Load Development - Virgin Brass or Fire Formed???

[EXSOCAL]

I searched around the best I could as well as read through all of the stickies in this page and didn't find anything to answer my question. Sooooo.

When doing load dev. for a platform, is the general consensus to use prepped brass that has been fire formed to the chamber of the rifle you are developing for? Or, is it acceptable to use virgin brass, eg. new Winchester brass, never fired?

My previous load development experience was finding a 175 SMK load for my 308 Win which is a very forgiving load to start with and easy to dial in to shoot in the 2's adn 3's... This time I plan on using the new 178 Hornady's and possibly 155 Scenars.

Thanks!

SOCAL

 

[rcamuglia]

Re: Load Development - Virgin Brass or Fire Formed???

I always use fire formed brass, cream 'o wheat method.

All bets are off if you use brass out of the box. Concentricity will suck, it'll have excessive head space and generally be too small for your chamber.

 

[turbo54]

Re: Load Development - Virgin Brass or Fire Formed???

The textbook method for load development is to perform full case prep on virgin brass, then fire full charge loads with bullets seated into the lands. Note that full power loads with bullets in the lands are LIGHTER charges than full power loads with bullets off the lands.

I don't know how big a deal it is to follow this prescription. I've had better than good results running a mandrel into virgin Lapua brass, neck sizing, charging and shooting.

 

[memilanuk]

Re: Load Development - Virgin Brass or Fire Formed???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: turbo54</div><div class="ubbcode-body">I've had better than good results running a mandrel into virgin Lapua brass, neck sizing, charging and shooting.</div></div>

True... but virgin Lapua .308 Win brass bears a passing resemblance to a finished .308 Win case - there isn't a whole lot for fire-forming to improve.

Virgin Winchester .308 Win brass, on the other hand... definitely needs fire-formed first. That stuff has its virtues (cheap, tough, high case volume, can be surprisingly consistent in some dimensions) but it also tends to be grossly undersized and fully forming the cases before bagging them doesn't seem to be something their QC folks are looking at. Add to that it seems like the shipping folks play hackey-sack with those plastic baggies of brass... and you need to run the case mouth over a mandrel or expander ball to round it out then fire-form it, at a minimum.

YMMV,

Monte

 

[EXSOCAL]

Re: Load Development - Virgin Brass or Fire Formed???

So would it be worth while or a waste of time to take out 100 pcs of Win brass and load up some cheaper slugs ( such as Sierra game kings...) and not worry about development, accuracy or anything and take this fire formed brass and start from there? This is a freshy Krieger as well, so I am thinking this will be the best route, since I plan on running a barrel break-in session... or not?

 

[95LTZ]

Re: Load Development - Virgin Brass or Fire Formed???

Right or wrong this method works for me. I use virgin brass & the bullets that I intend on using for the final load. I load up 4 rds. with each powder weight & powder "flavor" that I think will work. I use 4 rds. because normally I have one oops! in a three shot group. If I manage to pull off 3 good shots then the 4th rd. I have is a physical example of what worked well. I cannot remember when I have not had a very accurate load show up with virgin brass. Also, when you are shooting at different distances you can use the "flavors" that aren't doing so well to get rough zero's. Once I find a load that I am happy with and have more virgin brass I just load what worked and use that for practice. Of the rounds that I have fired looking for "the Load" I will then go ahead & do the full tilt brass prep & use these for matches. Depending on your shooting soon you will have all your brass formed to the chamber & fully prepped. I hope it works as well for you as it does for me.

 

[Tripwire]

Re: Load Development - Virgin Brass or Fire Formed???

Tons of ways to over complicate this....

The way I look at it, with a fresh rifle, and fresh brass, is that I'm going to get pretty damn close to a pretty damn good idea where I want to be with load developement in formed hulls while I'm foreforming those virgin brass.

 

[vman]

Re: Load Development - Virgin Brass or Fire Formed???

Fireformed

 

[WDL]

Re: Load Development - Virgin Brass or Fire Formed???

When you measure case capacity (water capacity), fired cases, not sized cases are measured. Cases INSTANTLY expand to fit the chamber upon ignition, so it doesn't matter whether it is a new case or a fired case.

 

[rcamuglia]

Re: Load Development - Virgin Brass or Fire Formed???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CamoWildcat</div><div class="ubbcode-body">When you measure case capacity (water capacity), fired cases, not sized cases are measured. Cases INSTANTLY expand to fit the chamber upon ignition, so it doesn't matter whether it is a new case or a fired case. </div></div>


That's not the issue.

The issue is how the brass fits the camber and how concentric the loaded round is. If you're developing, you want to do so with brass in the same form that it will be after it's fired for consistencies sake.

 

[SPAK]

Re: Load Development - Virgin Brass or Fire Formed???

If you're properly doing your load development and select your opitimal charge weight it really won't matter if you shoot it in new or fireformed, your results should the same if not really really close.

I run my ladder test and pressure testing with new brass, then fine tune my load from my results.

 

[djtjr]

Re: Load Development - Virgin Brass or Fire Formed???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: rcamuglia</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CamoWildcat</div><div class="ubbcode-body">When you measure case capacity (water capacity), fired cases, not sized cases are measured. Cases INSTANTLY expand to fit the chamber upon ignition, so it doesn't matter whether it is a new case or a fired case. </div></div>


That's not the issue.

The issue is how the brass fits the camber and how concentric the loaded round is. If
you're developing, you want to do so with brass in the same form that it will be after it's fired for consistencies sake. </div></div>

actually it's both. Concentricity is an issue but so is an undersized case. For many rifles it may not matter much but if you were anal as perhaps a bench shooter would be
the undersized case does form to the chamber fast but differently than a well fit fire formed case that no longer needs to form. This changes the pressure in the two respective cases which can cause some differences in the way the new and firerormed brass shoot because the already fire formed does not need to expand to the same degree. I will often with good Brass do load dev with the virgin fully prepped brass but then do it again to verify and tweak the loads once fire formed. Virgin will often get you close but I can usually refine it to get a bit more out of them.

 

[bowhunter_0311]

Re: Load Development - Virgin Brass or Fire Formed???

Full brass prep, then shoot I doubt that you will be able to tell the diff.

 

[jwoolf]

Re: Load Development - Virgin Brass or Fire Formed???

Neck tension on new brass is different than once fired brass. Even if you straighten the necks out, the tension will be different because the inside of the neck is new and has no carbon on it. So, no only do you have issues with headspace but, you also have neck tension differences as well.

You may find that you can get a decent shooting load from the first firing of new brass but, it won't be the same when you load the cases back up after the first firing. It may be close but, I'd check to make sure it's still shooting like before and not just assume that it is.

 

[AKAce]

Re: Load Development - Virgin Brass or Fire Formed???

If you have to Modify the load between New and 1X brass, you needed a better load anyway, on a larger Node. Yes, there will be minor differences, but Damn... Temp, D/A, Etc Etc Etc will cause just as many variables. Find a load that is Consistent. If I can't go Up or Down a couple tenths in powder charge without a major change in Velocity or POI I am not done looking for my load. I guarantee when you hit the range at 30 degree warmer or colder temps then you did load dev.. you will see the same.

OR, Buy 1000 new brass, and Waste 1000 bullets, 8 lb of powder and 1/4 of your barrel life Fire Forming them.

IF the 1X brass Show you that they shoot a bit better.. Use them for Matches or when it counts. Practice with the New stuff.

Tons of people shoot Factory ammo... It's new Brass. Just Saying.

 

[SPAK]

Re: Load Development - Virgin Brass or Fire Formed???

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ~Ace~</div><div class="ubbcode-body">If you have to Modify the load between New and 1X brass, you needed a better load anyway, on a larger Node. Yes, there will be minor differences, but Damn... Temp, D/A, Etc Etc Etc will cause just as many variables. Find a load that is Consistent. If I can't go Up or Down a couple tenths in powder charge without a major change in Velocity or POI I am not done looking for my load. I guarantee when you hit the range at 30 degree warmer or colder temps then you did load dev.. you will see the same. </div></div>

Yup.....