulder bump to make sure the neck and body are in alignment. To prevent extruding the case (lengthening it), I adjust the die, so the case shoulder makes contact with the die but does not push the shoulder back.

Seems to work for me.

 

[Gater]

Hey guys again thanks for the in put.
I reloaded the once fired brass lightened the load to 24.3 gr Varget .005 jump still shot like crap.
Loosened all screws from action rail and rings re-torque everything to factory specs.
Going to try a couple different bullets if that doesn’t change things I’ll call barrel manufacturer see what they suggest.

 

[Old Navy]

Probably not "one thing", new brass is just part of the equation.

Some Lapua I have bought was long on headspace. Try jamming them the first firing.

 

[Old Navy]

Hey guys again thanks for the in put.
I reloaded the once fired brass lightened the load to 24.3 gr Varget .005 jump still shot like crap.
Loosened all screws from action rail and rings re-torque everything to factory specs.
Going to try a couple different bullets if that doesn’t change things I’ll call barrel manufacturer see what they suggest.

What twist is your barrel?

 

[tommeboy]

Lapua brass needs to have a mandrel or neck sized before firing new brass. They do not do this when they are made. You will have very high neck tension and probably bent neck by shoving a bullet in without sizing it first.

 

[Gater]

What twist is your barrel?

1-7 twist and the new brass was necked sized and yes tommeboy is correct neck tension was all over the place. I have a handful of different weight bullets from 73 gr to 85.5 going to try a few of each at mid chart loads see how it does then